(Continued from Chapter 11, Section 1)
Fig. 11.66. Schematic drawing showing the general layout of Station 3 on the rim of Ballet Crater to the east of Lara.
“All right, Bob,” I agreed, “we’ve got us some boulders over here that are in the light mantle.”
“Okay, now, let me brief you on Station 3.” Parker has returned to his old problem of giving us instructions when we obviously have other things to take care of. “It’s going to be a very brief station to make up for the…” Until we can get things settled with the Rover and other preparations for work at Station 3, we ignore Parker. I am surprised that the Flight Director did not tell him to shut up and wait until we were ready to listen.
“We can see a little bit down into Lara, now, too,” I noted.
[The Lara impact crater lay partially on the face of the Lee-Lincoln Scarp so the west rim projected higher than the east rim. Lara’s age relative to the light mantle avalanche is clear as LROC images show lobes of light mantle that have back-flowed from the northeast wall into the crater. Its age appears to be significantly older than the 75-107 Myr Scarp as indicated by the absence of boulders on its rim large enough to project through several meters of light mantle and the presence of large boulders on its wall. These features suggest an age comparable to Horatio Crater which is geomophologically older than the ~500 million year old Camelot Crater. As the Lee-Lincoln Scarp formed through relatively recent thrust faulting, Lara has been modified and tilted somewhat since its formation. Ejecta from Lara would underlie the light mantle at Station 3. (The geology and ages of the Lee-Lincoln Scarp, Horatio and Camelot will be discussed further, below.]
Cernan began to orient the Rover to a heading of 045. “How’d we get up here, again?” I asked, probably referring to the fact that we had driven near this point on the way to Station 2.
“I just drove [to 089/6.1] (Mission Control’s last update for Station 3). [We need to go to] 045 [when parked].” Cernan had missed the call out in the Cuff Checklist for a navigation update that required heading near 270 and zeroing the sun gnomon’s shadow.
Parker broke in, again, finally being helpful. “First of all, remember we want to get the NAV update. Let me go into a heading of 270 more or less and give us the NAV readout so we can start that here.”
“[Jack] Can you get [to] where you want to from here? No, this is no good. I wanted to get a high spot,” Cernan said but then changed his mind. “Yeah, let’s… Let me park down here, Jack.”
“Well, you should have stayed up there (higher),” I commented.
“Yeah, I want… This is good right here.”
“It’s not going to be very level for the gravimeter,” I said.
Parker again: “Gene, remember, we want to head for the west so we can get the Nav update.”
“[Why don’t] you park right out here,” I suggested,” and we can work those blocks right up behind us.” Cernan was not making good decisions for some reason. Lack of sleep due to worry about the broken Rover fender may have been catching up with him.
Then, he responded to Parker without deciding where to park. “Okay, you want a NAV update here?”
“Roger. That’s affirm.” Parker mixed his pilot jargon, again.
“[Gene,] You need to get your [low-gain] antenna [pointed right],” I told him, as Parker’s voice broke in and out.
“Why don’t you get off, Jack? Oh, I was looking at the wrong dang [Checklist page]. …Oh, no, I’m not. …Okay. I’ll get a NAV update. …Get off and look around. I’ll give them a NAV update, Jack, and we’ll press on. Yes, sir, you’re right, Bob.” I was happy to leave Cernan to deal with the Rover housekeeping. He seemed to be getting refocused, when he said, “Hey, get your [scoop]…”
“I will.” I wanted to look around a little and try to come up with a plan for what to sample.
“Go ahead.” I had not realized that he was going to move the Rover, again.
“What do you need? Take your scoop or whatever you need [off the gate].”
“Oh, you’re going to move?” I finally broke the code for his intentions.
“Yeah. I want to give them a NAV update real quick.”
“Oh, I’m sorry,” I apologized as I went behind the Rover to the gate. “Okay. I’ve got the scoop.” I also should have taken the SCB off the gate to have something in which to put samples.
“And, Jack, an update for you,” Parker said, apparently after some intense discussion in the MOCR. “We’re going to want you to do some documented sampling on your own. I’ll get with you guys on the rest of the station plan, shortly. Go ahead, Gene, we’re ready [for the NAV update].”
“Okay, I ought to get the gnomon, I guess.” I was not happy about this. One-person, documented sampling took more time versus our usual practice of working together, and we were about 30 minutes behind the EVA-2 planned time line and that meant only 15 minutes at this station.
“Okay, let me find a level spot; I’ll come back towards you,” declared Cernan.
“I’ll get it.” I walked to the Rover’s left side as the folded gnomon rested in a holster behind Cernan’s seat.
“Well, there is [no level spot]. Well, okay, if you got any [suggestions]…”
“No, go ahead, make your park,” I directed.
“Yeah, I’m looking for a level spot, but my God, there sure aren’t very many,” he replied.
“That’s (where you are now) probably pretty good…”
“It will be in a minute.”
“It doesn’t have to be all that level, Gene,” Parker advised.
“Okay; 087 (bearing), 12.6 (distance), 6.0 (range).” Cernan read from the gauges.
“I got your gnomon,” I informed Cernan.
“Sun shadow is zero. Pitch, …if I can get it over to read it, pitch is…pitch is zero. …Roll is zero. …[No,] about one (degree) left, Bob, …about one left.” Like I thought by visual estimate, if the gauges were accurate, the spot was pretty level.
“And how about heading?” asked Parker.
“Heading is 282.”
“Okay, go ahead and park. We’ll give you an update [for the NAV] when you get done.”
“What else do you need?”
“That’s all we need. Go ahead and park on your 045. We’ll give you an [NAV] update when you are done.” To calculate an update, all Mission Control needed was the heading with the sun shadow on zero. The 045 heading helped thermal control of the batteries and the LCRU and the NAV correction could be applied to any heading.
“Jack, is it worth coming right there?”
“Looks like a pretty good location,” I answered. “We can sample the rim materials of this crater. …Bob, I’m at, let’s say, the east-southeast rim of a, oh, 30 meter [diameter] crater – in the light mantle, of course – up on the Scarp and maybe 300…[possibly] 200 meters from the rim of Lara in a northeast direction [from here]. …It (the crater) probably shows up as a bright crater on your map. There’s only about a half a centimeter of gray [regolith] cover over very white material that forms the rim.”
[Post-mission photographic measurement showed that the crater diameter was about 10 m, not 30 m. I have no idea why my estimate was so far off. If anything, I should have underestimated the size, not over estimated it. Also, we were only about 50 m southeast of the rim of Lara. I am not sure what I was referring to when I said we were two to three hundred meters from the rim of Lara. I might have confused the top of the scarp with that crater rim.]
“And, Gene, give me a call when you get parked and I’ll give you an update on what we want to do.”
“Okay, I am parked.
“We’ll take the Rover readout first.”
“Okay. 087, 12.7, 6.0,” he repeated. “[Amp-hours] 105 and 100. On the battery temps: 100, 120. The rear motors are off scale low and the forward motors are 0 and 240.” The temperatures of the motors continue to be inconsistent or Cernan has trouble reading the gauges.
“Okay, we copy that. Understand that 240 now instead of a 340. And what is the heading, 045?”
“Heading is 043 …If I ever gave you a motor temperature of 340, that figure was erroneous.” When we stopped at Station 2, he read 340 for the temperature of the forward right motor but no one had questioned it at the time.
“Roger. And what we’d like you to do, Gene, is we’d like you to get the CSVC (Core Sample Vacuum Container) by yourself. That will essentially be your sole task at this station. We’d like Jack to do some solo sampling. We’d like to get one pan and the gravimeter, and then we’ll leave this station. We’re going to absorb some of the time we spent with the extra gravimeter reading and some of the time we absorbed at Station 2 in the longer stay time in sampling at Station 3. That’s our plan. So it will be CDR for the CSVC – or the ‘long can’, excuse me – and LMP for solo sampling and then a pan by Jack, I presume, and then the gravimeter and then leave. And, Jack, you might check your film. We aren’t quite sure where you are right now, before you get too far from the Rover.” While Parker spoke, Cernan got off the Rover and turned on the TV without comment.
“Okay, Bob,” I acknowledged. This meant that we would not get a rake sample as planned nor would there be as much documented sampling. The lack of variation in the surface of the light mantle from Station 2 to here, however, probably meant that not much knowledge would be lost.
[The drive tubes we carried consisted of “lower” sections that had a hardened end so that they could be driven into the regolith. Each would give a core of about 35 cm in length. An “upper” section could be attached to the lowers to provide a core of about 70cm. Lowers made up the majority of the sections. An adapter fitted into the top of either type of tube so that an Extension Handle could be attached and the hammer could be used to drive the tube into the regolith.]
“Bob, you got…any preference up in this area where you want that long can [core sample]?”
[The purpose of getting the Station 3 double drive tube core in a vacuum-sealed container was to see if any volatile anomalies exist near the presumed fault that formed the Scarp. Based on my later analysis of the features of the Lee-Lincoln Scarp, we were about 50 to 100 meters east of where the thrust fault plane broke through the surface of the pre-existing ejecta blanket of Lara, reducing the chances of sampling fault-related volatiles. On the other hand, volatiles related to fluidization of the light mantle avalanche might still be trapped in the deeper part of the drive tube (maximum 70 cm) as the ALSEP heat flow experiment measured a minmum steady-state temperature of –20˚C at 80 cm. NASA has attempted to preserve the full integrity of the lower section of this core (73001) by freezing and by double sealed containment in order to maintain the vacuum to which it was exposed on the Moon. In 2019, the entire core became the focus of a comprehensive consortium investigation, almost 50 years since it was collected. The author is a participating member of this consortium, led by Dr. Charles Shearer of the University of New Mexico.]
“Negative. That’s something that was sort of near the Scarp, but you’re parked so near the Scarp and that’s something, remember when we do it in solo, we only did it with the Rover, so you’d have to stay right there beside the Rover and do it. No expectations of doing it otherwise.” Cernan would need a Rover seat to work on, anyway, as he capped and sealed the long can without my help. Doing this together would have given us more flexibility. All in all, I think it would have taken less total time if we had done both the core sample and the documented sampling together. We may have been too tired at this point to argue.
“Well, that’s what I figured,” Cernan agreed.
“Gene. I think you’re in good shape [as to location],” I said to bolster the decision.
“Yeah, I don’t have any other choice.
“Matter of fact,” I added, “if there is a scarp, and if it is a fault, …you’re right on it because the projection of it (the fault plane) would be uphill [west] a little bit.” Cernan parked the Rover on the light mantle covering on the Scarp and the buried trace of the fault across the underlying light and dark mantles probably lay several hundred meters to the west. My more recent analysis indicates that Station 3 is several hundred meters east of the trace of the fault. The lobes of the scarp represent collapsed portions of the hanging wall of a low angle thrust fault (see Chapter 13).
“Yeah, I’ll be right on the side of it (the scarp). I’m parked on the side of it (the fault) if it exists.”
“Okay, and, Jack, what’s your frame count?”
“Well, …122… Bob, I’ve dug a trench in the [ejecta of this crater]…”
Parker interrupted with, “You can work the rest [of the Station] without a [B&W film] Mag change.”
“What do you need, Gene?” I asked, noticing that he had been moving around the Rover, looking for something. I then saw that he had found the drive tubes and the long can under my seat where they had been placed during EVA-2 PREP. “Oh, yeah…” I took several cross-sun and down-sun photos (AS17-138-21143-47) before digging a ~15 cm deep half trench in the rim with the trench wall facing toward the Sun (AS17-138-21148-49).
“Bob, I dug a trench in the side of this crater (Fig. 11.67↓). I’ve got down-Sun pictures of it. There’s quite a marbling of light and dark soil or fine grain material. It looks as if there’s a uniform, about 3-centimeter (thick) layer of light material over that marbled light and dark. On the very top surface, there’s a half-centimeter of light-gray – and”, interrupting myself, “when I say ‘dark,’ I mean a ‘medium gray’.” In the heat of the moment, my use of “light”, “medium” and “dark” here and below in describing the three units exposed in the trench tends to be confusing. In the following paragraphs, parentheses will be used to insure that each reference to these trench materials distinguish between light-gray surface material, medium-gray marbling, and light-gray marbling.
[The half-centimeter of light-gray surface material probably consists of regolith developed since this impact crater formed. At Station 4, discussed below, I would find that about the same thickness of new regolith has formed since the impact that created Shorty Crater. This indicates that, like Shorty, this 10 m crater formed about 3 million years ago (see Chapter 13). The light-gray material and underlying medium-gray marbled material may consist of ejecta of mixed pristine light mantle and an older regolith, possibly that developed on the underlying, older avalanche deposit first recognized in high-sun angle LROC images (see Chapter 13).]
“Okay, copy that. Sounds like a great sample site.”
“Okay, I’m going to start sampling the soils, and then I’ll get you the fragments.”
“Okay, I presume that we’ll at least have the single upper core,” Parker said, “which we can use to sample that stuff in the soil.” He probably was referring to the seemingly undisturbed light mantle we discussed and sampled at Station 2A, the last gravimeter stop. Here on the rim of a relatively fresh crater, however, we did not have a relatively undisturbed area of light mantle. Indeed, the impact that formed this crater probably ejected material over the site of the double drive tube (see Chapter 13).
Fig. 11.67. Trench in the rim of the 10 m diameter Ballet Crater at Station 3. This photograph was taken before collection of several samples of the exposed regolith units. The marbling of the various regolith units of differing exposure ages probably is the result of mixing caused by the lateral explosive pressures from the impact that created the crater. (NASA Photo AS17-138-21149).
“Oh, there’s no guarantee [that we can reach undisturbed light mantle]. This is a crater rim,” I reminded Parker. The thickness of the impact ejecta probably would prevent reaching the pre-impact surface of the light mantle.
“Okay. And, Gene, are you still near the Rover?” Parker asked, interrupting Cernan’s long can sampling activities. He should have asked Cernan to call when he had a minute.
“Yeah, I am.”
“Okay, we’d like to get the SEP blankets opened, Gene, and dusted if they’re dirty, so they can cool some more.” Clearly, this could have waited until Cernan hit a stopping point.
Clearly irritated, Cernan exclaimed, “Oh, boy!”
“Yup,” Parker replied, missing that his interruptions with respect to the SEP was the reason for Cernan’s irritation. I quietly kept digging and sampling away at my trench.
“Okay!” Cernan said, even more upset. “Now I can’t give you the gravimeter reading while I’m working on the Rover, so I’ll have to time it when I get away from it.”
“Okay. Roger on that. I think you’ll be pounding on the hammer for a long [time] while you can take the gravimeter reading.” Parker really did not know when to stop talking.
“Yeah. …Well, we’ll see.” Cernan did not sound mollified at all. “Let me get your [dust] brush back [here]…”
I had taken the first scoop sample and poured it into a bag taken from under my camera. Then, I stuck the scoop in the ground to have both hands for twisting the sample bag closed. “Okay, bag 520 (73220-25) has a skim sample of the upper light-gray [surface] soil.”
I then continued, “…Don’t know where I’m going to put these things, I’ve got to come down [to the Rover] and get a bag (SCB)…” Normally, Cernan would have been with me with his PLSS mounted SCB. Another illustration of why it is better to stick to normal procedures whenever possible.
“Have you punched the gravimeter?” I asked Cernan. “No,” I said answering my own question as I looked at the TGE display upon returning to the Rover.
“No, I can’t punch it until I get out of here (the SEP location on the Rover). …These [SEP] switches are in OFF and STANDBY, right?” he asked in return.
“They should be,” I replied, only half listening as I concentrated on getting the SCB off the gate.
“Okay, that’s where they are and the temperature is about 104 and…” This indicated a rise of six degrees since we left Station 2.
“No, they [both] should be OFF. Isn’t it OFF?” I asked.
“No, it was STANDBY.”
“No, push it OFF.”
“Okay, it doesn’t matter whether it’s STANDBY,” Parker finally interjected. “It won’t be [working at] that temperature anyway, but put it OFF.”
“Okay. It might have gotten hit when I changed the blanket,” I suggested.
“I’ve got to go to INTERMEDIATE cooling here,” Cernan asserted. “[First, I’ll] zap me with a [bit of] cold. …Nice to know those PLSSs got charged okay last night.”
“Yeah, Seventeen,” confirmed Parker, “the PLSSs look great. They’re both looking [good].”
“Okay, back to INTERMEDIATE. How’s Ron doing?”
“Stand by. …Ron’s doing great, too. He’s (Evan’s CapComm, Overmyer) sitting here busily…”
“No, no,” Cernan interrupted, not certain who Parker meant.
“I mean Captain America.”
“Yeah, I’m just inquiring of Bob (Overmyer). I think he’s doing great. He’s just passed a little bit north of you a couple of minutes ago and took some pictures of you.”
“Okay!” Cernan exclaimed, finally able to get to the long can sampling. “I do my work around the LMP seat here. That’s lock [on the extension handle]. That must be unlock. Okay, unlock. Rake is off [the extension handle].” He needs to attach the handle to the upper drive tube. “Core [tube] is coming in.”
Meanwhile, I returned to my trench, setting the open SCB on a flat spot a few meters away. “Okay, Bob, the upper…the upper 5 centimeters…[make that] 3 centimeters [of light gray marbling], mixed with that upper half centimeter [of light-gray surface soil], is the next sample.”
“Okay, Bob, I guess I’m going to go pound away (on a drive tube),” updated Cernan, “and, Jack, I’m going to hit the gravimeter.”
Planting the scoop, again, I responded, “Okay…”
“Okay. MARK it,” Cernan said.
“And 521 (73240-45) is the sample bag.”
[73245 is a small fragment, found in the sample bag and given its own sample number in the Lunar Receiving Laboratory. It apparently is a, homogeneous, fine-grained granulite that appears to have been a polymict breccia metamorphosed by a large impact event. No other data is available, but 73245 may be a good candidate for 40-39Ar dating.]
“Well, the first core [tube] (35cm) has gone down pretty good, Bob.”
“Oh, you won’t have any problem in here coring.” My extrapolation to the ease of driving the drive tubes came from having easily dug the trench.
“Oh, man, I tell you, I wish I was putting a drill hole in here. This is pretty nice.” Cernan gets about two inches a stroke, using the area of the flat side of the hammer rather than the smaller end. As discussed earlier, the upper portion of the light mantle probably lacked any significant amount of course, rock fragments, due to their downward migration in the fluidized avalanche, and would make driving the core tubes much easier than sinking the ALSEP drill holes in normal basaltic regolith.
After cleaning out the trench of slumped material, I took another sample. “Okay, Bob. The next sample is mostly the medium-gray fraction of the marbling. It’s mixed with the lighter gray marbled [component], though. …That’s in bag 522 (73260-64)…”
I apparently had tired myself out with this activity. The two of us could bag samples fairly easily; but, solo, I had to hold the bag in my left hand and move the scoop over it with my right. This meant working and holding against the pressure in the suit as well as simultaneously griping the bag and the scoop.
“Okay, I think I got it. I think I got it, Bob.” Cernan returns the hammer to his right shin pocket, as he has the double core embedded to its full, 70cm length.
“…And, Jack, when you get done with this trench you might hit one or two of those blocks there, but then we’d, …since we’re really trying to cut this station down to a minimum, after that you’d probably better get to the pan.” I ignored this unnecessary suggestion. Parker or someone else seems to think I had stopped being a geologist on the Moon.
“Bob, what do you think, can I read a gravimeter?” asked Cernan, forgetting that a non-flashing light indicates a completed reading.
“Yup, if it’s not flashing…”
“The light’s out.”
“Yeah, it should be just done.”
“670, 049, 701; 670, 049, 701.
“Bob, the [lower] white (light gray) fraction in the marble zone [is] in [bag] 523 (73280-85).” This completed collecting the four samples from the trench at the rim of this crater.
[These four regolith samples (73220, 73240, 73260, 73280) from the trench at Ballet Crater, along with 73211 collected from the crater rim surface in conjunction with collecting a number of rock samples (73210-19), show the complexities of light mantle and ejecta stratigraphy in the rims of small impact craters (Chapter 13). This complexity probably results from the compression folding and shearing of zones within the light mantle located between the point of impact and the crater rim. Mixed ejecta excavated explosively from the area of direct impact is deposited as an ejecta blanket extending many crater diameters from the crater rim. The transition zone between explosive ejection and overturn and compression will be examined again at Shorty Crater (Station 4), while my recent studies of the ALSEP deep drill core (Chapter 13) shows that regolith present at an impact target area is spread radially, six crater diameters or more. As this ~10 m diameter impact crater roughly sampled the upper two meters or so of the light mantle at the point of impact, the four samples eventually may provide insights into the stratigraphy preserved by the double drive tube core (73001/2) before that drive tube is opened for analysis (see Chapter 13).]
“Bob, I forgot to give you the core (drive tube) numbers, but I will.” Cernan can read off the numbers as he extracts the tubes. Before he does so, he takes stereo photographs of the embedded tubes and extension handle (AS17-137-20981-82).
“And don’t forget to put your little note in the long can there.” Parker kids the geochemists with this spontaneous joke, as Cernan takes his camera back to the workplace on my Rover seat.
“Oh, I’ll get the note in there. I’ll get it in there. …Nobody will ever know!”
“Okay, Bob, 524 is what I think is a blue-gray rock, probably the breccia. It got a little dust cover [on it]. …From just off the rim of this little (10 m diameter) crater.” Although I just mention this one rock, I put another nine rocks in the same bag (73210-14 and 73215-19).
“Okay, copy that,” Parker acknowledged. “It’s a blue-gray rock, it’s not part of the trench, right? You finish with the trench?”
[The samples collected during all my problems with solo sampling turned out to be very interesting but extraordinarily complex with much study left to understand their varied histories (see Chapter 13).
Of these 10 individual rocks I collected near the trench at the crater rim, ranging in weight from 3 to 1000 g, all but one turned out to be impact breccias according to post-mission examination The other rock (73219), an olivine-basalt, is consistent with there being less than 10% dark mantle components in the samples from the trench. Breccia sample 73217 has been studied extensively (Fig. 11.67↑). It is described as a mult-generational (polymict) impact melt/breccia.
Several one-third to one-meter diameter boulders on the rim and in the inner wall of the crater show in photographs of the sampling area. The abundance of breccia fragments near this ~10 m-diameter impact crater, versus their paucity on the surrounding surface of the light mantle, suggests that such fragments had concentrated a meter or so down in local portions of the light mantle deposit. As basaltic dark mantle material has not been ejected from the crater, the combined older and younger light mantles are probably at least 2 m thick at Ballet Crater.]
Cernan easily extracted the double core tube and turned the bottom end toward the TV cameral “If you see it, Bob, it’s full. See that?” This demonstration also showed that the relatively large diameter, thin-walled drive tubes retain cores of the slightly cohesive, fine regolith very well.
“Roger. We see a long thing (can) in your hand there, Gene…”
“Well, I didn’t think that was supposed to happen,” I mused about the fact that the sample bag holder had come off my camera.
“Well, I know [I put them somewhere]. …Jack? Shoot. Thought I had them (the drive tube caps) on the Rover.”
Fig. 11.68. Lunar Receiving Laboratory image of impact melt covered breccia sample 73217 from the rim of Ballet Crater at Station 3, as unpacked and dusted. This example of an impact breccia illustrates the great complexity of material that has been subject to several high energy impact events. (NASA Photo S95-06605).
“What?” I asked.
“Oh, [I need] the core cap covers. I’ll get them.”
“No, you got some there in that little…pocket.”
“Yeah, and there’s so many bags in here, I can’t get at them.”
“No,” I insisted, “I mean the pocket on the Rover, on the back. Remember?” Actually, I thought that both sets of cap dispensers were under my seat, one in SCB-7 and the other in SCB-8 that Station 2 samples. It is not clear to what Rover “pocket” I was referring.
“No, they’re not. I took them out (of SCB-8) and put them on you [in SCB-4].” Cernan must have done this without saying anything while we prepared to leave Station 2.
“The rest of them are in this bag (SCB-7). I’ll come and get them [from you]. …See, there’s others, but I don’t want to get under your seat. We got those bags packed in there like gangbusters. How are you doing there by yourself?”
“Well, it’s hard,” I admitted, as Cernan came to my side to retrieve the core caps from SCB-7 attached to my PLSS.
“Your [SCB to PLSS] hook came off. If you wait a minute, I’ll hook it on this bag.”
“Okay. …I didn’t think the sample bags could come off the camera. But they can.” Later, I would determine that the mounting point of the holder to the camera has been bent. I fixed it in Challenger’s cabin before we started EVA-3.
“Well. Doggone it,” Cernan complains.
“What’s your problem?”
“[Might] just as well fix this bag (SCB) now. Let me get this bag. It’s going to come off at the bottom if I don’t. It’s going to come off again. I don’t think the harness is tight enough now.”
“Want to tighten the harness?”
“Yeah. I got to, Jack.”
“Okay.” It felt good to have a chance to rest a bit.
“Let me get your harness. I might just as well do it, so it’s right.” Rightly, Cernan is exasperated. “If it’s worth doing at all, it’s worth doing right…” More time being lost due to equipment problems. “Now, let me try getting that bag back on. …No, don’t bend over; I can’t get down there. …You’re plenty short enough.”
“Thanks. Thanks a lot,” I responded with a laugh.
“This bag, that hook…there’s something changing the geometry.”
“Okay, don’t worry about it too much, guys,” Parker said, getting advice from the EVA console. “I’m sure the bag will stay on without the hook.”
‘Yeah, it will; [that’s] the conclusion I just came to.”
“You through?” I asked.
“Yeah, go ahead.” Cernan had retrieved his drive tube caps and also remembered to get the rammer that fit these tubes.
“Okay, Bob,” I reported, “what I know is a blue-gray breccia is in bag 525 (73255).”
“And, Jack, [are] you just scooping up little rocks along the surface there…in your little xenolith mode?”
“Yeah, you read my mind,” I told Parker. “I do want to get one of these light-colored rocks [at the crater rim], though.”
[Parker referred to a mode of sampling I used when studying the varied clast- or “xenolith-rich”, intrusive kimberlite breccias of the Colorado Plateau in Northern Arizona and Southern Utah. As their geological context defined the origin of the xenoliths (literally, foreign rocks), I could collect as many different rock types as time allowed and put them in one bag. My first study of applying xenolith sampling to lunar exploration came in 1964 on surface exposures of the Mexican Hat kimberlites in southern Utah. As part of the Geological Survey’s Apollo Lunar Geological Methods project that I managed, Gordon Swann, Spence Titley, and I employed freshmen from the University of Arizona in a statistical analysis of the quality and quantity of samples per unit time that could be collected by relatively inexperienced individuals.
Neil Armstrong used the xenolith mode of sampling on Apollo 11 to collect an outstanding suite of basalt and impact breccia samples near the Lunar Module Eagle. Armstrong had been exposed to this technique on an alluvial fan at the base of the Guadalupe Mountains in West Texas in the spring of 1969, during the Apollo 11 crew’s one and only, pre-mission lunar geology simulation.]
[Post-mission examination of 73255 disclosed that it had a rind or shell of vesicular impact melt in sharp contact with a core of impact breccia (Fig. 11.69). The core of the rock consists of an aggregation of melt-breccias containing clasts of orthopyroxene gabbro-norite, ferroan-anorthosite, basalt, felsite and very fine grain micro-breccia in a dark, very fine grain matrix. Observers have described 73255 as being an impact melt “bomb” comparable to some terrestrial volcanic bombs. A boulder of Mg-suite norite studied and sampled on EVA-3 at Station 8 (78236) has a similar bomb-like rind of impact glass (Chapter 12).
73255’s exposure age is ~90 million years, roughly consistant with other light mantle exposure ages and a crater count age of 75-86 million years determined using LROC images]
Fig. 11.69. Lunar Receiving Laboratory image of impact melt covered breccia sample 73255 from the rim of Ballet Crater at Station 3, as unpacked and dusted. The lines mark the approximate positions of a slab cut. Note the light-colored clasts in a vesicular matrix. (NASA Photo S73-16951).
“Go ahead, Gene.
“Bob, when I broke the cores apart, there’s just a lot of dry clods; and the bottom core’s full, the top core about — oh, I got to look — it’s dark down there — but about an inch [or] inch and a half [inch?] of the [top] core has just ‘zero-g’d’ or ‘one-sixth-g’d’ itself right out.”
“Okay, we copy that,” Parker replied. “I guess we still just cover it, and see what we got. Might just again trying compacting it after that’s through… — after you’re done with the lower core.” Parker is suggesting that Cernan use the drive tube rammer to compact the end of the upper core against its lower cap before he caps the top.
“Yeah. I’ll do that…”
Up on the slope, I had put the scoop down to close the bag on the sample from the crater rim. To pick the scoop up again, I just bobbed down and grabbed it. This maneuver in the suit worked well on an uphill slope but became much more difficult for me on flat terrain. “Bag 526 (73235, 73275),” I reported, but as I reached for another sample bag, the entire pack of bags came off the camera, again. Fortunately, on this slope, I could lean on the scoop and easily pick up the bags. “That may have been a piece of gabbro. But again, I can’t be completely sure. …It’s either that or anorthositic gabbro [like] we saw up on the front…up on the [South] Massif. …And my bags aren’t staying on my camera worth a darn.” I then made a surprisingly successful attempt to do a blind reattachment of the bags under my camera.
[73235 consists of a very fine-grained micro-breccia containing a wide variety of mineral and rock clasts, including the minerals anorthite, Mg-olivine, Mg-orthopyroxene, and spinel and rocks such as troctolite, Cr-spinel troctolite, and a zircon-plagioclase rock (Fig. 11.70↓). Early reported 40-39Ar ages for 73235 are 3.98 ± 0.04 and 3.96 ± 0.04 billion years. Its reported 81Kr exposure age is 95 ± 5 Myr.
U-Pb and Pb-Pb zircon ages between about 4.35 and 4.15 billion years suggest 73235 records at least two high temperature melting events capable of leading to zircon crystallization or recrystallization. As the older zircon age is the same as many reported Mg-Suite ages, it may be related to impact melt from the Procellarum, very large basin-forming event to the west and discussed in Chapter 13. An average of eight Pb-Pb measurements from a large aggregate of zircons in this sample provided a date of 4.187 ± 0.011 billion years, an age within similar ages that may record crystallization of impact melt from a second very large basin-forming event, possibly South Pole Aitken located on the lunar farside.
Sample 73275 consists of a clast-rich, impact-melt breccia that has fine-grained plagioclase intergrown with very fine-grained Mg-orthopyroxene and Mg-olivine (micropoikilitic texture). Exsolution lamellae in the orthopyroxene and sodium-rich overgrowths on plagioclase cores suggest annealing at high temperture, possibly within impact-melt magma. The sample also contains meteoritic iron fragments.]
Fig. 11.70. Lunar Receiving Laboratory image of breccia sample 73235 from the rim of Ballet Crater at Station 3, as unpacked and dusted. Note the brownish glass patina and the micro-meteor impact pits (“zap pits”) that cover all sides of this rock, indicating repeated impact re-orientation at the surface without burial. (NASA Photo S73-16962).
“And, Geno, how about some core numbers.”
“Okay, into the long can…I’ll give it (the number) to you; wait a minute. …[Lower drive tube] 46 (73001), Bob, is gone into the long can. …Boy, another exercise in dexterity.”
“Okay, the LMP has gone to INTERMEDIATE [cooling]…”
With this reminder, Cernan added, “And, by the way, I’m at about 49 percent [oxygen] and 3.85 [psi] and INTERMEDIATE cooling and no flags.”
“Have you got a number for the upper core when you’re done? I guess you’re probably putting the other one (the lower) in the long can, aren’t you, right now?” Parker can be persistent if nothing else.
“Yeah, yeah, yeah; that’s right,” confirmed Cernan.
“And somewhere here along the line, Jack, I guess maybe when you get those [samples], you ought to stop and take the pan.”
“Okay, Bob.” Obviously, I thought the samples are more important than a pan.
“Okay, Bob, the long can is sealed, and I guess nobody knows what’s in it but me.”
“No one ever will, probably.”
“And I may not even tell…”
Meanwhile, my solo sampling proceeded. I tried a technique of angling the scoop head to 90 degrees from the extension handle. Then, I collected a rock, tossed the scoop so as to catch it near the head while letting the rock settle into the partially closed rear of the scoop. Lowering the scoop head to the ground, again, allowed me to collect another rock. I did this four times before pouring the samples into another bag. After pouring, I tried to rest the scoop on the front of my suit in order to close the bag, but the scoop slipped to the ground, anyway.
“It does not…,” Cernan begins and then starts over. “None of the material in that core — in either the top section or the bottom section — looks unlike that stuff just beneath the surface that we sampled at that special [gravimeter] stop back there [after Station 2]. It’s a bluish-gray, and it tends to clod and break up in your hands. And that’s core 31. The upper [drive tube] is 31 (73002).”
“Copy. Thirty-one on the upper”
“…Oh, man… Bob, you’ve got better than…, oh, you’ve got two-thirds of a core (upper) after I packed it down a little bit.”
[As indicated above, the bottom section of the Station 3 drive core, 73001, resides in cold storage and has recently been designated for a broad study by a consortium of multi-discipline scientists. 73001 has been kept sealed in the Long Can (SCRC) since collected, and was put into a second vacuum container after return to Earth, awaiting future study. In 2018, NASA asked for proposals for its study so that analytical techniques not available 45 years ago could be utilized. As this portion of the Diary of the 12th Man is being prepared, NASA has funded a consortium study of this core and other preserved and unopened samples. I am a participant in this consortium, providing operational history and geological context, as well as new petrological data and synthesis.
The pre-mission plan to collect a core at the base of the Lee-Lincoln Scarp rested on the possibility that indigenous volatiles might have migrated upwards along the plane of the fault, as often happens on Earth. When the Long Can sample container was sealed on the Moon, the temperature of the core would have been about 250ºK (-23ºC), based on the ALSEP heat flow temperature measurements. Originally condensed or frozen volatiles may be preserved in the can provided that the indium-knife edge vacuum seal has maintained its integrity since December 1972. It is likely that several deposits of light mantle derived crater ejecta exisit in this core as a consequence of the three nearby impacts. It will take careful stratigraphic study, however, to distinquish one ejecta deposit from another due to the uniformity of light mantle materials. Maturity index profiles may be the best means of making these distinctions.
The top section of this core, 73002, also has not been studied except for being imaged by X-rays. It consists of 23 cm of material with the upper 12 cm being devoid of rock fragments greater than about 0.5 cm in diameter, consistent with my previous observations that fine material is concentrated at the top of the avalanche deposit. The remaining lower 11 cm contains numerous sub-rounded rock fragments up to about 4.1 cm in image length.]
“Okay, that little set of four samples is in [bag] 527 (73216-19), barely,” I added after almost spilling all of them back on the ground.
“Okay, we hope it was worth the effort.”
“Oh, it’s all worth the effort; it just hurts [the hands],” I continued as I dropped the bag in the SCB… “I won’t… Aaaahh!” I gag as the SCB falls over, spilling sample bags downhill. All I can do, is get down on my knees, bracing with my left hand, and put the bags back in the SCB, saying, “You don’t mind a little dirt here and there, do you, gang?”
By just leaning back, getting back on my feet is fairly easy, but hanging on to the SCB is another matter, and I lost my grip and it dropped back to the surface, fortunately landing upright. I went down to one knee to retrieve it again, but stumble and fall forward. Leaning back, I again get to my feet and finally hold on to the SCB as well. Not my best athletic performance.
Meanwhile, Cernan tries to re-attach the extension handle to the rake. “Oh, dadgummit! …Well…”
But Parker can’t resist calling attention to my recent pratfall, well recorded on TV.
“Hey, Gene, would you go over and help Twinkletoes, please?”
Somewhat annoyed, I say to Parker, “I tell you, you fix that camera bracket so the bags stay on, and I’ll be a lot better off.”
“Roger.” Parker may have backed off, some.
“Want some help, Jack? I’ll be there.”
“No! I don’t need any help,” I bark, trying to decide if my camera lens is now dirty and upset with myself as much as with the sample bag problem.
“I just need better bags.”
“Jack, you might worry about whether your camera lens is dirty or clean, Jack. I don’t know what you’d do about it.”
“I’m very worried about that.” Parker’s not making any friends at this point, on top of my temporary tiredness due to the solo sampling.
“I don’t know what you’d do about it, but you might worry about it.”
“I don’t have a thing to do…” This time I bit my tongue, controlled my tiredness temper, and, instead, took the camera out of its slide holder and checked the lens. “It’s clean.”
“Well, I’ll be a son of a…gun!” Cernan nearly swore, still struggling with getting the extension handle attached the rake for transport on the back of the Rover.
“What’s your problem?” I asked from near the crater.
“I can’t get this thing locked on.”
“What the…” I had no idea what “this thing” might be.
“The rake!” he exclaimed.
“The rake!?” I had lost track of the fact that he used the rake’s extension handle for his double core.
“Yeah. That should lock. And I turn that like that. There it comes.” Dust in the open mechanical parts of our tools had started to work against us.
“Jack, if you haven’t started your pan, could we get an EMU check from you?” Parker had resorted to the code for “Slow down. We think you need a rest.”
“Well, it’s about 50 percent [oxygen]…, about 3.85 [psi]… And no flags.” With that, I began to take a panorama of photos from near the rim of the crater where I had been sampling (AS17-138-21150-77), adjusting my pointing depending of whether I had to face up or down slope. This panorama shows just how extensively I had disturbed the surface around the Station 3 sampling site as well as the increase in the proportion of larger blocks around this 10-meter diameter crater.
Fig. 11.71. Part of the pan I took at Ballet Crater (the name arising from my modified “pas de chat” maneuver with the SCB just before taking the pan, and a later refinement of this ballet move for the TV). The sampling Crater is at left, the LRV at right, and the extensively trampled surface in between. I picked up rock sample 73275 (Fig. 11.70↑) just on the rim of the crater a couple of meters directly ahead of the sample scoop head. My SCB with samples is next to the scoop. (Partial composite of NASA photos AS17-138-21160, -61, -63, -64, -65, -66, -67).
“Come on [rake]. Get back in there (the gate stowage bracket). …Okay, that’s all put away. That (rammer) goes back in your bag.”
“Why don’t you go over towards Jack, Gene, and then the two of you can pick up the scoop and the bag together and get back towards the Rover after that?” Parker can’t resist directing traffic when we are doing other things.
“Yeah, I’m cleaning up his seat here. I’ll do that.”
“I think I can hack it,” I countered. Cernan had other stuff to do.
“And then, at that point, we’re ready for you guys to leave.” In spite of Mission Control thinking we would make up some time at Station 3 by splitting tasks, we had lost another 15 minutes, so far. Only 10 minutes remained before we broke into the supposed walk-back envelope.
[I am certain that we would have used far less time, if Cernan and I had worked together on the drive tube sample for the Long Can and then sampled the crater material in our usual manner. I would have been right there when he needed the caps and the rammer from my PLSS SCB. While he drove the double drive tube, extracted it, and broke it apart, I could have been planning the crater sampling or making more detailed observations of the crater’s walls. In my activities, I needed him to hold the sample bags as well as to have his SCB handy for stowing the samples. That would have avoided the dropping and falling routine that wasted time and energy. It is just not smart to deviate from what has been your normal routine – “train as you fly and fly like you train” – is the old Air Force mantra. We should not have let Mission Control call the shots like we did. Cernan’s comments many years later indicate that he did not realize how inefficient Station 3 activities became as a result of Mission Control’s decision to separate us. As will be evident, when I took charge of activities with the limited time available at Station 4, we performed much better. ]
“Whew. …Okay. …Jack, I’ve got the rammer I’ve got to put on you. I’ll just leave it on your seat right now.”
“Okay.” I finally finished the panorama.
“We’re watching you, Jack,” Parker informed me as he watched the big TV screen in the MOCR.
“I said we’re watching you, but don’t let that inhibit you.”
“Bob, I don’t let anything inhibit me. And I don’t stay mad very long.” I then stepped on the scoop to raise the handle so I could grab it.
“That was very good!” said Parker in admiration, but then, with a laugh, I dropped the scoop again.
“Well, there’s an easy way to do everything,” Cernan commented.
“The question is can you hang on to it once you’ve done it?” I replied, as I picked up the still upright SCB I had been using and headed for the packet of empty sample bags that had ended up on the ground, again.
“Let me get those [bags], Jack. Don’t get down there. Let me get those.”
“Where are you?” He was behind me, coming with the tongs. “They (the bags) don’t stay on my camera anymore.”
“Well, we’ll fix it. There’s no reason why they shouldn’t, according to this.”
“[I have] the samples from that [trench]. … Oh, …I need it (the gnomon]. …I gotta go up there [on the crater rim for an after photo]. Wait!” I called loudly to Cernan. “Take an after [photo]. Cross-Sun, from over to the north of the gnomon.
“You didn’t get an after, huh?”
“No,” I admitted, but hurrying to get a panorama probably caused me to miss it.
“[Do you want me to get the gnomon?]”
“Oh, I got it; I’ll get it. If you’ll mount this thing (the loose SCB) [on the gate].”
“Just set it there. Just set it there. Take four deep breaths. Bob, what else do you want us to do here?”
“Nothing! Get on the Rover and leave.”
“Get the heck out,” I translated.
“Don’t forget the gnomon,” Parker added.
“Okay. We’re going back to get that after,” declared Cernan, “and we won’t forget it…”
“I think you might be able to decipher this station, Bob,” I said with some skepticism as I took the delayed, after sampling photographs (AS17-138-21178-80).
Fig. 11.72. The cross-sun photo of the trench (lower left from the gnomon) that I took just before we left Station 3. Ballet Crater rim is at upper right. The large boulder at upper right with the reseau cross on it is the one near the scoop in Fig. 11.71↑. (NASA photo AS17-139-21178).
“That’s the general idea. …And be advised that the switchboard here at MSC (Manned Spacecraft Center) has been lit up by calls from the Houston Ballet Foundation requesting your services for next season.
“I should hope so,” I replied more lightheartedly than I had felt over the last half hour. This dig by Parker led to the crater I sampled being subsequently referred to as “Ballet Crater”. In response, I did a space-suited version of a grand jeté (leaping split) or pas de chat (ballet leap with feet drawn up, knees bent, and legs forming a diamond) for the TV camera, succeeding in falling forward on my knees and camera, again.
While I performed my version of “Swan Lake,” Cernan was trying to hook the SCB to the gate. “Well, we can’t use that one. The right-hand gate lock is…non-functional, …and the left one is almost non-functional.”
“How’s that?” I asked the dance critics in Mission Control.
“Once you get it (the gate bag latch) open, you can’t get it locked. I’ll dust them if I get a chance, but it’s locked on the left side.”
“Okay, well, we’ll keep those bags underneath the seat, anyway,” Parker advises, correctly.
“Here, I’ll work on it,” I told Cernan as I returned to the Rover from my ballet demonstration at the crater. I handed the gnomon to Cernan who put it in the holster behind his seat.
“I think the samples are safer under there (the seat), anyway.”
“We don’t have any room! …Well, we can take bag 7 out.”
“That one’s locked [on the gate]…in good shape. Let’s press on. We got the [gravimeter] reading. Let me put the rammer on your back and see if we can’t get this (sample bag holder) on your camera.”
“Are we going to run the SEP this time?” I queried.
“I don’t know; he hasn’t said anything,” replied Cernan. “I expect he will.”
“No, we will not turn the SEP on, guys. You might cover it with the (thermal) blankets as well as you can. And how about a temperature reading before you leave, when you do that?”
“Copy that. 100, and understand both switches are OFF and the covers are closed.
“Well, the covers are closed now. They weren’t… They’re not going to stay closed.”
“…That’s what I mean,” Parker corrected.
After these exchanges with Parker about the SEP, Cernan turned to me to stow the rammer in my PLSS SCB. “Okay. Turn the other way. Left. Let me just slip this [in]…”
“Well, I don’t know why it (the sample bag holder) isn’t staying on [the camera], but it certainly isn’t.”
“Move over and turn. …Okay.”
“Is that the same one (bag holder)?” I asked. “I may have bent it.”
“I think you did, [just] now.”
“Yeah. I just bent that, didn’t I?” Very little feeling comes through the cover gloves and the gloves themselves.
“Yeah, that’s not going to stay on. Yeah, you bent it very well,” Cernan said with a chuckle.
“Wonder how I did that?”
“I don’t know. You’ll lose these bags.”
“Okay, well, we’ll…revise our procedures
“I got bags.”
“I guess I bent my camera bracket…mounting point… — the camera point,” I told Parker.
“We may have to think about a fix there.”
“We might be able to fix that in the cockpit.” Cernan meant fixing it in the Challenger between EVAs.
“Yep,” I agreed. “Okay, are we all through, have you got…”
“[We’ll] worry about that [camera bracket] when you get back in [the LM],” Parker said with an unnecessary interruption.
“Okay, where are we here?” Cernan asked himself, looking at his Cuff Checklist, as I waved at the TV camera on the way to my side of the Rover.
“I’ll get on,” I said, looking forward to some physical and mental rest for a few minutes. …Oh, I guess I need to get another film mag, huh?” I headed for the magazine supply under Cernan’s seat.
“Okay, how about frame counts on both you guys before you start?”
“152 for the LMP…”
“We suggest magaline…magazine Juliet, please.”
“Okay,” I responded to Parker’s twisted tongue with a laugh. “We’ll get ‘magaline’ Julieing (AS17-133)”.
“CDR’s on 118.”
“Fire, fire, two frames,” I said as I advanced the film on my camera to protect the last pictures I had taken. “You know, I’d enjoy this if it weren’t so much fun.”
“Okay, you going to change your mag?” Cernan asked, apparently missing my by-play with Parker.
“[I’ll] shoot a 500 [mm set of pictures] while you’re doing that. …No sense in me sucking my thumb.”
“I know,” I agreed with a laugh.
“Seventeen, we’d really like the…, we’d like to press on as quickly as possible.” The walk-back constraint would be violated in 4 minutes.
“Any time you want to do something, though,” Cernan laughed, as he had to get the 500 mm camera from beneath his seat, “[they want us to get a move on]. I got it.”
“In case you didn’t get…” Parker, or probably the Flight Director, was getting anxious, but we continued to ignore him, knowing how conservative they had made the walk-back constraint.
“Take a portion of the Scarp over there you can see,” I suggested.
“Seventeen, do you copy? Houston.”
“What?” answered Cernan.
“We’d like to press on…”
“…as soon as possible, please.”
“Yes.” I acknowledged, as I took the new film magazine Juliet from under Cernan’s seat.
“We are, Bob, but he’s got to change his mag.”
“I’m going to stand here and look around,” Cernan said, disguising the fact that he was taking 500 mm photographs… “Okay, I’m picking up with [500 mm] mag — or [rather] with frame 56 — and I’m going to try to get a little bit of where the Scarp overlaps the North Massif (Fig. 11.73a↓). I can’t see much of it. …All I could get was three frames of that. Now I’m picking up the South Massif…” (AS17-144-22047-77)
[AS17-144-22047 is the first of this series of telephoto photographs illustrating the clear textural contrast between the smoothness of the south side of the Lee-Lincoln Scarp and the roughness of the North Massif it crosses. The “shaken, not stirred” nature of the dynamics of the thrust fault that formed the Scarp probably explains this difference. The Massif would have been far more stable and resistant to shaking than the thin, upper portion of the fault’s hanging wall overriding it.
The first four of the 500 mm photographs taken at Station 3 also show very clearly that there is a roughly horizontal lineation on the south face of the North Massif. This lineation consists of slightly depressed (less resistant) zones about 20 m wide (estimated as horizontal on the ~25º slope), separated by slightly raised (more resistant) zones about 100 m wide (AS17-144-22047-50) (Fig. 11.73a). The separations are remarkably uniform and may delineate separate shear planes within a single ejecta mass, or, conceivably, compositional or induration differences within the lower portions of the Massif. Comparison of the surface textures on the North Massif shown in Fig. 11.73a and those of crossing lineations on the Sculptured Hills in Fig. 11.73b, taken with a similar grazing sun-angle, emphasizes the contrast between structures underlying these two physiographic features.]
Fig. 11.73a,b. Comparison of the surface textures of south-facing slopes of the North Massif (a, top) and Sculptured Hills (b, bottom). Contrasts between surface lineaments suggest very different underlying structures within these two physiographic features. (Composite NASA Photos AS17-144-22047, -48, -49, -50 (top) and 144-22072, -73, -74 (bottom)).
[The photographs of the South Massif included in this sequence of 500 mm shots show numerous concentrations of boulders of varying albedo on its slopes that may be indicative of underlying outcrops. Mapping of these concentrations on a complete photo-mosaic of these pictures might disclose structural trends within the north facing portions of the South Massif. Multiple sun-angle and perspective views in LROC images may assist in such a photo-structural study, in fact, oblique LROC images have suggested that a large area of solidified impact melt overlaps the north crest of the South Massif. Unfortunately, no boulder tracks are apparent that might indicate the source of the rocks sampled at Station 2.]
To change the film magazine on my camera, I removed the protective dark slide from the front of the magazine and put them both on Cernan’s seat. Then, I took the used magazine off the camera and latched the new magazine on to the Hasselblad and advanced the film a couple of frames. Finally, I inserted the dark slide in the old magazine and stowed it under the seat. We followed this standard routine for each magazine change. Even with its large, open wire handle, handling the dark slide became increasingly difficult as our hands tired.
“Okay, how are you coming, Jack?” asked Cernan.
“Okay. Oh, I ought to put that (used mag) in there (the under-seat compartment) so you’ve got room for your [500 mm] camera.
“You got a final frame count there, Gene?” requested Parker.
“Okay, I’m all set,” I told Cernan and went around the back of the Rover, headed for my seat. To help me get on the seat, I would grab the auxiliary staff on the console with my left hand and kick my feet up while moving my body to the left so that I come down in the seat.
“Okay, Bob. When I finished the South Massif, I was on [frame] 94 and now I’m on 99. I took five more pictures back over to the northeast.”
And we assume you guys are ready to go by now.”
“Yes, sir. …And, Bob, they (photos) were all [taken] with the lens cap off.”
“Splendid.” Cernan referred here to a training episode when the lens cap stayed on during a series of photos. To sight the 500 mm, we used a gun sight mounted on the lens barrel.
“Why don’t you fix that high-gain so you can see?” I suggested, as Cernan moved towards the LCRU to turn off the TV.
“And, Jack, what’s the heading say?” Parker asked.
“We’ll get the reading we need for the NAV update. Do you think you can give us the heading right now?”
“Okay, heading is four…one…I think. I’m at a little bit of an angle. Better let Gene do it for you.”
“Okay. We’re waiting.”
“I’ve got some parallax. I think it’s four one, though.”
“What you looking at?” asked Cernan.
“043 is what I gave ‘em earlier.
“Yeah,” agreed Parker, “[but] we were wondering if it drifted while you were there, because we’re going to give you, now, a… one (a heading) to update it, if it has drifted at all.”
“Okay, it did drift, 041 is a good number,” Cernan confirmed.
“Okay. Stand by. …Okay. That’s fine. No torque [to the heading] necessary, Geno.”
“I’m strapped [in],” I informed Cernan.
“You liked the drift, huh?” Cernan commented to the LRV support team of Bill Perry and Jim Sisson.
“Great,” Parker replied for them.
Cernan then did his kick mount of the Rover and immediately said, “Oh, Dadgummit!”
“What’s wrong?” I asked. “Oh, the hammer [again]?”
“Yeah. Every time. Okay, let’s go.”
“All right, sport…”
“I’m going to head…”
“We didn’t really do all the things we wanted to do,” I summarized, “but I think we did everything we could.”
“We did everything we wanted to,” Parker countered, apparently forgetting that our original plans for Station 3 included more field observations related to the Scarp, more documented sampling, a rake sample, and a long flight-line stereo photographic series of the face of the Scarp. In hindsight, just more rock samples would have been the most valuable. The light mantle covered all the original features of the Scarp, a rake sample would have been very much like that of Station 2A, and the LROC images from LRO has provided, 40 years later, high-resolution coverage of the entire Scarp.
“Okay, let’s get ready to roll,” stated Cernan
“[We missed getting the] flight line stereo,” I added, continuing my summary, “[but] you got the TGE [and 500 mm] camera [shots]. …The low gain is 060 [for this leg].
“You get the gnomon in?” asked Cernan, forgetting that I had handed it to him.
“Didn’t you get it? Wait a minute.”
“You took the after. It’s not sitting out there,” he observed.
“No, I thought I handed [it to you]. …Didn’t you stick it in [its holster]?”
“Yes, I stuck it in. I got it.”
“Okay. We can look back [to be sure],” I said with a laugh.
“[We’re rolling], Bob.”
“I sure thought I handed it to you, Geno.”
“You did, and I put it in.”
“Okay, that’s good,” I concluded. “Okay! Whoo— boy, rest the old hands.”
“Okay, we’ve recommendations for MINIMUM [cooling] for you. Gene, [I mean], Jack.”
“I think I am in MINUMUM,” Cernan responded.
“Jack, what was [what I meant]. Sorry: ‘Jack’.”
“I am already.”
“Yeah, I’ll go to MINIMUM,” I said. “Yes, I will…”
“And give us a mark rolling, please.”
“Yeah, Bob, I gave you one. We’ve been rolling for about 30 seconds. …We’re at 087 and 5.9 on the range.
“Copy that,” Parker acknowledged. “And the drive to Station 4 will be nominal and we’ll get a Rover sample at about 094/5.1, but it will be the track as indicated on the map and the Cuff Checklist…”
“Okay. …Going to Shorty,” I said in my travelogue voice.
“Okay. On our way,” Cernan said.
“You got your checklist there?” I inquired, just to be sure Cernan knew where we were going next.
“Yeah, I got it in front of me.
“Okay. And, we’re heading…?”
“Heading is 069, around… Well…I got it. I know where we’re going.”
“Yeah, that’s (069) pretty close [to the right heading].”
“I know we’re next to that bend [in checklist map path], but I know where we’re going. My next is 094 (bearing) /5.1 (range) is what I want for that sample.”
“Yeah. Zero what?” I had looked at the path on the Cuff Checklist and seen “052” but no 094. I had looked at a heading number to the sample site.
“I think he said 094/5.1.”
“He meant… 052 is what’s nominal. …What’s the sample [location] again, Bob?” I asked.
“Five point one; zero nine four, five decimal one…
“Oh, okay, that’s (052) the ‘heading’ [and not bearing],” I said, realizing my mistake.
“All right. You got 094/5.1.”
“Yeah, got it. …You going to drive by this big rock?” I asked Cernan.
“Want to look at it? Can’t see it. I can’t see when that LCRU [reflection] shines into my eyes…”
“Looks like one of the gray breccias,” I reported. “Big 3- to 4-meter block out here all by itself on the light mantle. I got some pictures. It was at 088/5.6. …And it looked like a gray breccia. I’m not sure, though. All I could see was the surface texture, and it had the nodular or elongate nodular texture that those breccias (Boulder 1) had up on the South Massif.”
Fig. 11.74. Driving almost into the sun, we passed by this isolated boulder after leaving Station 3 heading for Shorty Crater. (NASA photo AS17-133-20201).
Then, as if calling a pet, I said, “Where are you, Shorty?”
[The closest photograph (Fig. 11.74) we obtained shows that this isolated boulder between Stations 3 and 4 is extensively fractured. A shallow depression surrounds the boulder on three sides with a regolith filet on the south side, suggesting that the boulder may have been thrown onto the light mantle from the north. In retrospect, a sample of this isolated boulder would have been interesting but could have only been obtained at the expense of time at Station 4. In reviewing high resolution images from LROC (NAC Image M104311715LR), it is the only obviously large boulder showing within the light mantle other than those we saw from a distance within Lara. Whether an impact breccia or a block of the subfloor, the boulder had to have been thrown here at relatively low velocity from some nearby, large crater. The responsible impact probably occurred within the last ~50 Myr as other regolith maturation observations and exposure ages related to massif boulder tracks suggests that the depression and filet would have disappeared due to macro-impact redistribution (see Chapter 13).]
Fig. 11.75. Continuing the traverse to Station 4, small craters have few boulders on their rims. (NASA photo AS17-133-20204).
“And the [Rover] battery temperatures are 100 and 130,” Cernan reported.
“Okay, Bob, as far as any of the things we talked about trying to see at the surface — dynamics or a variation of the light mantle — I think you’ve heard it all. There isn’t much to say about the dynamics right now. I have a feeling that the surfaces are old enough that all those kind of detailed relationships have been obscured. Filleting is just about the same all over here. It varies, but there are no systematics that I’ve seen.” (Traverse photographs AS17-133-20193-204; see Fig. 11.75)
“Okay, copy that.” Changing the subject back to batteries, Parker asked, “Do we ever see a Rover flag come up when you’ve got high temperatures there on the battery. Have you seen the flag up yet?”
“No, you didn’t. No, you did not; you did not,” Cernan declared with emphasis.
“Okay, that may be telling us something, we hope. Press on.” Mission Control has begun to assume that we have a gauge problem rather than a hot battery. A sensor on the battery, not the gauge, activates the warning flag at 125 ± 5 degrees (and at 400 ± 12 degrees for any drive motor).
“Okay. LMP is in MINIMUM [cooling],” I informed the guys watching our cooling water walk-back limits.
“[I] ought to cut left up here a little bit,” Cernan said.
“Yeah, I think so.”
“Ooh!” Cernan exclaimed as he hit a crater with the right wheels.
“Don’t [worry]. …Keep her going.”
“Good lord!” he yelled with a laugh. “What was the aspect ratio of that little thing.” Cernan referred to the crater’s depth divided by its width.
“Yeah, that’s what they call a pit crater,” I reminded him.
[I had begun to suspect that pit craters form in regolith when very high velocity, small meteors penetrate a relatively low strength upper zone before they explode in more compacted material below.]
“Hey, can you swing a little bit and let me get [photos of] that fragment [rimmed] crater?” I directed. “See that one on your left there?” (AS17-133-20205-07)
Fig. 11.76. A much larger crater seen in the distance had a rim of fragmented boulders. It is at left just below the HGA pointing handle. Compare with the smaller craters (also see Fig. 11.77↓). (NASA photo AS17-133-20205).
[I had been storing up mental images of the presence and size of boulders around craters of different diameters in the light mantle and, therefore, depths of excavation. I had the distinct impression that the deeper the excavation, the larger and more abundant were the boulders. Examination of my Rover traverse photographs across the light mantle indicate that craters less than about 3 m in diameter, or ~0.6 m deep, do not have rocks larger than a few centimeters in diameter and most of those are regolith breccias. As the diameters of craters increase, and depth of penetration increases, larger and larger boulders sit on their walls and rims. This observation is consistent with the hypothesis that gases fluidized the light mantle avalanche, resulting in the downward migration or sorting of entrained fragments and boulders relative to their size, that is, their surface area to mass ratio. The larger the fragment, the deeper it would migrate downward into a fluidized avalanche.]
Fig. 11.77. Driving on the fragmental boulder field, mostly regolith breccia, of the crater left of the TV camera. Hanover Crater and the scarp on the North Massif are above the camera (NASA photo AS17-133-20208).
“[That is the first blocky rimmed] crater we’ve seen up here [on the light mantle]. Got your pictures?” Cernan asked.
“Yeah, I got them.”
“Okay, Bob. We’re at 090/5.3 for a quick Rover sample of a very, very fragmental crater. The ejecta is about fifty percent small, angular fragments; much different than we have seen before [on the light mantle] in terms of the type of patterns.” As Cernan spoke, I reached down and easily corralled several small fragments and took a photograph of this highly fragmental ejecta blanket (AS17-133-20208). Cernan took a color photograph at the same time (AS17-137-20983), forming a partial stereo pair.
Fig. 11.78. Cernan’s version of Fig. 11.77↑. One can also see how much the HGA blocks his view when driving, remembering that his camera is at chest height. (NASA photo AS-17-137-20983).
“Okay, and that’s in bag 41 Yankee (74110-19).
“And we’re on our way.”
“Get your (after) picture, Jack?”
“Yeh. LMP frame count is one-five.”
“About a 30-second stop! Okay, I’m 090, 5.3 now, Bob. We’re heading toward your [planned LRV sample] stop.”
[The fragments around this crater appear to have been largely regolith breccias. As those breccias are destroyed rapidly due to macro and micro-meteor impacts, this crater probably is about the same age as Van Serg , a crater we would visit on EVA-3. Van Serg also has abundant regolith breccias around it and is significantly younger than 3 million years old, the likely age of Shorty crater where no regolith breccias have survived space weathering (see below and Chapter 13).]
“See Shorty [Crater] out there yet?” The run from Station 3 to Station 4 took us through relatively flat terrain, so I thought that we might pick up Shorty’s dark rim about this time. Although photographs from Station 3 include the slightly darker rim of Shorty Crater in the dark zone at the foot of the North Massif at left in Fig. 11.71↑, a ridge blocks out Shorty from this portion of our traverse (AS17-133-20209-13), Fig. 11.79.
Fig. 11.79. Traverse to Shorty Crater after leaving the crater with fragmented boulders. The view of Shorty is blocked by the ridge crossing the photo. The central reseau cross is on and just above the ridge. (NASA photo AS-17-133-20210).
“Well, I…” Cernan’s view was not as good as mine, but neither of us could be sure of seeing Shorty.
“Bob, I couldn’t tell whether that was just…” I began, thinking about the last sample site. “It (the crater) looked like that might have been a crater that had got to bedrock. There may have been a high point [in the subfloor], or let’s say a thin point in the light mantle, and it got down to bedrock. But I can’t [be sure]. It’s the most blocky-rimmed crater we’ve seen for a long time.”
“Yeah. All these others are nowhere near that. …Look at that.”
“No. It [the sampled crater] was about 15 meters in diameter.”
[Post-mission examination of 74110-19 shows that the fragments consist of regolith breccias of light mantle material. The flat bottom of the crater, as shown in LROC images, suggests that the impact did not excavate into the denser top of the dark mantle but may have been shaped by the presence of more resistant dark mantle at depth. Given the ~15 m diameter of the crater, the light mantle probably is at ~3 m thick at this point.]
“Bob, there are no obvious lineations — at the scale we can observe — on the light mantle,” I observed (AS17-133-20214-17). “I think the pan photography and the metric stuff (America’s SIM-BAY cameras) may be what you’ll have to use for any directional trends out in here— depending on what we decide the origin [of the light mantle] is…”
[The photographs that Evans took of Taurus-Littrow with his Hasselblad, as well as those from the SIM-BAY cameras and LROC (Fig. 11.80a,b), show a northeast-southwest bearing, finger-like reach of the terminal portion of the two light mantle deposits. The LROC high resolution images also show a lineation of subdued ridges and troughs (ridges-and-swales) on the light mantle surface with a 100-200 m wavelength, crest to crest. Our Rover course between Stations 3 and 4 had us going roughly parallel to this lineation, so it is not surprising that we could not observe the parallel ridges as we traveled, either with respect to their scale or direction. Our route from Station 3 to Shorty was more or less in a straight, NNE line across this image.]
Fig. 11.80a. LROC QuickMap view of the light mantle unit with SW to NE parallel lineations of ridges and swales crossing it that are characteristic of fluidized avalanches on Earth. The photo resolution is 8 m/px. The Nansen trough is the dark curving area just under the black rectangle at its lower right. Lara (~600 m E-W diameter) is the large crater-like depression partly cut by the black rectangle at its upper right. The dark Shorty Crater (~110 m diameter) is further to the upper right. Station 3 is located at the upper right tip of the rectangle. An enlargement of the ridges and swells dark-light lineations in the rectangular box is given in Fig. 11.80b. North is at top. (NASA LROC NAC ROI mosaic available by clicking here.)
Fig. 11.80b. The enlargement (photo resolution, 2 m/px) from Fig. 11.80a showing details of the ridges and swales prominently beginning at the base of the South Massif. The crest-to-crest wavelength of the dark-light lineations is variable, ranging from 75-100 m at the Massif base at upper left to 100-200 m further away from the Massif towards the middle of the rectangle. The QuickMap URL of Fig. 11.80a will also give this view by using the mouse wheel to enlarge the frame or the ± buttons on the web page.
“Bob,” Cernan called, “you still reading?”
“We’re still reading you, Jack.” Parker mistook Cernan’s voice for mine. Our voices sounded similar in short sentences when high and low frequencies were clipped through the voice activated (VOX) communication system.
“Okay. Are you reading us through the LM or through the low-gain?” Cernan asked out of curiosity.
“As far as I can tell, we’re reading you through the low-gain. …It’s been working just great tonight, Geno.”
“Okay, that’s great, …because I just scraped bottom on the LCRU. If it’s still working, I’m glad to hear that.”
“Tonight?” I questioned Parker’s use of the word with some mock incredulity as broad daylight reigned in Taurus-Littrow.
“Okay, we’re 093 (bearing) and 5.2 (range). We’re almost there. Going to be right on the rim of that crater…”
“Okay. And, 17, the word from the [Science] Backroom is: with that last Rover sample you got, we’d like to go straight to Station 4. We won’t get the one here at 094 and 5.3…(Correcting himself) 5.1, excuse me.”
“Bob, I thought the purpose was to sample the light mantle?” I, regrettably, pushed back on this spur of the moment decision. More time at Station 4 would have turned out to be the right decision, but no one knew that at the moment. Not knowing, I felt we needed to try to understand the light mantle rather than some unknown, probable impact crater.
“We talked to them about that, but they…”
“We didn’t sample light mantle at that last one.” I argued, not knowing that significant light mantle was included in 74110.
“I agree. I talked to them about that. But they are so anxious to get to Station 4, I guess they don’t want to do it.”
“Well, how about it, Gene? A little real time [crew decision]…”
“I think we got to, right here.” We already had stopped, and I had the Rover Sampler ready to go.
“I think we got to.”
“094, 5.1. You got your picture?”
“Yeah. …That’s good enough (Fig. 11.81).”
“We’ll get the sample, …anyway.
“094, 5.1. …That’s good, Jack… Sample is in 42 Yankee (74120-24)… And we are rolling!” Cernan exclaimed in a victorious tone. We had used about 20 seconds in this spat of insubordination. “And give me a bearing and a range to Station 4.”
Fig. 11.81. During a brief prevarication with Mission Control, we stopped here for 20 seconds so that I could lean out and pick up a sample. (NASA photo AS17-133-20218).
[Post-mission examination of the 90-150 µm fraction of 74121 contains about 6.3% combined basalt and volcanic ash, about 50% higher than other comparable light mantle regolith samples. As the sample site lies closer to dark mantle sources of these components, this higher amount is not surprising. Agglutinates are 42-52% and the maturity index is high at 88, both quantitites as high as measured for some other light mantle samples.]
“It will be bearing of 100 and range of 4.6.” Mission Control had recalculated the position of Shorty Crater versus the 101/4.1 we had in the Cuff Checklist. We hoped to at least get close enough to recognize what we expected would be a distinctive crater.
“Okay. We’re now at 094 and 5.0.”
“LMP frame count is 25.”
“Was that one-zero-zero, four point six [for Station 4]?”
“Houston,” I called, “there aren’t very many rocks that just sit on the surface. All of them seem to be slightly buried to moderately buried. …That one looked like it might be vesicular. There’s a trench, …[that is, a] linear set of craters (AS17-133-20219-22).”
Fig. 11.82. Slightly further along our route to Shorty Crater, a linear set of craters can be seen between the HGA handle and the TV camera. (NASA photo AS17-133-20220).
[Pre-mission photographs of the valley of Taurus-Littrow had given planners a clear definition of the plume-like, light mantle unit, with fingers extending as much as 5 km from the base of the ~2200 m high South Massif. In preparation for the geological exploration of the light mantle unit, it occurred to me that this feature might have been the result of a landslide or an avalanche of regolith previously residing on the Massif’s nearly constant, 26°, northeast facing slope. I discussed these possibilities with UCLA Professor of Geophysics, the late Ronald Shreve, a Caltech friend and early researcher on fluidization of rock debris flows. After some discussion, Shreve and I concluded that, in order for the material of the light mantle to travel as far as it did, it probably resulted from fluidization of an avalanche of regolith in the Moon’s one-sixth Earth’s gravity. Plume-like distal ends of the light mantle unit also suggested such an origin. Solar wind volatiles released by agitation in the moving avalanche provided the most likely source of fluidizing gases. Analysis of regolith samples from previous Apollo missions indicated that solar wind hydrogen, helium, nitrogen and carbon present these materials at levels of 100s of ppm, each. Detailed consideration of the characteristics and origin of the light mantle, and of an older avalanche deposit partially hidden beneath the more prominent younger deposit, is provided in Chapter 13.]
“Hold it, babe,” Cernan warned me. “We got to do a little detouring.”
“Okay, what we’re looking for is 101…” I had been observing and not listening when Parker sent up the change and had just referred to the numbers in the Checklist.
“Yeah. 100, 4.6. …I’ll detour. I’ll just get down this slope. I don’t see Shorty though, do you?”
“Wait a minute, is that it?” I pointed out in front of us. “Is that it out there straight ahead?”
“Well, let me get down this slope.
“Something’s dark out there. I think that’s it.” I became more certain.
“It might be right over there to the left a little bit?”
“Your left, yeah.”
“Yeah, right over there. I think I can cut it right across there. That’s going to be about the right place.”
“Seems a little far from here,” I wondered, “but…maybe not. …Oh, I forgot to take pictures again. Trying to shade my eyes… That Scarp certainly is spectacular going up there by Hanover, isn’t it?”
“It just rolls over the side, doesn’t it?”
“Yeah. …I don’t know what else we can say about it, though,” I added with a chuckle. “Okay, we’re getting a good view of the North Massif, and the cross-hatched lineaments that Gene has talked about are over there, also. There seems to be a set that plunge about, oh, 30 degrees to the east and another set that plunge about the same to the west. Plus the boulder tracks…we see occasionally over there. And there are areas of boulder fields up on the Massif itself, such as we saw on the South Massif. As a matter of fact, it looks like there’s one just above where Station 6 may be. Straight ahead of us there, Geno, …about bearing 060 from our present position, which is 098 and 4.8…”
“If I change that heading,” interrupted Cernan, “that [reflection off the] LCRU comes right in on me…”
“I don’t see anything like layering up there,” I continued. “Although the upper boundary of those boulder fields on the North Massif, and, as a matter of fact, on the South Massif, …all tend to have a linear boundary. That’s the upper portion of the field; the lower portion is strung out down-slope.”
“That’s Shorty straight ahead of us, I think,” Cernan broke in.
“Yep, that’s got to be it.” Our approach to Shorty Crater and Station 4 is shown in photographs AS17-133-20223-28 (Figs. 11.83, Fig. 11.84↓).
Fig. 11.83. We are finally able to see Shorty Crater as the dark band at left, just below the HGA pointing handle. (NASA photo AS17-133-2024).
“That looks like it might be Shorty,” I agreed.
“Yep. We’re at 099/4.7, Bob.”
“Okay, great. Sounds like you’re just about there,” Parker replied.
“Yeah, I think we got it in front of us.”
“Bob, looking at the Sculptured Hills,” I said, taking advantage of my straight ahead view to the northeast (Fig. 11.83), I think Cernan’s comments the other day about Bear Mountain would apply. There’s a small relief — or small amplitude hummockiness — to the surface. It’s formed by a cross-hatch of [lineaments]. …Let’s say [that] the slope I’m looking at is sort of [a] west-facing slope, on the other (east) side of Wessex Cleft, [and] it’s (the cross-hatch) formed by lineaments plunging about 10 degrees to the north and about 10 degrees to the south. And the combination gives some hummocks that are quite distinct…”
“Well, you know it’s hard to see a blanket (ejecta) here,” Cernan observed, “but that’s got to be Shorty right there…It’s the only real large [crater near here]…”
“We want to park,” I began but left the thought unfinished. “I don’t think we’ll see a blanket [of ejecta]…”
“I don’t either.”
“Well, at least we’re going to see where the break in slope is for the rim,” I said, stating the obvious. Then I obtained my first full view of Shorty and its far wall. “My goodness!”
“Oh, look at the boulder sitting on that rim.
“It (the boulder) is darker. Let’s go over there,” suggested Cernan.
“No question,” I agreed. The big boulder on the rim would be the place to start and probably would have been ejected from near the deepest point of the Shorty excavation (Fig. 11.84↓).
“We’re at 101, 4.5.”
“Let us know when you stop and where you’re [at],” Parker reminded us.”
“Which rim did I want to park on?” Cernan asked me.
“Well, I think we ought to park over here near that big boulder.” I didn’t much care about the Checklist plan at this point. We could judge better about parking now than we could have been in pre-mission planning.
“Yeah, if I can get up there. I think I can.
“You can swing in, you know, and just park parallel to the [rim]. …Of course, that will put them looking back [at the boulder]. What [about]…can you park any direction?” This may be the first and only time I gave some consideration to the TV camera view.
“Well, yeah, but 045 gives me a good [sun orientation]. …Let me work on it. …Let me get up there slowly. I’ll put them on this low saddle here. 045 will give them a good heading. “
Station 4 – Shorty Crater
I began my description of what we saw with, “Shorty is a crater, the size of which you know (about 110 meters in diameter). It’s obviously darker rimmed, although the fragment population for most of the blanket does not seem too different than the light mantle. But inside… whoo, whoo, whoo!” Fig. 11.84 shows the appearance of Shorty Crater as we approached it, and Fig.11.85 gives the general layout of Station 4.
Fig. 11.84. Shorty Crater as we approached from the south. Sampling activities took place near the large boulder on the crater rim to the left of the image underneath the HGA pointing handle. The boulder is about 4 m wide. (NASA Photo AS17-133-20228).
Fig. 11.84 provides a clear view of the raised rim of Shorty relative to the surrounding light mantle area; however, the stark contrast between the dark ejecta blanket and the light mantle that one sees in the overhead imagery does not appear from this perspective. The absence of a large number of blocks on the ejecta blanket of this relatively young crater indicates that the Shorty impact largely excavated relatively fine-grained, unconsolidated material.
Fig. 11.85. Schematic drawing showing the general layout of Station 4 on the rim of Shorty Crater.
“Man, are you going to get a picture now,” added Cernan, ever thinking about the TV.
“We can hardly wait,” replied Parker.
“That’s about as far as I want to take it!” Cernan said as he approached the south rim of the crater.
“Okay. And when you stop and get off, give me [the] word, and I’ll read you up some revised plans for Station 4.” Parker may have been told to be more careful about interrupting the flow of our initial activities at a Station. 4 hours and 49 minutes had passed in EVA-2 and, at this distance from the Challenger we had about 30 minutes before the walkback curve raised its ugly, inexorable curse.
“Okay, Bob, we’re heading 041; bearing is 102; distance, 5.1; and 4.2 on the range. Amp-hours are 92 (and) 90; 102 (degrees) and 128 on the batteries. Off-scale low on the fronts (motors); and off-scale low on the rears (motors).” As the four temperature sensors on the motors fed the temperature display gauge independently, this probably indicated that the MOTOR temperature gauge had failed to off-scale low. The range would appear to be short by about 200 m, but there is some question as to whether Cernan said 4.2 or 4.4. The actual distance of Station 4 from the SEP is 4.4 km.
“I don’t know whether you’re wrong,” Cernan stated, “or we are, but…this is an impressive one (crater). Wait until you see the bottom of it.”
After I got out of my seat, I began to describe the crater. “Okay, Houston. Shorty is clearly a darker-rimmed crater. The inner wall is quite blocky but…, except for the western portion of it, which is less blocky than the others. The floor is hummocky, as we thought it was in the [Apollo 15] photographs. The central peak, if you will, or central mound, is very blocky and jagged. And the impression I have of the other mounds in the bottom is that they look like slump masses that may have come off the side [of the crater].” I had felt tired after the work and frustration of Station 3; but no more. I came here to make new discoveries. “That’s just what they look like. I’m not sure [of] that. …They have a bench appearance.”
“Okay,” Parker replied, “and the number 1 and 2 priorities at this station will be samples from the crater rim and the pan from the crater rim. Over.” That may have been the MOCR’s priorities, but mine had much more to do with exploring this fascinating, apparently quite fresh impact crater that we scheduled as a stop largely because there was some thought it might be a volcanic vent. Also, anytime you have an opportunity to investigate an obvious contrast in stratigraphy, it is worth a look.
Ignoring Parker for the moment, I said, “Okay, we’ve got a large boulder of very intensely fractured rock, right on the rim, right near the Rover. …It looks like a finely vesicular version of our clinopyroxene gabbro. It’s obviously crystalline and has generally that same appearance. There is (are), in one spot here, some inclusions of a darker gray rock, also intensely fractured. The fracture systems, I think, will show up well in the flight-line stereo.”
Fig. 11.86a. Down-sun view of the distinctive, intensely fractured, 4 m wide boulder on the southern rim of Shorty Crater which I took at the west pan location marked in Fig. 11.85↑. (Excerpt from NASA photo AS17-133-20232).
Fig. 11.86b. An excerpt from Fig. 11.88 which shows the right side of the boulder more in focus so that the intense fracturing of the boulder can be seen. (Excerpt from NASA photo AS17-137-20990).
[The panorama I took a few minutes later shows that the Shorty ejecta blanket has more small blocks in it, up to perhaps a meter in diameter, than had been apparent on our approach. It also documents the network of fractures in the large boulder I had just described. The walls and floor of Shorty Crater have a much higher concentration of large boulders than does its rim or ejecta. A band of dark material crosses the upper, west crater wall. Disconnected, elliptical benches, with major axes of several tens of meters and possibly caused by post-impact slumping, adhere to the northeast wall and probably to other, less well-lit portions of the crater wall. Several of the hummocks on the crater floor consist of concentrations of boulders, possibly intensely fractured outcrops of subfloor basalt. (also see the composite color-balanced pan in Fig. 11.107↓)]
As I did reconnaissance, Cernan began his list of duties at the Rover, partially documented in my panorama. “Bob, do you have TV?”
“Rog. We have TV, and you might brush the [TV] lens for us before you run away.
“Yeah, I’ll get it. I’ve got to get my battery covers cleaned.”
“Okay, I’m going to take a pan while I’m waiting for you,” I told Cernan, not wanting to get into solo sampling again.
“And we’re going to want the SEP opened and dusted as well here,” Parker insisted, again, “…with the switches turned OFF.”
“O-kaay! O-kaay,” Cernan said, somewhat put off by these continued interruptions for the SEP.
“Oh, hey!” I said at the moment of discovery. …“Wait a minute…”
“Where are the reflections?” I asked myself, remembering the Rover’s orange reflections I almost tried to sample up on the light mantle (see Fig. 11.58↑). “I’ve been fooled once. …There is orange soil!!” More certain now of what I had found, I raised my gold visor and looked more closely at my tracks to the fractured boulder I had just described. The tracks had stirred up regolith along the rim of Shorty that had an orange tint to it.
“Well, don’t move it until I see it,” Cernan ordered, facetiously.
“It’s all over!! Orange!!!”
“Don’t move it until I see it.”
“I stirred it up with my feet.”
“Hey, it is!! I can see it from here!” Cernan still stood next to the Rover some meters away.
“Wait a minute, let me put my visor up,” I said. “It’s still orange!” A thin film of gold plated the inside of our visors to filter out UV radiation and might give a little gold tint to things but was hardly noticeable.
“Sure it is! Crazy!”
“I’ve got to dig a trench, Houston,” I asserted.
“Copy that. I guess we’d better work fast.” Parker seemed unimpressed at this point. Meanwhile, I spent about a minute and a half taking a panorama of Shorty from the crater rim near the area of the orange regolith (AS-17-133-20229-59.)
Fig. 11.87. My b&w pan of Shorty Crater taken on the west side of the south rim (Fig. 11.85↑) just after I discovered the top layer of orange soil and near where I will trench across it. Cf. this aspect with Cernan’s perspective that he will make later on the east side of the rim as given in Fig. 11.107↓. (From NASA photos AS17-133-20233, -234, -235, -238, -240, -242).
“Hey, he’s not going out of his wits. It really is [orange].”
“Is it the same color as cheese?” Again, Parker did not take this very seriously, making an allusion to the Moon being made of cheese. He actually may have thought that Cernan and I were joking with him as we had on EVA-1.
“Temperature on the SEP’s about 102.” Cernan still worked on to complete his Rover housekeeping duties.
“It’s almost the same color as the LMP decal on my camera.” Surprisingly, I said this even before I had dug into the pure deposit of orange material under the regolith. My view was essentially down sun (zero phase angle), giving the best definition of color.
“That is orange, Jack!” exclaimed Cernan as he looked up from dusting. “Boy, this brush is getting harder to get on and off [the gate], too. But I sure don’t want to lose it. Man, I may start putting that under my seat. …Well, zap me with a little cold water. …Okay, the SEP has been dusted. I think I gave you 102 or something like that [for the SEP receiver temperature].”
To take the panorama, I had dropped the scoop on the relatively level rim of the crater, but it had landed with the angled scoop portion pointed down so that I could not step on it to raise the handle. Rather than go down to my knees to pick it up there, I kicked it to the slope of the inner rim. This made it easier to both pick up the scoop and get back to my feet by rotating backwards until my center of gravity moved behind me and the spring in the pressure suit could help force me up.
“Fantastic, sports fans!” I exclaimed. “It’s trench time! You can see this in your color television, I’ll bet you.”
“How can there be orange soil on the Moon?! …Jack, that is really orange. It’s been oxidized. Tell Ron [Evans] to get the lunar sounder over here.” It is not clear what Cernan had in mind with this last statement. The Apollo Lunar Sounder Experiment housed in America’s SIM-BAY was a very low spatial resolution, long wavelength, five band radar system, designed to sense major changes in radar reflectivity to various depths beneath the lunar surface. In the highly unlikely event that oxidizing, water-rich zones exist under a broad expanse of the area, bright radar reflections would have shown them. Maybe that was on Cernan’s mind.
“It looks just like an oxidized desert soil, that’s exactly right.”
“Well, I’m going to clean their glasses (TV camera lenses) so they know we’re [not crazy]. …Can you wait a minute on that pan you’re taking?”
Thinking Cernan had addressed me, I said, “I already took it (the panorama).”
“No, I mean the television camera. I’ll put you (the TV) back where I had you. …Now, I’ll put you right where you finished your pan.”
“You know,” I started and then paused as I looked at the outline of the orangish regolith, “that orange [exposure] is along a line, Geno, along the rim crest.”
“Yeah. Man, if there ever was a, …I’m not going to say it,” I began with a laugh but nonetheless went on to say what I was thinking, “but if there ever was something that looked like a fumarole alteration, this is it.” On Earth, “fumaroles” are hot, volatile and water-rich springs often found around active volcanos. Colorful, altered and oxidized rock material are evidence of such activity around extinct volcanos.
“Okay, let me give you a gravimeter. MARK it. …And she is flashing. Oh, never mind, Bob,” Cernan said remembering that he would disturb the Rover, again. “I’m going to go to STANDBY. I got to get my gnomon…”
“Hey, I think we hit one of those things we’ve got to reconsider on [time], Houston,” I told Parker as I began to dig a trench across the long axis of the orange area. I called this a “trench”, but it actually was a half trench as were all my trenches. Facing the trench line, I would cut a wall that roughly faced the sun by throwing scoop-fulls behind me much like a dog digs for a gopher. This would scrape out a clean, nearly vertical, sun-lit facing wall that we could examine, photograph and sample. Like a dog, I jabbed the scoop downward into the orangish dust, drew it toward my right side, and flicked its contents toward my right boot. This motion was not only the most natural but it reduced the disturbance of the area over the deposit away from the trench wall. Within a minute or two, I had carved a ~20 cm high wall across the crest of the crater rim and exposed a vertical surface of apparently pure, brilliantly orange and red-orange material.
“Yeah,” Parker agreed, “but the problem is we’re looking at PLSS [walk-back] constraints right now, as luck would have it, of course.” My suggestion that we “reconsider on [time]” was aimed at getting the Flight Director to bend the walkback constraints a little.
“MARK it. Gravimeter,” Cernan reported after he retrieved the gnomon. Then he noted that the TV had stuck when Fendell had looked at a Rover wheel. “What’s wrong with the TV? Aren’t you watching this?” Again, Fendell followed his own interests rather than the action.
“It seems to have died slowly there.”
“Well, stand by.” Cernan went to the Rover’s right front corner and raised the TV to an operating position, but, of course, moved the Rover in the process. “Now, I’m going to give you another STANDBY and another MARK… STANDBY…ON…and MARK it.”
“Okay, Bob, I’ve trenched across the trend of the yellow…or [rather] the orange. There is light-gray material on either side.” (Fig. 11.88 ).
Fig. 11.88. Orange, red and yellow pyroclastic ash exposed in the half trench on the rim of Shorty Crater (Station 4). Note also that black ash is visible in the lower right of the image, having been stirred up by my feet as I dug the trench. Although I did not notice the black ash at this point, it later became obvious on the lower portions of the double drive tube core. Color layers within the original image (Ektachrome SO-368 film) have been contrast-balanced and adjusted, ) so as to match my initial descriptions (NASA Apollo 17 air-to-ground transcript: 145:27:15 and 145:40:09 GET and 145:45:28 GET) of the near Sun zero phase colors present in the wall of the trench. This image was taken at about 45º off zero phase; however, the original prints and later digital scans of the films did not properly bring out the colors described13 (see discussion below, Fig. 11.89↓, Fig. 11.90↓. Note both the presence of light-gray regolith in the trench on either side of the orange ash deposit and the yellowish hues in the orange ash at the contact (Fig. 11.91↓, Fig. 11.92↓). (Color-balanced derivative of NASA photo AS17-137-20990; Copyright © 2018 by Tranquillity Enterprises, s.p. Courtesy of Tranquillity Enterprises, s.p.).
Fig. 11.89. The original digital scan of the prime film made at Johnson Space Center ca. 2005 and available for downloading from the Project Apollo Archive website. It is clear from the gnomon and the over-all pale appearance of the view that both the brightness, contrast and the color need balancing across the image. This process was facilitated with the software programs Adobe Lightroom™ and Corel Photo-Paint™. It required 8 iterations of the procedural steps involved before Fig. 11.88↑ matched my in situ observations and later visual inspection of the prime color reversal film in Houston10. (NASA photo AS17-137-20990).
Fig. 11.90. The front cover of the Apollo 17 Preliminary Science Report published by NASA in 1973. The orange soil illustration on the cover and Fig. 4.34 on p. 4-18 of that report were improvements on most available images in depicting the true bright colors and their variations of the trench; however, Fig. 11.88↑ shows the actual observed colors. (NASA SP-330).
“Oh, man, that’s incredible!” Cernan saw the fresh orange soil for the first time.
“Gene, we’re going to have to…” I knew that Mission Control would not be able to react quickly to this discovery, so I immediately began to organize our sampling and documentation plan. We needed a good systematic sampling of the various, differently colored materials in the trench as well as a drive tube sample into the undisturbed deposit. I also wanted a good sample of the boulder on the rim as it probably came from the deepest part of the crater.
“You need to get a down-Sun color…as well as…I’ll get my black-and-white.”
“That’s incredible,” Cernan repeated. “I’ll get it (the before photograph.)”
“We also got to get that rock up there,” I added.
“Yeah, we’ll get that. Okay, let’s start sampling that trench. We’ve got to get…”
“That’s phenomenal. Look at where the contact between the gray and the [yellowish orange]…”
“Yes. Right, and it’s (the contact) on both sides [of the deposit],” I noted. Many years later, after detailed consideration of the stratigraphy in the core (74001/2), I proposed that the deposit actually was a partially overturned, anticlinal fold and this light gray material on either side were part of the same ejecta unit from a nearby crater. That light gray ejecta unit had protected the orange soil for ~3.5 billion years from being mixed into the dark mantle regolith.
Fig. 11.91. An enlargment of the trench from Fig. 11.88↑ showing the central reddish area, the transition to yellow in the left and right wings of the trench wall, and the light gray regolith beyond the latter. The original orange appearance that I saw is that on the top surface between the gnomon at left and my shadow at right. (Excerpt of derivative NASA photo AS17-137-20990; Copyright © 2018 by Tranquillity Enterprises, s.p. Courtesy of Tranquillity Enterprises, s.p.)
Fig. 11.92. A contemporary cross-section of my observations of the trench in Fig. 11.88↑, Fig. 11.90↑ published in 1973. It shows the color profile of the trench material and the position of the double core drive tube located ca. 30 cm behind the trench (Fig. 11.99↓).
Fig. 11.93. A transmission photomicrograph of the orange soil made up of orange, orange-red, yellow, and black glass spherules and shards. (NASA photo S73-15171).
“Before you disturb it, let me just get a couple of close-ups of that.” Cernan set up the gnomon and went to work with the partially cross-sun before photographs (AS17-137-20984-90). I took the near-zero-phase black and white shot, however, for some reason, my post-panorama photographs (AS17-133-20257-68) are badly over-exposed. On the other hand, Cernan obtained an excellent set of before sampling color photographs.
“Hey, can you get a down-Sun? I think your color will be best down-Sun.” To the eye, the color showed up extremely strongly at zero-phase. It turned out that this resulted from the “soil” being made up of tiny beads of glass, creating an effect like that of a beaded reflector.
“Go to f/11,” I told him in order to account for the direct reflection of the Sun off the trench wall. “Get a little closer, Geno, if you think you’re minimum focus… There you go.”
Fig. 11.94a,b. Cernan began his documentation of the trench with the largest phase angle. (top): AS17-137-20984, about half of the trench, taken at ca. 60°; (bottom): AS17-137-20985. (Derivative photos Copyright © 2018 by Tranquillity Enterprises, s.p. Courtesy of Tranquillity Enterprises, s.p.).
Fig. 11.95a,b. (top): AS17-137-20986, slightly smaller phase angle than Fig. 11.94b. (bottom): AS17-137-20987, Cernan has moved in closer on the left half of the trench, blurring the image slightly. The effect of increased shadow sizes on color intensity was compensated for in the balancing process (ref. , Section 1). (Derivative photos Copyright © 2018 by Tranquillity Enterprises, s.p. Courtesy of Tranquillity Enterprises, s.p.).
Fig. 11.96a,b. (top): AS17-137-20988, similar to Fig. 11.95b. (bottom): AS17-137-20989, after this last of the close-up photos Cernan moved to the smallest phase angle of ca. 45° and backed off enough to frame part of the rim boulder and the entire trench in the field of view, obtaining the best of the trench photos, Fig. 11.88↑. (Derivative photos Copyright © 2018 by Tranquillity Enterprises, s.p. Courtesy of Tranquillity Enterprises, s.p.).
“Let me get one more.” But, for some reason, Cernan did not take another photograph at this point.
“Hey, you want any of this bagged in the [short (vacuum)] can, Bob?” I asked, thinking that we probably should sample any retained volatiles. The “short can” was shorthand for the Special Environmental Sample Container, a 13 by 6 cm, indium-knife edge, vacuum-sealed aluminum can. “Canned in the bag…or whatever it is?” I was thinking ahead of myself, as I positioned the scoop for a sample of the reddish, center portion of the trench wall.
“Stand by. They’re debating that right now.”
“[Do you want me to get the short can?]” Cernan had already left the Rover so doing so would break into the flow of sampling preparation.
“Roger. Let’s get the short can for some of that (orange soil) and…” The Science Back Room finally made a recommendation.
“Okay, the color is…,” I began and then responded to Parker. “Okay, let us get the [scoop samples first]…”
Cernan completed my thought. “Better sample it first, then we’ll get it (the short can).”
“It’s quite indurated,” I said, referring to the cohesiveness of the main portion of the deposit exposed in the trench.
“Aaaah,” Cernan said as I failed in my first attempt to get the sample in the bag he held a bit too high. “Go back and get that one. Go get a new chunk!”
“I’ll go get a new chunk.” When an action is obvious, I had a tendency to repeat what someone says.
“Give me that,” Cernan directed, “and get a new one (scoop full). Give me that. Get some more.”
“I’m going to slow down here.” I had been going full out since getting off the Rover.
“Yep, just take it easy,” agreed Cernan.
“I can’t see into this [trench].” I had moved so that my shadow covered the cut I had made.
“I can’t see when your shadow is there.”
“Can you get around on the other side?” I needed for us to change positions so that he would be on my left.
“Because I can’t see to sample…”
“Oh, Hell!’ As I went to a knee to get another sample, I lost my balance and as I jumped up, I scuffed some surface debris into the trench. I changed my technique to just as deep a knee bend as possible. “Yeah, that’s [the way to do] it,” I said as I poured more of the reddish orange from the center of the deposit into the first bag.
“See if you can get a sample right across that contact too.”
“I will. Okay, bag that one”, I said.
“Bag 509 (74220) has got the [reddish] orange material from, oh, about 2 to 3 inches down.” Cernan reported this as I extended the trench a quarter of a meter or so towards the crater. The center, reddish portion of the orange material (see Fig. 11.96↑) appeared highly compact, showing roughly parallel fractures with an apparent dip to the south-southeast of about 45 degrees. In situ, the orange material broke in to angular chunks several centimeters in average diameter. The material also took on a more yellowish hue toward its essentially vertical contacts with light-gray, regolith-looking material on either side of the one-meter wide deposit.
“Copy that… Okay, we’re suggesting INTERMEDIATE [cooling] for you, Jack.”
“Okay, the light-gray [wall material], which is on either side [of the orange material]… – we sampled the [center portion first] – …Want me to get some more?” Cernan could tell how full the bag had become better than I could.
Fig. 11.97. Red and reddish-brown clods from the sample 74220 (see Fig. 11.100↓ for location) taken from the central red wall area of the trench. Also cf. Fig. 11.91↑, where the color matches are good for rows 1, 3 and 4. Row 2 matches the reddish-brown clods in front of the trench. The scale at right is in mm. (NASA photo S75-34259).
“Yeah, a little more,” he replied.
“All of this (sample) is getting mixed a little bit with about a half-centimeter thick light-gray or medium-gray [regolith] covering over the whole area.” I refer here to the thin covering of mixed regolith and orange material that covered the orange deposit before I dug the trench. (A discussion of this thin cover is in Chapter 13.)
“Bob, the gray material that’s adjacent to the red material is in – what would I say – 510 (74240-49; Fig. 11.100↓)… I had it (the number), and I can’t see it now.” While Cernan closed the bag and reported the number, I turned to present my SCB to him so he could stow the first two samples.
“And the LMP is INTERMEDIATE.”
“510, Bob,” Cernan confirmed the bag number as he put it in my SCB. “And that orange band is about a meter wide, I think.”
“About a meter,” I agreed.
“You can’t get to the bottom of it (the deposit) though, can you?”
“I haven’t been able to yet,” I replied. “Just to be sure, why don’t we sample this (crater) side of it (the wall of the deposit), too.”
“Then I’m going to go get the [short] can, …if I can remember where we put it. Bob, where did we put the small can?”
“It’s in bag 7 under my seat,” I answered while I poured the sample of the right hand wall material in a second bag.
“Okay. That’s good,” Cernan said, as I filled the bag.
“511 (74260; Fig. 11.100↓) has the gray [material] from the other side of the orange band. …And the other side happens to be the crater side,” Cernan added.
“That’s right. North side.”
“Okay,” Cernan said as he stowed the third sample in my SCB. “Why don’t you look around a minute, and I’ll get that [short] can.”
“Okay. I’m going to see if this goes on down here [along the rim] as a zone.” As I drag the scoop along the rim, I say, “It looks like it’s an ellipsoidal area if my footprints are any indication.”
“Seventeen, Houston. We’d like to get the double core here instead of the small can. Double core, please, instead of the small can.” Parker’s call shows that active discussions have been going on in the Science Back Room.
“Okay,” Cernan replies from the Rover.
“Did you want it in the orange [material]?” I asked to make sure that all other possibilities had been considered, such a driving the tube at an angle from outside the orange area, through the contact, and into the deposit.
“Roger. That affirm,” Parker replied, finally using the right pilot terminology. “We can put cores in gray soil all the time.” The problem with this statement, of course, was that no one knew whether the light gray wall material was the same as other material we had sampled or if the process that created the orange soil or put it in place had altered pre-existing material.
“Well, [from the vertical contacts,] it’s a vertical stratigraphy,” I reminded Mission Control as I removed the scoop from the extension handle so we could attach it to the drive tube. “Do you want to go sideways a little with it? Or you just want to get it as deep as you can, huh?”
[In recent years, I determined that the stratigraphy of the deposit is not vertical, but inclined (see Chapter 13) but had no way to find that out during our brief stay at Shorty. The only on-site evidence of these inclined beds, that I did not recognize as a fold at the time, is the color symmetry exposed in the trench: light gray / contact / yellowish-orange / orange / reddish-orange / orange / yellowish-orange / contact / light gray (Fig. 11.91↑, Fig. 11.92↑). Knowing what I know now, over 46 years later, a core inclined at about 45°, starting in the crater side light gray material and driven from north to south, probably would have provided the maximum information. On the other hand, “knowing what I know now” is based on the core we have. Fortunately, decades later, the suggestion from the Science Back Room turned out to be the best one with the knowledge at hand. ]
“I expect we want to get… Let’s go as deep as we can in the orange, please, there, Jack. And the one problem at this station, Jack, is not that we can decide priorities between this station or any other station. (Rather,) it’s the fact that we’re running up against the walk-back constraints here in just a very few minutes, about two-zero (20) minutes.”
“All right.” I do not recall ever being personally concerned about the safety issue represented by the walk-back constraint. Its limits on exploration, however, did concern me, but I left it to Mission Control to worry about our backpack supplies as they had information and models that I could not access.
“Okay, Bob, and the bottom [core] will be 44 (74001),” reported Cernan, “and the top will be 35 (74002).” (see Fig. 11.100↓ for locations)
“Copy that. …And after the core, we’d like for you to go over and sample some of the big rocks there on the rim, if you could very quickly. That’ll be the next order of priority after that.”
“We will,” I replied, wondering if anyone realized that they had experienced and trained humans on the Moon.
“Yes, sir.” Cernan added.
“And I’m not sure whether your pan will look down into the crater or not, Jack. But if it didn’t, we’d like to get another one from there. Hey, there’s the crater [on the TV].” Fendell had continued to operate the camera without supervision, but had finally panned over to Shorty Crater.
“It (the black and white photo pan) did [include the crater],” I confirmed.
“Yeah, look into it yourself and then,” Cernan said with enthusiasm. “I’ll also get you a stereo pan before we leave. I can do that.
“Roger. That’s some crater!” Parker had his first view of Shorty.
“Got your hammer?” I asked.
“Yeah,” he replied and then added, “I’ve practiced too long on taking stereo pans of craters, without getting one here.”
“I got mine from right down there, Gene. So…” I was going to suggest where he positioned his color panorama to get stereo, but he interrupted.
“What is that right there?”
“That right there.”
“I don’t see [what you mean]. …Oh, it’s a piece of glass, probably.
“Boy, it sure is.”
“Hey, how about right up here [for the core – just west of the trench]?” I looked for a place that still had undisturbed regolith over the orange material. “…You know, we just about got to the upper (western) edge of this little ellipsoid zone,” I said with a laugh, thinking that I almost missed the zone with my trench. “I think we’re going to have to… we’ve messed up most of it. Let’s try right over here.”
“I’ve got a little piece of [solid black] glass in my pocket.”
[Back in the Lunar Receiving Laboratory, this 59 gm sample became 74235 (Fig. 11.98). It was discovered that, rather than glass, this rock was an extremely fine-grained (vitrophyric) Type A ilmenite basalt with a “metallic sheen” that made it look like glass. The sides of the rock cut through large, smooth walled vesicles up to ~5 cm in diameter. 74235 is one of only a very few Taurus-Littrow basalts we sampled that came from the rapidly quenched top of a flow and may be a good candidate for investigating the nature of volatiles that originally formed the vesicles. (Later, after we were back in Challenger’s cabin, we transferred the rock to LRV sample bag 12 and put it in SCB 8.)]
Fig. 11.98. Lunar Receiving Laboratory photograph of sample 74235. Note the large, broken vesicles on the two visible sides of this rock. (NASA Photo S73-16017).
“Bob, the upper portion of the core is going to be a little bit disturbed, because we’ve walked around the area so much. …You may want to get uphill, [Gene]. …Okay. …Did you get a [before photo]? …Hold it, and I’ll get a shot.”
“Take your picture,” Cernan said with some impatience. After taking the before photo, I took the drive tube and extension handle from Cernan and tried to push it in by hand.
“That’s about as far as I could shove it in.”
“Okay. And, Seventeen, while you’re doing that, was the gray mantle over the top of this [orange soil], or was this [orange] showing all the way through to the surface?”
“No, it was over the top. …About a half a centimeter over the top.” The Science Back Room apparently missed my earlier description.
“He’s getting about 3 centimeters a whack,” I reported as Cernan wielded the flat side of the hammer against the top end of the extension handle.
“I’ll tell you, it’s a lot harder going in than that double core was back there [at Station 3].”
“Yeah, it’s pretty hard,” I agreed. As I reached out and stabilized the drive tube and monitored Cernan’s progress, I began to give more details of what I could see in the wall of the trench. “It (the orange soil) acts like it’s inherently cohesive. It breaks up in angular fragments. …The central portion of the zone actually has a crimson hue, or a red hue (Fig. 11.91↑). Outside of that it’s orange. And outside of that, it’s (the wall material) gray.”
“Wait a minute, Jack,” Cernan said, breathing hard.
“That’s all right, take it easy. I’d offer to hit it, but I don’t think I can, my hands are so tired.”
“I’m going up to MAX [cooling] here for just a minute or two. …Okay, let me hit some more. Ready?”
“Yeah, go ahead,” I said.
“Why don’t you. …I’m afraid… Jack, it’s (the drive tube) stable enough. Why don’t you get out of the way? I’m afraid if I leave go of this thing, you’ll get it in the head.”
“Okay. Have at it. He’s still getting a centimeter a whack, poor guy. Let’s see. I didn’t get a locator, I better get a locator… Oh, it’s in the [pan]. …No, it isn’t.”
“The only thing I question is our ability to get it out.” Cernan stops to rest and says, “Man, that’s really hit bottom.”
“Okay, do I have core tubes on me now?” I asked, referring to my SCB. “I mean [tube] caps?”
“And the rammer.”
“Yes…” After about seven more strikes, Cernan comments, “That’s all the way down. But, I really, …I really wonder about getting it out.
“That’s it. Thanks, Geno. …Well, we’ll give it the old college try.”
“Yeah, we ought to be good at getting cores out by now.”
“It’ll come out.”
“It wouldn’t dare not come out. Wait a minute,” I said, as I repositioned to grab part of the crosspiece of the extension handle.
“Is there enough [tube projecting] to hold on to?” Cernan asked.
“Whoops,” I said as a foot slipped. “Which side you got?”
“I was just getting this (crosspiece end) out for you. Let me. I can get this side better.” Cernan faced into the Sun, on the south side of the drive tube, and took hold of the top of the extension handle with his left hand. I faced away from the Sun, on the north side of the projecting tube, and also grabbed with my left hand.
“Okay,” I told him.
“Okay,” I repeated.
“Go. Okay, pull slowly.” As we lifted, the drive tube easily rose about 30 cm. “…Slowly so I can cap it all right. Let me get a cap [from your SCB].”
“Okay. Hold it. Hold it. Let me get a cap. Turn.”
“All right, get the cap,” I said.
“Okay. Now, wait a minute,” he replied.
“Are you ready [with the cap]?” I, of course, could not see what Cernan was doing at my right side.
“Okay, very slow,” he said as I pulled the rest of the drive tube out of the hole. “Even the [outside] core tube is red!”
“Look at that!” I exclaimed, as the bottom tube came into view.
“Even the core is red!” Cernan broke in. “The bottom one’s black and orange, and the top one’s gray and orange!
“The fact is,” I observed, “the bottom of the core is very black compared to anything we’ve seen.”
“Hey, we must have gone through the red soil because it’s (the bottom of the tube) filled, but it’s filled with a black material.”
“Let me see, Gene.”
“Dark gray, almost a very, very fine grained…”
As he finally showed me the extremely fine-grained material in the bottom end of the lower tube, I said, “That might be a magnetite [deposit]…” In the back of my mind, I still had thoughts of alteration by hot fluids that might have oxidized iron and produced red hematite (Fe2O3) and black magnetite (Fe3O4). How wrong this thinking would turn out to be!
“Fantastic,” interjected Parker.
“[You have the cap?”] I asked.
“I got it,” he answered.
“Go ahead [and cap it],” I said, trying to get our activities moving again.
“Okay, …But it, it, it [is binding a bit]…”
“Let me [brush some off the outside]. …God, it is black, isn’t it?!” I exclaimed.
“Yeah. I’ve got to get it [cleaner] so I can get the [cap on]. …Boy, it is black and is it contrasted to that orange stuff.”
“Very black,” I agreed. “Well, not very black. It’s a good dark gray.”
“Very dark bluish gray.”
“Yeah, …[sharp] contrast.”
“Okay, turn that thing (tube) so I can push this cap a little bit. Just turn.”
“Which way?” I could not be sure what he had in mind.
“Either way. Just turn the whole tube.”
“Oh, okay.” Cernan had the cap partially on and wanted me to turn the tube to work it on further as he pushed the cap.
“It’s just easier to turn the tube than my hand,” Cernan explained, bringing a laugh of sympathy from me. “[Turn] some more. I don’t want this cap to come off. Okay. I’m going to INTERMEDIATE cooling. Okay. Now you don’t have any caps [left in your SCB], so let’s take this back to the Rover.
“Where’s the hole?” I asked, wanting to be sure I did not step on it before I took a photograph of it.
“Why don’t you take a picture of the hole, while you’ve got a camera there?”
“Be careful with that (core),” I warned Cernan. The last thing I wanted was to damage what might turn out to be the most important sample from the mission.
“The [other] caps are in SCB-7,” Parker offered. “They’re under the LMP’s seat.
“Well, the hole’s mostly in shadow,” I described, stating the obvious as I took a photo of the well-defined edges of the core hole.
“Yeah, I got them (the caps) Bob,” replied Cernan to Parker’s heads up on the caps.
“And, Seventeen, for your thought, …we have to be leaving here, …not ‘like [‘to be leaving here’], …[but] we have to be leaving here in fourteen minutes [and] on the move, because of walk-back constraints. And we’d like to get a quick sample of the basalt up there on the rim, and Cernan’s stereo pan, and then press on. And I emphasize that it’s walk-back constraint we’re up against in 14 minutes. 13 now.”
With this reminder, I stopped heading for the Rover, picked up the gnomon and replied, “Okay, Bob, I’ll sample it by hand. But it’ll be documented. And I’ll get it in a bag in a minute since I don’t have any (bags).”
“Come back this way when you do. I need that rammer again.”
“Oh, okay. Well, I better come there first, I guess,” I replied, thinking he needed it right away.
“Well, I don’t need it right this second…”
“Why don’t you leave the core there Gene,” Parker suggested, “and you can take your stereo pan while Jack’s getting that sample. And then you can get together and ram the core home.”
“Okay. Bob, the bottom of the upper core is also dark.” Cernan has separated the two drive tube sections so that he can complete capping them.
“Copy that. …Sounds (like the orange zone is) a little thin…”
Meanwhile, I took before and down-sun photographs of the southeast face of the boulder before leaning on it to get a close look. I then pulled off a large sample of this highly fractured, basaltic-looking rock. These photographs, as well as my after sampling shot, are badly over exposed. The reason for this is unclear. Later photographs on the drive from Shorty to Camelot were properly exposed. After the panorama I took at the rim of Shorty, I may have accidentally moved the f-stop Mouse ear to f-2.8 and not realized it in my excitement. This seems unlikely relative to the extensive, habit-forming training we had relative to Sun-angle. It is more likely that a temporary sticking of the f-stop mechanism occurred. To my knowledge, no one investigated this possibility after the mission.
“And, like you might expect,” reported Cernan, “the top of the bottom core is dark, too!”
With gnomon in hand, I headed for the Rover to help Cernan with the drive tube cores and to bag my sample of the rim boulder. Thinking about what we had seen, however, I started to speculate. “If I ever saw a classic alteration halo around (near) a volcanic crater, this is it. It’s ellipsoidal; it appears to be zoned. There’s one sample we didn’t get. We didn’t get the more yellowy stuff [next to the light-gray contact, but] we got the [red-orange] center portion…”
“Let me get those caps, Jack.”
“What’s holding [this cap in the dispenser]. …That’s (the tight packing) what’s holding it, …holding it from coming out.”
While Cernan struggles with the cap dispenser, I said “Let me steal a [sample] bag.”
“Okay. …Here,” he replied, as he removed a bag from under his camera and handed it to me.
“Okay, I got it (the rim boulder sample). …Okay, the [rim] basalt is in bag 512 (74255, Fig.11.99).” I had turned the top of my RCU into a workbench to help bag the boulder sample. “…I’m getting in your bag (SCB) here, Gene.”
Fig. 11.99. Lunar Receiving Laboratory image of sample 74255 from the large, intensely fractured basalt boulder on the rim of Shorty Crater (Station 4). Note the strong alignment of larger flattened vesicles as compared to the more random distribution of small, more rounded vesicles, suggesting that the former formed early while the lava was still flowing. See Fig. 11.100 for its in situ location. (NASA Photo S73-16905).
Fig. 11.100. In situ locations of rock sample 74255 from the big rim boulder, gray wall samples 74240, 74260, and clod sample 74220 (Fig. 11.97↑) from the base of the central reddish trench wall. 74275 is the rock I picked up just before we were getting ready to leave. 74001/2 is the position of the core drive tube in the orange oval. (Wolfe et al. 1981 data for sample locations on color-balanced derivative of NASA photo AS17-137-20990).
“[You] Got it?”
“Okay,” I replied as I dropped the sample bag into his SCB.
“Jack, our [gate] lock [rod] is on the outside here, so we ought to watch this gate.”
“What happened?” I asked as I folded the gnomon legs and inserted it into its pouch behind Cernan’s seat.
Fig. 11.101. An enlarged portion of an LRO photo of Shorty Crater’s southern rim and ejecta blanket. The horizontal arrow points to the trench (dark line) that I dug across the orange oval area. The cup-shaped dark zone below the arrow marks Cernan’s and my movements photographing the trench. Other dark trails up to the large rim boulder mark my sampling activities. Cernan’s parallel footprint trail, marked by the rightmost vertical arrow, is clearly seen going to the large oval dark spot where he took stereo pans of the crater interior. The middle vertical arrow marks a red streak (dark line) in an orange oval next to a couple of rocks seen in Fig. 11.109↓. The diagonal arrow at top left marks the position of the red streak within the orange band that descends to the crater floor as seen in Fig. 11.102↓. The orange dashed curves outline orangish areas on the ejecta blanket seen in Fig. 11.109↓, Fig. 11.110↓; and the blue dashed curve marks the approximate track of the LRV as we drove up to park on Shorty’s rim from between the two small craters at left, also seen in Fig. 11.109↓ (Base map NASA/ASU/Goddard LROC photo M175077349L. The full crater LROC photo can be seen here).
“Not going to worry about it. This [gate] lock [rod] is on the outside of that lever lock. You’ll see what I mean when you look at the lock. …Okay, I’m going to go get my pan.”
“The cores are not rammed yet,” I noted. “You want to ram them while you’re here?” “What did you do with my extension handle? Oh, it’s…”
“Here. And, if you want to ram them, …here you are,” Cernan said as he handed me the rammer. “They’re not rammed.” The process of “ramming” would insert a plug that would keep the core from mixing during transit.
“Okay, …I’ll get them.”
As he then walked about 40 m around the east rim of Shorty to reach a good spot for a panorama, Cernan said, “Okay, Bob, I’m going several meters around to the east and towards the south (he meant north) to get this pan. …I’m going upslope. I’m circum…I’m on the circum…oh, you know, on the rim. And I’m up [higher than Jack]. Oh, that ought to be a beautiful shot, if I could see what my settings are.” Cernan was starting his pan with his shadow in the camera settings. A LROC image of Shorty Crater (Fig. 11.101↑) shows parallel trails that Cernan left going to and and from the pan site, apparently stirring up black material like that in the bottom of the core.
“Okay, the lower core is ‘chucky-jam full’. I don’t think I’ve budged that thing (the plug).” Richard H. “Dick” Jahns, one of my most remarkable Caltech geology professors, often used the expression, “chucky-jam full”.
“Okay, and, Jack,” Parker acknowledged, “I copied – aside from three trench samples – I copied one single bag of basalt samples. Is that correct?”
“That’s right. [Bag] 512.”
“Hey, Bob, from where I am,” Cernan observed, looking toward the west wall of Shorty, “about 100 meters around the west side of the rim of this crater [from where we sampled], the mantle on the inside of the rim turns from this gray material (general regolith) we’ve been sampling, in here, to a very dark gray material. And there’s a lot of orange stuff that goes down— radially down— into the pit of the crater” (Fig. 11.102). Here, with a near-zero phase view of the west wall of Shorty, Cernan described features in the crater that I missed as I took my initial, black and white panorama from the rim of Shorty. At that time, I had just discovered the orange soil and may have been concentrating on how to best sample that deposit. Not a good excuse for being too focused, but still an excuse.
Fig. 11.102. The west and northwest interior wall of Shorty Crater showing the apparently northeast dipping, ~2 m thick dark layer (right and Fig. 11.103), presumably consisting primarily of black material like that which the drive tube revealed underlies the orange soil deposit. Orange material is exposed to the left of the black layer (see also Fig. 11.104↓ for a view further right). Note the bright red streaks in the leftmost orange ash layer descending to the crater floor. The orange color in front of where Cernan is standing closely approximates the appearance of the surface color when I first saw the area I trenched. The color layers of this image have been contrast balanced to show where orange material is present. (Derivative of NASA photo AS17-137-21005; Copyright © 2018 by Tranquillity Enterprises, s.p. Courtesy of Tranquillity Enterprises, s.p.).
Fig. 11.103. Enlargement of the long black layer curving over the west rim of Shorty Crater and that appears to the right in Fig. 11.102, or to the left in Fig. 11.104. The geometry of the layer and rim indicate that it lies within a synclinal fold, plunging to the north or northeast (See Chapter 13). (Extract from derivative NASA photo AS17-137-21001; Copyright © 2018 by Tranquillity Enterprises, s.p. Courtesy of Tranquillity Enterprises, s.p.).
Fig. 11.104. A photo looking further right from Figs. 11.102-3. The black layer is at left. Note the two red splotches just below the small rim boulder at ~110 m distance (Fig. 11.105). (Derivative of NASA photo AS17-137-21001; Copyright © 2018 by Tranquillity Enterprises, s.p. Courtesy of Tranquillity Enterprises, s.p.)
Fig. 11.105. The far (~110 m) northwestern wall of Shorty Crater showing the two red ash splotches on the mottled orangish surface of the wall. These all can be seen in an enlargement of the northern rim of the crater (Fig. 11.106). The two white arrows mark the identifying boulders in each figure. (Extract from derivative NASA photo AS17-137-21001; Copyright © 2018 by Tranquillity Enterprises, s.p. Courtesy of Tranquillity Enterprises, s.p.).
Fig. 11.106. Extract from the LROC photo of the north rim of Shorty Crater. Arrows point to the same boulders seen in Fig. 11.105. The two red splotches are above the smallest two boulders and just above and left of the first of 3 black nodules. (LROC photo M175077349L).
[Cernan’s photographs (Fig. 11.102↑, 11.103, 11.104, Fig. 11.105↑) make it clear what he saw. In addition to more orange material exposed in the south crater wall of Shorty, an apparently northeast-dipping, ~2 m thick layer of dark material cuts across the upper third of the northwest wall (Fig. 11.103↑), and an exposure of orange material is present to its left and right. In the LRO image in Fig. 11.106, the trace of this dark layer over the raised crater rim indicates that it lies within a syncline with the strike of the axial plane and the plunge of the axis estimated to be about N30ºE and 45ºNE, respectively. This almost certainly is a bed of the nearly black material we sampled with the lower part of the drive tube core. It should have been my first clue that the Shorty impact had exposed relatively shallow beds of volcanic ash.
I had not concentrated on listening to Cernan’s description but, instead, focused on capping the cores. As he did not mention a “layer” or “bed,” it did not register at the time what actually crosses the west wall of Shorty. My first realization of what he saw came with viewing the photographs after the mission that showed the trace of the black layer but not the extensive distribution of orange material. The full extent of orange only became apparent with the more recent color balancing work of my editor, Dr. Wells. I wish, of course, that, while on the spot, I had more time to explore and think about the geology of Station 4; but this might be called the universal “field geologist’s lament” that I have expressed about every major mapping project I have had on Earth.]
“Okay. Copy that. Outstanding!”
“Hey, Bob,” I called, “those cores didn’t feel like the follower went down at all. …Shouldn’t it (the follower) have gone [in] a little bit?”
“Not necessarily, if it’s pretty compact stuff. You were having a hard time getting it (the core tubes) in.”
“Well, I thought there was a little space up there [in the tube], but maybe I just didn’t feel it. …I don’t think there’s much danger of them coming apart.”
“Okay. Great,” replied Parker.
“I got to take a couple of more pictures at that contact slope over there,” reported Cernan. “You can’t see it from where you are, Jack, but I guess we got to leave. Otherwise it would be nice to sample that dark stuff up on top.” Yes, it would have been nice, as would have been another trench across the bed; however, with black ash in the core tube, we already had a good sample.
Fig. 11.107. Cernan’s color panorama assembled from 7 of his photos taken on the east end of the south rim (see Fig. 11.101↑ for location) (AS17-137-21005, -21000, -21001, ‑21002, -21003, -21004, and -21024; left to right, respectively). Notable features were seen more easily in Fig. 11.102↑–Fig. 11.105↑, and are re-iterated below. (Copyright © 2018 by Tranquillity Enterprises, s.p. Courtesy of Tranquillity Enterprises, s.p.).
Fig. 11.108a. Extract from the assembled pan of Fig. 11.107 with the central mound of jagged boulders, right of center. At a higher level above it along the bottom of the photo is part of a bench that wraps around towards the right. Its continuation is at the lower left of Fig. 108b. (Copyright © 2018 by Tranquillity Enterprises, s.p. Courtesy of Tranquillity Enterprises, s.p.).
Fig. 11.108b. The continuation of the bench from Fig. 11.108a is at bottom left dropping towards the middle. Another smaller bench above the slump blocks is at right. A small part of the central mound with boulders from Fig. 11.108a is visible at middle left. (Copyright © 2018 by Tranquillity Enterprises, s.p. Courtesy of Tranquillity Enterprises, s.p.).
[Cernan’s color panorama, Fig. 11.107↑, of the interior of Shorty Crater, taken counter-clockwise from the north (AS17-137-20991-21027), shows various features exceptionally well, in addition to the black ash layer in Fig. 11.102↑, Fig. 11.103↑. The central mound of jagged boulders jut out from the floor in AS17-137-20993-4 and the benches on the top of slump blocks stand out particularly clearly in AS17-137-20991-2 (Figs. 11.108a,b). Photographs AS17-137-20994, -20996 and -21011 image spots of orange material and light-gray regolith that crop out in the wall of the crater, some of which resemble the deposit we sampled and others appear to be part of slumps or down slope migration of orange material from higher outcrops (Fig. 11.102↑,Fig. 11.103↑, Fig. 11.104↑, Fig. 11.105↑).]
Fig. 11.109. A combination of NASA frames AS17-137-21012-13 from Cernan’s pan location. The large rim boulder that I sampled is at far right. The orange-red trench I dug is seen between the LRV and the boulder. I am returning to the trench to grab one more sample from between the boulder and the trench. There is a red streak in the foreground just beyond the small boulders. A faint deposit of orange ash can be seen on the ejecta blanket, and the rover tracks are just visible between the two light mantle craters. All of these locations are depicted in the LRO overhead enlargement in Fig. 11.101↑). (Copyright © 2018 by Tranquillity Enterprises, s.p. Courtesy of Tranquillity Enterprises, s.p.).
Fig. 11.110. Further left (counter-clockwise) from Fig. 11.109 showing a fainter deposit or mixture of orange ash in the regolith. Also see Fig. 11.101↑ (Derivative of NASA photo AS17-137-21015 copyright © 2018 by Tranquillity Enterprises, s.p. Courtesy of Tranquillity Enterprises, s.p.).
[The actual sampling site of Station 4, along with the author next to the Rover, is covered by AS17-137-21011 (Fig. 11.109↑) and includes the orange ash deposit and the fractured rim boulder. Color balanced versions of this image accent orange and black ash splashes in the Shorty ejecta blanket resembling the photographs of green ash that document Apollo 15 samples 15425, 15426. (Fig. 11.114a,b↓-Fig. 11.115a,b↓)
Finally, photograph AS17-137-21022 also captures the very large boulder on the Shorty ejecta blanket that was thrown from the crater. The photo was taken up-sun, but the boulder can just be seen to the right of center below the small reseau cross in the copy shown below.
In addition to its coverage of Shorty Crater, photograph AS17-137-21001 (Fig. 11.104↑) illustrates the strong change in texture between the main slope of the North Massif and the upper surface of the Lee-Lincoln Scarp where it crosses the slope. Hanover Crater in this same photograph clearly shows the roughly one crater diameter extent of most continuous ejecta characteristics of small impact craters, although some near surface regolith ejecta is distributed radially for many crater diameters (See Chapter 13).]
“We need you guys rolling in 7 minutes,” Parker reminded us.
“We can get a… Oh, I bet I’m out of film!”, exclaimed Cernan. “Well, I got them all anyway, Bob. I’m at (frame) 162. I’m out of film. …That stuff [inside the crater rim]— and you’re looking at me with the (TV) camera— that stuff is up toward that boulder. About as far away from that boulder on the other side as we are on this side. And we want a hack at that boulder, too. Jack, let’s see if we can’t get [a sample of] that boulder, anyway. …But I don’t have any film.” It had not registered on Cernan that I had sampled the boulder on the rim. In our urgency to do as much as possible at this station, we both missed noting some of what the other was reporting.
“Guys, we don’t have that much time.”
“I know, Bob, I know… There’s a lot of little pieces— not a lot— but enough that I’ve seen five or six of them. Little pieces of obsidian-like glass. I got one in my pocket. Unbagged. Undocumented. …This boulder that you were looking at with the TV, I’m going to take a sample. Undocumented.”
I waved him off with, “I got it! I got it!”
“Oh, you got it?”
“Yeah. …Let’s go,” I urged.
“I’m sorry, I didn’t know you got that…”
“Bag 461 (74275) has another sample of basalt that I picked up right near where we dug the trench,” I reported. This sample came from between the trench and the large, fractured boulder on the rim and just outside the edge of the oval exposure orange soil.
Fig. 11.111. Rock sample 74275 seen edge-on taken from near the orange-red trench that I dug on Shorty’s rim near the large rim boulder (see Fig. 11.100↑ for its location). The numerous small dark/black spots are micrometeorite zap pits. (NASA photo S73-16018).
“Okay, Bob, I’m going to give you something with the TV,” Cernan said, as he moved the camera to point toward the northwest. “I want to show you where that dark material starts on [the top of the rim].”
“Hold still, now,” I told Cernan as I put the bag into his SCB.
“Okay. As you look at the inner rim,” Cernan continued, “as it goes down…to the right — you see a lot of boulders, a lot of rocks — that are protruding out. Where that rock pattern thins out, just beyond that is an orange — a visible orange — radial pattern, and then beyond that is a definite change in albedo where you get the gray material, and a definite change in the number of rocks on the slope.”
“And that particular…”
“…and that particular material…that par… Let me finish, Bob!” An exasperated Commander finally came up against the problem I kept having with Parker. “That particular rim material there continues around to the due north, and then there’s a drastic change again where you see the inner rim completely terraced with this boulder fill”. This is an excellent description what is visible in Fig. 11.107↑, and Fig. 11.108↑a,b.
“Okay, copy that, Gene…” Parker would have saved time by letting him finish.
“And I can’t bet on it, but I can see it…”
“…and you can talk about it when you get home.” I am almost certain that Fight Director Griffin had started to lean on Parker to get us on the Rover and moving.
“Okay. As long as you’re happy, I am.” But I don’t think Cernan was at all “happy.”
“Wait, Gene. Wait, wait, wait.” I thought Cernan was about to get into his seat on the Rover, but he was just starting to get a film magazine from under his seat.
“I got to get the film changed, Jack…”
But Mission Control had other ideas. “All right, Gene, change the film at the next station,” Parker said. “We can save time that way.”
“All right,” agreed Cernan; however, this meant that we would only have black and white film in my camera between Stations 4 and 5.
“And we would like the SEP turned ON before you leave,” Parker continued, “and we’d like EP number 1 taken, Jack, so you can deploy that at Victory.”
“Okay.” Had I not been coming off my adrenaline high, I probably would have commented on the lack of color film for the traverse to Camelot.
“I’ll get your scoop for you,” Cernan said. I had taken the scoop head off the extension handle so he could attach the handle to the drive tubes. “Have you been leaving it (the scoop head) cocked [at an angle] like that?”
“Of course, we haven’t been taking any SEP measurements,” Cernan commented, “and I don’t know what difference it makes. …Okay, everything is locked on. I guess I owe you a reading, Bob?”
Parker thought Cernan had asked “how are you reading, Bob”. “We’ve been reading you loud and…
“670, 012, 501; 670, 012, 501.” During his earlier housekeeping at the Rover, Cernan had activated the TGE for a gravity reading.
“Charge number 1, and we need the SEP, ON…” Parker continued to assume that we would not remember what he just said and would not look at our Cuff Checklist.
“We got the gnomon, we got the rake,” I said, looking at the list on the Checklist.
“SEP – ON, Jack?” Cernan asked. “I’ll get charge number 1 for you.”
“Okay. I’ll get the SEP – ON,” I acknowledged.
“I’ll just hand it (the charge) to you [when you get seated].”
“And what’s your frame count, Jack?” Parker’s knack for out-of-context interruptions never ceased.
“Charge number 1,” Cernan noted as he took it off the EP pallet.
“Okay, [SEP] power’s ON, recorder’s ON, the temperature is one-twelve. …Can you get it (the charge), Geno?”
“Yep. …You get in [your seat]. …I’ll hand it to you.”
“And then I’m going to get the TV.”
“And, Jack, what’s your frame count, please?”
“Wait, Bob, I can give you that on the Rover.”
“Okay. I thought you were on there.” Who did he think had turned the SEP on?
Cernan began his final list of things to do before leaving Shorty Crater. “Okay, camera MODE switch is 1; camera’s going AFT. Well, I guess that’s the breaks of life. Low-gain I’ll set when I get on. I’ll give you this [charge] when you’re ready. First thing I got to do, Bob, is change film at the next station.”
“And, Bob, LMP is at [frame count] seven-five.”
“Say again, there, Jack, I missed that.” But at least ten other people in the MOCR probably did not.
“I must be getting fatter, you know it.”
“Fatter?” I queried, briefly puzzled.
“Depends on how you get in. [Watch] your hammer,” I warned.
“Okay, we got a [warning] flag on the Rover,” Cernan reported. This “flag” consisted of a thin, red, metal plate, held against its spring hinge unless released by out-of-limits temperatures on the batteries or drive motors, respectively, 125° and 400 °F. The flag, of course, could be reset.
“Your hammer’s caught again.”
“That’s all right. We got a flag on the Rover, and I’m reading 136 on battery number 2.”
“Say again on that one, Gene.” I never understood why Parker could not turn around in the MOCR, as others usually did when I was working various missions, and ask, “Did anyone get that?”
“I’m reading 136° — make that 132° — on battery number 2, and we did get a flag.” The Rover team at the Marshall Space Flight Center had already told everyone that 140° was okay, and I am sure there were good margins on top of that. Anyway, we never had a problem with power for the Rover.
[Shorty Crater, that is, Station 4, has become one of the most important, if not the most important, geological sites visited during Apollo explorations of the Moon (see Chapter 13).
As we drove toward Station 5 on the rim of Camelot Crater, I continued to verbalize thoughts about scenarios that might explain what we saw at Shorty Crater, considering the observations and logic available at the time. During fieldwork on Earth, I would have used a notebook to keep track of these streams of speculative thoughts.
If there had been time for me to notice and consider the dark layer that Cernan tried to describe when he took the color panorama of Shorty, I might have saved a lot of later discussion by immediately raising the possibility that we had sampled dark mantle pyroclastic material. For some reason, possibly because I had never seen, heard of or imagined volcanic ash as extremely fine grained as the Shorty samples turned out to be, the black coating on the outside of the drive tube also did not trigger a thought about pyroclastic ash but rather led to my speculation that it might be magnetite produced by oxidizing fluids.
The coating on the core looked more like a smear of black mineral dust than of ash. I had not yet made the mental connection between my Station 4 observations and the pre-mission interpretation of the dark mantle as being a young pyroclastic unit. In fact, I suspected at the time, based on EVA-1 observations, that the “dark mantle” might be just ground up, ilmenite-rich subfloor basalt. All I knew at the time was the fact that the dark mantle consisted of regolith developed on the very dark subfloor basalts. The fact that 10-15% of dark mantle regolith consisted of the remnants of a very old, very fine, largely black pyroclastic ash remained unknown until it was examined back on Earth; and the pyroclastic nature of the Apollo 15 green ash (15426) had escaped my notice and that of many others in the press of training for Apollo 17.
Fig. 11.112. An overhead LRO NAC view of Spur Crater at 28 cm/px resolution. Spur Crater is Apollo 15’s rough equivalent to Apollo 17’s Shorty Crater relative to the exposure of pyroclastic ash. The black arrow marks a large rim boulder. The dark partial circle around this boulder was made by Apollo 15 astronauts Scott and Irwin during their examination and photographing of the boulder. The vertical arrow denotes the green soil sampling area. The site of Irwin’s Pan D-11 is marked at right and the rover parking spot is just below that. North is at top and the crater diameter is ~80 m. (from LRO NAC photo M175252641RL).
The Apollo 15 photos below were taken by Dave Scott at Spur Crater, Station 7, a crater similar in size, but with a less blocky interior than Shorty Crater (Fig. 11.112). Jim Irwin was the first to notice that the soil was green, and both astronauts at first agreed: “It is green” (GET 145:38:31 in the ALSJ). However, Scott raised his visor and stated that the color was a light gray. But when the soil was returned to the laboratory in Houston, Swann et al. of the Geology team noted that: “The samples are unique, however, by virtue of the soft, green coating and the general friable nature”. Additionally, Meyer referred to the samples as “…clods of green glass…” and that one of the sieved soil samples derived from the break-up of the friable clods contained “…greater than 80% green glass beads.”
Scott himself in a later interview with Eric Jones noted that the soil in the laboratory turned out to be green glass spherules (GET 145:39:53, ALSJ). As the four green soil photos below indicate, Scott is taking the photos in the cross-sun direction, whereas Irwin’s shadow indicates he was facing down-sun. The latter is a direction that increases the intensity of the green for Irwin, compared with Scott’s less intense cross-sun view, that was similar to my zero-phase view of the very bright orange, red and yellow colored beads in the trench at Shorty Crater. These positions may account for the differences between Irwin’s and Scott’s initial perceptions of the green color.
(Editor’s note: The color balancing process first consisted of balancing the contrast of the image, and then adjusting the color channels in Adobe Lightroom™, especially the green channel, until the green soil color visually matched the green in the contrast-balanced gnomon. The same settings for AS15-86-11666 were also used for the other three photos. The gnomon itself was not altered after it was contrast-balanced because it served as a standard reference. Even though the solid green color paint of the gnomon chip was brighter facing the sun, the goal was to determine any green patterns in the more porous soil texture and their variations.)
Fig. 11.113. The original Johnson Space Center digital scan of Apollo 15 frame AS15-86-11666. The distribution patterns of green soil are not visible in this overexposure. The color of the green chip on the gnomon (third from the top) is also barely visible. (NASA photo AS15-86-11666).
Fig. 11.114a. AS15-86-11666 in which the color contrasts in the image were first balanced and then matched to the green of the contrast-balanced gnomon green chip14. In this manner, the green soil patterns become more clearly visible. Rock sample 15426 is the small rock to the left of the gnomon leg, marked by the white horizontal arrow. A smaller, triangular-shaped rock sample 15425 just above and slightly to the left, marked by the diagonal arrow, was also picked up. (Derivative photo copyright © 2018 by Tranquillity Enterprises, s.p. Courtesy of Tranquillity Enterprises, s.p.).
Fig. 11.114b. AS15-86-11667 with the color channels balanced with the same settings as before. Here rock sample 15426 is almost in the center of the photo. (Derivative photo copyright © 2018 by Tranquillity Enterprises, s.p. Courtesy of Tranquillity Enterprises, s.p.)
Fig. 11.115a. AS15-86-11668 taken after the rock samples were removed. The obvious cavity with small green spots (clods) in its interior located in the center of the photo marks its location. The sample 15425 cavity location is just below Irwin’s long shadow. (Derivative photo copyright © 2018 by Tranquillity Enterprises, s.p. Courtesy of Tranquillity Enterprises, s.p.)
Fig. 11.115b. AS15-86-11669 also taken after removal of both rock samples. In this view, Scott has stepped very close to the cavity left by sample 15425. It is of interest because the previous 3 photos show a flat gray area where now the small boot print has left green stripes from the material clinging to the boot treads. (Derivative photo copyright © 2018 by Tranquillity Enterprises, s.p. Courtesy of Tranquillity Enterprises, s.p.)
Fig. 11.115c. Enlargement of the small boot print area left of center from the previous two photos showing the “before and after” step into the plain gray area in which green soil was adhering to the boot tread. (Derivative photos copyright © 2018 by Tranquillity Enterprises, s.p. Courtesy of Tranquillity Enterprises, s.p.).
It is noteworthy that the small boot print pattern seen left of center in Fig. 11.115b does not appear in the other photos. The area where the print will be made is gray, implying that green soil was adhering to the tread of the boot, which became compressed and left behind forming the striped tread pattern when Astronaut Scott stepped away (Fig. 11.115c compares the “before and after” step). This green emplacement is confirmation of the soil color seen in the laboratory and in the photomicrograph of Fig. 11.116.
Fig. 11.116. A transmission photomicrograph of the beads adhering to the rock sample 15426 and showing the green glassy nature of the spheres, spheroids, and shards. (NASA photo S79-32188).]
“Okay, Jack, I’m going to make a very sharp right turn here,” Cernan informed me, “because I do not want to go down that hill (crater wall).”
“Okay. We’re moving, Houston.”
“Roger. You’re moving exactly 37 seconds early.”
“Early!?” exclaimed Cernan, “I could have gotten that dark mantle on the other side of that crater. That’s all it would have taken me.”
“So you saw a radial orange (soil distribution inside the crater wall), huh?” I asked, finally adsorbing part of what Cernan had said as he took his color panorama but still missing the fact that he had seen a layer of black material in the wall of Shorty and had referred to it as “dark mantle”. Unknowingly, Cernan had anticipated that the darkness of the valley’s dark mantle unit came from the presence of black pyroclastic ash mixed with basaltic regolith.
“Yeah, it (orange soil) was…radial, Jack. You could see it very [clearly]. …It’ll be in the pictures. (Fig. 11.102↑) Oh, man, I can’t drive into that heading [because of sunlight reflection off the LCRU]. Let me get my [heading off the sun line]…”
“That [orange] was on the inside of the crater?” I continued.
“On the inside rim (wall) of the crater.”
“Yeah, that’s where the surface stuff keeps slumping off as it’s exposed, probably,” I mused, as I finally had time to take a breather.
“Quite a station, men. We thought Station 2 was a good station!” It sounded like Parker and others were still quite excited.
“I’m going to get myself [warmer],” Cernan said. Okay. “I’m MIN. …Okay, I’m MIN [cooling]. Man, I’ll tell you, that heading is going to put us right [into the Sun]. Okay, Bob, give me a… Dang. Wait a minute.”
“The heading you should be generally taking toward Victory is 090, Gene.”
“Where we at?” I asked.
“Okay, can you give me a bearing and range at Victory?” requested Cernan.
“Did you get the TGE read?” I enquired of Cernan while we waited on Parker.
“Yeah, I did. I got it read. They got everything [they wanted at] that station; but not everything I’d like to give them.”
“Okay, it’s (bearing and range) going to be 105 and 3.1,” Parker finally responded.
“Okay. …Man, I tell you that LCRU is terrible when it flashes into you.”
“Well, you can always zigzag,” I reminded him.
“Yeah, that’s what I’ve got to do. I’ve got to tack into (away from) that Sun. …Okay. We got to go to Victory.”
“Houston, I didn’t have time to really think at that station,” I said as I began to speculate about Shorty, again, “…I think, based on having seen the alteration…, [rather,] if I hadn’t seen that alteration and all I’d seen was the fractured block on the rim – which looked like the stuff (the blocks) in the bottom — I might have said it (Shorty) was just another impact [crater]. But having all the color changes and everything, I think we might have to [still] consider that it could be a volcanic vent.”
[Although these verbalized thoughts were far too premature, they illustrate what field geologists do and that is mull over implications and various explanations to what they have observed in order to enhance future observations. All I had to speculate with at this point included 1) the pre-mission interpretation that Shorty Crater might be either an impact crater or just possibly a volcanic vent; 2) orange-colored deposits exist both on Shorty’s rim and at other points inside the crater, 3) black material underlies the orange; 4) the orange and black materials we sampled consisted of particles too fine-grained to be resolved by the eye; and 5) Shorty still looked like an impact crater with a shattered, large block on its rim and other large, broken blocks on its floor.
It had not registered on me that Cernan had observed that “about 100 meters around the west side of the rim of this crater the mantle on the inside of the rim turns from this gray material we’ve been sampling, in here, to a very dark gray material”. If I had realized that this material, rather than consisting of a “mantle”, consisted of a distinct and coherent layer in the wall of Shorty, as I later saw in the photographs of the color panorama (Fig. 11.107↑), I might have concluded sooner that the Shorty impact had penetrated layers of volcanic ash as well as part of an underlying lava flow.]
“Roger. It surely was different, anyway,” Parker added.
“I’m not sure how we prove it [was a vent]. We didn’t have time to prove it.”
“We noticed. …I guess that’s the breaks of the game, sometime.”
[My recent work to synthesize all the available analytical information on the samples collected at Shorty Crater began in 2014. Since then, the geology of the crater and the pyroclastics deposits discovered there has become reasonably well-defined (see Chapter 13). In spite of our very limited time at the location, observations, photographs, and sample examination and analysis have led me to the following interpretations related to Shorty Crater and its pyroclastic ash deposits:
- Pyroclastic ash erupted late in a period of mare basalt vulcanism between about 3.66 and 3.48 Ga.
- Exposure age data indicates that pyroclastic eruptions were intermittent for at least 170 million years.
- Black ash is the partially devitrified equivalent of orange glassy ash.
- At least five separate eruptions can be identified in the double drive tube core.
- The structure of the pyroclastic ash outcrop is that of a partially overturned, isoclinal anticline.
- The uppermost and youngest pyroclastic ash layer (orange ash) at Shorty Crater site was exposed to limited maturation for about 21 Myr before being protected from incorporation in Taurus-Littrow regolith by a covering of light gray regolith ejecta from Fitzgibbon Crater at ~3.52 Ga.
- The protective light gray regolith initially formed on a surface of Mg-suite rocks and closely resembles regolith formed on the Sculptured Hills (Chapter 12 – Station 8).
- The impact that formed Shorty Crater and exposed outcrops of pyroclastic ash and light gray regolith occurred about 3 million years ago.
- Dynamics of pyroclastic eruptions in hard vacuum and one-sixth gravity create extremely fine ash and distribute that ash at least six times more broadly than would the same eruption on Earth.
- Reservoirs of indigenous volatiles with chondritic affinities exist in the lunar interior below ~500 km (the depth of the original magma ocean).
- Compositional variability in sources of subfloor gabbros and basalts may relate, in part, to variable factional crystallization at depth.
- Stable isotope ratios for nitrogen in the material of the solar nebula give a δ15N of about +13‰ at the time of lunar accretion.
- Indigenous lunar water contributed to the pyroclastic eruption and, along with other volatiles, indicates that the mantle below ~500 km is chondritic.
- Ancient pyroclastic water is a potential source of water now concentrated as ice in permanently shadowed regions at the poles.
- Low maturity of the light-gray regolith and the pyroclastic ash extend the existence of a global magnetic field to at least 3.5 Ga.
- Significant amounts of fragile, ropy impact glass in the light gray regolith indicate a period of low micro-meteor flux at least between 3.8 and 3.5 Ga.
- A possible origin of the Moon by independent accretion and capture rather than through a giant impact.
Consideration of these interpretations continues.]
“Hey, Bob,” Cernan broke in, “I forgot your numbers at Victory. How about giving them to me again?”
“Okay. 105, 3.1. And it’ll be a heading of 090. …That’s the general heading in that direction.”
“Okay. Thank you…105, 3.1.”
“I guess we always have Station 9 (Van Serg Crater) to look forward to, guys. That may be the same thing. …We’ll probably be out of time when we get to that one, too…” Little did anyone know how different Van Serg Crater would be from Shorty (see Chapter 12).
“Nobody likes a pessimist,” Cernan countered.
Everyone remained quiet for almost a minute as we maneuvered through the craters on the way to Camelot. I certainly needed to let the adrenaline subside and collect my thoughts. Shorty Crater had been more of an emotional high than I fully realized at the time.
Cernan broke the silence with, “Hey, Bob, a note on those [battery] radiators: I have been dusting the covers at every stop, whether that’s any help or not.”
“Okay; we copy that…”
“Okay, sports fans,” I said. “We’re still about on the, …well, I think we moved [from light mantle to dark mantle]. …Yeah, we moved out into the Tortilla Flat area, I guess. [It’s] not very flat,” I added as we bounced through a number of shallow depressions and craters as Cernan tacked left and right across the sun line.
“Those kind [of craters] I can go through,” Cernan agreed. “…If I can see them coming.
“102, 3.8. And where’s Victory [Crater]?” I asked.
“Dead ahead,” assumed Parker.
“Boy,” Cernan exclaimed, “Victory is going to be subtle, I’ll tell you. …Bob, how long we been out?”
“Stand by. …5 [hours] plus 26 [minutes]…”
“Hey, Bob,” I called, “I recommend that, if we ever do this again, let me get off and pick the charge off when we want to deploy it. [Holding] it really adds to the fatigue of the hands.”
“Couldn’t you just hook it onto your fingers?” suggested Cernan.
“We copy that, Jack. And Charlie (Duke)’s got a big smile on his face here…”
“Mark my words,” I said with dramatic emphasis. I am not sure why this issue never was addressed in training, and Duke served as my backup.
“There’s Victory over there, I’ll bet,” Cernan observed. “See that’s the long [crater] edge?” Victory Crater is “V” shaped with the apex pointed south. We were approaching the western leg of the V.
“Yeah, yeah,” I agreed. “I can’t see over there, but I got too much Sun in my eyes.”
“That’s the right way to go. That’ll be about it, too, [on range and bearing].”
“Man, I don’t think I’ve really seen the LM, except…” He stopped speaking as a large boulder loomed in front of us, out of the Sun.
“[You have a] big rock in front of you,” I quickly warned.
“I got it [in view].”
“Okay. …Well, you can’t tell much about the countryside going into the Sun, can you?” I had not been able to describe or photograph much due to looking both into the Sun through a dusty visor and into the long, deep shadows behind rocks and the east walls of craters. During planning for EVA-2, I had hoped to have another chance along this route to observe the contacts between the plumes of light mantle and the dark mantle of Tortilla Flat. My traverse photographs (AS17-133-20269-79; Fig. 11.117↓) through this area, however, show that the frequency of exposed boulders change from few if any on the light mantle to about 1% as we approached Victory Crater.
“Put your upper visor down,” Cernan suggested. “That’ll give you a whole different perspective.
“It doesn’t ‘vise’ very well. It’s stuck…” By putting my sunshade up part way to get better visibility, I had allowed dust to get into its track on the LEVA.
“That’s got to be Victory over there, Jack.”
“We’re at 103 (bearing), 3.4 (range),” reported Cernan. “…That is Victory.”
“We’re still seeing the…glass-lined pit-bottomed craters,” I observed. “How’s that [for terminology]? That’s geology-ese if I ever heard it.”
Fig. 11.117. One of the traverse photos I took on the way to Victory Crater, its east wall shadow visible in the middle distance as a linear dark line at the apparent base of the Sculptured Hills above the central reseau cross. (NASA photo AS17-133-20272).
“Otherwise known as…the GLPBC,” responded Parker after a moment.
“Took you a while [for the acronym], didn’t it?” I kidded. Parker’s delayed use of a long acronym for “glass-lined, pit-bottom crater.” My Harvard economic geology professor, Hugh McKinstry (pen-name “Nicolas Vanserg”), used the term “geologese” to characterize complex terminology that would be hard for both geologists and non-geologists to decipher.
“It’s 11 o’clock [p.m.] down here, guys,” Parker said as an excuse for his less than normal quickness.
“It’s 11 o’clock up here, too, Bob,” countered Cernan.
[The relatively common pit-bottom craters probably tell us something about the mechanical properties of the regolith. At the very least, the morphological differences between normal impact craters and pit bottom impact craters indicate either 1) a significant variation in the impact energies so that a linear explosion rather than a point explosion occurred during some impacts; or 2) the existence of a sharp reduction in cohesion or increase in porosity with depth that permits deeper penetration and excavation to form a pit. The change in cohesion and/or porosity with depth might come with the development of mature regolith on a relatively immature ejecta layer as exist, for example, in the ALSEP deep drill core 70001-9.]
“There’s a square boulder. Look at that one!’ exclaimed Cernan.
“Yeah, it’s square all right, …or at least one side of it is,” I acknowledged with a little hedging.
“No, three sides of it are square,” insisted Cernan. “It just fractured that way. That’s by accident, looking at it. …So how do we get over here?” He asked about navigating around an approaching crater.
“Go left, probably…and along the rim.”
“Yeah, that’s where I’m going to go. Hold on.”
“I’m holding,” I told him. “Whew! …If Charlie [Duke] is smiling because my hands are tired, why did he let me get the charge off? …Fine backup crew we got.” This may sound as if I was peeved at Duke, but it was just banter between colleagues.
“You guys didn’t really mean to say that, did you?” Parker asked.
[Our Backup Crew of John Young, Ken (T. K.) Mattingly, and Charlie Duke had been the prime crew on Apollo 16 and went above and beyond to serve in this capacity as no more lunar flights would be flown. In addition, crew assignments were set through the three, crewed Skylab missions and the Apollo-Soyuz Test Project (ASTP). Being our backup crew meant a 15-month delay in starting any new activities related to the Space Shuttle; however, having a Backup Crew was essential to training the prime crew and Flight Controllers for Apollo 17, as well as assuring that this last science mission would not be canceled if something had happened to any of the three prime crewmen. Young went on to command two of the early Space Shuttle missions; Mattingly also commanded two such missions; and Duke spent three more years in NASA before retiring and entering private business.]
“106 [bearing], 3.2 [range]… We’re approaching the rim of Victory,” I reported. …And the LMP frame count is somewhere around seven. …Well, [at] eight-five, maybe.” Dust had accumulated on the top of my camera, making reading the frame count difficult.
“That’s Victory,” Cernan declared. “Look at it (the rim) go to the left and look at it go to the right (Fig. 11.118↓). That’s Victory; we’re right on the [west] ridge.”
“Okay,” acknowledged Parker, “and we’re planning on [a seismic charge and] a Rover pan, you guys.”
“106, 3.2,” repeated Cernan. This indicates that the navigation system had done well relative to the update Parker gave earlier of 105 and 3.1, bearing and distance to the SEP transmitter.
“Tell me where you want that thing (the seismic charge),” Cernan requested, “and we’ll get a pan around it.”
“Okay, I tell you what. You see right ahead of you?” I replied.
“Looks like a place you could spin a circle on,” I suggested, further.
Fig. 11.118. East meets West at the southern tip of Victory Crater (actually a series of 6 overlapping craters. See EVA-2, LRV7 in route map of Fig. 11.8↑ in Section 1). The TV camera provides a fulcrum with the western arm of the ‘V’ to its left, with scattered boulders on one of the crater walls near the rim, and the eastern arm to its right. Part of the Wessex Cleft is at upper right. (NASA photo AS17-133-20296).
“Yeah, I could do it. Right up in here,” Cernan said as he maneuvered into position.
“And [I’ll] deploy the charge. Tell me where you’re going.”
“I’m going, right here,” he replied. “You could put it (the charge) in that hole. No, you don’t want to do that (put the charge in a hole).”
“Oh, that’s all right,” I told him, as I had discussed this possibility with the experiment’s Principle Investigator, Robert Kovach. He told me that the transmitter at the ALSEP would communicate through a ground-wave and that there would be no seismic coupling problem in a hole or depression.
“Just pick a spot and take your photos.”
“Okay, I’ve got them (the before photo AS17-133-20280 unfortunately has a lot of sun glare). Now, go just beyond there. Little bit more. That’s good.”
“Okay, Bob, we’re at 106, 3.2.” Cernan again confirmed the location of the seismic charge.
“Okay,” I then said, preparing to activate the seismic charge. “Pull out [the antenna]. …Pin 1 is pulled and safe. Pin…2 is pulled and safe. Pin… Boy, these [pins] are stiff this time around. …Push it in. Try again,” I said, talking to myself.
“That’s a big black box. Don’t pull it too hard,” Cernan advised, unnecessarily.
“Aah,” I strained. “Stand by on Pin 3, gang.”
“Copying that. Remember to push it all the way back in, Jack, and start from scratch.” Parker had not been listening, again.
“I did; I did; I did. I remembered; I remembered!”
“Good, good, good,” Parker replied, not really being a fully supportive Capcom.
“But now I can’t get to the [ring]…”
“Your hands are tired,” Cernan decided. “Let me try it once.”
“No, it’s not that,” I told him. ‘It’s just [hard to grip the ring]. It’s coming. Got it! Pin 3 is out and safe.”
“And look at the orange flag. Zowie!” Cernan exclaimed. The orange flag on the tip of the antenna supposedly would keep us from running over the charge if we came this way again. Figure the chances of that happening!
“That’s what you guys were sampling at Station 4, I bet,” joked Parker.
“Huh?” queried Cernan, not yet getting the joke. “Yeah, it’s about that orange [in color], only not quite as bright. Same shade. Okay. Okay, let me turn my [Rover power] switch [back] on. Hey, Bob…”
“Wait a minute,” I interrupted, “wait a minute. Let me get that [charge] out a little more [away from the Rover].”
“Bob, there’s no question but that we’re at Victory,” Cernan commented. “…It’s the first crater that looked like I thought it would. Okay [Jack]. You ready [to photograph]?”
“Let me change my [camera] setting here… Go ahead (AS17-133-20281-300).”
Fig. 11.119. One of the frames I took while Cernan was driving in a circle. The tongue of light mantle material that we just left is clearly seen below the (West) Family and Family Mountains right of the HGA handle. (NASA photo AS17-133-20290).
“Okay, let’s get a nice Rover pan here.”
“Okay, turn the other way first.” I wanted Cernan to turn counterclockwise a little to get more space between the rear of the Rover and the charge. “Take her slow.”
“And we’ll get a Rover sample here before you guys leave, too, after the circular pan,” Parker reminded us.
“We will,” I replied.
“Slow enough?” Cernan asked.
“Yeah. …Look at the light mantle over there,” I told him as we pointed to the west.
“You can sure see it now, can’t you now?”
[The contrast of the light mantle with the dark mantle is quite clear in photograph AS-17-133-20290, taken at zero phase-angle relative to the Sun (Fig. 11.119↑). The panorama clearly illustrates how pointing relative to sun angle affects the definition of various features. It also gives a good cross-sun view of Victory Crater (see AS17-133-20296) from our position on the west arm of the V near its apex. The crater wall of the east arm of the V near the apex has a concentration of large boulders. (Fig. 11.118↑)]
“Getting your [camera] settings changed fast enough?” asked Cernan.
“I got it; yeah. …Okay,” I said, finishing the panorama.
“Okay, let’s get our Rover sample.”
“Okay. …And the Rover sample will be from the same locality,” I reported.
“Boy, it’s just a couple of meters from the charge, isn’t it?”
“Yeah. I hope I didn’t put too much soil in there for you [to close]. Wait a minute. …Rover Sampler works just as advertised. …Not bad.”
“Bag 43 Yankee (75110-15).” This sample’s location lay in the dark mantle, about 500 m east of that unit’s approximate contact with the eastern-most finger of light mantle through which the Shorty impact had penetrated.
[Post-mission examination of the 90-150 µm fraction of 75111 documented that it consisted of mature regolith with about 52% agglutinate and about 17.6% volcanic ash for a combined 69% of very fine particles. Unlike normal regolith samples that have a bell-shaped particle size frequency distribution peaking at ~60 , 75111 has a highly asymmetric distribution, peaking at about 20 , suggesting the presence of unusual quantities of fine particles relative to other dark mantle regolith. It has an intermediate maturity index of 54, consistent with its high titanium content as well as with massif maturity indexes. The large component of fine ash in this Victory Crater LRV sample contributed to my later discovery on LROC and NAC images of a debris flow of pyroclastic ash. The debris flow apparently originated as an accumulation around a pyroclastic fissure on the side of the North Massif. Once in motion down the massif’s ~26º slope, the flow apparently ejected fine ash along with eruptive volatiles released by agitation (see Chapter 13). Other evidence of the flow’s release of fine particles will be found in rover sample 75121. The toe of this debris flow lies ~1.5 km north of Victory Crater (see Chapter 13).]
“Copy; 43 Yankee,” acknowledged Parker. “And how about a frame count now, Jack.”
“I will. Stand by. You’re jumping the gun occasionally but not very often.” Parker just never could stay quiet when he knew we were busy with something else. “…One hundred and six.”
“It’s in the bag (SCB), Jack. Okay? …I guess we’re ready to leave here, huh?”
“Well, if they don’t want us to stop here, I guess we leave.” I said to Cernan.
“No, there’s nothing else here now [in the Checklist].”
“Roger. We’re ready for you guys to leave there, …and we’re pressing on toward Station 5 (Camelot Crater),” he replied.
“Okay, and I want to go about [on a heading of] 120.”
“Gene, can you swing out there and give me one look down north into Victory?”
“Yeah, I can do that. I’ve got to go by that way anyway… North?”
“Well, you know, just swing around and point north so I can look in there. …I never got a good look at it.” I had been concentrating on getting the camera settings right.
“Well, it’s a series of three craters,” Cernan recalled as he turned. “There’s some boulders on the talus slope of the easternmost…eastern slope of the west…eastern slope of the southernmost crater, the one we’re closest to. …Now, how does that look to you?”
“Well, it looks like… I don’t know what it looks like,” I said, uncertainly. “The northwest end of the ‘V’ has white [that is] light blocks on it – boulders – on the inner wall and right at the rim. And the northeast end of the ‘V’ looks like it has somewhat darker rocks. …Part of that is shadow (phase-angle) [effect], but I think they are darker. And they look like about the same as down here near the tip (apex) of the ‘V’.”
“Got to be careful on that one, because there’s one sloping away and one sloping towards us,” Cernan correctly observed like I had previously noted.
“Yeah, I know. I’ve qualified it (my description).” After examination of photographs in my panorama, this apparent albedo difference looks as if it is primarily the effect of the angle of the sun on the sides of boulders. The boulders probably consist of subfloor basalt based on the location of Victory Crater as being about 3 km from the base of the North Massif; however, as was noted at Shorty Crater and will be noted elsewhere, evidence exists that the top of the very hilly pre-mare surface of Sculptured Hills material may have been penetrated by several valley craters.
“Okay; we are rolling, by the way. And we’re at 106 and… Well, we’re still 3.1.”
“And the rim itself, though, of Victory, is not blocky,” I continued. “There is some increase in fragment size, but that seems to be the result of some craters in the rim that have gotten below the debris that’s covering it. I’d say that Victory’s somewhat like Horatio in that it has blocky inner walls but essentially a normal block population on the rim.”
“Okay,” Parker acknowledged. “And we’ve got a Rover sample going toward Station 5 at about 103 and 2.5…”
“Okay. 103 and 2.5.”
“Roger. And that’ll be just a grid sample,” Parker said without thinking that we were sampling more or less as our traverse permitted for the specific purpose of having broad coverage of the valley regolith cover.
“They’re none of them [are] just grid samples, Bob,” I replied with this in mind. Then I laughed as Cernan made a sharp turn to avoid a crater.
“You see, you can’t tell how deep they are until you get up to them,” he explained. “…That one I could have gone through.”
“Yea. …Okay; Station 5 is Camelot. …Good old Camelot,” and I began to hum stanzas from Lerner and Lowe’s hit Broadway musical by the same name.
“Look at the size of that one,” exclaimed Cernan. “That’s another one of those [pit bottom craters]…”
“Yeah,” I agreed.
“There’s another one on the right. Lookit.”
“Some of them have…” I began to add detail to the features of these craters, but Cernan interrupted.
“Well, that one doesn’t have any fragments in the bottom of it.”
“Looks like someone walked across it,” Cernan said, seeing a linear pattern of small craters crossing the crater.
“Yeah,” I again agreed, but then went on, “I think that there’s quite a variability in the thickness of the dark mantle in here. Did you…I didn’t notice us crossing that one tongue of light mantle.”
“No, I didn’t either. We obviously did…”
“I think we did,” I continued. “Right at Victory, but it didn’t show up [to the eye].”
“Looking into the Sun, you can’t tell any difference anyway.” Cernan commented.
“However, I tell you, I certainly get the impression there is a [covering] mantle. I would say that. …I don’t know what it (the dark mantle) is, but the dark mantle exists. …The craters, …these craters are just too big not to have thrown up blocks. And they’re either subdued by the mantle or they haven’t penetrated it. …And I think you probably have both.” Both the Active Seismic Experiment’s data and that of the SEP indicate regolith (dark mantle) development as deep as 15 m over the mare basalt (subfloor) surface. Of course, the dark mantle includes pyroclastic ash as well as ejecta from craters on the massifs and would be expected to be thicker that regolith at other Apollo landing sites.
[Photographs AS17-133-20291-306, taken during this portion of the traverse, are obscured by glare from the Sun; however, it can be seen that the surface has very few rock fragments exposed except around some of the craters that penetrated the dark mantle and into subfloor basalt.]
“And a lot of these blocks, …I’d say, they’ve been subdued by the mantle” added Cernan. “That really imposes an impression on me.”
“…There are those (craters) that appear that way,” I continued, “like Horatio, for example, or the [really] big ones. But others, I think, are too young. They just don’t penetrate [the dark mantle]. Particularly those (craters) that are big and have bright halos.”
“Well, yeah; but the only ones that look fresh and not [big] enough to penetrate are these little ones with the glass in them.”
“Well, there’s been some big fresh ones,” I corrected. “We’ll look for one.”
“Now there’s one with glass in it, probably,” Cernan pointed out, “and without any blocks on it. That may not have penetrated.”
“Yeah. Yeah, that just has mostly the shock-indurated rock…instant rock.” Most people who worked on returned lunar samples use the term “regolith breccia” for these rocks formed by the shock pressure of an impact. “Instant rock,” however, continued to be used as a field term. (AS17-133-20307-18 are photographs along this portion of the traverse, but glare is still a problem other than for defining fragment distribution on the surface.)
“We’re coming up to 103 (bearing) at 2.6 (range) now,” noted Cernan, looking at his Checklist, “so we need a sample up here.”
“103, 2.5. Anywhere?” he confirmed with Parker.
“Roger. That’s affirm.”
“Okay, let me slowly go to the right here.”
“Okay. Right out in that little inter-crater area,” I directed, “right out in there is good. If you let me guide you a little, I might get a rock fragment. Whoa, whoa, whoa.”
“Yeah. That wasn’t quite enough,” I said.
“Okay. Pick a place.”
“Move ahead about… Yeah, right… Just… No, that’s good. Straight ahead. Straight ahead. Good, good, good, good, good, good, whoa! …Now we’ll give it a try.” We were about 740 m east of Victory Crater.
“Okay, 103, 2.5. …And that battery is still at about 132.”
“Okay. Copy that. We’re allowed to go to 140, tonight,” Parker informed us.
“I don’t expect we’ll make it [past 140]. I think we’ll get done before that. Save that for tomorrow. I’ll tell you those batteries deserve any temperature they want today, after going up that…that scarp.
“That’s the soil [sample],” I interrupted. “Okay. The soil is in 44 Yankee (75120-24). …That [instant rock] block’s too big. I can’t get it. Too big!” The Dixie Cup bag wouldn’t go around the regolith breccia fragment I had hoped to get. These “instant rock” samples are very helpful in determining the in situ concentration of loosely held solar wind gases as normal disaggregated regolith samples lose significant quantities of such gases through agitation during the long sequence of handling required from sampling to analysis.
“Okay. Get your picture?”
“No. …Okay, got mine (AS17-133-20319),” I said. Cernan had run out of film back at Shorty.
[Post-mission examination of the 90-150 µm fraction of 75121 confirmed that it consisted of mature regolith with about 63% agglutinate and about 8% combined orange, black and clear volcanic ash. Its maturity index is intermediate at 67, unexpectedly low for an ilmenite content of only 0.7%. This ilmenite content also is unusually low for a dark mantle regolith. These data do not fit the usual pattern of reduced maturity indexes for high ilmenite regolith (Chapter 13). Additionally, the average particle size of 75121 of 56 resembles massif regolith and is 10-20 less than mare regolith at Station 1 or near the Challenger. The unusual character of 75121 extends to its higher than average concentration of measured hydrogen (60.2 ppm) that may be related to its high content of agglutinates.
A possible explanation for the anomalous nature of 75121 lies in its location only 1.3 km southeast of the edge of the apparent pyroclastic debris flow at the base of the North Massif (Chapter 13). If a fine-grained, volatile rich ash cloud was associated with the debris flow as suggested by the very fine-grained nature of sample 75121 and the apparent surface mantling and fine-grained character of 75111 found at Victory Crater, that cloud may have also entrained fine particles from the North Massif regolith at the edges of the debris flow.]
“Okay. What’s the [next location}? …Well, we’ll find Camelot.”
“And 125’s the LMP frame count.”
“Copy that,” acknowledged Parker. “And just press on the same heading you’ve been carrying there, Gene, and that will get you to Camelot.”
“We want the southwestern edge, huh?” Cernan inquired”
Parker did not respond, so I asked, “Do you [still] want to go where Station 5 is [planned], Bob?”
“That’s my understanding, Jack. So press on towards there unless I tell you otherwise.”
“Well, but you were talking about changing Station 5. I think Station 5 is a pretty good spot [as planned].” I had made this observation as we went by Camelot on the way to the base of the South Massif (Station 2).
“Roger. And I think that’s where we want to go. I’m just trying to verify that. You can go in that direction, though. I’ll get with you if it’s not.” Parker obviously wanted a faster response from the Science Back Room where some esoteric debate may have been raging or my discovery at Shorty still monopolized the geologists’ attention. Jim Lovell was the final decision maker in the room; however, he was up against some strong personalities and egos.
“Okay. …It’s probably the most concentrated boulder field on Camelot.” I said this to influence the Field Team’s thinking.
“Okay. You know where it is, and we think it’s about 092 and 1.6.”
“092 and 1.6.”
“Roger. But you know where it is, so you’ll find it when you get there.
“You know this country…is rugged [and] is undulating…,” Cernan commented as we began to move again.
“It’s different,” I agreed, wondering if we had driven on to a major ejecta blanket. “Wonder where Horatio [Crater] is?” Horatio actually lay off to the southwest of our position, but it is big enough that we could have been crossing regolith developed on its ejecta.
“Well, we’re going to run into something in a minute if it’s… It’s (Horatio) probably right over that rim (ridge) on the right, Jack. Right off your right hand at 2 o’clock.”
“Right. I guess so,” I more or less agreed. “You know, it (the ejecta blanket) doesn’t have boulders on it.” This observation referred to the lack of rim boulders on Horatio as well as to the probable ejecta blanket. It suggests that Horatio had formed significantly before Camelot and ejected boulders had been ground into regolith, a conclusion I also reached many years later for ejected Camelot boulders as well; but in the case of the rim of Camelot, boulders are still present but now I interpret them to be exposed wall rocks rather than ejecta (Chapter 13).
“It should be over there,” Cernan asserted. “That should be it right over that rim. You know, I see why Al (Shepard) and Ed (Mitchell) had trouble walking up Cone Crater [on Apollo 14]. You could stand right on the edge of the rim of a crater and not know it’s there.”
“Yup…” Traverse photographs AS17-133-20320-27 were taken on the approach to Station 5 and the rim of Camelot. A few more large rocks gradually become apparent in this sequence, along with a distant view of the boulders we would sample at the rim.
“Man, that [last station] was spectacular,” I mused as Shorty came back to mind. “It’s color on the Moon! Whooo!”
“It was really orange!” Cernan agreed. “[Bob,] Could you see that color on the television?”
“No answer,” I said.
“I’ll bet they couldn’t.”
“No,” Parker finally responded, “we couldn’t see it, Gene. [Sorry] guys…” Later, enhanced TV footage, indeed, distinctly showed the orange color.
“Look at the Sculptured Hills,” Cernan called out, and then responded to Parker. “Okay. I’m sure glad I went up to take that second pan (at Shorty) to see that stuff go radially down into the center of the crater at that contact.”
“Yeah, that’s good,” I emphasized, still thinking Cernan referred to orange ash slumping down Shorty’s wall rather than the layer of black ash he saw. Cernan’s use of the word “radially” rather than possibly “diagonally” confused me until I saw the pictures he took.
Fig. 11.120 Nearing Camelot, the boulder field on the southwestern rim appears at left. We are skirting around it to park on the southeastern rim. The East Massif is directly ahead with a series of parallel lineaments following the contours of the slope beneath the massive dark ridge near the top (above the TV camera). (NASA photo AS17-133-20327).
“Hope that comes out.”
“Doesn’t make any difference. It’s (the orange deposit) there [whether the picture] comes out or not.” Much of field geology is discovery and then placing the spot of that discovery on a map, followed by reporting that discovery, its analysis, and its implications in a published article. Field geologists expect that others will take that information at face value whether it is possible to document it with a photograph or not. Many subtle observations just cannot be photographed, and the orange color at Shorty was far from subtle (Figs. 11.88↑, Fig. 11.91↑). Cernan, not having a field geologist’s cultural background, probably thought that we would not be believed without a photograph.
“Okay. Look at…look at up…up the [Wessex] Cleft over there. You can see definite change in albedo now between the North Massif and the Sculptured Hills. Lookit, right up the valley. Well, you can’t see it. …Let me [turn north a little].” The High Gain Antenna blocked my view of what Cernan described.
“You’re right, [I can’t see it],” I said with a laugh.
“You got to see this. See that?”
“Yeah. But, again, that may be your photometric effects.” The angle of the Sun on the two sides of Wessex Cleft was very different with a glancing angle on the Sculptured Hills side making it look dark and a direct illumination on the North Massif side making it bright.
“Yeah, one’s an upslope and one’s a down slope,” agreed Cernan, but not describing the Sun angle difference very clearly.
“Yeah. Yeah. Just about right; but it’s supposed to be darker in the Cleft, you know [due to Sun angle].” Then, talking to Parker, I said, “I guess I’ve been on [INTERMEDIATE cooling]. LMP’s back to MINIMUM.”
“Whoa! Whoop, whoop, whoop!” I exclaimed as Cernan went through a crater he had not seen while gazing at Wessex Cleft.
“I wish I had a movie picture of us driving.”
“You’re doing the driving,” I reminded him.
“Who’s going to take it (the movie)?” interjected Parker.
“That (movie) would be the classic of the century,” Cernan replied. “…Well, there must be somebody out there.”
“Bob, the fragment population,” I began to look at the near field, again, “— we’re at 099 (bearing), 2.0 (range) — is still about the one-percent category of [coverage]. …And it’s hard to tell, going into the Sun, what kind of blocks you’re dealing with. But my guess is— well, more than a guess— [is that] most of them (the blocks) look like they’re slightly vesicular. And, in that regard, resemble the gabbros… …There’s a class of boulders that is flat topped and fairly well-rounded that is just about completely buried. Only the… Not more than 5 centimeters of it (the flat topped boulders) projects above the surface. We’ve seen those off and on, both days. Remember, Geno?”
“And they seem to be quite distinct. At least you notice them. Now, whether it’s just a continuation of the mantling, I don’t know. But most other boulders – the big ones – seem to project above the surface more than just that 5 or 10 centimeters…” It may be that ejected boulders that land with an exposed flat top rather than having sloping sides are more resistant to micro-meteor erosion. A micro-meteor impact on a sloping side may chip more rock off than a direct hit on a flat top – something that could be studied experimentally.
“I tell you, the Sculptured Hills just have that wrinkled old-face feeling.” Cernan here refers to the seemingly crosscutting surface lineations that grazing sunlight accents.
“Yeah. There are blocks over there though, aren’t there?” I ask as the antenna, once again, blocked my view.
“There’s blocks,” Cernan stated, “but I don’t see any concentrated outcrops…or concentrated masses of blocks up on the slope anywhere, …like you did on the Massif.” I tried to break into his description with a possible explanation but never succeeded. “Oh. Do you think that’s Camelot or not?”
“I think that might be Camelot,” I agreed. (Our approach to Station 5 appears in photographs AS17-133-20325-27, Fig. 11.120↑.)
“Look at that!” Cernan exclaimed as the northeastern wall of this 600 m diameter crater came into view.
“Look at that. Right on the southeastern…”
“Now, wait a minute,” I cautioned.
“Yeah, because Horatio’s got to be on our right. Well, wait a minute… doggone it.”
“It’s not Horatio, is it?” I wanted to be sure the Rover navigation system had not moved us a kilometer or so to the west.
“Well, we’re at 094, 1.7.”
“No, I think that’s Camelot,” I deduced. “Horatio didn’t… have blocks that far up the rim.”
“Let me… Yeah, let me look in the bottom. I’ll tell you. I remember.”
“That kind of sounds like Camelot to us,” Parker added.
“[I recognize] these blocks [from before]…”
“Yeah. Yeah, that’s it, Bob,” Cernan finally agreed. “We’re coming right up at Station 5— right at it.”
“Only way to fly,” I said. “Okay. You going to park up on the rim so they can have a good [TV] panorama?”
“Yes, sir. I’d like to get a little on the other side of those blocks, if I can.”
“Yeah, you better. Then they can look with the Sun on them (the rocks).”
“Yeah. Because, otherwise, they can’t see that other rim over there,” Cernan agreed. “Same heading [as usual]. So, I’ll be all right, there. Yeah. I’ll get to the other side. Then they can look at these blocks and those across the way. I got to go around this block field, though.”
“I should hope so! …I missed seeing Druid [Crater]. …There’s Horatio back there! I can see Horatio now,” I reported as Cernan turned to the southwest to avoid the boulder field we would later sample. “Looks just like it did before.”
“So, we came right where we were supposed to.”
“All the blocks look very much the same in the wall of Horatio,” I observed.
“There’s a path through [the boulders]…”
“Watch it. Watch it!” Cernan had missed seeing a large boulder in front of the right wheel and hit it hard. “Okay.”
“Well, that’s a test,” he said, nonchalantly.
“That was a good one,” I said with somewhat more concern.
“That was a good test. Didn’t let any air out of that tire, did it?”
“No, I don’t think so,” I replied. The tires, of course, consisted of an open wire mesh with attached metal chevrons.
“Talk about a block field!” exclaimed Cernan.
“I think my [earlier] guess of 30 percent [block coverage] was reasonably good before. Where are you going to park? Right over there?”
“I’ll park right over here, so that they can look in it. …Okay. Yeah. I got to head 045, so I head right into those blocks.”
“You still got to turn, remember?” I warned him as he moved close to a boulder.
“Yeah, that’s why I want to leave myself a little room over there.”
“Whoa,” I said.
Station 5 – Camelot Crater
“Okay, Bob. We’re stopped (Fig. 11.121). 086 (bearing) and 1.4 (range).”
Fig. 11.121. Planimetric sketch of Station 5 near the rim of Camelot Crater.
Fig. 11.122. The b&w pan I took on the east side of the south rim of Camelot (Pan 20 marked in Fig. 11.121). The boulders are concentrated along the rim— much less so on the inner walls or ejecta blanket. (Composite of NASA photos AS17-133-20344-347).
Fig. 11.123. A counter-clockwise rotation from Fig. 11.122 continuing the pan to the west, showing the LRV Sta. 5 parking spot. At right the boulders are concentrated close to the rim of Camelot with no comparable boulders on the middle and left half of the frame. The bright spot in the center results from the intense back-scattering of sunlight directly back to the camera. The boulder field on the rim beyond the rover is the sampling area at this stop (Fig. 11.121↑). (Composite of NASA photos AS17-133-20340-347).
Fig. 11.124. Part of Cernan’s Pan 19 on the western side of the south Camelot rim. The abrupt end of large boulders just away from the rim is clearly seen. The bright back-scattering from the surface is present at right, above the helmet shadow. In the right distance, ahead of (West) Family Mountain, is the lobe of the Lee-Lincoln Scarp and the light mantle that we drove along earlier as we approached Shorty Crater. The South Massif dominates the frame from far center to left. (Composite from NASA photos AS17-145-22168-172).
Fig. 11.125. Continuing from Fig 11.124 right, the portion of Cernan’s Pan 19 showing the entire 600 m diameter Camelot Crater. Here the south rim is seen to be densely populated with large boulders. A more comprehensive view of the large boulder distribution around the rim is given in Fig. 11.126. (Composite from NASA photos AS17-145-22175, -76, -78, -79, ‑80, -81, -82, -83, -60).
Fig. 11.126. LRO view of the 600 m diameter Camelot Crater. Note the concentration of boulders to discrete areas around the rim. The major sampling area discussed below took place in the boulder field at about the 7:00 o’clock position at lower left. (Excerpt from LRO NAC frame M162107606).
“Not very level for the gravimeter,” I observed as I left my seat. “What’s their [tilt] limit?”
“I don’t know, but it’s taken a couple [tilts] better than this. …Now, I’ve got to change film. …Let me get things going here.” Cernan got off the Rover without commenting on battery and motor status for some reason. I didn’t remind him as everything looked okay during the drive to Camelot and “daylight was a-burning”.
“I think I can get by this station without it (a magazine change),” I responded.
“How’s our time, Bob?” queried Cernan.
“Stand by,” replied Parker. “We’re talking about that now. Stand by. …You’ve got 25 minutes at this station, guys. We’ve given you somewhat of an extension here. You’re using up some of it back at the LM, but we’ve given you somewhat of an extension.” Too bad we did not get this extension of time at Shorty, I thought. “You’ve got 25 minutes at this station. The primary priority will be sub-floor documented samples, and then sub-floor [regolith] rake soil, …as you can imagine.”
“Okay.” As a 600-meter diameter impact crater, Camelot’s rim boulders might have come from as deep as 120 m below the surface; however, its current depth is about 80 m.
“As you get off, we’d also like to open the SEP and again get that to cool.”
“Okay. You wanted to turn it OFF?”
“That’s affirm. …Turn it OFF, open, dust…”
“You want it OFF?” I repeated as the communication’s delay had us talking on top of each other.
“…The same thing we’ve been doing to it all aft…, …[that is,] all evening,” Parker finished.
“Well, it’s midday here, Bob,” I clarified.
“Leave it open, and I’ll dust it, Jack,” Cernan told me.
“Okay. Oh, the [SEP] temperature, …they’d like to know [that]. …Temperature is still about 112.” Although the thermal switch normally would have turned the SEP receiver off at 108 degrees, post-mission examination showed that it had collected data between Shorty and Camelot.
“You know, the thing I dread most? About close-out?” Cernan had joined me at the Gate after turning on the TV.
“Is dusting you [before you go up the ladder].”
“Yeah, I’m not going to be able to do much [about your dust] today, I don’t think.” My forearms and hands had not recovered much from their earlier fatigue.
“Well, you know, we don’t have nearly as much dust. Yesterday we were wallowing around in it. Today, we’re…”
“Who? Me!” I interrupted with a guffaw. Cernan had forgotten my antics at Station 3’s Ballet Crater.
“Okay, and, Gene, if you’re not off the Rover, how about the rest of the Rover readouts?” Parker had missed the fact that Cernan had turned the TV on and had to be off the Rover.
“Okay, Bob, I’m off, but I’ll get them for you. I’m sorry. I looked at them, and they all look good to me. And, you know, I keep forgetting to give them to you.”
“Bob, I have [a reading at] 135 frames. I think I can finish the station, don’t you?” Actually, I had already made the decision not to change magazines and skied away from the Rover toward the boulder field just to the west.
“You know that SEP isn’t getting much [dust],” Cernan reported. “Well, it’s getting a little [dust] on it, but those mirrors don’t clean off as nice as the LCRU mirrors…”
“Okay, Bob. This [first boulder] looks just like our old friend, the pyroxene gabbro, with the shiny ilmenite platelets in the vugs and [in] partially recrystallized vesicles. The textural variations are planar, and they’re primarily – or, subplanar – [shown] in the concentrations of vesicles.”
“Jack, I’m going to put this brush under my seat. It’s just getting too hard to get off that place up there [on the LCRU].
“Bob, what magazine?” Cernan inquired of Zedekar and his group at the EVA Console.
“Magazine Delta (AS17-145),” transmitted Parker.
“Watch yourself through here, Geno.” As I looked back at the Rover, I saw Cernan stumble over one of the many large rocks.
“Yeah. …Delta, huh? …Okay, Delta…” Cernan had to look through the various film magazines under his Rover seat. “Bravo, …there’s Delta.”
“Boy, this is certainly a uniform subfloor [set of boulders],” I commented as I went from one, two meter-sized boulder to another, “[just] as we mapped it. It’s certainly a uniform rock type. I’ll tell you, …the only variations are those gray zones which just seem to be either finer [grained] or (have an) absence of vesicles.” Leaning close to the face of a large boulder, I said, “Boy, I’m nose to nose with a piece of it (subfloor) right now…”
“Say, Bob, where can I get a new set of bags?” Cernan may have been getting tired, whereas, there is nothing like a new bunch of rocks to perk me up.
“Okay, you want new bags, …they’ll be under Jack’s seat,” Parker replied without asking Zedekar.
“Under my seat, there’s some, Geno,” I repeated before hearing Parker due to the approximately one second delay in Earth to Moon communications.
“Okay. Just loose?” Cernan asked me.
“Here I am, folks, in the middle of a boulder field. Just minding my own business…” This last comment played on a routine common to Clem Kadiddlehopper, one of Red Skelton’s characters I knew from my radio dominated childhood. Having seen how uniform the various boulders are, I proceeded to evaluate where we could get the most representative samples. Their uniformity probably means they are rocks from approximately the same depth in the subfloor gabbro.
[The mechanics of impact excavation would suggest that the boulders have come from at least 120 m below the original top of the subfloor lava. If there had been time, we might have systematically gathered samples from higher levels by going on a line radial to the crater for about one crater diameter in distance, or about 600 m. Discussion of this mode of sampling at Camelot took place before the mission but was discarded due to time constraints. Subsequent considerations (Chapter 13), however, indicate that Camelot Crater is hundreds of millions of years older than originally thought, and the boulders we sampled likely are wall boulders exposed by this long period of regolith formation and its movement down slope into the crater. Indeed, re-orientation of the samples collected at Station 5 has enabled the determination that the magnetic field of the Moon at the time the rocks cooled consisted of a dipole field oriented roughly along the current axis of rotation (Chapter 13). The boulders formerly at the rim and away from the rim on the ejecta blanket, have been ground into regolith and/or migrated into the crater as macro- and micro-meteor erosion gradually moves the rim outward and downward. The boulders currently on the rim are portions of the upper crater wall exposed by the migration of the rim. The relatively sharp edge of the rim boulder field that shows the lack of remaining boulders on the ejecta blanket is shown in Fig. 11.123↑, Fig. 11.124↑, and Fig. 11.126↑. Boulders originally on the ejecta blanket have been ground down as well as covered by regolith ejected from other craters over about 500 million years.]
Fig. 11.127. Another view of the sharp drop-off in boulder concentration away from the rim of Camelot Crater. The rim of the crater is at left and immediately behind the viewer at right. I am in motion in the image, using my cross-country skiing technique, and headed back to the Rover after completing the investigation and sampling at Station 5. (Composite of NASA photos AS17-145-22162, -63, -65, -66).
Fig. 127a. A 3D anaglyphic view of part of my Camelot run taken from Wells for readers with red-cyan glasses. (Excerpt of a derivative image from NASA photos AS17-145-22165, -22164; courtesy of R. A. Wells).
“I don’t know whether I mentioned it,” I continued, “the mineral texture appears to be subophitic to…[ophitic]— like a good diabase, although a little coarser [grained than that]. …But it’s unquestionably organized [internally]…with that [planar] variation in vesicle concentration.” (“Ophitic” refers to a texture in which plagioclase and pyroxene laths appear intergrown to form a mat of randomly oriented crystals. “Diabase” is a name often applied to basaltic rocks with this texture.)
“Starting on [Magazine] frame 4, Bob,” Cernan reported, and then said to me, “Jack, I’ve got to get new bags. I’ve only got one [group of bags] left, and you don’t have any, I don’t believe.
“I don’t have any. …Bob, I have the impression that these blocks are [partially] buried up here; that the mantle does exist, even on Camelot. There are a few blocks that are lying out on the…[actually, it] looks like they’re lying more or less on the surface, but you can attribute those to craters that have disrupted the block field. The big ones seem to be projecting out of the [dark] mantle, …although I can’t see how the mantle in here could…[not cover the flat tops of some boulders].”
[This statement indicates that I still thought of the dark mantle as a young deposit. My observation should have suggested to me that the dark mantle consisted of an old deposit that had been removed from the surfaces of boulders by small and micro-meteor impacts. Back in the laboratory, the dating of the volcanic ash sampled at Shorty would show that the ash component of the dark mantle would have ~3.5 billion years for continued impacts to mix the ash into the dominant basaltic regolith and move it around the valley.]
“Do you see any such mantle…on top of them?” Parker broke in.
“No, I don’t. What’s there seems to be [on the tops is] what could have been knocked up there [by impacts in nearby regolith]. …I see a place where I think we can skim some off that ejecta off the top of a rock, which I think we probably ought to do. …But I don’t have the impression of draping [by the mantle] so much as I have just of partial burial. And I have a feeling that the zap-pitting process just has cleaned these boulders off of anything that may have been on top of them, in excess of what’s around them, right now. …Most of the rocks seem [clean]. That [cleaning] seems to be what has happened all over the Moon that we’ve looked at. But the rocks are always cleaner than the surface, of course.”
[Through the decades back on Earth, I would emphasize this observation when others began to speculate that lunar dust was being levitated by changes in electrostatic charges at sunrise and sunset. A spacecraft called the ‘Lunar Atmosphere and Dust Environment Experiment’ (LADEE) eventually flew in lunar orbit to see, among other things, if levitated dust could be detected in orbit and was responsible for an alleged horizon glow the Surveyor camera had imaged from the surface and that Cernan had sketched later in our mission (see Chapter 15). LADEE detected no exosphere of dust, only transient dust as ejecta from occasional impacts on the lunar surface. LADEE’s instruments, however, added significant new knowledge about the transient lunar atmosphere, which actually may be causing the horizon glow due to the long path length view through that extremely thin atmosphere.]
“The far rim of Camelot, you can see,” I continued, “—[in] fact, everywhere but where we are and on the rim near (toward) the LM— the rim seems to be completely covered [with regolith] or, at least, the blocks don’t show through [the regolith]. They (the blocks) show up in the wall but not at the rim. That’s much like Horatio, but not to the extreme that we saw at Horatio [as we drove by earlier]. I’d say, at Camelot, the mantle [depth] is— oh, maybe, at the most, the [raised crater] rim thickness, if that’s mantle,— is on the order of a half of what we saw at Horatio. …The pan should let you measure that [difference]. Well, we didn’t get a pan at Horatio, but we got some Rover shots of it. But you may be able to quantify that a little bit.”
[This relatively disjointed description shows the difference between observing and talking, as necessary on the Moon, and observing and taking notes, as is normal procedure during field exploration on Earth. Of course, now we have the high-resolution images from LRO that make this type of comparison much more straight forward.]
“How you coming, Geno?” I asked, wanting to get with the sampling of Camelot boulders.
“Oh, I’ve got new bags. I’ve got new mags. I’ve got everything cleaned up and, MARK, [I got the] gravimeter.” While I had reconnoitered the boulder area, Cernan also had dusted the battery radiator surfaces as best he could.
As Cernan came up to where I was standing, I suggested, “Here’s a nicely structured rock that we probably ought to work on here. Structured, again, in the vesicle concentration. And then I think we ought to try to get— right over there— we can get mantle.”
“Hey, I’ll tell you what impresses me about some of these rocks. There’s a lot of [white spots]. …They may be zap pits. …I guess you looked at them closer than I did, but there sure is a lot of lineation in some of that white material, Jack.” This begins a confused interaction as I try to understand what Cernan is talking about.
“But at what scale?” I ask.
“Well, on a…on a… on a… on a visual-obvious scale.
“Well, I mean the… Okay.”
“I’ll show you. If you don’t… Let me see if it’s up here…”
“The crystal grains seem to be linear, but they are more or less random [in the planar dimensions]. Is that what you mean?”
“No, they’re linear, though. It can’t…can’t be really linear and random. There’s some rocks here that are…that are highly vesicular and there’s others that are not.”
“That’s right. Gene, if this is what you mean, it’s…”
“…And a reminder, Seventeen,” Parker finally interrupts this meaningless conversation, “you guys, that the primary priority is the blocks and then a rake soil of the white subfloor soil there. And you’ve only got 15 minutes before we want you driving back to the LM. Over.
“Okay” acknowledges Cernan. “We’ll get to work…”
“Let’s sample this,” I say, indicating the large boulder I had looked at closely earlier. I also was happy to be out of that uncomfortable discussion with the Commander.
“Okay. Let me get these two first, and then we’ll go get that one,” Cernan said, pointing with the tongs to the two major textural variations in a boulder, “because there’s two different kinds here, …at least [two] apparent kinds. One’s a relatively new fracture.”
“Well…” I said, not sure what he meant by “new fracture” and wanting to work on a different boulder where we could sample at chest level.
“Boy, I tell you, watch when you back up…”
“…I told you [there are lots of blocks].”
“[I have] learned that.”
“We need to sample the structures, though, in this thing (boulder). We haven’t really done that.” Cernan would just not pay attention to a sampling strategy that seemed obvious to me.
“We’ll try and get a[n] ‘around-the-corner’ picture.”
“We need to get that stuff on the mantle, too,” I reminded him. “I mean [the mantle] on the blocks.”
“Yup. Okay, we want to get an “around-the-corner” picture of one of those big ones, too,” Cernan insisted, apparently referring to a series of stereo photos of two sides of a large boulder. “See if we can get the structure of it. Okay, you get your picture?” meaning a before shot.
[These before sampling photographs (AS17-145-22136-38) show the high density of boulders at this point on the rim of Camelot and why they appear as a unit distinct from the dark mantle in the pre-mission, Apollo 15 photographs. Also, one can see the high density of micro-meteor impact points on some rock surfaces (AS17-145-20138) with far fewer on a more recently broken surface to the left of the gnomon (AS17-145-20137). A large boulder in the background of photograph AS17-145-20138 contains three sub-parallel fractures that appear to reflect the type of rock structure to which I previously had referred, Fig. 11.128.]
Cernan then began to hit the boulder and after three good whacks, a fragment came off and fell to the surface.
“Here’s a piece right here,” he said
“Okay, can you hand me a bag,” I said, “…or I’ll pick it up with a scoop, whichever you prefer.”
Fig. 11.128. Rock samples 75015 (right) and 75035 (left). The gnomon shadow and one leg are at right. The 3 sub-parallel fractures are in the boulder at top center-left. (NASA photo AS17-145-20138).
Instead, Cernan used his tongs to pick up the rock fragment. “[Can you] get the bag? Let’s see if we can fix your [sample] bag thing (bracket) tonight.”
“Okay, I got it (the sample).” Looking at the fresh surface of the rock, I added, “Okay, that looks like our old friend, the gabbro, all right…” Then, I put it into the bag.
“How’s that for a piece.” Cernan had broken off another fresh fragment.
“462 (75015) is Cernan’s fairly freshly fractured rock.”
Fig. 11.129. Lunar Receiving Laboratory image of basalt sample 75015 from the rim of Camelot Crater (Station 5). Note the small craters formed by micrometeor impacts (zap pits). For the in situ location of the sample see Fig. 11.128↑. (NASA photo S73-16676).
Fig. 11.130. Photos at the LRL of sample 75015 remaining today (01/19/2016) as fragment 75015.31. A cm scale is located below the i.d. tag at lower left. (Editor photos WE100-3840, -3845).
After I twirled the sample bag and bent the aluminum mouse ears inward to close it, Cernan said, “Okay, you can put it (the sample) in the bag (Cernan’s SCB).”
“Okay, here’s another one right here.” He pointed to the second fragment.
“That one?” I asked, as I picked it up with my scoop.
“Yup. I can’t squeeze these things (the tongs) anymore [because of the dust]. Here they go (broke loose, again). Got a bag?”
“Not yet.” I grabbed another bag from under his camera. “Okay.”
“You in there (with the sample)?”
“Ahh!” I can’t open the bag with one hand, so I hand the rock fragment to Cernan and use two hands so he can drop the sample in. “[Bag number] 463 (75035), is another [fragment] of the same variety [of gabbro].” This was my way of saying that we did not need the second sample. I wish we’d started on that structured rock because we’re going to run out of time. “Let’s go over there and get at least one off of it.” By not following my original lead and then taking two samples from the same uniform boulder, we now had the risk of not sampling the boulder with the greatest apparent variety of structures in it.
Fig. 11.131. Lunar Receiving Laboratory image of basalt sample 75035 from the rim of Camelot Crater (Station 5). Note the small craters formed by micrometeor impacts (zap pits). For the in situ location of the sample see Fig. 11.128↑. (NASA photo S73-16257).
“Yeah, we’ll get it.”
“Get the after [photo],” I told him. “Whoops.” I had dropped the scoop. “Got it?”
I stepped on the scoop to grab its handle and moved toward the boulder I wanted to sample. “Okay, why don’t we [work on this one]?” Cernan picked up the gnomon and moved toward me.
“What did you have picked out?” he asked.
“This in here with the layering in it.
“Okay, guys, looks like you’ll be going in about 10 minutes,” warned Parker.
“I’ll get a flight line photo. …Yeah, [Bob]. …”Why don’t you get a flight line,” I then suggested.
Fig. 11.132. In situ location of Type B basalt sample 75055 from the rim of Camelot Crater at Station 5. This oriented sample also provided a measurement of the paleo-intensity and orientation of the lunar magnetic field about 3.7 billion years ago. All of Cernan’s flight line photos here were blocked on the left by the sample bags. (NASA Photo AS17-145-22149).
Fig. 11.133. Two frames of my flight line photos showing the layering of the boulder. Cf. Fig. 11.132 for the location of the 75055 sample. (NASA photos AS17-133-20330-31).
“I’m going to get that [set of photos] from here,” Cernan replied.
“Sort of [on a] northeast [line]. How [are] you going to go [with it]?”
“I’ll come around from this end [on the east] and go around to that side [to the west].” (AS17-145-22141-52) For some reason, Cernan’s pointing for these photographs gives roughly the same view of the south-facing part of the boulder rather than being an example of flight line stereo (e.g., Fig. 11.132).
“Okay, I’ll go perpendicular to you more or less, [looking north].” (AS17-133-20330-35) I wanted to make sure we documented the layering for future analysis (e.g., Fig. 11.133).
[My set of flight line stereo photographs further document the fracturing that parallels the vesicle layering in many of the larger rim boulders. These fractures may explain the existence of flat top boulders I discussed on the approach to Station 5.]
Fig. 11.134. My up-sun locator photo showing the rover at a distance of ca. 25 m (as determined from the reseau spacing and size of the LRV wheel base). Note the drop-off in large boulder frequency to the right and away from the rim of Camelot (Cf. Fig. 11.127↑). The sky has been intentionally blackened and the surface contrast increased to bring out the features. (NASA photo AS17-133-20336).
“Boy, that one (boulder) right behind you is just vesicular, by comparison [to other blocks], to a high degree— like three times as much. Oh, I hope those [sample] bags weren’t in the way of every one of those pictures (The bags do obscure a portion of each of his photographs.). Okay. …Boy, I tell you there ought to be a lot of permanent shaded samples in here, Jack.”
“Okay, I got the down-Sun,” I noted, as Cernan began to hit the boulder at least ten times and still did not get a piece to break off. Photograph AS17-133-20336 (Fig. 11.134) is a locator shot back to the Rover and also shows the line of boulders that lie along the rim of Camelot but not farther out on the ejecta blanket to the right. Similarly, AS17-145-22158 that looks to the northwest shows the same relationships. The down-Sun, before sampling photograph, AS17-133-20337, looks into this line of boulders, toward the crater rim, and illustrates the relatively clean surfaces of even flat-topped boulders.
Fig. 11.135. Down-sun photo of flat top boulders at Station 5, Camelot Crater rim. The white circle denotes the location of sample 75075. (NASA photo AS17-133-20337).
“Man!… That’s a hard Moon,” he said. “Just a little piece but that’s [all I can get]. See…”
“How about this chunk down there, Gene?” I pointed with my scoop to a projection from the boulder where I would have gotten a sample.
“Where you looking? …I don’t think that’ll [break off]… [You mean] that plate [shaped] piece?”
“I don’t think that’ll come off very easy,” Cernan said with some skepticism.
“Let’s see your [hammer],” I requested.
“I’ll try… Here [you] try it. You’re over there [closer].” Cernan and I traded tools. “You know I’ve worn the RTV (Room Temperature Vulcanizing silicone rubber insulation that served as a gripping surface) off that hammer already.”
“Yeah, I saw that.” I took a short swing of the hammer and the sample broke right off (Fig. 11.135↑). “That comes from 15 years as a trained hammer bearer,” I commented.
Fig. 11.136. (left): Lunar Receiving Laboratory image of basalt sample 75055 from the rim of Camelot Crater (Station 5). Note the small craters formed by micrometeor impacts. This sample has been used to determine the paleo-intensity and orientation of the lunar magnetic field at ~3.7 Ga. The right photo shows the present day appearance of the top piece of the 3 at the left. (Left, NASA photo S73-15097; Right, Editor photo WE100-3483).
“By golly, your geology training is coming in handy.”
“You learn where to hit rocks,” I explained, as we again traded tools, and I retrieved the sample with the scoop.
“Well, [Bag] 464 (75055, Fig. 11.135↑),” Cernan reported. “Won’t all go in there (the bag) but…”
“That’s all right, you can wrap it around it.”
“I’ll get it… No, I’ll get it, babe. It’s in there,” he said, finally, and put the sample in my SCB.
[Post-mission analysis disclosed that the first three rock samples we obtained from large boulders on the rim of Camelot (75015, 75035 and 75055) are olivine basalts or fine-grained gabbros with very similar major element concentrations. They have been classified as Type B basalts. They vary from each other largely in their grain-sizes and textures. 75055 has recently provided data on the strength and paleo-orientation of the lunar magnetic field when the basalt from which it came cooled (Chapter 13).
Rb/Sr and 40-39Ar dating of 75035 and 75055 give apparent crystallization ages at 3.8 ± 0.1 billion years, roughly consistent with the range of other ages (average is 3.74 Ga) determined for samples of subfloor gabbro boulders from Steno and Shorty Craters and near the Challenger.
The solar wind exposure ages of the three rock samples range from 70 to 95 million years and a track exposure dating on 75055 gives 70 million years. These exposure ages originally were thought to bracket the minium age of the Camelot impact; however, a topographic diffusion age indicates that this impact occurred at 500 200 Myr before present, millions of years earlier than these minimum ages would suggest. The exposure ages probably roughly give the time when the boulders were first exposed by erosion of rim regolith into the crater (Chapter 13).]
Parker became insistent as time disappeared: “…if you could get that rake soil and maybe also get the soil off the top of one of those boulders that you thought you saw.”
“Yep,” I said in response to Parker, and then moved through the boulder field toward the south, leaving the scoop on a flat boulder (Fig. 11.137) where I could sample the regolith that apparently had been thrown on top. I wanted to be sure that we had sampled boulders that are representative all the Camelot rim rocks. “Whew. I’ve got to have Gene with me since I can’t carry sample bags. …I probably can if I’m careful; but I keep dropping them.”
Fig. 11.137. Large flat topped, Type A basalt boulder on the rim of Camelot Crater. This type of flat, largely buried large boulder was one of several observed at Station 5. I sampled both the regolith material on its surface and pried a large fragment from the fracture using the scoop as a lever (75060 and 75075, respectively). The dashed oval at left shows where I sampled the soil (75060), and the white arrow points to the location of the removed 75075 sample (Fig. 11.135↑). Note how much the lunar dust has impregnated the fabric of my space suit. (NASA Photo AS17-145-22157).
Cernan continued to look at the boulders we just sampled, saying, “These rocks here have an awful lot…a much greater density of the white minerals in them – or crystals – than I’ve ever seen before, Jack. Where did we see these kind before?”
“Well, when I looked at them right at first, that’s what I thought. But I think that the zap pits are making the white stand out more. They’re fooling you a little bit.”
“They might,” he acknowledged, and the photographs of the boulders clearly show the small, white spots created by micrometeor impacts on the plagioclase that makes up about 30% of the gabbros (See the enlarged AS17-145-22147 below).
Fig. 11.138. An enlargement of the top layer of the large boulder from which the 3-piece sample of 75055 was taken. Myriads of white spots produced by micrometeoritic impact in the plagioclase can be seen across the face. (Portion of NASA photo AS17-145-22147).
“Because,” I continued, “when I looked at it [in the cabin] with the hand lens, it looked like a fairly normal gabbro, like some of those that have crystallized with the mare basalt.”
“Where are you?” Cernan asked as I had move behind him. You ready to take them back…?” He had started to sound as tired as I felt. “Them” may have referred to the samples.
“I’m back over here. What I want is a sample of this soil off one of these rocks.”
“Okay, let’s get that now,” Cernan said, grabbing the gnomon, “and then let’s get the rake sample…”
“But it looks to me like it’s soil (regolith) that’s been thrown up there rather than [being a true, secondary mantle]. This rock is about 3 meters in diameter, but it’s one of the flat-surfaced rocks. It only stands about – at the most – one-third of a meter high. But we can get up about a meter from the soil/rock interface and get soil off the rock, I think.” The documentation photographs of the top of this boulder are AS17-145-22154-55 (Fig. 11.137↑) and AS17-133-20337-38 (Fig. 11.135↑). A general examination of other photographs taken at Station 5 shows that a large number of the large boulders have flat tops, probably reflecting the planar layering of vesicle concentrations in the original lava flows.
“Okay. See what you can do.” In the context of the pre-mission interpretation of the dark mantle as a volcanic pyroclastic deposit that might be very young, this sample might allow the geologists to decide if pyroclastic dark mantle had been deposited on the boulder or if regolith had be thrown up there by a nearby impact (see AS17-145-22156, or the similar photo in Fig. 11.137↑).
“Whoops,” I said as I stumbled against the edge of the boulder. Oh, yeah. …I got some soil [off the rock].
“Don’t kick up anything new.”
“No, that’s all right,” meaning that I had not contaminated the sample.
“455 (75060-66) is that bag number, Bob,” reported Cernan.
As I poured the soil from the scoop into the bag, I said, “Okay, this is soil from a half a meter in [from the outer edge] – it’s about a centimeter deep and a half a meter in.”
[Post-mission examination of the 90-150 µm fraction of 75061 showed it consisted of relatively immature regolith with agglutinate at 24% and only about 1% orange volcanic ash and no black ash. Its low to intermediate maturity index is 33. These facts make it highly unlikely that any eruptions of volcanic ash occurred after the boulder exposure. Rather, the sample consists of regolith thrown onto the rock surface by one or more nearby meteor impacts.
Track densities measured on particles from this sample give an exposure age of about 40 million years.]
“Let’s take that chip there, that’s lying on top, with the next scoop.” Cernan referred to a small rock fragment in the material near where I took the last sample.
“I’m going to…”
“Let’s take the soil on that. No. I was talking [about that one]. …No. …Okay, take that one then. Well, that’s [needs] another bag. Put this… Before you pick that one [soil sample] up, pick that little chip up…” Cernan wanted that chip!
“Well, …I don’t want to get the chips. I want the soil. Either that or a coherent rock.” I wanted to keep the finest material on the rock separate from obvious coarse fragments of regolith in order to be sure what might be dark mantle and what might be regolith.
“Okay, there you go.” Cernan finally was happy.
“I think we better leave it at that,” I said.
Fig. 11.139a. (left): Lunar Receiving Laboratory image of sample 75075 from the rim of Camelot Crater (Station 5). Note the irregular shape of vesicles that are transitioning to “vugs” in which crystals project into the open space rather than lining that space. The right view was taken on 01/19/2016. Both show the side that was resting on the lunar soil. (Left, NASA Photo S73-15337; Right, Editor photo WE3884).
Fig. 139b. As in Fig. 139a, but the exposed top-side. There is a patina covering parts of this side. (Left, NASA photo S73-15342; Right, Editor photo WE3876).
“Okay, [Bag] 465 (75075, Fig. 11.139a,b),” reported Cernan. “Pick that other one up, and I’ll bag it real quick. …That’s [(455) 75060 is] the soil from on top the rock. And we’re taking a piece of the rock itself, which looks pretty much like the other one, Bob. It might be a little bit more vesicular.”
Now, I was trying to pry a piece of the actual boulder from out of a fracture, using the edge of the scoop, levered into the fracture. As it came loose, Cernan conceded, “You’re right again [about where to break rocks. …Here we are,” he said as the piece came loose, “and I’ll be able to grab it with my hand. If I put this away [in the sample bag]…” He put the second mantle/regolith sample in my SCB while I used the scoop to gather the rock I had pried off the main boulder (Fig. 11.135↑, Fig. 11.137↑).
[This verbal record of our sampling confused the USGS team that did the wonderful work of locating and determining the original in situ orientation of our samples. Cernan wanted me to bag one of the small loose fragments we saw within the “soil from on top of the rock”. I resisted doing this because I wanted specifically to sample what might or might not be dark mantle material (75060) deposited on this flat rock surface. Instead, I pried off a large, in situ piece of the flat rock that Cernan then picked up with his hand and placed in Bag 465. As 75075 is a large rock (15 × 12 × 5 cm and about one kilogram in mass), it is the rock we put in Bag 465, and we did not try to sample the smaller, loose chips originally targeted by Cernan.
75075 differs from the other three samples from rim boulders by being compositionally similar to Type A basalts sampled at Station 1 near Steno Crater. It has a few percent lower SiO2, Al2O3, and CaO and higher MgO and TiO2 than Type B basalts, 75015, 75035 and 75055. The fact that the flat-topped boulder from which 75075 came is almost fully buried, in contrast to the other boulders we sampled, may indicate that it came from a thinner, less differentiated flow. It also is more vesicular and porphrytic in texture than the Type B samples.
The cosmogenic 81Kr and 37-38Ar exposure ages of 75075 appear to be about 140 million years or about twice that of the other sampled boulders on the rim of Camelot. A second Ar exposure date gives 118 million years. The exposure dates suggest that the boulder might have spent about 50 million years at the surface before its isolation by another lava flow, although an alternate explanation will be discussed below. Later exhumation on the rim of Camelot added about 40-90 million years more exposure. Although 75075’s Ba/Rb ratio is that of Type A or B basalt, its major element composition is close to the two Type C basalts sampled at Shorty (Station 4) except for slightly lower MgO and slightly higher TiO2. As discussed in the Station 4 Section, above, samples of Type C basalt from Station 4 also would appear to represent a late subfloor lava eruption.
Rb-Sr and 40-39Ar ages, respectively, at about 3.82 ± 0.06 and 3.84 ± 0.12 billion years, however, cannot be distinguished from those of 75035 and 75055 within the various error bands of about ± 0.1 billion years. 75075’s Sm-Nb age of 3.70 ± 0.07, and its 40-39Ar ages of 3.74 ± 0.04, 3.71 ± 0.05, 3.74 ± 0.02 (coarse plagioclase), and 3.66 ± 0.02 (plagioclase fines) lie closer to the 3.74 billion years average of all Taurus-Littrow basalt samples (see mare basalt age analysis in Chapter 13).]
“Okay, the soil [sample] came from a half a meter in from the soil (regolith) boundary. We need to get a… Let me get over here and try to get one bag of soil that’s away from the boulder.” I moved a couple of meters farther south, to get a regolith sample to compare with the material on the rock and photograph AS17-145-22157 (Fig. 11.137↑) caught me taking the sample.
“I’m going to get my ‘after’ while I’m here.”
“And the present time,” Parker told us, “we [want to] drop the rake [sample]; we’d just like to get the kilogram of soil somewhere between the boulders – [in] as open [area] as you can.”
“[Is] my scoop in that [picture]?” I asked Cernan.
“It will be [if I move over here]. …Okay, it is now.
“Oh, you want a kilogram?” I asked, responding to Parker.
“From between the boulders?”
“Roger. That’ll replace the rake soil sample we were going to get. And we’d like you moving in 3 minutes.
“Let’s do it right here.” I stood at the spot where I wanted the sample to compare with the regolith from on top of the boulder (75060).
“Yeah, right there. Let me [get to your SCB].” (see Fig. 11.137↑ for the SCB attached to my PLSS behind my right shoulder).
“Oh, okay… This will be a matched pair with our soil sample [from the boulder], too,” I clarified for Parker.
“Okay, bag 467 (75080-89) is where your kilogram is coming from,” reported Cernan, as I took a full scoop of the Camelot rim regolith. “Another scoopful.”
“Yeah… I’m sampling down to about 5 centimeters,” I estimated for the Science Support Room records.
“Get your hand down, please,” I requested of Cernan. “I’m coming down to you.”
“Oh, okay… That’s full. That’s 467.”
“Pinch her down tight,” I told him, “or that will leak out…”
As Cernan puts the sample in my SCB, he says, “Now let me get your big bag (SCB) tight.” Not having time for a rake sample probably did not lose us much. The uniformity of the rim boulder population suggests that there would not be much variety, although, the rake sample at Station 1 near Steno Crater provided significant insights into mare lava fractional crystallization differentiation.
[Post-mission examination of the 90-150 µm fraction of 75081 showed it consisted of relatively mature regolith with agglutinate at 35% and about 15% orange, black and colorless volcanic ash. This suggests that the less mature regolith, with a low volcanic ash content, sampled on the nearby flat-topped boulder (see 75061) did not derive from local regolith but from some more distant impact, possibly one on the wall of Camelot where less mature regolith would be expected to exist.]
“Okay, let me try to get a [photo]. You got a shot of where my scoop was [for that kilogram sample], didn’t you?”
“Yeah. Let me get an after of it, though,” Cernan said, but began a full panorama (AS17-145-22159-83, Fig. 11.125↑). This is an excellent set of images that show the boulder field at Station 5 and provided a representative sample of other crater rim fields around Camelot.
[The panorama also covered the west side of the East Massif. In AS17-133-20355 and AS17-145-22165 (Fig. 11.127↑ above my helmet), layering appears to be reflected in five or six distinct and roughly parallel cliffs. The significance of these cliffs will be discussed in connection with Station 8 and the Sculptured Hills. These apparent cliffs, however, are not resolved on the NAC Digital Terrain Model.]
“Okay, Houston, we sampled about 3 meters southwest of the gnomon that was set up for the top-of-boulder soil sample (75060). So it’s a match pair, really, in that regard… Don’t forget your gnomon,” I reminded Cernan.
“I’m not. …Now I need to get a pan…”
“Are you getting a pan?”
“I’ve already started it.”
“Okay, I’ll go over near the Rover and get one (a panorama).” I started back to the Rover using my patented skiing technique (see Fig. 11.127↑).
Fig. 11.140. Our sampling in the southwest boulder field of Camelot (see Fig. 11.126↑) is summarized in Cernan’s partial pan taken just before we left this area. Rock sample 75055 broken from the sloping boulder face is marked by the arrow at right. Sample 75075 is just out of view marked by the arrow at the lower left. A, B, C are i.d. boulder markers also denoted in Fig. 11.141 below. (Composite from NASA photos AS17‑145‑22175, -76, -78, -79, -80, -81, -82, -83, -60).
Fig. 11.141. The southwest boulder field at Camelot. A, B, C denote the boulders in Fig. 11.140. The zig-zag dashed line marks our footsteps between the boulders where 75055 and 75075 were sampled. And the curving dashed line is the trace of my skiing on the way back to the LRV seen in Fig. 11.127↑. An enlargement of this view shows the footprints quite clearly. (Extract from base photo LRO frame M162107606).
“Okay, I got the gnomon,” Cernan said after he finished the panorama. “When do you want us to leave, Bob?” Parker did not answer.
“Jack, do you read me?” Cernan asked to make sure his communications were okay.
“Yeah. …Hello, Houston.” I completed my black and white panorama (AS17-133-20339-61) as I called Parker.
[Examination of the photographs we took of the interior of Camelot on the outbound leg to Station 2 (AS17-135-20588-97; see Fig. 11.12↑ (bottom)), as well as the Station 5 panoramas (AS17-133-20339-61 (Fig. 11.122↑, Fig. 11.123↑) and AS17-145-22159-83 (Fig. 11.124↑, Fig. 11.125↑), document well that the concentrations of blocks at the rim appear to be surface extensions of groups of block concentrations on the interior wall, separated by plumes of dark mantle material that extend down the wall (see also the LRO overhead, Fig. 11.126↑). The plumes narrow with depth into the crater as they become increasingly confined with narrowing of the crater’s bowl-shaped interior. The lack of blocks and rock fragments on the ejecta blanket away from the rim is in sharp contrast to the blocky ejecta blanket around Steno Crater (Station 1, Chapter 10). This contrast suggests that Camelot is significantly older than Steno, as its ejected blocks largely have been converted to regolith. This is consistent with the ~500 Myr topographic diffusion age of the crater. Careful mapping of large block orientations on the rim of Camelot, using surface panoramas and LROC images, may help to confirm the tentative conclusion that these blocks are exposed wall rock rather than ejecta. The age of Camelot Crater and other implications of observations at Station 5 are discussed in detail in Chapter 13.]
“Hello, Seventeen. Loud and clear. We’d like you to leave immediately, if not sooner.”
“Hippity-hoppity, hippity-hoppity, hippity-hopping over hill and dale.” Cernan had switched from a walking gait to his skipping motion, paraphrasing a line from the late 1940s and early 1950s song, “Mule Train”, by Johnny Lange, Hy Heath, Doc Tommy Scott, and Fred Glickman. I always had preferred Tennessee Ernie Ford’s vocal for this popular early crossover from country music, although it is most often associated with Frankie Laine.
“Hippity-hopping along,” he continued. “Okay. My golly, this time goes fast!”
“That’s affirm,” agreed Parker from afar.
[Like everywhere else we had been in Taurus-Littrow, I would have liked to have had more time, in this case, to move along the rim of Camelot, down the inner wall as far as prudent, and radially out from the rim, looking for variations in the structure and mineral composition in the subfloor lying beneath us that might show up in ejected blocks. Such a study of Camelot and the subfloor basalt unit would have been normal for a field geologist on Earth but not under the time constraints of an Apollo mission. On the other hand, because Camelot has turned out to be much older than thought before the mission, the development of deep and fragment-poor regolith on its ejecta blanket also indicates a mature age for the crater.]
“Okay, and when you leave here,” Parker began, again before we were ready to listen, “Seventeen, remember that we want to pick-up EP number 8.”
“Where did it (the time) go?” Cernan asked no one in particular… “I’m giving you (gravimeter) readings.”
“Roger. We’re ready.”
“Go,” I said, but really meaning ignore Parker for a minute.
“670, 031, and 401. 670, 031, and, 401.”
“Copy that.” And when we leave we want to take EP number 8 with us, guys.” I’ll say one thing for Parker— he never gave up. “We’d like the SEP turned back on and the blankets closed. …Okay, Jack, I guess that’s your option, you may…stop and take the charge off when you get to the distance or, if it’s only a short one, you might like carrying it in your lap.”
Meanwhile, Cernan and I were trying to finish our post-station housekeeping. “Let me fix your [harness]…”
“Jack, I can hold it (EP-8) in my left arm on the seat.”
“No, I’ll get it! I’ll get it!” Obviously, Parker’s interruptions were irritating me, again.
“Okay, you want the SEP ON?” Cernan asked.
“Okay, both DSEA (Data Storage and Electronics Assembly) and the other switch [are ON]. You want the blankets open?”
“CLOSED? Well, closed is [going to cause it to heat up]. …What happened to the Velcro on that other side? …I thought they mounted that thing so that [you could close it].”
“It came off, Gene,” I reminded him. “It stuck to the [lid] Velcro.” The glue used to hold the Velcro patch to the main body of the SEP had failed.
“That thing (Velcro) that [holds it down is gone]/ …Okay, you got the TGE [reading]. We’ll get EP-8. The (TV) camera’s going (OFF).”
“We (I) made a mistake earlier,” I groused, “and it’s too late to rectify it (the fatigue) in carrying these charges.”
“Oh, I don’t know…,” Cernan disagreed, but he had not made the original mistake in planning that I had.
“Negative, Jack,” joined in Parker, “if you don’t have it off, we could stop and get off and get it, if you want to? But this is a short distance. You might want to carry this one.”
“That’s right, that’s right. I say the mistake was made earlier. There’s no problem now.” My irritation consisted of a combination of running out of time, Parker’s interruptions, and the fatigue in my forearms.
“Okay, traverse to LM, low-gain 100,” Cernan read from his Cuff Checklist.
“Did you turn this ON?” I asked, standing in front of the SEP.
“It’s all ON; all squared away.”
“Push that thing (the SEP cover) down and it’ll stay. [Guess not]. Well, sometimes it will. Okay.”
“And how about a frame callout before you get back on, guys.”
“Yeah, I need some new [film]. Do you want me to get it (a new magazine) here?” I asked the keeper of the inventory in Mission Control. The fact that I asked indicated that I had become more tired than I wanted to admit.
“CDR’s at fifty [frames].”
“[LMP’s at] A hundred and seventy.”
“And, Jack, it’d be my opinion,” Parker said, “since you’re just going back over the same path, that you came up this morning, it’s probably not necessary.”
“Okay, I’ll use it until it runs out.”
“I’ve got a lot of film anyway,” added Cernan.
“But when you leave me at [the ALSEP]. …Okay.” I realized that I could just take his camera if I needed it.
“Yeah, we’ll let Gene take some of the photos near the bomb, Parker said, “or near the charge, perhaps…”
I missed getting into my seat on the Rover on my first try so Cernan advised me to, “Just jump up again and get your bottom [to the left]. …Yeah, there you go. You got to come this way quite a bit.”
“Yeah. [You parked on quite a] slope.” It seem natural for Cernan to park rolled right, increasing the difficultly for me to get into my seat.
“Your seat’s rising [up] with you, for some reason. There it is, I guess. You’re all right. …[Move the buckle] Up closer to you…”
“Let’s go,” I said.
“Okay, the switch is coming ON.” Cernan had neglected to give Rover systems’ readouts when he stopped here, but Mission Control must have been all right with that as Parker never asked for them. “Okay. ‘Traverse to LM: 12 minutes, 085/1.4.’ That’s [amazing]. …Man, that [Rover indicator] says 086/1.4 to the LM, and my checklist [says] 085/1.4. We must have landed where they wanted us to!”
“Just about,” I said, taking Cernan’s interpretation rather than thinking about it. Cernan actually had forgotten that the 086/1.4 Rover reading referred to the position of Station 5 relative to the SEP transmitter rather than the Challenger. The Checklist indication of a 1.4 km planned drive to the Challenger also included some additional distance to allow for maneuvering around boulders and craters.
“Hey, Bob?” Cernan called. “You know where we landed yet?”
“Well, we think so,” Parker replied. We’ve been transecting [to various known] positions tonight.”
“It must be pretty close.” Earlier, I had been trying to tell Cernan not to worry about knowing exactly where we landed.
“You bet your life!” Cernan exclaimed, very proud of himself. I’m reading 085/1.4, and that’s what my checklist said.” Oh well. He could think what he wanted.
“Okay, Bob,” I began to summarize as we started toward the ALSEP. “I guess my impression— and it’s pure speculation right at this stage— is that Camelot is mantled by whatever has formed the dark mantle. …[But] it does not seem to be mantled to the degree that Horatio is.”
[This conclusion would turn out to be totally wrong. At this point, I still thought in terms of the dark regolith being equivalent to dark mantle and that the latter came in very late in the history of the valley. This is the same mistake the pre-mission geology mappers had made and would only be made right when post-mission examination disclosed that the orange and black ash sampled at Shorty had an age three billion years older than Camelot, Horatio and most other craters in the valley and over that time, this ash had been incorporated into the regolith developing on the basalt flows to give it a darker than normal albedo when imaged from orbit. From eye level, I could not distinguish the difference between dark mantle regolith and the dark gray regolith developed between the boulders on the rim of Camelot. Both types of regolith had been moved around by repeated impacts to create the impression of mantling, but the true, primary mantling effects of the orange and black ash eruptions had long since disappeared. Photometric analysis, however, might distinguish between (1) regolith containing significant quantities of ash and (2) regolith developed on subfloor ejecta from craters like Camelot.
The apparent greater degree of mantling of Horatio probably is because Horatio is significantly older than Camelot and has Camelot ejecta partially covering its eastern features.]
“And give us a MARK when you’re going,” requested Parker.
“Oh, I’m sorry,” I apologized. “We’ve been going about a minute.”
“Okay, copy that. And we don’t have battery temperatures there, if you could quickly give them to us.”
“Okay, I never did give you that. It’s 110 and 136.” This continued the steady rise in battery temperatures since we arrived at Shorty.
“But I tell you,” I interjected, “the inner wall of Camelot to the [north]east is certainly blocky (AS17-133-20363-64; Fig. 11.142↓).”
“Well, there were a few blocks where you guys were, too,” Parker countered.
“[The wall has some] mantle, too, Jack.”
“Yeah, well, I don’t know [if] you could see the other (west) wall, too. It’s [just as blocky].”
‘Hey, here’s some Rover tracks!”
“Hey, somebody’s been here before,” I said, theatrically (AS17-133-20365).
“Okay, and, Seventeen, what we’re looking for is deploying charge number eight at [bearing] 082 and 0 decimal 4 on the range.”
“Okay,” I replied.
“Okay, we’re at 083 and 1.1,” Cernan reported. “We’re just about abeam the eastern rim of Camelot. And there is Challenger!”
Fig. 11.142. The northeast inner wall slope of Camelot as we were leaving Station 5. Cf. Fig. 11.126↑. (NASA photo AS17-133-20363).
“Hey, hello, Challenger. You can even see the ALSEP,” I added as if greeting an old friend.
“I think I’ll go this way,” Cernan commented casually as he avoided a large crater that unexpectedly came out of the Sun, producing a nervous laugh from me.
“Gee, it seems like a short day,” I said, facetiously.
“Well, I’ll tell you, the time went fast.”
“Okay, you’ve heard about this country [before],” I told Parker. “Hey, looking over there, though, there’s no [change in the appearance of the Camelot rim boulders]. …[Now,] we’re about, oh, 50 meters from boulders on [the east rim of] Camelot. And their appearance from this distance is the same as what we sampled at [Station] 5. I think we’ve pretty well identified the subfloor, Bob.”
“Okay, sounds like we have,” Cernan concurred “…and sounds like …from the very deepest – even from the bottom of Camelot – it looks like it’s about the same.”
“It sure does,” I replied. “…I can’t say I understand it. But that’s the way it appears right now. …Whatever filled this valley, it certainly was different than the Massifs. I think we’ve proved that. And, it presumably [was igneous], at least everything I see indicates that it was an igneous extrusion of some kind. Either that, or the whole valley’s been tilted and we’re looking at some strange cross section – planar, more or less, relative to the other mountains – of a crystalline body that was formed at depth. But I don’t think that’s likely.”
[My nature as a field geologist is to keep questioning and testing any hypothesis that presents itself until it passes all conceivable, rational tests. The possible tilting of the valley suggested here is highly unlikely in the lunar geological environment; however, our terrestrial experience dictated that the hypothesis at least be tested against available evidence. Also, as field and image data is evaluated, the question will be asked if the rim boulders around Camelot actually came from near its floor or from significantly higher in the stratigraphy of the flow or flows that constitute the subfloor basalt (See Chapter 13). ]
“Man; we’ve covered 19.3 kilometers, Jack,” observed Cernan, looking at the readout for distance traveled on the Rover console.
“Is that what we planned to cover?” I wondered out loud.
“That’s outstanding,” Parker added.
“I don’t know, [Jack]. What did we plan to cover, Bob?”
“Stand by. But we’ve been everywhere we’ve planned to go, so, we must have gone just about as far as we’ve planned to go.”
“Yeah, but it’s a straight line. I don’t know what the wander factor was, but I’m sure it was pretty high.”
“17.6[ km], they’re telling me,” Parker relayed.
“So we went a little bit out of our way.” Cernan’s “little bit out of our way” added about 10% (1.7 km) to the total straight-line distance.
“Well, it’s all mileage.”
“0.7 [range] and what was the bearing? 083?” I wanted to get rid of EP-8 as soon as I could.
“082, I think, but we want 0.4 [for range].”
“Zero decimal four. Zero decimal four, guys, “confirmed Parker.
“Oh, zero decimal four,” repeated Cernan.
“Yeah, that’s the range,” I said.
“Yeah, that’s what I said: 0.4.”
“But you want to bear north, don’t you, a little?” I suggested.
“Yeah, I want… What’d you say, 082, didn’t you, Bob?”
“That’s affirm. That’ll be close enough. It’ll probably be right on your track, there.”
“Well, I don’t make a habit of following myself. I like to cover new ground.”
“Watch out for that new ground there,” I warned. “Looks like in the [distance] …Look at the Italian flag!” (This is in reference to the International Orange colored flags on the seismic charges, a reference that has now forgotten origins.)
“Hey, there is one there,” Cernan shouted. “I saw the box before I saw the flag. …No, I didn’t, I saw the flag first, I’ve got to admit it.”
“Come on now!” I kidded.
“I got to admit it, I saw the flag first.”
“The boss said you saw the flag first.”
This exchange about the warning flag on the Explosive Devices was for the benefit of Deke Slayton, head of the Flight Crew Directorate at the Manned Spacecraft Center and our “Boss”. He had insisted that these charges have a bright orange flag on the end of their receiving antennae so that we would not drive over them. Gene had seen the box first, realized that he had contradicted “the Boss”, and then we corrected the “record” in a tongue-in-cheek manner. Parker recalls that Rocco Petrone, at the time NASA’s Associate Administrator, had become involved in this discussion of having orange flags and that this may be the origin of calling them the “Italian Flags”.
“I’m 082 and I’m 0.5,” reported Cernan. “I’ll just head right in towards the LM. Man, I want to stay away from ALSEP, I see the big boulder near the Geophones, so I’ll… I’m going to go around…”
“0.5. Okay, you’ll have to swing right after we deploy, probably.”
“Whee!” Another exciting drive through a crater gave the Rover a bounce and kept the wheels off the surface for a second or two.
“Did we ever get any glass out of the bottom of those craters?” queried Cernan.”
“No, we haven’t, we’ve got to try to do that before we leave. There haven’t been any good [opportunities].” I had talked with Cernan some before the mission about getting an oriented sample of glass from a fresh crater to determine if iron particles in impact glass record the existence and orientation of any current or recent lunar magnetic field. Eventually, I would get such a sample.
“Yeah, sometime you’ll have time to do that, I guess, guys. I’m not sure when…” Parker: ever the optimist.
[Zero point] four!” I called out as the range gauge clicked over as I watched it closely. Okay.” This put us 440m from the SEP transmitter, based on post-mission analysis. The navigation error came to between 40 and 90m over a closed 20 km course or between 0.4 to 0.8%.
“Okay, 08… Well, she just went to 1. Okay, 081/0.4..”
“Okay, let’s put it in that little depression there,” I directed. “See right ahead of us to the right?” We were fairly close to the ALSEP so I wanted to be sure that there would be no direct line from the explosion to the those experiments and their Central Station.
“Okay. …Got your pictures?”
“I’m getting them… (AS17-133-20266-70) Okay. Now just swing into that depression, and I’ll put it there. …Beautiful. Whoa, whoa. Okay, charge number 8.”
“You didn’t get a [locator] picture to the LM then, did you?
“Yeah, I did. I got several of them.”
“Well, we don’t have to take any more, do we?”
“No. …Okay, antenna is deployed. Pin 1 is PULLED and SAFE. And, let me check that [indicator]. It’s dusty. Yeah, it’s SAFE. Pin 2 is PULLED and SAFE. Pin 3, PULLED and SAFE. I guess as long as it didn’t go off, it’s safe.”
“Ooh, don’t bang it,” Cernan pleaded, and we both laughed. “I don’t care what they say, that’s an explosive] charge. You’re having great luck with those [charge deployments].”
“[Not bad at that],” I replied. …Okay, the LM was in the approach shot, I believe. Let me [just be sure]. Go ahead and turn around.”
“Yeah, I got to go around anyway…This way I can get a running shot of [of the both the charge and the LM]. [Both are] right in the middle of it [the photo]. Let me get them both in it (AS17-133-20371-75).” Apparently, I was not successful in photographing the deployed EP-8; however, Cernan imaged both the LM and EP-8, as well as Geophone Rock, in AS17-145-22184 (Fig. 11.143).
Fig. 11.143. Explosive charge (EP-08) with its “Italian” flag partially blocked by the HGA aiming handle. Geophone Rock is at left under the HGA dish. And the LM is in the distance just left of the “Italian” flag. The reseau cross spacing and a reference dimension on the LM put it at ~285 m (see photo crop below). (NASA photo AS17-145-22184).
“Okay, I ran out of film, too.”
“Now that’s pretty well located,” I noted. “When you come around, take a picture of the LM on your camera.”
“I will. I’ll take it right out the front looking right at the thing.
“Yeah, and give them a frame count.”
“Five-six,” complied Cernan. “Bob, I’ve got the ‘locator’ of the charge and the LM all in the same order here, and I’m one more [frame] than what I just gave you. I can’t look at it now.”
“Okay, one more than what you gave me at Station 5 (which was frame 50),” Parker replied. “Understand.” Clearly, Parker did not understand as Cernan meant he was at 57 on the frame count.”
“Okay, Bob. You want me to go to the [Lunar Surface] Gravimeter now?” I asked.
“Roger. And if you guys will start out, we’ll drive you by the ALSEP, Jack, and if you’ll get out at the ALSEP, we’ll have you take a look at the surface gravimeter and Gene can press on home to the LM.”
“Jack, I’m going to drive you in this way [from the southwest], and then I’ll drive all the way back around that one [eastern] geophone.”
“[If you go] to the north,” Parker suggested, wisely, “you could drive in toward the heat flow, towards that big rock, if you can see that.”
“Yeah, well, okay; that’s as good as anything.” Cernan may have originally planned to drive over one of the geophone lines.
“Bob, you want me to get some ALSEP pictures?”
“Negative, …Okay, and Jack, you can stand by…”
Interrupting, I said, “I got a [warning] flag [for PLSS FEEDWATER].” This indicated that my primary cooling water tank had been used up.
Not hearing me, Parker warned, “[Look] for a FEEDWATER dump (flag) very shortly. …Okay, [PLSS] FEEDWATER, go to AUX[ILLERY], please.”
“I just got it [to AUX]…”
“Man, look at that mess of cable,” Cernan noted, maybe for the first time. “I hope that thing (the ALSEP)’s working, Bob.”
“Every…,” Parker began, but then thought better of it. “Well, a lot of it’s working. We’ve just got to try and see if we can’t level this thing (the LSG) tonight. When you get off there, Jack, I’ll talk to you a bit about procedures for that. And in the meanwhile, it’s my understanding that the second UHT is not in the immediate vicinity, where it’s accessible, is that right?”
As we approached the area of the heat flow probes, I said, “Okay; that’s good, Gene…” Then, in answer to Parker, I replied, “No, it is [accessible], I can get it.”
“Okay, and watch my heat flow (cables) over there, don’t trip over them…”
“Okay, I’m going to take a pair of tongs,” I told him.
“Do you have any film at all?” he asked.
“No, I want your camera.”
“You want my camera?” Cernan was puzzled because he did not know that I was going to try to find some fresh impact glass to sample and needed the camera to document its orientation.
“Okay, Jack, you won’t need [a camera]. …We aren’t planning on taking the ALSEP photos right now.”
“Okay.” Parker also was clueless about my plan.”
“And, Jack, we’re not sure you went to AUX on your water yet.”
“I thought I did.”
“Okay, it’s coming up, now, we see it coming, Jack, don’t worry.”
“Let me take a set of tongs in case I drop something,” I repeated for Cernan.
“Can you reach them?”
“Yeah…” I probably took his tongs off the yo-yo lanyard on his side. Why I did not take the other pair off the gate, I don’t know.
“You got everything you need?”
“Okay, Jack’s got my camera and tongs, and I’m on my way.” I must have put my own camera under my seat without comment.
“Okay, Bob, I got a [FEEDWATER] tone again,” I reported.
“Okay, what’s it [the indicator] say? Probably just your water [flow] been building up…”
“I can’t read my [RCU] gauges.” During the day, dust had built up on the top of my Remote Control Unit.
“Want me to take [a look]?” Cernan offered
“Well, we better take a look. Okay, I’m coming over there [to the Rover].”
“I think I just got my water tone, Bob,” reported Cernan as I headed back to his side of the Rover.
“Okay, that’s right, also,” Parker said.
“Okay, AUX water’s ON.”
“We got our tones yesterday [about this time].” Bending toward him, I asked, “Can you see anything?”
“Well, not unless… Let me see, let me brush your… Bend over [more]. …You don’t have a brush to brush off [the dust]… Okay, no flags. …Now, wait a minute,” Cernan said, looking again. “…Okay. You got no…flags.”
“You look good to us, Jack,” added Parker. If the transfer to the AUXILLERY feed water tank had not occurred, I would have had to return to the Challenger immediately and EVA-2 would have been over.
“[Bend over] once more. [I’ll take] a good look.”
“Jack, you look good to us,” Parker repeated.
“No flags. All right, no flags, Jack.”
“Okay, and, Gene, I think you need to go to AUX, …if you didn’t,” Parker said, having not listened to Cernan’s previous statement to that effect. This suggests that he would transmit before checking with the EVA console team who would have been listening.
“Yeah, I just did, Bob, and my water flag cleared. …No, it didn’t. Not yet.”
“Yeah, it’s (the flow) probably still coming up.”
“Okay, Jack, just be careful of the cables.” This is something that we never could remind each other about too often.
“Okay, you want me to get a UHT, huh?”
“It’s right over there by the [Station],” Cernan offered.
“Yeah, I know where it is…”
“If it’s quite close, but if it’s not, don’t bother,” Parker said, trying to be helpful. “I think we can probably try this by hand.”
“No, it’s there, Bob; he’ll get it.” Cernan then looked at his Cuff Checklist for closing out the EVA. “You got a (parking) heading for me at the Rover (meant the LM)? Is 017 good?”
“018. 018,” Parker said, gilding the lily.
“You don’t want me to kick the LEAM yet, huh?” I then jokingly asked Mission Control.”
“Negative,” Parker replied so seriously that I knew he had forgotten the times I accidentally had kicked the LEAM during training.
“Okay, Bob, I’ve got a UHT.”
“Okay, when you go back to the LSG, Jack, we first of all would like a reading on where the bubble is in the circle– whether it’s in the center. And what we’re going to have to have, unfortunately, is to have the bubble centered in the inner circle, …because this is, apparently, a requirement, even though we didn’t train to it. Apparently it’s something that’s come up, and it’s going to have to be within the inner circle of the bubble (indicator target). So, the first thing we need to do is, when you go up there, is to see whether the bubble is in the center of the circle.”
“Okay, Bob. …That bubble is centered!” I did not have to re-center it at all.”
“Okay, the next thing we want you to do is put the UHT in the socket there, and move the LSG from side to side. …Do not pick it up.”
“Okay, go ahead, Jack.”
“I did not have to touch it, it (the bubble) is centered.”
“Okay, but now they’re worried that it’s (the bubble) stuck like your gimbal thing (sticky bubble) was last night [on the Central Station antenna].” In the latter case, however, surface tension held the bubble to the outside edge of the level dome. Surface tension clearly was not a problem if the bubble had centered. “And, also,” Parker continued, “the thing is that maybe something’s hung up inside and, by moving it, we can jostle it free. They do not want it picked up, but they’d like to have UHT put in there and sort of have the instrument rocked from side to side to again see the bubble move. And once that is done, to then press it down into the ground and again re-align it and put the bubble within the inner circle. Over. …They would also like to see if the gimbal is free,” he added.
[The Experimenters would have tended to believe that I had not deployed the LSG properly rather than wondering, at this point, if the instrument had a problem.]
“How much do you want me to rock it? How far should I let the bubble travel?”
“Basically, we just want to see it move. [If] you go out to the outer circle, that’s plenty. And, again, you [need to re-level].”
“There’s only one circle. Okay?”
“Oh, I mean the outer rim of it.”
“Okay, I did that. It’s (the bubble) still centered and gimbal (balance beam) is swinging.” I could see the balance beam through the clear top of the LSG box.
“Okay, we copy the gimbal is swinging and we copy you moved the bubble out to the edge of the bubble level and come back into the inner circle.”
“That’s right…” I waited to see if they had any other ideas.
“Okay, Bob,” Cernan interjected, breathing hard because of leaning across his seat to make the readings, “I’m reading 089 (bearing), 20.1 (distance), 002 (range), 92 [and] 88 (amps). Volts are 65 and 66. Batteries are 114 and 138 (degrees). Rear motors are off-scale low. Forward left is off-scale low and right is 210 degrees.” The relatively simple Rover navigation system had done remarkably well in closing the traverse loop for EVA-2. The Rover thought the SEP transmitter was between 150 and 250 m away when it actually stood 150 m to the east. The bearing to the SEP should have been 080, so that 9º error was significant.
“What’s the first battery temperature there, Gene?”
“First battery temperature is 114.”
“Okay, Jack,” Parker said as he returned to the LSG problem. “They apparently don’t believe you when you said you aligned it last night, and they’re concerned the [sun]shade is not on 20 degrees.” The sunshade orientation to 20 degrees to the south compensated for our north latitude of about the same amount and would keep the sun from entering the radiative cooling port on the top of the instrument box.
“It’s (the sunshade) on 20, Bob.”
“Okay. Okay; in that case, I guess you’re free to come home.”
“Well, what is basically the problem with it (the LSG)?” Being kept in the dark on this prevented me from possibly suggesting a cause or a solution.
“They haven’t been able to level it for some reason, and they were afraid that the thing (entire experiment box) wasn’t level. They were hoping also maybe by moving it that you might jostle it a bit and it would come to level, but I think we’ll just have to think about it some more. Their first presumption – the easiest solution – was to have it unleveled, which case we could fix it this way. But I guess that’s not the case. We’ll have to see what happens overnight. Give us a chance to follow the tradition of coming back to the ALSEP tomorrow.”
“Well, do you want me to change its level a little bit? …Put it off level a little and see if you can work it?”
[This idea might have made sense if anyone had realized that the problem with the balance beam consisted of a gram (~2%) design error in its sensor mass weights. Biasing the leveling on one side of the fulcrum might have compensated for that error. They could adjust the balance beam remotely for only about 1.5% in accuracy. In the time we had left on the Moon, however, no one could admit that there might be an error in design or manufacturing— an error that could have been discovered by an appropriate test on an incline plane long before launch (see Chapter 4).]
“I don’t think so, Jack. That doesn’t sound very good to me.”
“Well, it might be some error in the level bubble or something.” I unknowingly came close to the actual problem with this statement. The three or four minutes I spent on this visit to the LSG seemed like three or four tens of minutes.
“Why don’t you just leave it there if it’s centered with the level bubble within the inner circle there. That’s the requirements as far as we can tell, and we’ll just have to leave it overnight again. And why don’t you come on back to the LM. …Okay, Gene, are you at the Rover?”
“Yes, sir. I’m parked. …Gave you my readings.”
“Okay. You gave me your readings,” Parker mused out loud, and then said, “And when you get done, let me know, because the first thing we want to do is work on the SEP [receiver] a little bit.”
“Okay. Stand by. …[You’ve] got TV. …Okay. What do you want to do to the SEP?” Cernan asked, as he went on with his dusting of the battery covers.
“Okay, Geno. When you go back to the SEP now— and let’s do this first and get it out of the way— you can probably do this anyway while Jack’s coming home. When you open the blankets, remember that at the back of the SEP there was a piece of Velcro on the case and a piece of Velcro just inside the rear hinge on the covers, and this is what you sort of peel back when you go to remove the back end there so you can get the DSEA out? You remember that piece of tape there?”
“Yeah. That [Velcro tape] came off,” I volunteered as I skied back to Challenger.
“That came off.” I had reported this at the end of EVA-1 and as we left Station 4.
“Okay. This is on the side away from you as you stand facing it. Right?” Parker asked, either ignoring me or not believing what I had reported.
“Oh, no,” I responded. “That’s the side [toward the rear as we face the SEP]… Go ahead, Gene, I’m sorry.” Cernan was at the Rover and could deal with the details better than I, but it appears that the engineering drawings Parker looked at did not show this particular Velcro tape latch.
“Okay, go ahead,” Cernan said as he moved into position facing the SEP on the back of the Rover.
“Gene, if you stand facing it (the SEP), in the back – away from you – there’s a strip of Velcro on the case and there’s another strip of Velcro on the blanket itself and this is the Velcro you have to tear off or to unhook, as it were, when you come to tear the blankets down to get the DSEA off. Remember that piece?”
“Yeah, but that’s on the side away from me. I’m on the LMP’s side and that’s on the other side.”
“Right. That’s on the other side of the top. And what we’re interested in, number one, is that piece of Velcro still mated? Or when you open the blankets to cool it, does that Velcro come open? Over.”
“Well, that’s the Velcro that’s so full of dust it comes open, Bob.” It seems that Cernan and Parker are not talking about the same piece of Velcro, but the communication here is not precise. Cernan appears to be talking about the Velcro straps that hold the covers open so that the mirror will radiate and cool the SEP and Parker is referring to the Velcro that holds the back of the SEP containment bag closed. We will open the bag when we remove the recording tape at the end of EVA-3.”
“Okay, and so what happens…”
“[I’m] trying to say,” Cernan interrupted, “it’s (the Velcro) hooked; it’ll stay [open]. …I don’t know if you can see that [on the TV] but it’s… Well, you can’t [because of the] back seat. …Bob, I swung the covers and they will stay open about 150 degrees…
“Stand by a minute.” Parker is confused, as they have been talking about different pieces of Velcro. “What you’re saying is that the cover actually stands up a little bit in space.”
“Now, if you want the cover open, I can open it and normally it should swing 180 degrees, [that is,] parallel with the top of the SEP. …Well, the Velcro holds – [that is] the way that we’ve been opening it, it holds.
“Okay, but does that Velcro in back [of the cover] stay mated?’
“Yes, it’s being mated and probably it holds the covers open 150 degrees!” The miscommunication has started to annoy Cernan.
“No. That’s okay. What the concern originally was— was that when this happened, the sunlight was getting down in the back there and warming up the back of the SEP. That’s apparently not the case. Over.”
“No, that’s not the case. The Velcro that came off is the Velcro that keeps the covers closed.” We had been trying to tell Mission Control that the heating problem related to the cover not being held closed and the mirror getting dirty, but someone had trouble picking up on these facts. There also may have been a design flaw that made the SEP too sensitive to heat or the cooling mirror too small for the heat loads it had to reject. The designers may have forgotten to account for a perpetually dirty mirror.
“Okay. We were concerned about both pieces of Velcro since the one had come off.”
“No. The other one is still on and it still holds and the back part of the SEP – where the DSEA is – is in the shade.” Cernan took the opportunity to dust the SEP cover and mirror.
“Okay. I copy that. Okay. While we’re talking about this – and I’ll get back with you – turn the DSEA and the receiver both to OFF, please. ….And read me a temperature, please.”
“Copy that. And I mark them both OFF, right?”
“Yes,” Cernan said, shortly. “Bob, I just dusted it as clean as it’ll get.”
“Hey, Bob,” I called.
“I cheated on you.”
“I was sure you would. What’d you do?”
“I just sampled the glass in the bottom of a crater. I documented it by shooting the LM across the crater at infinity and then shooting the crater with stereo at 11 feet and then a cross-Sun [stereo] pair at 7; and then I sampled it (AS17-145-22185-89).”
Fig. 11.144. The glass-coated rock sample 70019 which I picked up is marked by the white arrowhead in a crater ~3 m in diameter. The LM is ~119 m directly ahead, but out of the view because I am pointing the camera down into the crater. (NASA photo AS17-145-22187).
“Then I took a cross-Sun [stereo] pair at 7 [foot focus] ‘after’ (AS17-145-22190-91).”
Fig. 11.145. Lunar Receiving Laboratory photographs of sample 70019. The shiny glass that holds fragments of very fine-grained, gray regolith breccia together is difficult to see in these original lab photos. However, the glass is very apparent in the recent lab photos of Fig. 11.146. (NASA Photos S73-15332 and S73-15334).
“I guess now ‘gnomon is a LM’.” Parker stole a pun I had used occasionally in training, that is, “gnomon is not an island”, playing on a famous line by English poet John Donne, “No Man Is An Island” contained in his poem, Devotions Upon Emergent Occasions: Meditation XVII.
“It’s (the glass sample) very fragile. …It’s very fragile, and I double bagged it. I don’t know whether we can keep it [intact] or not.” I never reported a number for the outside bag, but the sample is one to which the Lunar Receiving Laboratory gave number 70019 (Fig. 11.145).
Fig. 11.146. Recent photographs (01/19/2016) of the major remaining pieces of rock sample 70019 at the Lunar Receiving Laboratory. (top): The largest pieces are from the ends of the rock seen in Fig. 11.145↑ (bottom): The right half of the largest piece at left in the top photo is enlarged to show the vitreous nature of the glass coating. (Editor photos WE3854, WE3890).
[Our understanding of lunar history in 1972 left some question about when the Moon lost its global magnetic field as well as whether impacts generated local magnetic fields. Glass in the bottom of fresh craters had been observed on other missions and an oriented sample of such glass, whose included iron particles had cooled through the Curie Point (770ºC for iron), might give at least one point of reference. It would have recorded any field present at the time of impact. Getting this sample was my idea; however, I do not recall much early enthusiasm from the sample analysts who had measured remnant magnetism in other rocks. I had concluded that this sample would provide an important data point and obviously manipulated the timeline a bit to obtain and protect it.
Sample 70019 consists a regolith breccia fragment in a shiny, black glass matrix. The Field Geology team’s write-up on 70019 does not refer to documentation of its orientation and location, instead stating that the location is unknown. Later cataloging by the Lunar and Planetary Institute recognized only that the sample had been “collected from the bottom of a 3 m crater near the Apollo 17 lunar module”. One early effort to use this impact glass to measure the lunar magnetic field intensity did not take advantage of the before and after photographs to determine the sample’s in situ orientation. This study confined itself to magnetic hysteresis measurements that reflected the concentration of iron metal in the sample. Examination of the high quality before, after and down-Sun stereo pairs, combined with the images of the sample taken in the Lunar Receiving Laboratory, indicates that it would be possible to orient this sample in three dimensions relative to its position as it cooled. This orientation work has been completed by my colleagues Ron Wells and Ben Weiss (Chapter 13). Later, it was determined that no paleofield is recorded in the glass, indicating that currently there is no global magnetic field. However, the close-range photogrammetry techniques used to determine the in situ orientation of the rock, without a gnomon being present, proved very useful to other paleomagnetism measurements. They can also be used by future astronauts in documenting sample sites and other local features of interest (Fig. 11.147).]
Fig. 11.147. Digital surface models of the rock sample 70019 crater computed from 4 of the 6 stereo photos I took of the crater. 15 million points in the photos were triangulated by automatic feature-based and dense image matching between the photos. Each point of this “point cloud” has an X,Y,Z value in Cartesian space as well as an RGB value. The data can be assembled into a “photorealistic” model of the site as seen in the upper view. By assigning color codes to the high (red) through low (blue) points of the model, the same data can be displayed as a topography elevation map (bottom). The latter is particularly useful in showing the circular nature of the crater. (Courtesy of Lee Dechanel).
I am not sure where I got bags for this sample unless I carried the sample in the tongs back to the Rover and used bags from under my seat to protect it. As noted earlier, my bracket for carrying bags under my RCU had failed at Station 3.
“Okay. We’ll hope.”
“You may [want to] think about how to preserve it. …While you’re thinking, I’ll put it on my (Rover) floor pan, I guess.” I did not want to mix the glass sample with other samples until people thought about how to keep it from being crushed. “Okay… What do I have to do here?” I asked myself, looking at the Cuff Checklist.
“Get this bag (SCB) off me to start,” Cernan requested.
“Get that bag off you to start with.” I repeated as if I had not heard him. I often did this to lighten the moment. “Be careful of that sample there [on the floor pan]…”
“Those are the cleanest battery covers in existence on a Rover right now, I tell you. …Oh, you don’t believe me,” Cernan added, seeing the TV camera pan down to look at the cover. “Look at that!”
“What?” I responded, not knowing what he was talking about.
“They don’t believe me.”
“Excuse me. Move forward just a little. And I’ll get your bag [off]. Here you go,” I said as Cernan’s SCB almost came loose but then stuck on a hook.
Noticing the TV still pointed down, Cernan kidded Fendell, saying, “Now you’re stuck down there, aren’t you? …No you’re not. Seems like you [would assume] I may be going nuts talking to that moving machine (the TV) over there…”
“Boy, we don’t need any [more PLSS SCB] hooks; I’ll tell you,” I said as the SCB remained stuck.
“I know it.”
“Can you stoop just a little bit?” I requested.
“Yeah, all that stuff [like hooks] is getting [too dusty]. There [you go].”
“[Now, I have to] get your hooks back [in place].”
“Yeah, hook my harness back up so we don’t forget that.”
“[PLSS’s] Velcro’s closed. Okay.” At this point I moved to the Gate at the back of the Rover
“You know,” Cernan randomly notes, “[as] you look at those little sparklies in the soil we’re walking on and they change colors on you.”
“Greens to purples.”
“Iridescent. …Iridescent sparklies,” I said, coining a term.
“Okay. I’ll come over, and I’ll unload your stuff (SCB with samples).”
“Okay. Now, we’ve got more samples than we’ve got sense, I think. Let’s see here (consulting my checklist), you’re taking care of the SEP.”
“Hey, Bob; the covers are open on the SEP,” reported Cernan.
“Hey, Bob, you think that glass sample would be better off in the SRC?” I remained concerned that this oriented glass sample would not survive handling on its way to the Lunar Receiving Laboratory.
“We’re still talking about that,” replied Parker.
“Wait a minute,” requested Cernan as I started to move away before he had taken my SCB off the PLSS. “Your core cap assembly is empty,” he noted and gave it a toss to the west. “Up and away it goes! …And that’s all closed. Let me check your bag (SCB). …Okay. Now, Bob, you’ve got to tell us which one of these (SCBs) you want in the SRC (rock box) and which one you want just taken in because we got our numbers all confused, …Got it, [Jack],” he said as the SCB came off.
“What we would like to do here,” Parker began, “on the close-out, guys. Let me read this to you first of all. In the SRC, we’d like the following stuff along with… Let’s see. …Stand by…” Parker realized this would get complicated. Again, he should have asked us to tell him when we were ready to listen.
“Is this (SCB) 9 or 6?” Cernan asked me. Actually, my SCB was number 4 and contained all the Station 4 (Shorty) samples with volcanic gases still on or in them, but we did not realize that at the time.
“Okay, guys,” Parker started again. “We’re going to follow an Apollo 16 mode and put stuff in [the SRC] loose, because they’d like to segregate stuff in the following way: We’d like to put the long can and four core tubes (Stations 3 and 4) in the SRC. I guess it’s going to take a while just carrying stuff back and forth [between the Rover and the MESA]. But they’d probably like to get this in because of the [possible] volatile stuff. They’d like to get the long can and ‘three’ core tubes in the SRC; [that’s priority] number 1.” Parker has realized that one of the four core tubes is sealed in the long can. “And then we’d like to get all the SCB-4 samples in the same SRC. Over.”
“Oh, wait a minute. Wait a minute,” I said to Cernan as he started to take SCB-5 to the Landing Pad below the ladder. He stopped and left it on the Rover seat.
“Yeah,” Cernan replied to Parker. “You want…three [core tubes] plus the long can; that’s four cores all together.”
“Right. Put those in the SRC…”
“All samples from [SCB] 4.”
“All the samples from SCB-4,” Parker repeated.
I lifted my Rover seat to get the core tubes and long can. “These are [from Stations 3 and] 4. You want to get the core tubes in [the SRC] first, though.”
“Yeah. I want to put these in [first]. If you’d give me the [one core tube]. …Yeah, I only got two hands. I’ll come back [to the Rover] by the time you dig them out.” Cernan went to the MESA where he had uncovered and opened the SRC.
“Okay, and then, Seventeen, do you guys remember where the [Station 4] trench samples – the three trench soil samples – which bag (SCB) those were put in? [The ones] from Station 4? Over.” These are the samples of the orange soil and the light-gray regolith from either end of the trench.
“Yeah, let’s see,” Cernan thought. “I’m the only one who had [sample] bags, so I bagged them and put them in whatever bag Jack had, I think.”
“Yeah,” I agreed. “The samples would be in SCB 4, the same as the core tubes and long can.” The last phrase of my statement was wrong, as the core tubes and long can were under my Rover seat.
“Okay, then that’ll be SCB-4,” confirmed Parker. “So we’d like those [to stay] in SCB-4. …Those are the ones that will go in the rock box (SRC) and that’s in agreement with what we want to do.”
“Okay, give me those other two cores, if you’ve got them, Jack.”
“Okay,” I said, bringing him one core at a time.
“Long can [next]…”
“The long can,” I repeated. “Here’s a [long can]. …Oh. Got it? It’s slippery.”
“Yeah, and we need one more core [tube].”
“One more core.”
“That right, now? Three core tubes and a long can?”
“Yep, got them all,” Cernan confirmed.
Parker, again: “…And then [dump in] all the samples in SCB-4. We won’t bother to try and sort them out, and then beyond that we’ll fill them up with samples from SCB-5. Over.”
I already had SCB-5 on its way to the MESA and Cernan asked, “Which one’s that? That’s 5. Let me get 4, first.”
“Here, hold this (SCB-5),” I told him. “I’ll get it (SCB-4).”
“Well, it’s on the gate right there,” Cernan said, “just hanging [loosely]. I just put it there [after taking it off your PLSS]…”
“Four is the one I had on there at Shorty?” I queried, trying to keep the numbers straight in my tired mind. “Or you had on at Shorty?”
“Well, you had it on. I don’t know [for sure], but they should have that logged. I don’t remember who had it on.”
“Well, now wait a minute,” I said. “I took the trench [samples]. You held the bags.”
“And I put them in you,” continued Cernan.
“You put them on me. Did I have 4 on at Shorty?” I finally asked Parker, after working up to the right answer.
“That’s what they said,” I then remembered hearing a few minutes earlier. I must have been tired.
“That’s affirm,” Parker confirmed, again. “That’s why we want SCB-4 dumped into the thing (the SRC). But it’s a dirty bag, so we just want to dump the samples in.”
“…and you want 5 to fill it up? …Okay, Bob…?”
“Okay,” Parker finally answered. “And, Jack, it probably would protect the [impact] glass a bit better if you put it in the SRC gently with the other rocks there. Particularly if you don’t fill the SRC too full. But, again, we’ll be putting SCB-5 samples in there to more or less flesh it out if there’s not too many SCB-4 samples.”
For some reason, I dumped all the SCB-5 Rover samples on my Rover foot pan. These included one partially bagged rock (72255) from the Station 2 boulder that I put back in the SCB. Then I called to Cernan, “Leave a space for a sample, I guess, Gene,” referring to the oriented impact glass sample.
“Well, you’d better give it to me. There’s not much space. It’s going fast.”
“You’re really [filling up]? …Well, can you leave one [space]?”
“Where is the sample?” Cernan asked.
“Well, it’s over here [under my seat].”
“I’ll get it.”
“No, I’ll bring it to you,” I tell him. “I just [worry about it]. …Is there some way to [protect it]?”
“Just set it in there. …I’ll set it (the sample) [in carefully]. I’ll be delicate with it. Take this bag (SCB-4) back.”
Okay.” Then I say to Parker, “It’s (the glass sample) in the right-hand back corner of the SRC.”
“Okay. Copy that”
“You’re just about full [in the SRC],” I said to Cernan. “You got some [samples] left in there (SCB-5)?”
“I’ll get some small ones and some big ones, too.
“Don’t fill it too full,” I recommended as I take SCB-4 back to the Rover for EVA-3.
“No, [I won’t], …Hey, we got some big rock samples.”
“Okay, Bob,” I said to Parker as I arrived at the Rover. “SCB-6 and SC[B-4 are back on the Rover]… Wait a minute. What’s [this] in [SCB] 6?”
“Six? Probably nothing. But tell us…”
“Well, there’s samples in 6.”
“Okay. You should also have SCB-8 under your seat with samples in it,” Parker noted.
Then I remembered. “This (SCB-6) is what I sampled [with] at [Station 3]. Six has the samples from…
“At Station 3, maybe.”
“Yes.” The folks at the EVA Console apparently had missed their notes on Station 3 and my sampling there.
“Okay. Let’s take up SCB-8 [into the LM]…”
Hearing this dialog, Cernan interjected, “We have more samples today than Carter…” He did not finish, but the rest of the expression of the time was “…has Little Liver Pills.” Carter Little Liver Pills were a popular patent medicine (laxative) in the post-WWII period.
“And let’s take up SCB-6 [into the LM],” Parker continued, “and why don’t you dump out the Rover samples into SCB-6?”
“Well, one reason not to take 6 is I don’t know if I can get it off (the Rover)!” Dust had jammed the SCB hooks on the Gate, but I finally worked it off the Gate.
“Okay. And let’s save SCB-4 because I think you may need that tomorrow.
“Four is on the rack, empty,” I informed Parker.
“Okay. How about SCB-5? Is that only partially emptied, or is it totally emptied?”
“No, it’s about half full, Bob,” Cernan replied from the MESA. I had put the samples I had dumped out back in SCB 5.
“Okay. We’ll take that [SCB) up with us.”
“Bob, I’ve already [put the SCB-6 samples into SCB-8],” I told Parker. “…Let me tell you what I’ve done. I’ve got SCB-8 full. …Let’s take it up [into the LM].”
“Roger, on that.”
“It’s [also] got Rover samples in it, …but I can’t get them all. …They won’t all be in there.”
“Okay; [they’re in] 8.”
As Cernan closed and latched the rock box, he said, “Bob, the seal [on the SRC] was clean. It was clear [of dust], and I got your four cores…[that is,] three cores, plus a long can. I got Jack’s glass. I got SCB-4 and a couple of samples out of SCB-5. …Okay. Now where was I? You got me all out of whack, here…” Looking at his Cuff Checklist, he read, “ ‘Core cap dispenser.’ Okay, your [PLSS is clean, [and the] Cosmic Ray [shade] is done.” I had deployed the Cosmic Ray Experiment shade on EVA-1. “SCB-5… Yeah, okay. Now, Jack, we’ve got SCB-5 that’s half full. What have you got over there?”
“Bring it over here, and I’ll put it (the SCB-5 samples) into 6. Six is a little more than half full.”
“Well, this is a little less than half full. Okay. …That ought to make one full bag. And these are big rocks so they’ll come out [of the SCB] easy. Where’s that big, big rock we got? That’s in one of those bags, too. Picked up a big rock [at Station 2].” Cernan probably is referring to 72255, the large sample I we took off Boulder 1 at Station 2. “Here let me see if I can’t dump it (SCB 5) [into 6]. …How’s that for a lunar dump? Huh?”
Moving to the back of the Rover, Cernan said, “I want to see if I can’t dust [the bag latches on the Gate]. …Did you lock this one [SCB] over here? …No, [I guess not].”
“Hey, don’t lock those! [We may never get them off].”
“No, I’m going to see if I can dust them and make them work easier.”
“Boy, I’ll tell you. …I really had to pull [to get SCB-6 off]. I pulled harder than I like to in a pressure suit.” My concern was that I might apply more stress to the bladder in the gloves than it could take. The pressure suit greatly reduced one’s sensitivity as to how much force you were applying in any given task.
“See if I can [help some],” Cernan replied.
“Okay, Bob. SCB-8 and 6 are going up,” I said as I closed the SCB covers. “…Or will go up.”
“Okay, and I understand 5 will be on the gate,” stated Parker.
“Yes, sir, Bob. It’ll be there,” confirmed Cernan.
“And 7 under the LMP’s seat,” I added, as I lifted SCB-6 and 8 off my seat and started to carry them to the front footpad of the Challenger.
“4 and 5 will be on the gate,” Cernan continued, for completeness. “You know, here’s a problem for you [to work on] tonight. You got any way of freeing up these gate hinges that lock the bags on? I’m dusting them, but they’re not going to lock, any of them. They’re frozen tight, just about.”
“Okay. Copy that. We’ll talk about it.”
“If you do get them locked, you may never get them off.” Also, if they did not lock, we might lose them on the drive to the North Massif on EVA-3.”
“Okay. We’ll give them something to work on overnight.” Unlike other problems, we received no suggestions on how to clean the locks. In fairness, I cannot think of anything we could do with what we had available, and even if there were, they would quickly get dusty, again.
“Okay, I’m dusting them right now,” reported Cernan, “but I still can’t free them up.
[This problem with exposed hinges and clips will be a continuing problem on the Moon and possibly on Mars, unless some means is devised for rejecting dust or removing it. Conceivably, negative charges on hinges and clips and/or air jets would help.]
“Man, those are heavy bags (SCBs),” I commented. Even in 1/6 g, I could notice the weight of the bags.
“Jack, have you got the top of the bag closed?” Parker asked, as I returned to the Rover.
“Yeah, what do you need [to put in them]?”
“Okay. No. John (Young) thought maybe they were still open. He was worried.” Young had seen one of the SCB covers flapping as I went to the footpad.
“Oh, no, I latched them [at the footpad]. I’ll check them again before I go up.”
“Okay, and we got no FSRs (football-sized rocks) underneath the seat, we understand. Roger,” Parker said, rhetorically.
“No,” I answered. “I just checked and they’re (the samples) all in the bags. …And the Rover sample bag (SCB) is empty.” Meanwhile, I took the EVA maps off the Rover Console and put them under my seat to keep them from being in direct sunlight. “No, nothing left,” I said, as I took the Rover SCB off the accessory staff and opened it for TV inspection.
“Bob, neither one of these bag latches are going to latch on the back. I dusted them, but they’re not going to work. I can’t free them up…”
“Okay, we’ll talk about it tonight…”
“We’ll use the seat [for SCB stowage],” I stated.
“Don’t worry about it now,” replied Parker.
“Yeah, we can probably use the seat,” Cernan agreed. “We’ve got a little more room than we had [before]. Okay. Let me get something else done.”
As I took a pack of new sample bags from under my seat, I thought out loud: “I wonder if I ought to take a sample bag holder up there (into the LM) to see if I can fix that [problem]— to see if it ‘fixes’.” I took the bag packet off the broken holder.
“Roger, Jack. I’d suggest that,” Parker broke in to my musings.
“Probably ought to, huh?” My being able to carry sample bags on EVA-3 would increase our sampling flexibility and efficiency, so I put the broken holder in the shin pocket of my suit and returned the sample bag packet to under my seat.
“…[The SEP] receiver’s been dusted and blankets are open,” Cernan began to finish up the EVA-2 Close-out portion of his Checklist. “[SEP] POWER is OFF and OFF. …Okay. I’m going to take the TGE off [the Rover] now – or dust it and then take it off – and then just leave it there [in the shade of the Challenger]. …Hey, congratulate Jose (John Young) on that fender will you? Because I think he just saved us an awful lot of problems. He and whoever else worked on it.” “Whoever else” turned out to be Terry Neal and a number of other support personnel.
“He mumbled something very humbly about ‘a thousand guys’,” replied Parker.
“Well, tell him that’s going to be my ‘bring home’ present to him: a picture of his fender.” Actually, we brought the entire substitute fender home, and it now resides in the Smithsonian National Air and Space Museum.
“Okay, Bob,” I said. “ ‘Unused Gear’ – which you have an inventory on – is under the LMP’s seat. …Okay. Where am I [in the Checklist]?”
“I’m bringing the TGE over here [to the ladder],” Cernan commented. “but, I’m not pushing it [ON] yet.”
“Cosmic Ray’s deployed!” I exclaimed, as I read this item in the Checklist and call attention to having given my Swiss colleague, Johannes Geiss, an extra day of solar wind and cosmic ray collection. “Man, I got the sorest hands in the world, right now.”
“How about on the Moon?” Parker never forgot his Caltech training to point out irrelevant technicalities.
“Bum, bum, bum, baa,” I sort of sang as I headed back to the Rover with the ETB (Equipment Transfer Bag) that had been hanging by the ladder. “I just can’t compete with you astronomers,” I said as a rejoinder to Parkers comment.
“Just keep trying,” continued Parker.
“Nothing’s in the big bag, is it?” Cernan asked.
“Nothing’s in the big bag, I replied. …Unless there’s one rock in there that disappeared yesterday. I don’t know what happened to it. …Hey, we forgot the polarizing filter work!” I noticed this camera filter under my seat and thought about it for the first time during the EVA.
“Nah, I saw it on the checklist,” Cernan said, joining me at the Rover, “and I mentioned it to Bob, and he didn’t come back with anything. And there was a [a lot to do at Shorty]…” The original plan for Station 4 included taking black and white photographs of the crater with the polarizing filter on my camera. “Okay. I guess I’m going to go ahead and…”
“Put those [unused packets of sample bags] under that (LMP) seat, please,” I requested.
“Yeah, there’s only one left.”
“One? No, there’s three or four…”
“There’s three left,” he confirmed.
“Just put them under there. Who knows, we may need them at the rate we’re going.”
“[I still have to] pull those [Rover circuit] breakers,” Cernan noted. We were jumping around doing those things that needed to be done and then verifying that we did everything by looking at the Checklist and occasionally checking with Mission Control. We had rehearsed so much, that we generally knew everything that had to be done and one or the other would notice anything that had been missed.
“And, Jack, while you’re unloading there,” Parker interjected, “on the 500 millimeter, you might squeeze off a few shots of the North and South Massif there, if there’s any lineations visible.”
“Okay. I’ll give it a try. Why, are we ahead of time?” I was really thinking that we had left Shorty sooner than necessary.
“No, we’re working right on time.”
“Why don’t you give it (the 500 mm camera) to me while you’re packing the ETB, Jack; I’ll do it.”
“Am I behind you, now [in the Checklist]?” I queried.
“Yeah, I’m going to start inventorying the Rover and pulling the breakers so [give me the 500 mm]…”
“Man, we are so far off nominal on what bags (SCBs) [we’ve used],” I commented with a laugh. “I sort of didn’t think [we would change the order]. The [EVA-3] checklist is going to have to be updated, I guess.”
“Totally,” agreed Parker.
“Oh, I should call [and tell Houston what is going in the ETB]. …Mag Charlie, …Mag Kilo, …Mag Bravo, …Mag Golf, …Mag India.” Without saying so, I must have put both the Hasselblads in the ETB.
“Copy all those,” Parker reported. “And tell Gene that we can confirm [from TV] that his lens cover’s off.” Another Parker dig, as remembering the lens cover tended to be a problem at times. Photographs AS17-144-22080-104 provide Cernan’s extensive 500 mm coverage of the South Massif. AS17-144-22105-32 cover the North Massif and the west-facing slope of the Sculptured Hills in Wessex Cleft.
Fig. 11.148a,b. Cernan’s 500 mm East Massif panorama, split in half, taken at the LM at the close-out of EVA-2. (a): The western part of the pan shows the boulders more clearly here. (b): Eastern half of the split pan. Gene actually made 2 pans— one starting right-to-left as shown here, and the other vice-versa. (NASA photos AS17-144-22093 to -103).
Fig. 11.149a,b. Cernan’s North Massif panorama taken at the LM at the close-out of EVA-2. It has been split in half to fit this column. (a): Eastern part of the N. Massif with the Wessex Cleft and part of the Sculptured Hills at right. (b): Western part of the pan. I made the smaller inset photo at lower right at the end of the previous EVA. It continues the boulder track seen in the panorama above. The track is shown enlarged in Fig. 11.150. (Composite of NASA photos AS17-144-22120 to -131. Inset photo is AS17-144-21991).
Fig. 11.150. The part of Fig. 11.149b enlarged to show details of the boulder track that originates about a third of the distance from the crest of the massif. The slightly longer, deeper shadows of the eastern wall of the track as a result of the lower elevation of the sun on the previous day accentuate track details such as the small dot centered in the convex part of each loop caused by a protuberance at the surface in the middle of the boulder seen at bottom. Note also another boulder track at left.
[A mosaic of these 500 mm photographic sequences, combined with high-resolution images from LROC, might provide the basis for mapping trends in the source-crops of boulders. Boulder tracks certainly would aid this project as related to the North Massif; however, the images of the South Massif above Station 2, again, fail to show any boulder tracks there. It seems likely that impact induced movement of newly developed regolith, since the avalanche cleaned the slope of boulders as well as old regolith, erased any such tracks to the boulders at Station 2. In fact, there may have been so little regolith on the slope after the avalanche that no significant tracks formed. In the case of the 500 mm images of the Sculptured Hills, significant albedo contrasts could be mapped that appear to correlate with variations in abundance of source-crops. These images add emphasis to the distinctive nature of the surface physiography of the Sculptured Hills, discussed further in Chapter 12 relative to Station 8.]
“They confirm that your lens cover’s off,” I joined in the fun and as I relayed the comment to Cernan. “The scissors are in (the ETB). …Lens brushes [also]…”
“I hope this is the right setting,” Cernan said as he faced toward the East and more into the sun. “It is.”
“Hey, try f/5.6 directly down-Sun …or, up-Sun, at [the] Sculptured Hills there in the distance. …See where I mean?”
“Yeah, I’ll get it.” The Sculptured Hills would have been largely in shadow, but I wanted to get some otherwise over-exposed photographs that might pickup backscattered sunlight in the shadowed areas.
“Yeah,” agree Parker. “I think we’ve got enough of those now, Gene. …[Jack,] You got the maps?”
“Yep, got them.”
“Some of these (photos) won’t overlap, Bob, because I’m hurrying.”
“Don’t smear them,” I warned.
“They’re not smeared, but I just didn’t overlap some of them.” (The jagged nature of the bottoms of the composites in Figs. 11.148 and 11.149 resulted from the less-than-perfect overlap pattern).
“Don’t hurry and smear them,” interjected Parker who may not have heard us.
“Okay. Everyone agrees to that. Don’t hurry and smear them.” I laughed at Cernan’s apparent annoyance. “I’ll get those others (photos), Jack, tomorrow.”
“Okay. You got the maps in there, too, Jack?” Clearly, Parker is getting distracted by other people, and forgot that this had already been asked and answered. He also may have been tired.
“Yes,” I replied.
“Frame count, Bob, is…152 on the 500.”
“Let go of it (the 500 mm),” I laughed, as Cernan seemed to want to take more pictures. “There’s…dynamic [transfer],” I said as he tossed the camera to me. “Did you cycle it (the film advance) twice?”
“No; cycle it twice.” This would protect the last shot when I removed the Magazine R from the camera.”
“Do you have the maps there, Jack?” What was his problem! I ignored him this time, knowing the EVA guys had heard me answer before.
“Okay. I guess I’ll go in and pull some Rover breakers. …Oh, boy. Pulling breakers is not going to be much fun.” Cernan’s fingers were very sore. My problem consisted mostly of forearm muscle fatigue; his fingers and hands had bad abrasions.
“You want me to [try]…? You want the scissors or something [as a lever]?” A pair of pliers would have been nice as the set breakers only protruded about a centimeter.
“No. …Oh, boy. …Oh, boy.” He should have pried them out with the scissors.
“Mag Romeo,” I reported as I put the dark slide in the magazine off the 500 mm camera and put it in the ETB.
“Copy that. You got the maps, Jack?” Parker asked for the third time.
“You ask me that one more time, Parker,” with a forced laugh, “and I’m going to get mad at ya.”
“Oh, I got to [get a better grip]. …Whew! What have you got over there? You got the scissors handy?”
“Yeah, you want them?”
“I got three of four breakers. Let me try this other one more time… Okay. I got it— with the old fingers.”
“Okay. Copy that. All four of them out, Gene?”
“Yes, sir. Alpha, Bravo, Charlie, Delta are OPEN. I’ll get the LCRU power.”
“Okay. And, Gene, when you leave the (TV) camera, [this is] a reminder to face it (the camera) away from the Sun and tilt it down.”
“Okay.” Cernan stands in front of the LCRU, points the TV toward the west and down toward the LCRU, and turns off the power.
“Hey, Gene,” Parker called. “That’s not quite away from the Sun. Really it ought to be, you know, down-Sun.” It is not clear why Parker thought the camera was not pointing down-Sun, which it was. (Fig. 11.152↓, right)
“I’ll get it, Bob. …Bob, are you reading?”
“Roger. Loud and clear,” responded Parker, but we did not hear him.
“I read you, Gene,” I confirmed, however, Parker was not coming through to either of us.
“Yeah. See, I just turned LCRU power off; they got to go [with comm] through the LM.”
“That’s right,” agreed Parker, but still we did not hear him.
“Bob, do you read?” Something in the LCRU to LM communications transfer is interfering with our hearing Houston’s uplink transmissions.
“Loud and clear…”
“Is this gravimeter working?” I had taken the ETB over to Challenger’s front landing pad and wanted to be careful I did not disturb a gravity reading Cernan might have started.
“No, it’s not. I didn’t push it yet. Hello, Houston – come on… Otherwise, I’ll turn this [LCRU] power back on.”
“Read you loud and clear, Gene. Do you read Houston?” was the reply that did not come through to us.
“Well, let me turn it on and talk to them.”
“We read you loud and clear, Gene.”
“Well, I just turned the LCRU back on. Are you reading us through the LM, now?”
“Yeah, we came through the LM that time.”
“Okay. I’m turning it (the LCRU) OFF and the camera is pointed down and it’s pointed effectively to the west. Down-Sun.”
“Okay. Copy that. Very good, thank you.”
“LCRU Power’s going Off. …Okay, LCRU Power is OFF.” Cernan went back to his Checklist: “ ‘Battery covers – OPEN battery covers’. They’re all dusted already.” With the Rover parked facing east, the battery covers shaded the radiators and they radiated heat into the 4ºC temperature of deep space.
Copy that,” Parker said, then, after a pause, added, “Seventeen, [do] you read Houston?” Parker kept trying to reach us as we continued our post-EVA tasks.
“Uh-oh, I got to work on [dust on] one battery.”
“Seventeen, you read Houston? …Seventeen, you read Houston? Over…” It would appear that the LM TELEMU team had something wrong in their set-up in Mission Control and were still trying to communicate through the Rover communications link.
“Hey, Bob?” Not having heard from Parker for some time, I decided to check in.”
“Roger, Seventeen. Do you read?” We did not know it, but our downlink transmissions were getting though using relay through the Challenger. It was just the uplink that had a problem without the LCRU Power being ON.
“Still there?” I called, again.
“Well, they’re supposed to be going through the LM.”
“Seventeen, do you read Houston?” No response from us.
“Got something fouled up,” I concluded. “Maybe we got the switches wrong, or something, up there [in the cabin]. Don’t think so, though.” We had communicated fine before powering-up the LCRU early in the EVA.
“They talked to us first [at the start of the EVA].”
“Let me give them a call [again through the LCRU].”
“Seventeen, do you read Houston? Over.
“Bob, you want to try again. We’re on the LCRU! …Yeah, we read you, but I’m on the LCRU again. We’re not reading you through the LM!”
“Yeah, I don’t understand that.” TELEMU should have figured this out before we did. “Stand by. …Press on with the rest of the close-out.”
“Well, I’ll leave you on the LCRU, here. …Yeah, we’re pressing on. Okay. For the first time, I’ve got to dust the center battery cover (meant battery radiator). All the others are good.”
“Okay. Roger, Seventeen. Do you read Houston now?”
“Well, yeah, but I’m on the LCRU. I don’t know [if we are going through the LM].
“No, now they say we’re going back to the LM again. Press on with the close-out.
“Okay, Bob. I’m going to go turn the LCRU power OFF. And for the first time, I’ve got to dust the center radiator on the batteries.”
“Okay. Copy that.”
“Up until this time, they’ve all been real clean. …Okay. Give me a short count. And in the interim I’m going to turn the LCRU Power, OFF.
“Okay. Roger. 1-2-3, 3-2-1… Okay, Seventeen, do you read Houston? Over.”
“Okay. We’ve got you,” answered Cernan.
“Okay; very good.”
“Yeah. We got you, Bob.” We never learned what inhibited the transfer to receiving the uplink through the LM, but the chances are that TELEMU had one of their switches wrong in Mission Control but never owned up to it to us.
“Okay. We’ve got about two-zero (20) minutes before we have to be inside the LM there, fellows. Let’s hustle on.”
“Oh, I think we’ll just sort of take it easy, Bob,” both joking about and resenting Parker’s unnecessary comment. “Okay. The MESA’s tidied.” While Cernan and Mission Control worked on restoring our uplink communications, I had continued to go through my Checklist items for CLOSEOUT. “I’ve got the (PLSS LiOH) canisters; pins are green, …The LM [LiOH] canister’s in the pocket [on the EVA pallet]. …And, let’s see, …I think I’m ready to dust. Could I help you, [Gene]?”
“No, I’m leaving here (the Rover) right now.”
“And, Gene, as you go by, how about giving us the SEP temperature readings.” Somebody really knew how to rub salt in the SEP wounds.
“Oh, me. I will…”
“[Gene,] I got to take these bags up.”
“Seventeen, Houston. It’s awfully quiet.” More than a minute of silence was too much for Parker.
“Okay, Bob. Here’s your [SEP] reading. About one hundred and…about 1 oh 8 to 10 degrees.
“Okay. Copy that. (Pause) Okay. We’ll leave it there, as is, overnight. Thank you.”
“And I’ll give her one good little smack with the brush. And it’s as clean as it’ll ever come.”
“Jack, you might just as well go cold water. There’s no more use for it now, if you’re warm,” Cernan suggested.
“No, I’m not warm. I’m just [tired]. …Want to hand me that other SCB there?” I had climbed part way up the ladder to put the various bags on the porch.”
“Oh, man!” Cernan exclaimed as he lifted an SCB up to where I could grab it. We both laughed at how tired we were.
“Oh! The cover’s open on this one,” Cernan noted. Parker had been right when he called my attention to an open cover, earlier.
“You wonder why it’s hard to get up the ladder,” I said as I had only one hand to grasp the railing, the other occupied with the SCB.
“Don’t hold it (the SCB) by the cover,” advised Cernan.
“What do I want these tongs on for?” I asked myself as I realized the tongs still were attached to my suit.
“Give them to me. I’ll take them down.”
“Just noticed them.”
“Don’t want them [into the cabin], Okay?”
“Thank you,” I said as I untethered the tongs and handed them down.
“Don’t take it by the cover. The (SCB) cover’s going to come open. Take it by this [strap].”
“Wait a minute.”
“I got it.”
“Okay,” Cernan replied. “[You] Probably got tongs on for the same reason I’ve got them on.” We both would put tongs on the suit yo-yo attachment so that we had them if we dropped something. Then, in the press of Closeout, we forgot they were there. In this case, I had taken his when I left the Rover at the ALSEP, and he had replaced them with the extra set from the Gate.
“And, Seventeen, we’re ready for a GRAV measurement.”
“Yes, sir, Bob. Just cleaning up the Rover. Getting our tongs out of the way.” Cernan had returned to the Rover and put both sets of tongs back on the Gate in preparation for EVA-3. “And for your information, at this heading [of 017], the westernmost battery cover, like I talked about yesterday, is just starting to cover the radiators.” The Sun slowly rises about 12 degrees each 24 hours. “Oh, hum-de-dum-de-dum! You know, I think it’s another good day’s work.”
“Uh-huh,” I agreed.
Reviewing his Checklist, again, Cernan, said, “Okay. I dusted all that.”
“I just knocked [on the ladder] as hard as I could, on my feet, several times.” I informed him, as we got ready to brush our suits as free of dust as possible. I remain convinced that all this brushing did was to tire us out further without helping to keep dust out of Challenger. Future suits either should stay out of the living module or reject dust automatically or both.
“What you’re going to say is you want me to brush you, huh? Let me keep this [gravimeter] out of the way so it doesn’t get dusty. …Wonder if our bouncing around that gravimeter is going to disturb it like this [near the landing gear].”
“Shouldn’t [bother it],” I responded. Cernan had punched the TGE GRAV button to start the measurement without saying “MARK” as he usually did.
“Want me down (off the ladder for dusting)?”
“You got to do me first,” he reminded me.
“Yeah,” and I jumped off the ladder, saying, “Plink,” as I landed.
“You’re not nearly as dusty as you were yesterday; you’re just dirty, that’s all.”
“Well,” I replied, implying, “What do you expect?”
“I think I can get everything off my shoes by banging, if you’ll just get my arms. I didn’t really fall in much today, except maybe my left arm. But…”
“I tell you, [if] we saw some of the things I think we saw today, we both ‘fell in’,” I added with a laugh.
“What? I hurt you?”
“Yeah, you’re hitting.”
“Well, you’re right. Sorry,” apologizing with a laugh. I don’t have much control.” I am surprised that Cernan could feel these brushing blows through the suit.
Laughing in return, Cernan said, “I know it. That’s the way mine (his arm) feels…”
“That’s dirty. Under there [between your legs]. …I’m glad they can’t see this…”
While I completely finished tiring my arms with dusting his suit, Cernan decided to orate, again. “Oh, I stand out here and I look at that flag, and I look at the Rover, and I look at those Massifs. It’s still hard to believe.”
“What did we deserve to do, [that is,] do to deserve being out here, huh?” I added. “Okay. That’s not very good. Let me get some [dust off] your PLSS, here. Keep… Go forward just a little.”
“There you go. [I] think your sharp [Rover] turns are [throwing dust on your arms].”
“Hey, that fender is really a classic.”
“One might say it’s a ‘young’ fender. …[We] just put it on.” This pun on John Young’s name showed how prone I was to think in puns, even when very tired.
“Do we need, …do we really need those [light] clamps?”
“No,” I answered, emphatically. We were in perpetual daylight on the lunar surface, our later rendezvous with Evans would be very fast and all before we reached the western terminator, and we had flashlights, if any contingency arose.
“I can’t think of anything we need them for. That light [might] be needed, …but you can tie that light somewhere…”
“We don’t [need the clamp],” I repeated. Well…”
“I might bring one back [tomorrow].”
“Yeah. We ought to leave one in tribute…to Dr. Young.” I did not know at the time who the others were who worked on the fender fix.
“Oh, that orange soil was something.” Cernan rambled on.
“And the way it went radially down that crater. …Let me turn, and then [you] take another look, and then I’ll [do you]. …Then you get up there [on the ladder].” (Fig. 11.101↑).
“You got quite a bit [of dust] around your hoses here,” I told him.”
“Okay, and I don’t know what I can do about it, Geno.”
“Oh, just give it a swat [across the] front, too.”
“Well, I got it the best I could. Let me get the top of your LCRU there.”
“Mine’s (RCU) pretty good.
“Or, RCU,” I corrected myself.
“Yeah, mine’s good. Okay. Let me get to your front.”
“No, I didn’t get your other arm here.” For something I didn’t believe made much difference, I was spending a lot of time and energy dusting.
“I don’t know that I can.” We both were standing on the landing pad, trying to keep our boots relatively free of dust and, reaching around Cernan to get to his right arm meant I would have to step off, again.
“It’s the inside [Rover] arm. I don’t have anything on it.”
“No, that’s right. You don’t. It isn’t [dusty]. It’s about the same.
“When you fall out [of the Rover], you fall out on your other arm.” Cernan remembers falling on his left side when he fell getting on the Rover at Station 3.
“There is some on that [left] leg there. …Don’t know what I’m going to do about it. …I think we’re just going to have to make do.”
“Let me see what I can do with you,” Cernan said, taking the brush. Just look at me. …What is this rock, right here, by the pad!”
“I don’t know… I…”
Cernan interrupted me, as he swiped across the top of my RCU: “Did I just turn your comm? Do you still hear me?”
“Yeah. I’ve just been intending to mention that [rock] several times. Anybody that lands on a rock ought to have their head examined. Put their ladder [strut right on a rock],” I continued to pull his chain about a nearly perfect landing.
“Boy, where have you been again today [to get so dirty]?”
“Oh, I played some games there around Station 3. …I’m sorry.”
“Boy, oh, boy!”
“Wasn’t intentional,” I insisted.
“But [a] lot of your turns…” Now, I was going to blame Cernan for some of the dust on the right side of my suit.
“Hold your arm up. Hold your arm up.”
“Lot of your turns threw dust on me…”
“Yeah, I noticed that,” Cernan admitted with a chuckle. “God dang that rock! If I was strong enough, I’d move it. Hey, I am strong enough. That’s one we ought to bring home!”
“Well, if we can’t fill up the LM with anything else…,” I suggested in jest.
“That’s about the size of the SRC. Stand up on the pad. …Oh, shoot! First time that’s happened.” Cernan had dropped the brush.
“Here, hold on to me,” I said, as he bent down to pick up the brush.
“You know, by rights, that (dropping the dust brush) should happen more. …I want to get around back and then I want you to get up on the ladder some [for your legs]. Oh, man, let me get the back of your PLSS. What did you bump against? I guess that’s from the Rover seat.”
“I think it is.”
“No, I mean you got a couple abrasions right on through the [fabric cover]… “
“So do you. I wasn’t going to mention them.” I did not want to alarm Mission Control over this small item.
“Well, these are only a pin-hole thick, but…” Cernan may have picked up on my concern.
“All I can say is it’s (the Rover) better than walking.”
“Oh, man, I’ll tell you, we covered over 20 kilometers today, babe. How’d you like to walk up and down those hills and ditches at 20 kilometers? Okay. Can you…turn towards me? I want to get the front of your legs one time. …Come back.” I had started to move up the ladder.
“Okay. And Seventeen, Houston. How’s the dusting coming?” Clearly, Griffin wanted Parker to move us along, as everyone could hear that the dusting was underway.
“Well, we’re almost there,” Cernan answered. “I’m going to send the LMP in [the Challenger] in about a minute.”
“Man, you’ve had your day of dusting, haven’t you?” I said, sympathetically, referring to the dusting he was responsible for at each station.
“Oh, I tell you, I’ve spent more hours on the dust brush…”
“We’re getting to a point where we need… where we need to be inside in less than 10 minutes,” Parker reported, “with the thing (the cabin) closed up.”
“Yes, sir. We’re on our way, Bob.” In spite of this warning, we still had 15 minutes or more of margin. Mission Control’s guidelines were very conservative.
“[Jack,] That takes care of it. Knock your feet off, Jack. Knock your feet off on the ladder.”
“Okay.” Even with six and a half minutes of dusting, we took a lot of dust into Challenger’s cabin.
“And don’t forget the antennas, guys.”
“Okay. I need the pallet.” Earlier, I had removed the second pallet from the MESA and propped it next to the ladder where Cernan could reach it. The pallet contained food and replacement PLSS batteries and LiOH canisters,
“Oh, Bob, you’re a beauty!” Cernan replied, referring back to the call on the antennas.
“How did you think of that?” I asked.
“John suggested it.”
“John who?” I said with a laugh, knowing it was John Young.
“He strikes again. …[Jack], you’d [have] broke yours off [for] sure, because I wouldn’t have seen it as you went up, …unless I took inventory with my book (Checklist), which I’ll do here in a minute. ‘Open Battery Covers’ – taken care of; dusted LCRU; blankets open 100 percent. They’ve been open 100 percent all day.
“Okay,” I said as I leaned over from the bottom rung of the ladder so he could stow my PLSS antenna.
“If I can just get up here,” Cernan said to himself as he worked on the top of my PLSS.
Then I started to stow his antenna. “Oh, shoot. I forgot a snap up there,” also talking to myself.
“Now, let’s make sure we got all of those [snaps]. I don’t want to get hung up on anything.”
“Yeah. I mean I forgot to put the antenna under the snap…under the other thing…”
“Wait a minute, get the snap… Okay. [Did you] get it?”
“Okay. You’re set.”
“Okay. Go on up, Jack, and I’m going to read the gravimeter.”
“I need that pallet before I go.”
“Okay, and, Gene, we don’t think you’ve punched the Grav reading yet,” Parker said, responding to someone’s note.
“Yes, I did, Bob. I’m going to read it for you in a minute. …The reading is 670, 023, 501; that’s 670, 023, 501.
“Okay. We got that. Go to STANDBY. Open the cover and dust the TGE radiator if it needs it. Or dust the radiator, period.”
“It’s dusted already; I took care of that. And I’m in STANDBY.”
“Okay. Copy that.”
“Okay. Final check,” Cernan said, referring to his Cuff Checklist. “ ‘LRV: [LCRU] Blankets – OPEN 100 [percent]; Battery Covers – OPEN’; Samples off.’ We checked under both seats. ‘Equipment stowed’. Okay. You’re all clean to go in. Okay. ‘Dust SEP [Receiver], Blankets A and B OPEN, verify Power – OFF; Recorder – OFF. TGE’ – that’s read; that’s dusted. ‘Tidy the MESA blankets’. They’re okay. …Okay, and I’ve got this [rock] box to bring up when I go. Okay, let’s see.” He had been standing in Challenger’s shadow during these checks but then moved into the Sun. “Oh, man, that’s bright! ‘…Stow PLSS antenna [done]; Brush to ladder hook; EVA Pallet  to LMP’. You got it (the Pallet). The [LiOH] pins are green; and [TGE] reading [done and in] STANDBY; ‘Open TGE thermal cover lid and dust.’ That’s done. Final check: we got the Pallet; ETB is on the hook (he means lanyard); [and] you inventoried the ‘S-IVBs’ (SCBs). Mr. Parker, and I guess you’re happy we got them all.”
“Roger.” While Cernan did the final verification that we had completed all the closeout items, I had begun to work my way through the hatch.
“SRC-2 is in my hand. The Big Bag is not required.”
“Roger that… And we’re ready to call you all ‘in’ as you go through the hatch.”
“Okay, Jack’s halfway through it now, and I’m going on up the ladder. …Oh, my; oh me!” Cernan anticipated jumping to the first rung of the ladder with one tired and sore hand holding the rock box. “How you coming?”
“Just about there,” I replied, as I again snaked my way into Challenger’s cabin while pushing the EVA Pallet ahead of me, bent backwards to clear the Ascent Engine housing, and finally stood up.
“Ohhhh! That’s a nice one-handed first step.” Cernan complimented himself and then pretended to read a note on the top rung of the ladder: “ ‘Godspeed the crew of Apollo 17’. I’m going to keep reading that. I like that message. …How’s Captain America, speaking of Apollo 17?”
“Captain America is sound asleep. Just about to come around to AOS (Acquisition of Signal). We think he’s sound asleep.”
“Hey, how does that always happen? That happened yesterday.”
“He got up before noon (Houston time) this morning, too.”
“Oh, okay,” acknowledged Cernan and then, noticing I was struggling with a release pin on the EVA Pallet, said, “Just take it easy, Jack, it’ll… Here you go…”
“Pip pin didn’t work,” I told him, as I tried to release pins that held the batteries, LiOH canisters, and food packages on the Pallet.
“Lot of things don’t work when your hands get tired; that’s the problem. …Wasn’t a bad day. How long we been out, Bob. Of course, we’re still out.”
“7 (hours) plus 27 (minutes), so far.”
“Cernan: 7 plus 27?!
“How does that grab you? …Well, we’re getting anxious to get you in and get the hatch closed.”
“Well, we understand that,” I said, annoyed at Parker’s habit of stating the obvious.
“Jack’s unloading the pallet and as soon as it comes out, I’ll shove this stuff (the SRC and the two SCBs) in, and we’ll be gone.”
“Just takes a certain amount of time,” I added.
“Okay, Gene. Are the three SCBs inside the hatch already?”
“Bob, I don’t think any of them are inside. Let’s see…”
“No,” I told him.
“I’ve got 8 here and 6 here and we emptied the contents of 4 into the SRC, and we emptied the contents of 5 into one of these other two bags. So we’ve only got two of them here, plus the SRC. … Five went into six. …And we’ve got two of them hanging on the tail of the Rover. (see LRV rear, Fig. 152↓, left, under my rake and the scoop) And I don’t know what it is under Jack’s seat right now.”
“Seven is under my seat.
“We copy that. Don’t worry about it.” Then, I wondered, “why did you ask?” This was information we had already provided, earlier.
“One more battery, Geno, and it’s (the empty pallet) yours.”
Knowing that Cernan probably was getting impatient, I told him, “You always used to stand and watch me do this, anyway.”
“Yeah, but we had some long EVAs [in training] at the Cape but…” The real world always seemed different.
“There you go,” I said, using my boot to push the empty Pallet through the hatch.”
“Okay. Just be careful of the [hatch seal]. …Let me get up there a little farther – careful of that hatch.” As he dropped the Pallet to the surface, Cernan noted, “Getting to look like a regular garbage dump down there. …Okay. Ready [for an SCB]?” he then asked, but only pushed the SCB part way across the hatch so that I had trouble grabbing it. “Sorry, babe.”
“It’s all right.”
“Now, this one’s (an SCB) going to come open if we’re not careful. Let me see if I’ve got one more step to go up. …No I think that’s the last one. I’ll just hold it here until you get it. …I could shove that in if I push it with the SRC. Jack, the cap’ll come open. Be careful. …Okay. Here’s that big silver box…”
“Can you push on that (SRC) a little bit?”
“Okay. …Okay.” I finally had both SCBs stowed temporarily on the Ascent Engine cover.
“Okay, Bob, you’ve got the two SCBs [in]. [Jack,] I’ll push it in – [the] SRC – and there goes the ETB. There’s only one thing left…”
“Copy that,” Parker said. “Now how about a CDR?
“That’s right, that’s the only thing left out here.”
“Are you on a checklist?” I joked; relaxing some as every thing was now in the cabin.
“No, I’m not even on my checklist, but I guess… Yeah, I am [on the Checklist]: it says ‘INGRESS’. Let me knock some more dust off…”
“Okay. Let me get behind the door.” I partially closed the hatch, so I could move into my corner of the cabin, and then opened the hatch as wide as possible, holding it tight against my legs.
“Well, I’m going to take what dust I got [on me] in with me… Ohhhh!” Cernan struggled to get his somewhat larger suit through the hatch.
“Push,” I told him. “There you go. …Keep your buttons close [to the floor], …You’re good. …Beautiful. Just float in. Hanging up a little on the Purse, but that’s all right. There you go…”
“Ohh!” a relieved Cernan exclaimed, standing and now facing aft.
“That’s my arm I’m getting in the way, there. Let me get out of the way [so you can turn around].”
“Let me just check that [hatch] seal [for dust] before we close that. Okay. Can you get your arm up? Okay. There’s no big rocks in it (the hatch seal) that I can see. Lots of dust on the floor.”
“Yeah, I think it’s okay,” I agreed. “Okay, the hatch is partially closed…”
“Let me get it. I think it (the Checklist) says to lock it, doesn’t it?”
“Well, we’re supposed to close our water first.”
This began the process of repressurizing the cabin and carefully repeating what we had done after EVA-1 (Chapter 10), following the procedures on the Post-EVA cue card. EVA-2 had resulted in the use of 75% of our battery power and oxygen and 80% of our cooling water. Obviously, we had good margins to deal with any unexpected delays during Closeout or repressurization. Possibly, the Mission Rules governing the time we could spend during an EVA were more conservative than they needed to be, but, on the other hand, we obviously were tired, as testified by our recent comments and verbal and memory slips. EVA-2 formally ended as the cabin pressure reached 3.5 psi, 7 hours, 37 minutes, and 22 seconds after it began. The Apollo 17 mission was almost half over, as we had left Florida six days, four hours and eight seconds before. Quite a week!
We noticed, as we prepared to get out of our suits, that the fingerless cover gloves worn over our EVA gloves had become badly worn. We had originally planned to take the cover gloves off after deploying the ALSEP on EVA-1, when we expected most glove abrasion to occur; however, it seem prudent to leave them on to prevent any damage to the EVA gloves from using the hammer or scoop for sampling. Clearly, this was a wise decision and the cover gloves would stay on for EVA-3 even though they further increased hand fatigue.
About six minutes after we reached 3.5 psi in the cabin, Cernan said, “Well, I never thought I’d wear my EV (ExtraVehicular) cover gloves through two EVAs.”
“Oh, I forgot all about them,” I admitted.
“No, I didn’t. I thought about taking them off until I started chipping those boulders. And I’m glad I wore them.”
“Yeah, I think it’s a good idea.”
“As hard as it is on your hands, these cover gloves are just ripped to a nub. Glad it’s not my [actual EVA] gloves,”
“[You] might consider taking them [cover gloves] off tomorrow,” I suggested.
“Roger, Seventeen. You’re talking about your cover gloves?” Parker asked, having been quiet for the last few minutes.
“Yeah. We’re still wearing them, Bob,” Cernan stated. “And, I swore I’d take them off after the drill, but I used a bit of real-time common sense.”
“Okay. Gloves are off,” I reported, having had much less trouble this time around. “LMP’s gloves are off. Need some help [Gene]?”
“Yeah, a bit…”
“I think you just about got it.”
“No, you went the other way,” Cernan said, as I turned the locking ring the wrong way – like trying to tie someone else’s necktie.
“Did I go the wrong way? Yeah, I did…” and off came his right glove. “What’s wrong with that one (the left)?”
“I don’t know.” The locking ring seemed harder to turn than it should have been.
“Shouldn’t have done that,” I said.
“Hey…, let me get this. …I had them (the locking ring tabs) [loose] then.”
“Yeah, I’m sorry,” I said as apparently the locking ring slipped back in place.
“Well, you get that one (one of two locking ring push tabs), and I’ll get these two. Get that one. I’ll get this one. …Hold that thing.”
“Okay. Let me try this one, now. …It wants to go.”
“Let me try that. Yeah, that one…”
“Got it?” I asked.
“It’s (pushing on the two tabs) usually easier when you do it yourself. The angle’s wrong [when I do it facing you].” The dialog here is unclear because it was accompanied by a lot of pointing.
“Oh, boy!” Cernan continued to struggle to make tired fingers push on the two tabs, simultaneously.
“(The wrist ring is) starting to get a little stiff,” I observed.
“Oh, they came off. Now, they came off. Oh, ho, ho, ho,” Cernan said with obvious great relief. In addition to the hand fatigue and bruising of quick under his nails that I and others experienced, the tops of his knuckles had abraded against the glove rubber bladder. It is not clear why this was a problem on the Moon and not in training. It is possible that Cernan’s hand had swollen just enough due to fluid-shift in one-sixth gravity that the glove no longer fit as it should have. Knuckle abrasion never became a problem for me, apparently because I wore the thin Nylon glove liners.
“Okay. Doff helmets, with visors. Here; I’ll get yours for you. Turn my way, if you can…”
“I know how you feel.” I sympathized, referring to his sore hands. As Cernan uncovered my helmet locking ring and lifted my helmet off my head.
“I don’t know how they’re (his hands) so wet. I don’t know whether it’s… They’re just soaking wet. …Everything is just twice as hard.” Wet hands also may have resulted from not having glove liners as well as from the tight fit constricting evaporative airflow into the gloves.
“Now comes the old hay fever, again,” I said as I caught the spent gunpowder smell of lunar dust. Later, Cernan would say, “[The dust] smells like someone’s been firing a carbine in here.”
“That one [visor] up and that one down…” Stow [helmets] in BRA’,” Cernan read ahead of himself. “Let’s get mine [helmet] off, though. …Velcroed. …Well, these things are off. Oh, man. Does that (dust) smell, doesn’t it? You sure can pick that up,” He said as I lifted his helmet off.
“Okay. You got yours (helmet)?” I asked, as I handed him his helmet with the protective visor assembly still attached.
“I’ve got mine. …Okay, Bob. Now, helmets and gloves are off.”
“[Cabin] pressure looks good, still,” I observed.
“Hello, Houston. Do you read?” Cernan seemed to want more words from Mission Control than I did.
“Roger, Seventeen. Read you loud and clear, Challenger.”
“Very good, Robert. The helmets and gloves are off.”
“Absolutely outstanding crew, there.”
“Why don’t you go home and get some sleep, Bob?” I suggested, knowing his CapCom shift should be ending.
“Absolutely outstanding. I can’t say more than that. And I mean it from the bottom of my heart, …or the bottom of my soul or something, my conscience.” Parker did sound tired.
“Thank you, Bob. Well, it’s [an achievement of] all [of] ours,” I replied, awkwardly, probably taken aback somewhat by Parker’s uncharacteristically appreciative tone.
“Bob, it’s all your good training and help,” added Cernan.
“7 (hours) plus 37 (minutes), from 3.5 (psi) to 3.5,” Parker summarized.
“As mission scientist, you’re totally responsible,” I reminded him. “Remember, it’s in your contract.”
“And the backup crew (John Young and Charlie Duke) says that you are even better than outstanding.”
“Well, thank you,” I acknowledged. “We enjoyed it.”
“Hey, I’ll turn you over to Little Joe (Allen), here, …while I go talk to some people.”
“Ohhh, boy!” Cernan knew that Allen and I would have a few choice banters before we would retire to the hammocks.
“Thanks again, Bob. We…” Parker interrupted my further expression of appreciation. I may have felt a little guilty for having gotten upset with him from time to time. Actually, instead of being able to go home, Parker would work with the Science Support Room on debriefing questions for us when we were able to settle down for a meal.
“We’ve got a 9 and 1/2 hour EVA scheduled for you tomorrow. We’re planning to spend 2 and 1/2 hours extra over there at Station 4 (Shorty Crater).”
“I hope those gloves that you’ve got packed in the back have got something in them [like a beer],” Cernan said with a laugh. “Oh, let’s read the Checklist. See if we can go to bed on time tonight.”
“Oh, man,” I sighed, thinking how nice that would be.
“That might be a change,” Parker said, not yet ready to leave the console.
“I feel better than I did last night, as a matter of fact,” I decided.
“Turn that [cabin] light on,” Cernan requested, for some reason. I reached down with my left arm and did so. “That didn’t do very much good.” The Challenger’s windows faced away from the Sun; but backscattered light from the surface still flooded the cabin.
“I’m going to turn you over to Joe. …See you guys tomorrow.”
“Okay, Bob. Get some sleep, huh?” I acknowledged. “Sorry to be touchy, occasionally.”
“ ‘Verify safety on dump valve.’ Yes.” Cernan went back to the Checklist. “Yeah, I verified them both.”
“ ‘Descent Water Valve, OPEN.’ “
“…Water Valve’s OPEN.”
As after EVA-1, we then continued to go through the routine of the Post-EVA Checklist (see Chapter 10): starting LM oxygen to flow through the cabin to filter out the remaining suspended dust; reconfiguring communications for cabin activities; taking off and recharging oxygen in the PLSSs; getting out of the suits and flowing LM oxygen through them for drying; and weighing and stowing our EVA-2 sample containers. Then, we set about eating.
A few minutes into the Post-EVA Checklist items, Cernan checked in with Joe Allen. “Hey, Little Joe? Are you there?”
“Seventeen, this is Houston. And, …how do you read Houston? Over.”
“Joe, we’re reading you loud and clear. We’re on the left-hand column [of the post-EVA card] and we’re both going PLSS mode to O, and we’ll be off the air for a skosh (short while).”
“Roger, Geno. I’ve been following you real close, and you two are mighty smooth. Boy, was that nice today.”
Touching my RCU, I said to Cernan, “Feel how hot that is.”
“Yeah, the whole thing.” The RCUs had been exposed to sunlight for over seven hours and had not yet cooled off.
“Okay, Joe. LMP’s PLSS is getting O2,” I reported, as we started the oxygen recharge.
“Thank you.” This early recharge had two purposes: first it would let us stow the PLSSs for the rest period, and, second, if any problem came up with the recharge, Mission Control would have at least eight hours to work on solving it.
About seven minutes later, I said, “Joe, O2 is off.”
“Roger.” We then repeated the recharge procedure for Cernan’s PLSS.
During this interval, I said, “Geno, I’m seeing the Cabin Pressure holding at five and a half. When we turned in, it was its normal five. I saw that after we got up, but the ground seemed to ignore the change, so I forgot about it.”
“Let me check with Joe,” Cernan replied.
“Hey, Joe. This is Gene.”
“Hey, Challenger has been holding at about 5.5 [psi] ever since we got in here. Are you all happy with that…?”
“Looks good to us, Geno. We have been watching it and everyone is happy down here.”
“Okay. Well, this morning, when we were getting ready, we saw it at 5.5, and part of that is that it’s been at 5.0 all of the time [previously]. Just so we are not venting anything [into the cabin], that’s all.”
“Geno, we hear you on that and we’ll be watching it.” We wanted a little more than that brush-off, however, from the LM team in Mission Control and its Back Room.
“Joe, we’re about 2 minutes into the CDR’s [PLSS] O2 charge.”
“Joe, LMP has 96 percent on his [PLSS O2] gauge.
“Thank you, Jack. We copy that.”
As Cernan and I talked our way through the EVA-2 Post Checklist, I realized that I had less nasal congestion than after EVA-1. It appeared that I was rapidly developing immunity to lunar dust.
“Geno, with regard to your observation made to us a few moments ago, I guess we will ask for the CABIN [GAS] RETURN [Valve] to the AUTO position and your SUIT [GAS] DIVERTER [valve] to CABIN, please. We are about two-tenths of a psi from [activation of the Cabin Relief [valve at 5.83psi]. Over.” Both these valves had been left in EGRESS prior to the start of EVA-2. Joe, by the way, had the great habit of using the term “Over” to indicate that a longer than normal transmission had been completed – good pilot procedure.
“Okay, we’re getting that now.” I turned so as to face the ECS panel and put the two valves in the requested positions. The LM team had begun to trouble-shoot this issue I raised with Cernan. There existed no danger but it was not wise to waste oxygen with the exploration mission only two-thirds complete.
“Joe,” Cernan called, “CDR is reading 94 percent on the O2 [PLSS] charge.
“Okay, Joe,” I followed up soon after, “LMP’s OPS pressure is 6300 (psi). …Commander’s OPS pressure is 6100. …Say, Joe, our cabin pressure is rising even higher, now. About 5.7.”
“We copy that.” My guess was that the Flight Director has now asked LM TELMU to get on top of this problem.
“Joe, we had the Commander’s hoses stowed, but [with the SUIT ISOLATION [valves] in SUIT FLOW. That might have done it. Is that right?” For some reason, Cernan had not connected his hoses (Red to Blue and Blue to Red) as called for in the Checklist.
“Sounds very plausible, Jack. We’ll look at it a little more here.” Actually, having LM hoses stowed would not have made any difference in the cabin pressure so long as the cabin pressure regulators were working correctly. As the pressure rise occurred with the CABIN GAS RETURN valve in EGRESS, no new oxygen should have been flowing into the cabin through the suit circuit.
“Challenger, this is Houston. Requesting you move your DEMAND REGS A and B to EGRESS, please.” LM ECCOM meant PRESSURE REGS. Their console jargon may have been to use DEMAND REGS, instead.
Knowing what was meant, I said, “They’re [back in] EGRESS.” Per Checklists, we had put these regulators in the CABIN position just after initiating repressurization of Challenger’s cabin.
“Okay. …Seventeen, Houston. We noted down here that your SUIT (GAS) DIVERTERS went to EGRESS, and we want the DEMAND REGS to the EGRESS position, please.”
“That’s right,” I acknowledged, “but the SUIT (GAS) DIVERTER valve extends when you go to EGRESS on the REGS.”
“You’re right, again.” Not often could I catch LM ECOMM in a misstatement.
“Houston, do you figure we’re relieving [oxygen overboard]?”
“Jack, we don’t think so. It looks like you’re pretty steady at between 5.5 and 5.6[psi]. We’re watching it very closely, however.”
“Okay, you know when we had that problem this morning, I hope the backflow did not hurt something when I had the LMP’s hoses stowed and the [SUIT] ISOL[ATION] valve in SUIT FLOW.” I had spent so much time with the Mission Control team, trouble-shooting various problems through the last four years, I could not help but begin to try to help on this one.
“Jack, just for your information, we saw about the same thing last night [while you were sleeping]. The only difference was the pressure didn’t climb quite so high. So, we think that, whatever it is, it really doesn’t involve the small problem you had this morning.”
“Okay, Joe…” During this exchange, Cernan had continued with the Checklist items related to getting the PLSSs ready for tomorrow’s trip to the North Massif.
“Okay, Joe,” Cernan began. “We got the commander’s PLSS back in the recharge station [and out of the way]. We got a new battery in it— odd numbers— and a new [LiOH] canister in it, and we are working on Jack’s right now.” The CDR’s batteries were numbered 1, 3 and 5, and the LMP’s were 2, 4 and 6 to help keep used ones separate from good ones.
“Okay, Gene. Sounds good. …Seventeen, Houston.”
“Go ahead, Joe.”
“We are still watching your cabin pressure down here. Could you check for us, please, if the PLSS [O2] FILL valve is securely CLOSED?
“Yes, it was CLOSED,” I reported after double-checking. “Joe, do you want me to check out the regulators?”
“Okay. ED Batts are 37.2,” I said as I continued through the Checklist. “[TELEMETRY] PCM’s going HIGH. …Let me know when you’re ready for the battery management.”
“Seventeen, Houston. Standby on the battery management for a few minutes, please. And, in the meantime, could you check the low pressure PLSS [O2] FILL valve, CLOSED, please? Over.
“Joe, I checked that. It’s CLOSED.” Someone down there missed my previous report.
“Houston, Challenger,” I called.
Still playing the LM ECCOM role, I asked, “Does your telemetry and our gauge come off the same telemetry? …[I mean, off the] same transducer on that [cabin pressure reading]?”
“That’s affirm. It does,” Joe responded after getting a thumbs up from LM ECCOM. “…And, Challenger, we’ve got a communications problem at one of the [antenna] sites and are going to ask you to go to Panel 12 and turn the POWER AMPLIFIER to PRIMARY, please.”
“Okay, it’s PRIMARY,” I replied after making the change.
“And, Challenger, we’re ready for battery management, at your convenience.”
“Okay, stand by.” During the preceding discussions, I had continued the change-out of the battery and LiOH canister in my PLSS. With that done, I put the PLSS flat on the floor in front of the hatch where it would stay until we began to prepare for EVA-3 in the morning.
“Hey, Joe,” Cernan called.
“Okay, this is Geno.” Cernan seems to have realized that our voices sounded similar after the clipping and processing they received going through the communications system. “I just dug a rock out of my pocket. No one back there probably remembers, but when we were at Shorty (at 145:39:00), fumbling around, trying to get everything done, I said there was a piece of very shiny, black, glass-like-looking material that reminded me of obsidian (black volcanic glass). Well, it’s not [obsidian]. It looks like a very fine-grained, gray rock. But, it’s a fractured piece; and I’ve picked up fractures of (through) about three or four vesicle faces on it. The vesicle faces are very shiny and that’s what reflected and caught my eye. I think the unique part about it is – Jack may want to say something else about it – the unique part about it is that I picked it up [at] Shorty. [It is] Undocumented; [picked up] halfway between the Rover and where we were sampling that orange stuff. And it will be in bag 12 Echo (74235).” (See Fig. 11.98↑ for 74235) (I do not recall how we came to have access to LRV sampler bags in the cabin. Cernan may have put it in rover sample bag 12 Echo during his work around the rover.)
“Okay, Geno. Copy, 12 Echo. And, I was assured by the folks here, when I came in, that you did indeed have a shiny sample of some kind in your pocket and would probably find it later on. So, they called that one… [Jack,] could you turn off the POWER AMPLIFIER?”
“Okay, we’ll put it (the sample) in SCB-8.”
“Okay, go ahead.”
“I got the POWER AMPLIFER – OFF,” I told Cernan, as I was now off communications.
“Okay, it’s (Power Amplifier) OFF, and we will put that rock in that sample bag and put in SCB-8.”
“Joe,” I called after looking at the rock Cernan referred to, “this rock (74235) looks very much like 12008 (a then well-known Apollo 12 sample). It’s a fine-grained, very coarsely vesicular, gray rock— probably basaltic.” In addition to the study I made of vesicles in the Apollo 11 basalts, I had looked carefully at all the basalt samples collected around craters of different sizes by Pete Conrad and Alan Bean on Apollo 12. The latter samples provided insight into layering within the olivine-rich basaltic flows at that site. Obviously, I remembered some of the samples from other missions by their numbers at that time.
“Okay, Jack,” Allen responded, seemingly amused by my reference to a particular Apollo 12 sample. “Real fine. …We want [PCM to] LOW BIT RATE. POWER AMPLIFIER – OFF, and [TELEMETRY PCM] – LOW BIT RATE.” The latter had been in HI for my battery management procedure. “…And we can maybe label that one 17008. How does that sound?”
“No, you got to label that ‘Cernan’s Rock’,” insisted Cernan. “I was going to tell you those other things, but I thought I’d let Jack.”
“Okay, thank you,” laughed Allen.
“The [broken] vesicles,” I continued, “if I may project the size of them, probably were up to 4 or 5 centimeters in diameter. They’re irregular in shape, but they’re clearly vesicles and it looks like they are lined with either glass or very fine-grained crystals. They’re very shiny… And for our next act…”
“Jack, we’re going to ask, for your next act, that you check for us both PLSS [O2] valves, OFF, and both OPS [O2] valves, OFF. Over.”
“Joe, they’re both verified OFF,” I reported after Cernan checked his PLSS, and I checked mine.
“Okay, Jack. We understand that all four valves are verified OFF.”
“That’s affirm, Joe.”
“Okay, thank you. I’m sure that you realize that we’re still showing that pressure increasing very, very slowly and are pretty well convinced that nothing is leaking in from the outside.” This is a good example of Allen’s dry humor – all we had “outside” was vacuum. “So, we are looking around on the inside here.”
“Joe, is our oxygen consumption abnormal at this point?” Cernan asked.
“No, not at all, Geno. Everything looks pretty normal, except this slow creep in the cabin pressure.”
“Well, I guess the possibility is a creeping Reg(ulator),” I speculated, “or a (faulty) transducer, is that right?” In my mind, I was following the thinking at the LM ECCOM console and with the back room engineers monitoring this discussion.
“Yeah, either that or it maybe we’re just watching some of the effects of the thermal shock that your tanks took from the repress itself. We’re not worried about it at all, but we are still watching it.” I have no idea what this “thermal shock” statement meant. The only thermal shock might be the introduction of the warm suits and other equipment into the cabin, causing some temperature-related pressure increase of the oxygen atmosphere except that would not explain the high cabin pressure as we prepared for EVA-2.
“Joe, you might make a note that my two S-E-P area samples went into bag [SCB] 8, also.” These are samples I picked up and put in my suit pocket when we calibrated the SEP transmitter and receiver at the beginning of our traverse to Station 2.
“Roger, Jack. That’s noted.
“Joe, [I] got some [SRC and SCB weight] numbers, if you’d like them?” While I helped with the cabin pressure problem, Cernan had weighed the EVA-2 sample containers.
“SRC is 41.5. Bag 6 is 24, bag 8 is 35.”
“Copy, 41.5; and 24 in bag 6; 35 for bag 8. These weights are given in Earth pounds, using our onboard scale. Mission Control would use these numbers to both calculate our liftoff weight at any given time and to stow the containers so that Challenger’s center of gravity could be optimized. Taking into account the empty weight of the containers and the long can and the various core tubes, the net weight of EVA-2 samples totaled about 75 pounds.
“Joe, how many samples did we get today?” I asked. “Don’t start a big investigation. I’m just curious.
“Seventeen, we think you have 54 samples from this EVA, plus some cores.”
“Thank you, Joe. Just curious.”
“That’s not half bad.”
“And, Joe,” Cernan said, “we’re on [Checklist page] 5-5, and I am going to start doffing [my suit].”
“Okay, Geno. Copy 5-5, and before you get started there, would you put both Demand (PRESSURE] REGS to CLOSED, please? As we continue to watch this [cabin] pressure.”
“Okay, Joe,” I replied. “Demand REG A, going CLOSED. …Demand REG B going CLOSED.”
“Thank you. And we verify ‘em both CLOSED”. These actions would stop the flow of oxygen into Challenger’s cabin; however, the internal fan would continue to circulate cabin air. As we metabolized the remaining oxygen, and the LiOH canisters would remove carbon dioxide, cabin pressure gradually should drop unless one of the PRESSURE REGULATORs had a leak.
As I helped Cernan get out of his suit and set it up for drying on the Ascent Engine Cover, Allen called, again. “Seventeen, this is Houston. We’d like the SUIT GAS DIVERTER [valve] back to CABIN, please?” LM ECS telemetry must have shown that cabin pressure was falling.
“CABIN,” I said as I complied. This action would test whether the leak existed in the suit circuit.
“Gene and Jack, you’ll be interested to hear that the cabin press[ure] is dropping down, very slowly now. So, we think we have a tiny leak in one of the [two] cabin DEMAND REGULATORS, and we’ll run a check [to isolate which one] after you get squared away there a little better…”
“Okay, Joe. We’ll be at your beck and call,” I acknowledged.
“I’ll only smile at that,” Allen replied.
A few minutes later, I called, “Houston, Challenger.”
“Joe, we’re going to air out the suits. We’re going to go to Suit Flow on the Commander’s [SUIT] ISOL[ATION] valve, now.” I wanted to be sure that this action would not interfere with the trouble-shooting on the cabin pressure problem.
“Say again,” I asked, to be sure I understood Allen’s not very formal reply.
“That sounds good.”
“Joe, I guess you guys are tired of looking at my heart beat. So, I’m gonna turn the BIOMED – OFF, as I get out of my suit.”
“Hey, Joe. This is Geno. How do you read me?” Cernan had reconnected to LM communications.”
“Geno, you’re five-by.” This is another way of saying “loud and clear”.
“Okay, we’re going to get Jack out of his suit. I’ll be monitoring [communications].” Cernan’s help consisted of unzipping the front of the suit so I could then wiggle out on my own.
“Roger. …From the way the two of you worked today, I’d think you could just about turn him upside down and pour him out…”
“Yeah. …If he’d fit through that little hole in the end of his wrist.”
“Joe,” I interjected, “the day they can pour me out of anything, they’ll call me ‘Slim’. Talk to you later.”
“Okay,” Allen said with a laugh, “among other things [they can call you].”
“Remember those nice white suits?” Cernan commented to Allen.
“The Clean Room will never be the same again.”
“You’d never believe it.” In their current condition, it seemed a little ridiculous to have taken all the pre-mission precautions to keep the suit clean. On the other hand, we knew that we at least had started with everything clean and we made sure to clean the zippers and wrist and helmet bearings after each EVA.
About 20 minutes later, Allen called. “Challenger, this is Houston.” Cernan and I had just about finished with everything related to cleaning and drying our suits and stowing other EVA gear.
“Go ahead, Houston. Challenger here.”
“Geno, we’re going to start to investigate which of your demand regulators is leaking and we’re going to ask you to put Demand REG ALPHA to CABIN now. And, as we watch it, please do not make any urine dumps. Over.” A urine dump would affect cabin pressure, slightly.
“Okay, we will not make any urine dumps, and we’ll go to CABIN now. …Okay, [REG] ALPHA’s in CABIN,” Cernan reported as I made the change from OFF to CABIN. “And we’ll be ready for your debriefing here in about 5 minutes.”
“Okay, Geno. And, it’s going to be a short one.”
“Okay, Houston,” I called. I was now out of my Liquid Cooled Garment and wearing my Constant Wear Garment, that is, out of my water-cooled underwear and in to my pajamas. I had reconnected to LM communications. “We’re going DOWN-VOICE – BACKUP [on the communications].
“Standby on that…”
“And, okay; we are ready for your EVA-2 debriefing,” added Cernan.
“Okay, Seventeen. To begin with, we want you to delete that step going to DOWN-VOICE – BACKUP. And I’ve got a surface block data to read up to you, a few minor changes in your Lunar Surface Checklist, and a couple of very quick questions for the debriefing when you’re ready. Over.”
“Go ahead, in the stated order,” I replied.
“Roger,” and Allen read and I confirmed the data for possible emergency liftoffs during the next five orbits (ten hours) of America.
“…And what’s our present rev?” I asked.
“Rev 32, Jack…” Evans actually is just about overhead on his 32nd orbit.
“Hey, Joe, for pantry purposes, what day is this.”
“We’ve checked around the room here and the consensus is that it’s Wednesday morning [13 December 1972]. Over.” What we really needed was the designated meal day.
“Oh, okay. I really wanted to know whether it was irradiated ham or frankfurter morning, and I guess we can work that out…”
“Roger, Gene. Apparently, the Surgeon is happy with either of those days. And we want you to turn, right now, to [page] 5-7 in the Checklist and perform that one particular step, at 150 hours, which will prevent the computer clock from overflowing. And that’s the ‘PROCEED, VERB 37 ENTER, 06 ENTER, PROCEED’ step. We’ll stand by for that. Give us a mark as you start it. Over.”
“Okay, we’re starting. PROCEED…, VERB 37 ENTER…,” I read as Cernan worked the DISKEY.
“Okay, Joe. You don’t want me to go on the VERB … You’re not going to give us an update, huh?”
“No update required. That was just to prevent an overflow [in the clock]. And then I’m ready for the quick changes in the Lunar Surface Checklist when you are.”
“Okay, Joe, go ahead,” I said, as Cernan entered NOUN 06 and PROCEEDED.
“Okay. Begin by putting the Demand REG BRAVO to CABIN position and leave the Demand REG ALPHA in the CABIN position where it now is. And I’ll continue on with the changes in the checklist here. Page 5-6, left-hand side, where it reads ‘Configure ETB.’ The fourth line down that starts out ‘Four b&w Mags,’ they should read, ‘Hotel, India, Juliet, and Romeo in LCG compartment.’ Then going up to the right-hand side under ‘Stow in ETB,’ change the line ‘One B&W Mag Romeo’ to read ‘One B&W Mag Kilo.’ Over.”
“Okay, Joe. I changed the Mags in the ‘Empty’ from Kilo to Romeo and the Mag in ‘Stow’ from Romeo to Kilo.”
“Okay, that sounds like the thing to do. And a note on your Demand REGULATORS, …we’re showing that the Demand REGULATOR ALPHA has good integrity and we’re now in the process of checking Demand REGULATOR BRAVO. I’ve got a couple of fairly quick questions here when you’re ready for those.
“Okay, Joe. Go ahead with your questions; and ‘integrity’ is certainly what we need around here, right…?”
“Okay,” Allen replied, ignoring my attempt at humor. “Jack, a question for you to begin with: Is your gold (electroplated) visor sticking halfway down? Apparently, that’s based on a discussion earlier. Over…” I pulled my helmet and LEVA out of the BRA so we could look at it. Cernan had made a comment about my “upper visor” being up as we left Station 4.
“Yeah. Apparently his visor is sticking. …Which one?”
“The gold visor?” Cernan asked… “No, he said his sunshade is sticking halfway down, but his gold visor’s not.”
“Okay, that answers the question. We couldn’t tell from the TV whether it was the visor or the sunshade. That’s fine. …We also heard some discussion about possible wear in the seats of the suits when you were dusting each other off. We want to know if you could see any hint of the aluminum layers showing through in the suits. Over.”
“No, Joe,” Cernan continued. “Not to worry. It’s just a few scars on the PLSS thermal blanket in back where you probably rub the seat when you get in. Nothing on the suits.”
“Okay, Geno. Now two real quick geology questions that will help us do the planning for your EVA tomorrow. The first one has to do with Station 4. And you called out some material on the rim [of] the crater at Station 4, which looked like ‘bedded spatter’. And we’re wondering if that resembled things that you’d seen in Hawaii? Over.”
“Hey, Joe,” I answered, “I think they misheard. I think I may have said ‘shattered’ and you might have thought ‘spattered’. No, I didn’t – neither one of us – intended to leave that impression. The big rock we sampled looked like intensely shattered gabbro, such as we’ve had around the LM. Probably more significantly, the rocks – one of which Gene picked up – [were] the fine-grained, coarsely vesicular basalts. And we didn’t have any time to really examine the interrelationships of those rock types there, but those were the two fragment types we saw.” I actually used the phrase “intensely fractured” to describe the boulder on the rim of Shorty. Had I seen any actual volcanic “splatter” there, we might have been headed back to Shorty on EVA-3.
“Okay, Jack. That’s quite clear to us now. Also a question about Station 4…”
“Joe…Joe,” I interrupted.
“Okay, go ahead.”
“The bottom of that crater, now, had material that was extremely disorganized in its aspect and, really, we didn’t have time to examine it in detail in order to decide why it was disorganized. It did not necessarily look [in structure and texture] like the boulder that we sampled at the rim.”
[My description at the time had been, “The central peak, if you will, or central mound, is very blocky and jagged. And the impression I have of the other mounds in the bottom is that they look like slump masses that may have come off the side.”]
“Okay, Jack. Understand that. A question about the boulder you sampled at the rim. Would you compare the basalt in this boulder – which you may have called a gabbro, I’m not sure, in any case, a basalt, to samples which you collected at Camelot (Station 5) and at [the] ALSEP [site]. Over.”
“Well, my impression was that they were the same rock types.”
“Okay, that’s our impression, too. Thank you. That’s it for us on the questions. And for information, we’re showing your cabin pressure is holding fairly steady even with both those Demand Regs on.
“Keep watching it for us, would you,” Cernan requested, “and let us know. I expect one of them is probably leaking pretty slow.”
“Yeah; no worry about that, Gene. We’re looking at it real close.”
Finally we could start to get some dinner. “What do you have over there to eat?” I asked Cernan. It now seemed a very long time since we had breakfast.
“Let’s see if I can find today’s meals. We may just have potluck since the packets are all jumbled up. …Here, I guess we both have chicken and rice soup.”
We finally both settled on an entrée of beefsteak from the wet packs.
“Looks like its butterscotch pudding for desert,” I noted. “I guess I’ll have cold tea again.”
“Sounds good to me. …Station 4 turned out to be something, didn’t it,” added Cernan.
We both avoided drinking the orange drink with its potassium additive, hoping to avoid the diarrhea that plagued Young and Duke on Apollo 16. More water provided a good substitute. I also had some cold tea with the fruitcake.
“Yep. I am sure the Science Room will be up all night debating what we may have found. I am not sure what, but there is something related to volcanism going on there. Wish we had had more time.”
“That dark layer going down the west side of Shorty seemed strange,” Cernan said between mouth fulls.
“It would have been good to go sample that one and see if it were the same as what we apparently got in the lower part of the core.”
“How’s America looking to you?” Cernan asked of Allen as we dug into our meals.
“It is just as clean as a whistle.”
“It may not be when we get back there, judging from the looks of us. …That’s good to hear, though. It’s a good bird. So is this one…”
“Joe, …you got any more debriefing questions?” I asked, thinking that our “Eat Period” would be a good time to go over any geology issues.
“Negative, Jack. And we’re interested that you move right along so we can get you turned in there and get some rest.”
“We’re moving,” I replied. “We’re eating now, and we feel the same way [about rest], I think.” I was surprised that the Science Back Room did not take advantage of the time. I can’t believe that everything we had done was entirely clear. The Flight Director, however, probably had said something to the effect that we needed to get back on the timeline now that we were about almost two hours behind the original plan.
While we ate, I told Cernan, “I bet they really are debating whether or not to send us back to Shorty.”
“Do you think they will do that?”
“No. I suspect that they finally will conclude that going for the unknown in the plan for EVA-3 is better than going back to Shorty. In spite of the short time there, we did a good job of sampling.”
“Troops,” Allen called, “enjoy your meal there. And at your convenience, you can go ahead with the [PLSS] feedwater recharge. We want you to hold off on the [PLSS] oxygen recharge (top off) until we watch these regs for about another 10 minutes. And give us a mark if you do start the water recharge, please. Over. …And if there are any ways we can cut corners on the time here, it’ll be helping us, because we’re still looking at being down a couple of hours nearly.”
“Okay, Joe,” Cernan replied. “We’re working at it as fast as we can. …Best place in the world to make it up is tomorrow night.” Cernan’s point was a good one. Don’t consider shortening EVA-3. With the three full EVAs over, we could forego some our sleep period before getting ready for Ascent and Rendezvous. We always had to be ready to do that, anyway. Five hours sleep in reduced gravity seemed to be plenty, at least for me. In addition, the Flight Plan included almost three days in lunar orbit before heading back to Earth.
“Right, Geno, and, actually, we’re going to pick up a good one [hour] shortly, because we’re coming up to a pad [built] in the timeline. So, as long as we don’t waste too much time, we’re doing pretty well.” This “pad” Allen referred to was in the Checklist as “MCC-H CONFERENCE”.
“Okay; be assured we’re not [wasting time]. There’s just a certain amount of housekeeping we have to do. But, very seriously, day after tomorrow is a very short day, and I think we ought to look at making up any time [we lose then]. I’m a hold-faster on sleep periods but tomorrow’s [rest period] is the one that I think is flexible.”
“Roger. We hear you.”
“Hey, Joe. This is Jack. We’re eating here. Won’t be too long at it, but if you’ve got any significant news or anything, why don’t you give it to us?”
“Jack, I don’t know if it’s significant news, but at least I know you’ll be interested. Both your demand REGS look good now. We show no evidence of a leak there and it may have been that just recycling them reseated them and solved whatever problem we had. You can go ahead with the O2 [top-off] recharge on the PLSS and the water recharge at your convenience. And let me poll the room here for other news items. Over.”
“Okay, Joe, we’re starting an O2 [top-off] charge of the CDR’s PLSS – [for] ten minutes.” This is something we could do while we finished our meals.
“Challenger, this is Houston.”
“Go ahead, Joe,” I answered.
“Roger. This is a news report to eat by. I’ll combine an orbital science report with a sports report, an unusual combination here. I’ll start out with a sports report on Monday Night Football, which you may not have heard yet. Joe Namath tried mightily to lead the New York Jets into the American Football League playoffs, but the Oakland Raiders grounded the Jets in a fourth quarter 24 to 16 blitz. Namath passed for more than 400 yards but, in spite of it, New York scored only one touchdown.
“Moving along to the successes of Captain America [i.e., Ron Evans], I’ll run down different items in the SIM bay here, beginning with the UV spectrometer. In general, the data has been excellent. We’re getting indications that the hydrogen atmosphere of the Moon is much less than expected. In fact, I don’t think we’re detecting any [hydrogen], but rather setting a limit on the [maximum] amount of hydrogen around the Moon. There was an Aerobee launch, …or, [rather] an attempt at an Aerobee launch from White Sands on Monday to calibrate solar UV radiation, but this launch failed because an instrument viewing port in the rocket failed to open. A second launch— let’s see— was scheduled, I think, for today, and I don’t know whether that was successful or not. …I guess it’ll be launched later today.
“The infrared scanning radiometer is performing beautifully. Indications are that subsolar-point surface temperatures are higher than we’ve detected from our Earth-based observations before. We’re seeing many thermal anomalies, particularly in [Mare] Procellarum— in the Procellarum area west of Copernicus. And we’re seeing also a few unusual cold spots, which apparently are indicating areas of very fine soil with a few or no blocks in and on the soil.
“The lunar sounder data is beautiful, and the power monitor signals we find correlate with the surface features. And the HF (high-frequency radio) data indicates to us that we are detecting a variety of layers in the mare areas…”
“Joe, this is Jack. Do you know where specifically they’re seeing the hot spots west of Copernicus?” In my photo-geological mapping of the Copernicus area in 1964-65, I had thought that there might be some small volcanic cones on that 80 km diameter crater’s ejecta blanket. This earlier work triggered my question.
“Jack, I don’t have it on the page in front of me here. We’re going to check into it and I’ll get back to you in a second. …Jack, this is Houston. With regard to your questions on the hot spots, apparently they’ve not yet indexed these warmer sources that they’re detecting to the CSM ephemeris, and so they don’t know exactly what they correspond to as far as the surface features themselves go. So I can’t help you on that right now.”
“Okay, Joe. Just curious.”
“Gene and Jack, [LM] TELMU handed me some numbers which I think you will be interested in. From the EVA-2 EMU summary, the elapsed EVA time was 7 hours plus 37 minutes plus 22 seconds for a new outdoor record under international rules. The rest of the sheet looks free from problems in a comforting way. Let’s see, average metabolic rates: for you, Geno, 855 [BTU per hour]; and, Jack, you’re running at around 920. And that’s relative to pre-mission [estimated] averages of around 850. And you have a grand total EVA time now of 14 hours 49 minutes and 35 seconds.” We broke the previous EVA record of Apollo 16 by about 12 minutes.
“Very interesting numbers, Joe,” acknowledged Cernan. “Do you have any idea how the metabolic rate compared to yesterday?”
“Good question. Let me ask on that one. …Yesterday you were running at 1045 and 1090 [BTU per hour]. So you’re down considerably from your work rates of yesterday, which is good news. Maybe you’re learning how to do it more easily or something like that.” The major difference between the two EVAs consisted of deploying ALSEP on EVA 1. That took much more work than riding the Rover for several hours. I never felt that any significant stress came from the emotions of being outside the Challenger. I only recall worrying about having enough time to get things done rather than any concern about being on the lunar surface, far from home.
“Yeah, but we spent a lot of time riding today and a lot of time working yesterday.” Cernan had the same thoughts about the ALSEP.
“That’s true,” agreed Allen. “I guess that’s not taken into consideration of the average here. It’s certainly true. We can ask for the ‘metabolic rate’ of the Rover,” he joked. “I bet that is pretty impressive for today.
For all EVA activities, post-mission analysis indicated that our individual metabolic rates were nearly identical at 946 and 950 [BTU per hour]. Cernan worked harder during ALSEP deployment (drilling, mostly) while I worked harder during Rover deployment and at the geology stations. Riding the Rover cut metabolic rates by about a third over other activities.
“Well, don’t get me wrong,” Cernan asserted. “Driving that Rover is soft; but I’ll tell you, it keeps your attention.”
“I’m sure it does.”
“It keeps the passenger’s attention, too!” I exclaimed.
“I’m sure it does,” repeated Allen. “We noted some comments when you were rolling along today; and reading between the lines from time to time.”
“Actually, Joe,” continued Cernan, “for good long spans of the run up to Station 2, except when we had to pick our way up the Hole-in-the-Wall, I was running full bore at anywhere from, I guess, what’d I say, 10 to 12 to 15 clicks. I didn’t hit 15 going up [to Station 2] very much. Coming down I did, but it’s really a ‘standby for a turn and watch where you’re going’ type of run. Because the small craters, of course, are the ones that can really jolt you. But the trouble is, you can never see what’s just over the next ridge, and the next ridge may be 20 meters away and you just can’t see it until you’re there, and you don’t know whether its a dish crater or whether it’s a pit crater.”
“Joe,” I added, “that description fits the geology up in there [on the light mantle], because we weren’t seeing blocky rimmed craters and otherwise you would have been able to tell more easily about the old versus new craters, which would be the ones you could either go through or not go through, respectively.”
“That’s a super machine to drive though, Joe, I’ll tell you. If you had enough time you could really learn to take it all the way. But you don’t really do that, just the second time around.”
“Geno, was it spraying dirt at you today?” Allen asked. “Could you notice that you still missed the real fender and that the patched fender wasn’t quite doing what maybe it could?”
“No, sir, I don’t think we missed it at all.”
“Fact is, we’re recommending a design change, Joe,” I said, tongue in cheek.
“That’ll be for next year’s models,” Allen added, joining in the fun.
“How soon do you think we can take a pee and dump the urine bags?” Cernan asked me, thinking that LM EECOM might still be trouble shooting the cabin pressure issue.
“I doubt if it would be a problem, but I’ll ask.”
We had begun to clean up our meal debris and filled the drink bags for EVA-3 when I asked Allen, “Hey, Joe. Is it all right to use the waste management system (to urinate and empty the Urine Collection bags from EVA-2)?”
“Rog. We’re happy with those demand REGS now. And you can proceed on with that [urine dump] and including all the PLSS recharges that you’ll need to do as well.”
“Joe, we’re filling my PLSS with water now,” reported Cernan.
“Gene, ask them to watch the change in water quantity while we fill the PLSSes.” I hoped to avoid the uncertainty about the amount of recharge that delayed the start of EVA-2.
“You might check on the water quantity [change in the Descent Stage tanks],” Cernan said, complying with my request.
“Roger. Thank you…”
“Joe, that should take care of my PLSS for tonight,” Cernan reported a few minutes later. His PLSS had new oxygen, water, battery and LiOH canister.
“Okay, Gene. Thank you. Out of curiosity, have you packed, or are you packing, the ETB now (for EVA-3)?”
“Yeah. Jack’s doing it right now.”
“Okay; we’ve got a last minute change. We show that your Mag Bravo is at about 77 frames, and we’d like for you to leave it in the ETB – it is already in the ETB – and take it out with you tomorrow. We can shoot up the remaining frames if we run out of film otherwise.” Mag Bravo, AS17 134, was the color film we used during EVA-1.
“Okay; fine. That goes along with our thinking…”
[During this wind-down toward getting some sleep, I took some color photographs out my window (AS17-140-21352-58; Fig. 11.151) that document the disturbance of the surface due to our activities near the Challenger and toward the ALSEP. The contrast between the lightened regolith surface near the lander and the darker regolith underneath shows up very clearly in these photographs. It is clear that the Descent Engine effluents had winnowed the fine-grained, dark agglutinates and ash away from our point of landing. AS17-140-21354 (Fig. 11.152↓) also illustrates how that surface loses its bearing strength with repeated disturbance. Future settlers on the Moon will need to stabilize surfaces exposed to repeated foot or vehicle traffic. A number of possibilities exist for doing this but a macadam made up of course rock fragments might be the simplest. Such material would be the natural by-product of processing the regolith for its solar wind volatile resources.]
Fig. 11.151. My panorama view from the right hand window of the Lunar Module Challenger showing the shadow of the American flag at far right, the Rover, and two of 16 small, re-startable 50 pound thrust rockets used to control the attitude of the spacecraft during flight. The photograph also documents the effects of our disturbance of the regolith after two periods of EVA. Note also the two SCBs in the left rear rover rack (see Fig. 11.152↓). (Composite of NASA Photos AS17-140-21356, -355, -357, -358).
“You know, [Gene],” Allen called, “apparently you made some comment earlier in the day about being bothered by comm noise during your egress from Challenger. Did that go away right away, or did it just cease to bother you? What was the story on that?”
“I don’t remember. So, it must have gone away, because the comm was great.”
“Okay; that’s what we kind of assumed…”
“Okay; we’re charging (topping off) Jack’s PLSS with oxygen…”
Thinking about what I had observed on our Rover traverses across the light mantle, I mused, “Gene, as we went across the light mantle, I sure felt like there were almost no boulders or large rocks that were part of it. Was that your impression?”
“Jack, …I was concentrating on missing craters and moving as fast as we could to get to Station 2 and then to Station 3..”
“Well, you certainly were doing that! …If the light mantle is the result of an avalanche off the South Massive, as Ron Shrieve and I have speculated, boulders must have sunk out of sight.”
Fig. 11.152. In this final excellent view of the LRV at the end of EVA-2, most of the design components can be seen. Starting from the rear at left and working towards the front, note the following: fender repair above right rear wheel; Two sample container boxes (SCBs) in the rear geopallet; the large rake for soil sieving; the shovel-like (scoop) sample tool; two explosive charges still to be deployed; and the diamond-shaped SEP receiving antenna. Next, the two seats; the console consisting of the T-shaped hand controller and the black panel of the navigation unit. In the front section, the cylindrical low gain antenna (LGA) is at left; next, the dish-shaped high gain antenna (HGA) for TV transmissions, both pointing to the Earth; and finally, the TV camera is pointing downwards away from the sun, looking into the opened LCRU battery compartment. Cernan has parked the rover at right angles to the sun. (Cropped from NASA photo AS17-140-21354).
Ten minutes after his last call, a tired Commander reports, “Houston, Challenger. The O2 fill is complete on the LMP’s PLSS, and we’re working on the water.”
“Roger. …Challenger, for your information, we’re coming up on [a] comm handover in about a minute and a half.” Allen may have misread the note handed him. A site handover from Honeysuckle to Madrid would occur in about an hour and a half.
“Hello, Houston; Challenger. The LMP’s PLSS is charged. …Joe, how’s the weather gotten down there? Any better?”
“Geno, the weather is better. We were really socked in yesterday. That front’s moved on through the Houston area, and it is cold and clear tonight, I suspect. It’s been a while since we’ve been out, but they are calling for it to go down right near freezing.”
“Okay. Thank you.”
During several long breaks in communications with Mission Control, Cernan and I went through a gradual unwinding from the events of the day. As we rehashed the various geology stations and the Rover performance, and speculated on possible changes in the plan for EVA-3, we seemed increasingly tired. My nasal reaction to lunar dust seem to worsen a bit but never became as bad as after EVA-1.
[Many years later, I learned that the flight surgeon assigned to retrieve our suits from America had such an allergic respiratory reaction to the residual dust that he had to let someone else finish the task. I am not aware of anyone else, astronaut or otherwise, having the kind of reaction to dust that this doctor had.]
“Hey, Joe; Challenger.”
“[Have] they succeeded in leveling the [Lunar Surface] Gravimeter, yet…?” I clearly wanted to discuss more about EVA-2 with Allen before hitting the hammock for the “night”.
“Jack, we’ll check it [and] update our information on that. My understanding at the moment is that they’ve not [leveled it]; but they’re thinking that the unit’s just too cold and they’re in the process of warming it up by dumping heat into it by running some of the equipment around it and in it, and they’ve by no means given up hope for that unit.”
“I figure that means that my fooling around with it didn’t help ‘em.”
“Apparently, it didn’t do too much for them, but what it did do was convince them that it’s probably somehow locked up because its temperature’s not right yet. And they’re not worrying about whether it’s level or not level now. They’re confident that it’s been set up okay, and now they’re just biding their time to bring that temperature up. We’ll get some more words to you sometime tomorrow on it as you make your traditional visit to the ALSEP site again, probably.”
[Forty-six years later, I cannot help but wonder why no one on the LSG team thought to check the design of the balance beam and to see if a proper tilt of the entire instrument, as I had suggested might compensate for the problem with the beam’s distribution of mass that was much later determined to be the issue.]
“How are you coming along with your sleep prep?” asked Joe.
“We’re just about there, Joe. We picked up some time somewhere in here. Couldn’t be much more than an hour behind, “I responded.
“No, that’s just about right. You’re looking pretty good on that.”
“If you get to sleep in the next 5 minutes, you’re one hour behind.” This was Deke Slayton joining in again at the end of the day with a not too subtle push.
“Yes, sir; I’m putting my hammock up now, as a matter of fact.” Once Cernan had his hammock strung up, fore to aft in the cabin, and had lain down, I could hook mine across the crew stations and below Cernan’s feet. Once I climbed in, I stayed in. Before doing so, however, I configured the Environmental Control System for the sleep period and covered the forward windows after one more look at the flag “waving” below the North Massif and a black sky.
“What’s he (Slayton) doing up so late?” I asked no one in particular.
“Well, somebody’s got to sit up and keep you guys honest,” Slayton answered for himself. …I think we’re getting more sleep down here than you are.”
“[I hope, so].”
“I might add that not only do we have to stay up late,” Allen joined in, “we have to get up mighty early to keep you honest, too.”
“Okay; you going to let us sleep 8 hours or what?” I remained worried that they would cut into EVA-3.
“That’s affirm, Jack. We’re looking good on the time[line], and not only will you get, we hope, 8 hours of good sleep, but you’ll have a full EVA tomorrow. So, it’s not costing us anything there.”
“Sounds great, Joe,” Cernan said. “I fully expect it won’t be much longer now [before we are asleep].”
“And, Gene, just for rough planning purposes, we’ll start to figure your sleep period starting around 152:30. And we’ll be looking at your getting up around 8 hours from that time.”
“Okay, Joe; I’ll buy that.”“
“Might add, also, that there are a lot of us looking forward to that third EVA tomorrow. It’s going to be the last one on the lunar surface for some time.”
“I tell you, if it’s anywhere near what the first two were like, we’re looking forward to it, also…”
“Gene and Jack, we’re still marveling at the beautiful television pictures that we’re getting from your TV camera there. It’s fun, in fact, to watch the tracks that you’re leaving behind in the lunar soil, both footprints and Rover tracks. And some of us are down here now reflecting on what sort of mark or track will — someday — disturb the tracks that you leave behind there tomorrow.”
“That’s an interesting thought, Joe, but I think we all know that somewhere, someday, someone will be here to disturb those tracks.”
“No doubt about it, Geno.”
“Don’t be too pessimistic, Joe,” I came on with my two philosophical cents. “I think it’s going to happen.” Little did I know that nearly fifty years later, I would be writing this narrative, and I would still be the last American, last human, and only and last scientist to step foot on the Moon.
“Oh, there’s no doubt about that. But it’s fun to think about what sort of device will ultimately disturb your tracks.”
“Well, that ‘device’ may look something like your little boy,” I speculated, referring to Joe and Bonnie Allen’s four-year old, David Christopher.
“Ah, he’d make short work of them…”
“Joe,” interjected Cernan, “I’ll tell you it’s also a pretty philosophical thought to think that you’re riding around out here on what is really undisturbed everything, you know. If there was someone here, way back when sometime, they didn’t leave much sign of their whereabouts, but that’s an interesting thought, too, as you drive around and all of a sudden cross your own Rover tracks and figure out those are the only ones that have maybe have ever been here.”
“And with that, I’m rolling out my hammock. …Okay, Joe. I’m waving goodnight to you. I’m rolling up my overhead (Rendezvous) window cover…”
“Okay, Gene and Jack. We’ll say good night to you from down here, unless there’s some other way we can help you.”
“No, sir. If there is, we’ll give you a call, though…”
“Just want to end by saying what a terrific job you did today, and we’re really looking forward to tomorrow. Have a good 8-hours rest.”
“Thank you, Joe.”
“Tomorrow,” I concluded, “we answer all the unanswered questions. Right?”
“If not more.”
(To be continued)
Wolfe, E. W., et al., 1981. The Geologic Investigation of the Taurus-Littrow Valley: Apollo 17 Landing Site, Geological Survey Professional Paper 1080, Fig. 98, p. 83. ↑
Schmitt H. H., Petro N. E., Wells R. A, Robinson M. S., Weiss B. P. and Mercer C. M., 2017. Revisiting the field geology of Taurus-Littrow. Icarus 298, 2-33. ↑
Mercer, C. M, Young, K. E., Weirich, J. R., Hodges, K. V., Jolliff, B. L., Wartho, J.-A., and van Soest, M. C., 2015. Refining lunar impact chronology through high spatial resolution 40Ar/39Ar dating of impact melts. Sci. Adv. 1 (e1400050) DOI.10.1126/sciadv.1400050. ↑
van der Bogert, C. H., Gaddis, L., Hiesinger, H., Ivanov, M., Jolliff, B., Mahanti, P., Pasckert, J.H., 2016. Revisiting the csfds of the Taurus Littrow dark mantle deposit: implications for age determinations of pyroclastic deposits, LPSC-47. Abstract 1616. ↑
Grange M., et al., 2009. Early history of the moon: Zircon perspective, Abstact #1473, Lunar and Planetary Science 40, Lunar Planetary Institute, Houston. ↑
Langseth, M. G., Keihm, S. J., and Chute, J. L., Jr., 1973. Heat Flow Experiment, Apollo 17 Preliminary Science Report, NASA SP-330. ↑
Robinson M. S., 2018. personal communication. ↑
Schreve, R. L., 1968. The Blackhawk Landslide, Geological Society of America, Special Paper 108, 1-48; see also, Mitchell, T. M., et al., 2015, Catastrophic emplacement of giant landslides aided by thermal decomposition: Heart Mountain, Wyoming, 411, Earth and Planetary Science Letters, 199-207. ↑
Schmitt H. H., Petro N. E., Wells R. A, Robinson M. S., Weiss B. P. and Mercer C. M., 2017. Revisiting the field geology of Taurus-Littrow. Icarus 298, 2-33. ↑
Wolfe, E. W., et al., 1981. The Geologic Investigation of the Taurus-Littrow Valley: Apollo 17 Landing Site, Geological Survey Professional Paper 1080, Fig. 119, p. 100. ↑
Phillips, R. J., G. F. Adams, W. E. Brown, et al., 1973. Apollo Lunar Sounder Experiment, Apollo 17 Preliminary Science Report, NASA SP-330, p. 22-1 to 22-26. ↑
Wells, R. A. and Schmitt, H. H., 2018. Color-balancing of in situ documentation photographs of the Apollo 17 orange and Apollo 15 green volcanic ashes. Paper presented at GSA 2018 Annual Meeting, Abstract 166-11, PDF copy available (here). Indianapolis, IN. ↑
Wells, R. A., Petro, N. E, and Schmitt H. H. 2019. Red/Orange Volcanic Ash Deposits on the Lunar Surface Documented in Color-Balanced Apollo 17 Hasselblad Surface and Orbital Photographs Compared with Apollo Panoramic, Metric Mapping, and Lunar Reconnaissance Orbiter Photos. J. Geophys. Res. – Planets, revision submitted. Details of the color-balancing process are given in the Supplemental Information file of this paper. ↑
Muehlberger, W. R. et al., 1973. Preliminary Geologic Investigation of the Apollo 17 Landing Site, Apollo 17 Prelim. Sci. Report, Fig. 6-61, p. 6-53, NASA SP-330; Wolfe, E. W., et al., 1981, The Geologic Investigation of the Taurus-Littrow Valley: Apollo 17 Landing Site, Geological Survey Professional Paper 1080, Fig. 122, p. 105. ↑
Schmitt H. H., 2017. Geology and stratigraphy of Shorty Crater pyroclastic ash deposits. Lunar Planet. Sci. XLVIII, Lunar Planet. Inst., Houston. #1072 (abst.). ↑
Wolfe, E. A., et al., 1981, The Geologic Investigation of the Taurus-Littrow Valley: Apollo 17 Landing Site, Geological Survey Prof. Paper 1080, U.S.Govt. Printing Office, Fig. 120, p. 103. ↑
Wells, R. A. and H. H. Schmitt, 2018. personal communication. ↑
Swann, G. A., Bailey, N. G., Batson, R. M., Freeman, V. L., Hait, M. H., Head, J. W., et al., 1972. Preliminary geologic investigation of the Apollo 15 landing site. In Apollo 15 Preliminary Science Report (NASA-SP-289, p. 5-95). Washington, DC: National Aeronautical and Space Administration. ↑
Schmitt, H. H., N. E., Petro, R. A. Wells, M. S. Robinson, B. P. Weiss, and C. M. Mercer, 2017. Revisiting the Field Geology of Taurus-Littrow, Icarus, 298, 2-33. ↑
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