Chapter 5 – 30 Seconds and Counting

Chapter 5

Thirty Seconds and Counting[1]

Ignition of the five F-1 engines of the Saturn V S-IC first stage of Apollo 17 at Pad 39A, Kennedy Space Center, December 7, 1972 (NASA photo S72-55482).

T-minus 30 seconds…we have a cutoff, we have a cutoff at T-minus 30 seconds. We are standing by at the T-minus 30 second mark. We’ll bring word to you just as soon as we get it. We have a cutoff at T-minus 30 seconds. T-minus 30 seconds and holding. This is Kennedy Launch Control…This is Apollo Saturn Launch Control. We’re holding at the 30 second mark. This was an automatic cutoff. Cutoff by the Terminal Sequencer…

“Thirty seconds and holding.”

We had no indications of a problem within the spacecraft and could only wait for information from the launch control center. As the spacecraft’s clock counted down from 30 seconds through zero, we lay there without moving, three pair of eyes rapidly scanning the instrument panels for any clues to why the countdown had stopped at this critical point.

“Nothing wrong on my gauges,” I told the others on the intercom after a quick scan.

The question bouncing around inside America at the time, however, was “Will management be convinced of any analysis or will we go into another month of training and quarantine.” No question existed in the spacecraft that we should go for launch! (See Mother’s diary, Appendix I for December 6c)

This is Apollo Saturn Launch Control. The astronaut crew aboard the spacecraft is going through their various safing now. Safing of all systems, and the launch team here continuing through their emergency procedures. We’ll be standing by to check out the problem just as soon as we can get word. T-minus 30 seconds and holding. This is Kennedy Launch Control.

Did the Saturn V know that we were at “30 seconds and holding?” I felt a rush of adrenalin along with waves of disappointment, followed by anticipation of the violence of a possible launch-pad abort or rapid evacuation of the spacecraft.

Meanwhile, working with Launch Control, we went through the process of putting America’s systems in a safe condition. After about five minutes of extreme uncertainty mixed with not-so-reassuring reports on the communications loop saying, “We’re looking at the problem,” Test Conductor Skip Chauvin’s calm and calming voice entered our ears: “It looks like the Countdown Sequencer thought the LOX (liquid oxygen) tank for the S-IVB (Saturn third stage) wasn’t pressurized even though we had pressurized it with a manual override command. It’s either a sensor or a computer problem. The Saturn’s fine. We’ll work it out and get back to you shortly. By the way, we’ve recycled to T minus 22 minutes and holding.”

Cernan appeared to remain tense even after this explanation. He, of course, as Commander, had control of the T-shaped hand controller at his left, a counter-clockwise twist of which could initiate a rapid sequence of events culminating in ignition of the launch escape rocket that would send us blazing off the top of the Saturn V. To me, however, Skip’s voice carried the familiar tone of competence and confidence I had grown use to from him in vacuum chamber and Launch Pad tests. It immediately told me that “we know what the problem is, we know how to fix it, and all we have to do is convince the bosses we can go ahead.” With this feeling of assurance, a light buzz in my ear phones, soft vibrations through my couch and suit back, and the hum of the of America’s fans and pumps, I went to sleep. Put me on my back with those soothing sounds, and I can sleep anywhere. Nothing I could do would help, and you never know when you many need the rest. Outside, Swing Arm #9, with its attached White Room, returned to its nearby, T-22 minutes ready position in case we were told to leave the spacecraft in a hurry.

About twenty minutes after Chauvin gave us his explanation for the hold, Launch Control announced over the public address system:

We’re at T minus 30 seconds and continuing our hold. The problem was with the Terminal Countdown Sequencer, which failed to give the command to…pressurize the third stage LOX [liquid oxygen] tank. The crew (team) in the firing room, seeing this [failure] happen, pressurized the tank manually, but this did not happen fast enough to satisfy the automatic sequencer. As was mentioned earlier, during this sequence everything must happen at a certain time, before the next step in the [countdown] sequence can take place. The next step that was to take place was the retraction of Swing Arm #1 and, at the time that was to take place, the Terminal Sequencer had not had an indication that the third stage LOX tank had been pressurized.

The plan now is to recycle to the T minus 22-minute mark in the countdown. Now this recycling procedure will take an additional 35 to 40 minutes. This still puts us well within our launch window. While we’re recycling, we’ll continue to review the data to determine just what the problem is and whether or not we can proceed from the T minus 22-minute mark for a launch later in the window. The crew aboard the spacecraft have been alerted to the problem and understand what is happening. They’re standing by there at this time. Now at T minus 30 seconds and holding; this is Kennedy Launch Control.

This night of December 6, 1972, the minutes turned into hours and we waited. Midnight came and it was December 7th in Florida— but still no final word.

We later learned that, at T-30 seconds, the Countdown Sequencer of the launch control computer had been programmed in the deep, dark past to look at whether a signal had been sent to pressurize the S-IVB liquid oxygen tank rather that to look at whether the tank actually had been pressurized. Indeed, the Sequencer had failed to send a pressurization signal, but the launch controller monitoring the flow of pre-launch events saw this failure and sent a backup signal that pressurized the tank. We were good to go, but the Sequencer just did not know “we were good to go” and put us into a hold when, at 30 seconds, it made its final complete check of all critical launch parameters prior to the full retraction of Swing Arm #1. This problem was quickly addressed by installing a shunt (hard-wiring) around a specific part in the IBM 360 computer circuitry so that Sequencer would ignore checking for that command execution. It would still take a couple of hours to verify everything and convince senior management that all was well. All through the wait, Parker and Launch Operations Manager Paul Donally kept us informed on the troubleshooting and remedial actions that were being considered.

Later, after Apollo 17 reached Earth-orbit, Launch Director Kapryan explained to the Press what happened and what was done to fix the problem as follows:

“At T-minus 2 minutes and 47 seconds the [Terminal] Countdown Sequencer [TCS] failed to output the proper command to pressurize the S-IVB LOX tank. The control room monitors noted it and immediately took steps to perform that pressurization manually. This was done, and at the time that we had the cutoff, we were up to pressure and everything was normal. The problem was that since the TCS did [not] output the command, the logic circuitry said that we really didn’t complete all of the launch prep for the S-IVB stage, and we do have an interlock in our countdown circuitry that precludes the retracting of Swing Arm #1 which occurs at T-minus 30 seconds if this has not occurred, and that is the reason for the cutoff.

“Now, it didn’t take us very long to determine that we should bypass this command failure and go through the pressurization, manually, and go through the rest of the countdown, except we weren’t completely certain that the final 30 seconds would all work properly. We did have a problem. How did we know that the last 30 seconds would work properly? How did we know that once we started igniting the 5 first-stage engines that perhaps we would get a cutoff on one of them, which we wanted to avoid at all costs.

“So that was the time consuming feature in the delay. We performed the operation of installing the jumper [shunt] which we were able to do in the firing room. We have a preplanned design where we can go in with banana plugs and put in jumpers to jumper any point in the circuitry that we desire to without having to go out to the mobile launcher, and that is what we did. [To test this,] The same jumper was installed in the breadboard [duplicate TCS circuit] at Huntsville, and the sequence was run through several times on the breadboard, and every time we had a successful run.

“We knew that there was in this particular [electronic computer] card where we had the problem, [and] there was a sequence that occurred at T-minus 22 seconds, the guidance alert sequence…that’s actually a discrete event. We were a little concerned over that one. Our logic told us that we could lose that and it would not interrupt the [launch] sequence what-so-ever. We went back to the breadboard in Huntsville, however, to demonstrate that. We actually cut that [S-IVB] command off and ran through the sequence again with the jumper and everything worked fine. We had every assurance that the failure we had was in no way connected with engine start circuit, which is the one [possibility] that personally gave me the greatest concern. Once we were satisfied that we had no problem in that area, we picked up the count and went on our merry way.

REPORTER QUERY: Did you have a premature ignition? Did we see something…

KAPRYAN: No, what you saw was a perfectly normal occurrence for the condition we were in. When we have a cutoff at T-minus 30 seconds, there’s…a lot of hydrogen being vented into the burn pond and it flames up quite a bit.

REPORTER QUERY: Were you at any time giving serious consideration at all to letting the launch slip until tomorrow’s window?

KAPRYAN: Well, when you run into a problem, before you get it resolved, you always have that concern. When we were about…an hour and fifteen minutes into the troubleshooting, we knew that we would not be able to recycle for tomorrow…We never did get to the point where we gave up and said, “it looks like we’re going to have to quit.” We knew we had quite a bit of time left [in the launch window], so we just worked the problem and didn’t think about scrubbing.

REPORTER QUERY: Due to the fact that TLI will be changed, how would this affect the timing of the whole mission as a whole [with] reference to the EVA’s and the TransEarth Insertion. Would this change anything in the timing or just the GET (Ground Elapsed Time)…?

KAPRYAN: It’s not going to change anything. The EVA’s and lunar activity will be exactly as scheduled. Now of course, the ground elapsed time when the spacecraft gets to the Moon is going to be different. But they’re going to get there at the same time that they would have gotten there, had we lifted off at 9:53. Now, I’m not certain how they’re going to play that [in detail]. If you recall, when we launched Apollo 14, we launched 40 minutes late. They of course made the TLI correction to get to the Moon [faster and] at the right [mission] time. And in order to simplify using the flight plan, I think they updated their GET reference [in Mission Control in Houston], so that they were using a fictitious GET reference that put them back on their flight plan [GET numbers].”

So, everything related to the launch of Apollo 17 was cycled back to the T minus 22-minute point in the countdown sequence. Cernan finally seemed to relax, Evans chatted and hummed away, and I took a nap. Outside, the viewers along the causeways and crowding the designated viewing areas of the Center consumed their snacks and drinks and Apollo Saturn Launch Control’s public affairs announcer kept providing his status reports.

“This is Apollo Saturn Launch Control, continuing to stand by at the T minus 22-minute mark in the countdown. Recycling operations have gone well. We’re back to the T minus 22-minute mark and at this mark which we will pick up the count if we are given a GO to resume. Check has been made of the Mission Control Center team at the Mission Control Center in Houston. All elements of that team report that they are ready to resume as soon as they get the word. Now standing by here at Kennedy Space Center, while data is reviewed and determination will be made if and when we can resume our countdown for Apollo 17. Now at T minus 22 minutes and holding; this is Kennedy Launch Control…

“This is Apollo Saturn Launch Control. We are continuing to standby at the T-22 minute mark. We are hoping to resume the count shortly. The problem has not been resolved. We’re continuing to look into it; however, it has been determined that a resolution one-way or the other should be able to be made shortly. So right now we are continuing our recycle procedures hoping to pick up the count perhaps just minutes from now. If the problem is not resolved by the time we reach the T-8 minute mark after we continue to count down, the clock will be held again. Right now we are continuing the recycling procedures hoping to pick up shortly at T-22 minutes. We are now T-22 minutes and holding. This is Kennedy Launch Control…

“This is Apollo Saturn Launch Control. We’re at T minus 21 minutes 10 seconds and counting. The countdown picked up, the launch team here made a quick check of the various elements, all reporting in to the test supervisor Bill Schick, indicating that they were ready to resume the count. Now counting at T minus 20 minutes 53 seconds, and we’ll continue to countdown here as we look at the problem which caused the hold at the T minus 30 second mark. Now at T minus 20 minutes 42 seconds and counting; this is Kennedy Launch Control…

“This is Apollo Saturn Launch Control. We’re at T-minus 9 minutes 36 seconds and we are counting. However, we do plan to continue the hold at the T-minus 8 minute mark. We can hold at that point for 20 minutes and plan a 20 minute hold while the launch crew here satisfies themselves that they have worked out a good solution and a work around to the problem. The crew has been alerted aboard the spacecraft. Schmitt indicated that perhaps they could start a nice conservation about a good book, Thomas Hardy or something like that. Countdown continuing now aiming toward the 8 minute mark at which time we’ll hold. T-minus 9 minutes now, T-minus 9 minutes and counting; this is Kennedy Launch Control…

“This is Apollo Saturn Launch Control. We’re now holding at the 8-minute mark, as planned. The hold at this time is planned for approximately 20 minutes. The [launch] crew feels that they have…a work-around to the problem, working around the indication going to the Terminal Sequencer that the tank has not been pressurized, when actually it had been done manually. They are checking all of their data, however, to insure that this is the proper method to work around the problem and that this will result in a smooth countdown from here on. Now at T minus 8 minutes and holding; this is Kennedy Launch Control…

“This is Apollo Saturn Launch Control. We’re continuing our hold at the 8-minute mark. The Launch Operations Manager has gone over with the launch team their proposed…work-around. The team appears to be satisfied that it is the proper one. They are now briefing management personnel on the problem and the work-around. Out at the pad the liquid oxygen continues to vent from the vehicle and is replenished. Liquid hydrogen is also vented from the vehicle as there is some boil off. However, because it is quite a volatile fuel it is vented through a burn-pond at the side of the pad. That burn-pond is at the north side of the pad and there it can be seen burning in a controlled condition at this time. This is a normal condition, actually during the day this burns in such a pure manner that it cannot be seen. However, at night it is clearly visible. Our countdown continuing to hold at the T-minus 8 minute mark at this time. T-minus 8 minutes and holding; this is Kennedy Launch Control…

“This is Apollo Saturn Launch Control. We’re continuing to hold at the T-8 minute mark. Meantime the [Apollo 17] crew is getting a variety of updates in the spacecraft, updating them on various aspects and the changes to their mission due to this hold period. Also, at the Manned Spacecraft Center they are continuing to update the flight azimuth as they get new times for the launch.

“Launch Operations Manager Paul Donnelly just went through quite an extensive briefing with the Spacecraft Test Conductor to pass on to the crew what they feel the problems were and how they plan to work around it. The crew aboard the spacecraft indicated that if the launch team was satisfied with these solutions, that they certainly were confident themselves. Now continuing our hold at the T-8 minute mark this is Kennedy Launch Control…

“This is Apollo Saturn Launch Control. We’re continuing in our hold at the T minus 8-minute mark. At this time, it’s been determined to take an additional 20 minutes, add an additional 20 minutes to that planned hold period. The reason for this is, the crews (teams) would like to take the work-around that they have devised and at Marshall Spaceflight Center, where the Saturn V launch vehicle was developed, they have what is called a bread board or a system, which is similar to this one [in the Terminal Sequencer] and run through the sequence and insure that it does operate properly. The crew aboard the spacecraft was informed of this additional 20-minute hold. They indicated that they expected to use all three stages of this Saturn V and they were happy to have the 20-minute hold if that was going to assure that all three were going to work properly. Now continuing our hold at the T minus 8-minute mark; this is Kennedy Launch Control…

“This is Apollo Saturn Launch Control. We’re continuing in our hold at the T minus 8-minute mark. Back at the Marshall Spaceflight Center in Huntsville, Alabama, the crews (teams) there are at work on a bread board, or a mock-up of the system in question, where they’re putting it through its paces, checking out the work around solution, that is, jumping (shunting) around this erroneous signal, and insuring that everything works properly. The crew is still standing by in the spacecraft, updating various systems there [and] updating their flight plan— all continuing to go well there. The [Flight Controller] crew at the Manned Spacecraft Center also is doing a considerable amount of updating. They’ll be continuing to update the [launch] azimuth, and the Launch Control Center here at Kennedy Space Center, the launch team manning their consoles, [is] standing by to pick up the count when we’re given the word to go. However, we’re standing by… At this time, we have no word from the Marshall Spaceflight Center. We’re expecting that to come within 10 to 15 minutes from this time. Now at T minus 8 minutes and holding; this is Kennedy Launch Control…

“This is Apollo Saturn Launch Control. We’re continuing in our hold period at this time. Test Supervisor Bill Schick just announced here in the Firing Room that the hold is expected to last approximately 20 more minutes. Liquid oxygen and liquid hydrogen [are] continuing to be replenished aboard the 3 stages of the launch vehicle at this time. That replenishing will continue during the hold period and during the final minutes of the countdown. The countdown is continuing in the hold. T-8 minutes and holding; this is Kennedy Launch Control…

“This is Apollo Saturn Launch Control. Continuing to hold at the T-minus 8-minute mark. The hold continues to be planned for approximately 5 to 7 more minutes. However, the launch window, it should be pointed out tonight, extends to 1:31 AM. Now if for any reason we could not make it in that launch window, we could recycle under our present configuration and resume our count aiming for a 9:53 PM EST launch tonight [December 7]. The window for tonight is the same as it was for last night and this morning— 9:53 PM to 1:31 AM. However, the launch team appears to be optimistic with the solution they’ve found in the problem and are just waiting for verification and confirmation from the testing going on at the Marshall Spaceflight Center at Huntsville, Alabama. The time now is 7 minutes after midnight. We’re continuing to hold at T-8 minutes. T-8 minutes and holding; this is Kennedy Launch Control…

“This is Apollo Saturn Launch Control. We’re at 15 minutes past the hour (12 midnight) continuing to hold at the T-minus 8-minute mark. The Supervisor just indicated that we finally pick up the clock at the T-minus 8-minute mark in 10 minutes. Planning to pick up the clock at 25 minutes past the hour. The tests being run or have been run now at the Marshall Space Flight Center and indicate that our system is good the way it has been reconfigured. All elements during this 10 minutes will be preparing their various systems to pick up the clock at the T-minus 8-minute mark. Meanwhile, at the Manned Spacecraft Center, the Flight Controllers there also [are] planning to pick up the clock. We just received a go from the Superintendent of Range Operations indicating that the range has been cleared around the new flight azimuth. The Manned Spacecraft Center Houston Flight Controllers indicate that they are go to pick up the clock at 25 minutes past the hour. Now at T-minus 8-minutes and holding; this is Kennedy Launch Control…”

“Seventeen, we have reset the countdown to T minus eight and we are go for launch!” Apollo 17 then repeated the events of the final eight minutes of the first launch attempt. Finally, the actual launch approached.

“This is Apollo Saturn Launch Control T-minus 5 minutes 40 seconds and counting. At this time, the various elements of the launch team have been reporting in to Bill Shigby, Test Supervisor, indicating that we are GO to continue. Mission director Chet Lee just verified that we are GO for launch. Safety indicates that we have a GO. First Stage Test Conductor – this is the man who has charge of those five first stage engines which will give us the lift off – has indicated a go for launch. Launch Operations Manager, Paul Donnley, also giving us a GO for launch, and finally the Launch Director, Walter Kapryan says we are GO for launch…

“Mark. T-minus 1-minute and counting. Now, in the final minute of the countdown – at T-minus 45-seconds, Gene Cernan will make the final guidance alignment.

“Mark. T-minus 45 and Gene Cernan made that final guidance alignment. That’s the last [pre-launch] action taken by the crew aboard the space vehicle. Now approaching the half-minute mark. T-minus 33.

“T minus 30 seconds and continuing on at T minus 26 seconds.”

Half a minute to go again! The animal-like preparatory movements and murmurs of the Saturn now seemed familiar.

“Mark. T minus 25 [seconds]. We’ll get a final guidance release at the T minus 17-second mark.

“T minus 17, final guidance release. We’ll expect engine ignition at 8.9 seconds… 10 . . . 9 . . . 8 . . . 7 . . . ignition sequence started – all engines are started…”


At T minus 9 seconds, heavy, low frequency, massaging vibrations began against our backs as the five F-1 engines quickly worked up to full power at the base of the Saturn’s first stage. Thousands of gallons of kerosene and liquid oxygen fed an insatiable appetite as the huge hold-down arms held us to the Earth for a final six seconds before releasing us to space. 7.5 million pounds of thrust would lift us slowly at first and then faster and faster toward orbit on a trail of brilliant flame, not visible to us but splitting open the night for everyone below. Pulsing waves of sound and searing streams of light buffeted the bodies and minds of onlookers, bringing spontaneous and unexpected hugs, cries and tears.

As the S-IC engines came up to full thrust, their respective lights on the panel in front of Evans went out. Once again, a life-tipped pillar of fire, the Saturn rocket, a massive tribute to boldness and imagination, became a blazing symbol of human potential for greatness. Except for reflected light coming through the small window in front of Gene and another in the Boost Protective Cover over the hatch, I had only a vague sense of the brilliant flame beneath us. An otherwise welcome protective shield covered the left and right side square windows and the small oblong window in front of me.


“Liftoff!” called Parker (Fig. 5.1).

“Roger. We have liftoff! The clock has started. We have you.” Launch program P11 took over from PO2 and laughter came from America over the communications loop.

Fig. 5.1. Release of the hold-down arms and initiation of the lift-off at 12:33 a.m. EST, Dec. 7, 1972 after a 2 hr 40 min delay from the scheduled launch time of 09:53 p.m., Dec. 6, 1972 (NASA photo KSC-72PC-598).

“We have a liftoff. We have a liftoff and it’s lighting up the area, it’s just like daylight here at Kennedy Space Center as the Saturn V is moving off the pad.”

Fourteen, heavily vibrating seconds went by: “Clear the tower,” reported Launch Control.

“Yaw’s complete. We’re into roll, Bob.” We were now communicating through Mission Control at the Manned Spacecraft Center in Houston. (Robert “Bob” Overmyer, one of the last group of astronauts to join the Apollo team, was serving as our CAPCOM for the initial launch and Earth orbit phases of the mission.)

Cernan made his calls as heavy, low frequency vibrations continued to shake us as if we were driving a pickup at high speed over the ties on a railroad bed. Immediately, the static launch simulations of the last sixteen months seemed ridiculous as the blur of vibrating needles and numbers prevented any onboard monitoring of spacecraft systems (Fig. 5.2). Unlike the simulations, when we competed with flight controllers in the rapidity of problem recognition, for the next two minutes and 45 seconds of shaking, we committed ourselves fully to the distant eyes and brains of controllers as they watched the flow of telemetry on their console screens.

“Looking great!” called Overmyer. “Thrust good on all five engines.”

“Roll is complete! We are pitching.”

“Wow woozle!”

To which Evans added, “Okay babe! …Let’s check the [attitude] angles… Thirty seconds. We’re going up! Man, oh, man!”

As the rocket pitched so that we were headed east as well as upwards, we began to take advantage of the nearly 1000 miles per hour rotation of the Earth at the launch site, about six percent of the velocity we would need to attain a stable orbit. Acceleration forces gradually increased, adding to the new experiences for the two rookies.

“Seventeen, you’re GO.”


Fig. 5.2. The main Apollo Command Module Block II instrument control panel (pre-Apollo 11). Enlarged sections of the line drawing, which show panel numbers, are available by clicking here. (NASA drawing).

Everything looks great over here, Gene,” I said as I completed as much of an instrument scan as the vibrations allowed. I particularly was monitoring cabin pressure to be sure that cabin pressure began to decrease as we passed about 14,000 feet in altitude. If this did not happen automatically, I would place the CABIN PRESSURE RELIEF valve to DUMP to solve that problem.[2]

“Seventeen, stand by for MODE ONE BRAVO…MARK. Mode I Bravo.” At about one minute, Overmyer called the phase of Abort Mode I we would be in to escape from an impending SI-C explosion in the atmosphere using the Launch Escape System (LES). This system’s rocket, called the Launch Escape Tower (LET), would pull America rapidly away from any such problem. Abort Mode I had three phases, Alpha, Bravo and Charlie, relating to how far downrange we would splashdown after leaving the Saturn.

“Roger. ONE BRAVO – we’re GO at one minute.

“Seventeen, you’re looking great. Right on the line.” Overmyer referred to the “line” of the planned trajectory displayed on the big screen in front of the MOCR (Missions Operations Control Room) in Mission Control.

Okay, we’ve got the RCS [Reaction Control System] Command,” Cernan reported to Evans and me. This ability to command the reaction control system from the spacecraft would allow Cernan to fly the launch vehicle using America’s guidance display instruments if, for some reason, the Saturn’s own control system ceased to function. Prior to this point, the RCS would automatically dump its dangerous hypergolic propellants (dymethyl hydrazine and nitrous oxide) if we had an abort.

“Seventeen, you are feet wet – feet wet.” Overmyer was telling us that after this one-minute point into launch, any abort off the Saturn with the Launch Escape System rocket, taking measured winds into consideration, would end up with a splashdown in the near-by Atlantic rather than in the Merritt Island National Wildlife Refuge surrounding the launch site.

Superposed on the heavy vibration, the forces of acceleration had gradually increased, adding to the new experience. These intense rocket and aerodynamic vibrations also continued to increase until at about one minute and 20 seconds and an altitude of about 50,000 feet we approached the point of maximum aerodynamic pressure, or “max q,” on the rocket – the point where aerodynamic stresses on the Saturn V reached their maximum and began to decline due to decreasing outside air density.

Evans broke in with “Hey, this thing shakes like a…son of a gun! …One thirty, about 50 degrees [pitch].

50 degrees. Okay, right on. One thirty, and we are GO, Bob.”

“Roger, Gene. You’re looking great,” replied Overmyer.

…two g…two and a half g. See it quiets down after max q…pushing 3 g’s.

Okay, I can’t hold my hand up there [on the instrument panel] any more,” Evans laughingly admitted.

Cabin’s still looking good,” I reported to Cernan and Evans after scanning the pressure and circulation gages I monitored in the right, systems engineering position of America.

“MODE I CHARLIE,” Overmyer called as we passed through about 100,000 feet.

“Roger. ONE CHARLIE,” Cernan acknowledged. “Two minutes and EDS (Emergency Detection System) [AUTO] is OFF and we are GO.” We also turned off other S-IC vehicle rate indicators in preparation for S-IC shutdown and staging.

“Seventeen, you’re GO.”

Three g’s…three and a half. Stand by for inboard cutoff [of one of the S-1C’s F-1 engines],” Cernan cautioned us.

Two minutes after liftoff, amid the continued intense shaking and with our weight headed toward four times normal, I wondered about having the strength to lift my arms to switches if an emergency made it necessary to reconfigure fuel cells, batteries or oxygen supplies. Of course, in any possible launch abort, as soon as the abort acceleration away from the Saturn stopped, and we would be in weightless ballistic flight, both the vibration and g’s would disappear. At least then I would be able to reach any switches that needed to be reached.

“Seventeen, you are GO for staging.”

“Inboard cut-off!” Suddenly, the S-IC’s first-stage center engine went out. Had two minutes and 20 seconds gone by already!?

Our acceleration continued to increase on the remaining four engines.

Okay, now hold on for staging.

Stand by, gang,” I said, unnecessarily.

Three and a half g’s. … Hold on. …Five seconds. …Pushing four g’s…

Then, 25 seconds after inboard engine cutoff, and at an altitude of about 220,000 feet, the four outer first-stage engines stopped, explosive bolt cutters immediately separated us from the first stage, the second stage S-II’s five J-2 engines ignited, and we continued on our way again with the S-II reaching full thrust over the next few seconds. This rapid sequence took us from a positive acceleration of four times Earth’s gravity (g), through a negative acceleration of 1.5 g’s, as acceleration briefly ceased and the entire stack unloaded, and, finally, to a positive 1.5 g’s on the second stage engines. All this happened in just over a second! That got my attention! You appreciate the lap belt and shoulder harness as checklists bounced back and forth on their lanyards.

Told you to hold on! …Look at that son of a gun!” Cernan was referring to the plume of fire that enveloped the rocket as our acceleration briefly ceased and actually went negative. Really spectacular even with all the windows still covered except for Cernan’s direct view toward a still invisible night horizon.

“Okay, Bob,” I called. “I guess we got all five [S-II engines burning],” looking at the status lights on the panel.

“Looking good here…looking good,” Overmyer replied.

“I think we saw them all [ignite] from here!” I exclaimed, referring to the light coming into America through the one window in front of Cernan.

“Jack, the thrust is GO on all five of them,” Overmyer assured me. “They’re running good.”

“Okay. Three minutes and we’re GO.”

“Roger, Seventeen.”

Hey, this is smooth,” observed Evans.

Being propelled into space by the five hydrogen-oxygen J-2 engines of the S-II felt like a ride on deep velvet by comparison with the raw violence of the five, kerosene-oxygen fueled F-1 engines of the S-IC. The displays and switches suddenly became recognizable again, and I could participate in monitoring the performance of the spacecraft systems that sustained us in the cabin and that might be needed immediately in the case of an abort.

If the Saturn V guidance had failed on us and everything else showed the rocket performing normally, Cernan could have taken control and flown an altitude-pitch profile for the rest of the boost phase. All that would need to be done would be to switch the Launch Vehicle Guidance switch to CMC (Command Module Computer) and to key and enter Verb 46 on the computer display for program P11.

Okay,” I said. “I got the Tower switches.” I referred to putting my hand on the Launch Escape Tower (LET) jettison switches that I would throw as backup if the automatic sequence did not do the job when it was soon supposed to. The LET solid rocket engine had 147,000 pounds of thrust, almost twice that of the Redstone rocket that carried Al Shepard to a sub-orbital flight in 1961. The LET, however, would be jettisoned using much smaller rocket engines when we entered the Abort MODE II (outside the atmosphere and aerodynamic forces) with speed and acceleration too great for its rockets to be capable of pulling the Command Module away from a failing Saturn. After jettisoning the Tower, we were above enough of the atmosphere so that we could depend on the Service Propulsion System (SPS) of our spacecraft for any necessary maneuvers in case of an abort.

But first, the short, cylindrical “skirt” between the S-II and the S-IC stages of the Saturn V had to be separated for its fall into the Atlantic. “Okay. We do have skirt sep,” Cernan reported about 25 seconds after staging and S-II ignition.

“There goes the Tower,” radioed Cernan. “Oh, there she goes!” At three minutes and 20 seconds, we had reached about 320,000 feet in altitude and 5590 miles per hour in velocity. When the tower left, it pulled the protective cover off the Command Module and its windows and suddenly the bright light of the LET’s jettison rockets filled the America’s cabin. Now, Ron and I could finally see outside and experience the decreasing glow from the flame of the Saturn V rocket plume diffusing through the atmosphere. Prior to jettisoning the Tower, Cernan’s one window directly in front of him was supposed to give him a view of the Earth’s horizon in case he ever had to fly the spacecraft without computer guidance during a launch abort. Not likely to happen with an essentially invisible night horizon but something that he thought he was prepared to do if necessary. Also, at this point, with little atmosphere remaining outside, I could activate the glycol cooling system that was dependent on radiating heat to space.

“You’re in MODE II.”

“Roger. MODE II,” confirmed Cernan. Mode II would require America’s independent separation and orientation to entry attitude for parachute deployment and splashdown in the Atlantic.

“The steering [guidance input] has converged. The CMC (Command Module Computer) is GO. You’re going right down the pike, Seventeen!” This information confirmed that, if necessary, we could continue to rely on America’s computer to fly the booster or perform an abort and entry sequence.

“Okay, Bob. I just confirmed guidance [here].”

And [pull] the ELS SEP (Escape Launch System Separation) circuit breakers, when you get a chance there, Gene,” Evans reminded Cernan. Those breakers were on the panel to Cernan’s left. With the LET gone, obviously, we did not need to have power to the system as a whole.

“Okay, Bob. I got the ELS SEP circuit breakers. And, we’ve seen it all – ignition, staging, and tower.”

“Roger. Got you.”

By the way, the cabin [has] sealed,” I assured Cernan and Evans after watching my cabin pressure gage and got a nervous laugh out of both.

“Okay. Four minutes and we’re GO here, Bob.”

“Roger, Gene. We’re going round the room.” Overmyer referred to a formal process that Flight Directors, in this case Gerald Griffin, conducted prior to various critical points of mission commitment, receiving a verbal “GO” from each Lead Flight Controller. “Looks GO here. You’re looking real good, Gene. Right down the line.”

21 degrees [pitch]. We’re MODE II, Ron,” Cernan remarked.

“Okay, 04:30 and we’re still GO on board, Overmyer reported. “Let me tell you, this night launch is something to behold.”

Okay. H [altitude] and H-dot [altitude change rate] are good,” I observed, looking at a cue card graph of those two parameters versus time from launch and comparing with the data displayed on the computer.

Okay, I don’t know if you’ll be able to pick up any horizon,” Cernan commented to Evans and me. If there was no other information on the pitch and roll of America during launch, a very unlikely set of failures, Cernan had trained in the simulator for the possibility of flying the rocket with hand-controller inputs and using the horizon as seen out the window (#2) directly in front of him that had a reference line for guidance. The window (#4) in front of me had the same potential view and Cernan’s comment related to such an eventuality.

Well,” I responded, “it’s [either] too dark [out there] or too light in here [to dark adapt].

Okay, let’s keep on looking. I got some stars out the right, but I don’t see [a horizon line].

“Five minutes, Geno, and you’re GO down here. You’re looking great.”

What’s that? Okay. Okay, Robert,” replied Cernan, caught a little off guard. “We’re GO here at five [minutes].”

Coming up on S-IVB to COI (Contingency Orbit Insertion), Evans warned. This meant that if the S-II quit on us, the third stage S-IVB had enough energy to get us into a stable orbit.

You guys believe me about that S-I staging now? said the guy who had been through it before on Apollo 10.

I acknowledged with a laugh and said, “I can’t believe how smooth! I can’t believe how smooth [this S-II burns].

Okay. Let’s keep this burn. We got a long way to go. We’re only halfway there [to orbit].” As if we had much to say about the performance of the Saturn V.

“Seventeen, Houston. Your [projected S-IVB cutoff and orbit insertion] times are nominal. Level Sense Arm (a sensor that determines ‘level’ relative to our eventual orbit) at 8 plus 36; S-II shutdown at 9 plus 20.”

Following the cue card checklist, Evans said, “Coming up on [SPS] gimbal motors [checks].

Okay. I forget anything, yet, Ron?


Okay. We’re still MODE II…” While Evans kept a close watch on the checklists, I kept scanning all the status indicators in front of me dealing with environmental controls, fuel cells, batteries, propulsion tank pressures, and communications.

Six minutes. “Standby for S-IVB to COI capability. MARK. S-IVB to COI capability,” noted Overmyer. At this point, if the S-II stage quit, we could ignite the S-IVB and have enough energy for a “contingency orbit insertion” from which we could have a controlled entry to a planned recovery area and ship.

Cernan acknowledged, “Roger, S-IVB to COI capability. We’re GO at six. …Okay, let’s check the gimbal motors [of America’s main rocket engine, the SPS]. After I confirmed the four GIMBLE MOTOR switches were in the START-ON position, he and Evans ran through those checks, he reported, “Okay Bob. We’ve got four good [gimbal] motors and we’re GO at 6:20.”

“Roger. And, Seventeen, we copied the gimbals and watched them and they looked good.” These gimbals would allow us to use the SPS to steer into orbit if the S-IVB failed late in its burn.

Then Evans said, incredulously, after looking at the g-meter, “One g? Just like sitting on the pad, isn’t it. That’s all there is to her.

I was watching hydrogen tank 3 that fed the Service Module’s fuel cells, saying, “Okay, our [gage] calibration on that tank changed a little bit again, apparently. …[Showing]…Down to 90%.” I was hoping that it was only a calibration variation and not an actual leak caused by the stresses of launch and staging. Mission Control had telemetry data on the status of the tank and would have alerted us if they saw a problem.

“Seventeen, MARK. S-IVB to orbit capability,” was Overmyer’s call at six minutes, forty-five seconds. This meant that after a premature second stage shutdown, the single J-2 engine of the S-IVB could deliver us to a stable, long term Earth orbit from which we could conduct a disappointing, but still productive Earth-orbit mission of observation and photography. “And we’d like OMNI [antenna] Delta, Jack.”

“Roger. You’ve got it.” In the midst of rockets moving us toward the Moon, the routine of space flight communications continued.

Okay, seven minutes, six degrees [pitch]. How does that sound?” Cernan asked Evans.

Okay. That’s good. …We’re a half a mile high [relative to plan].

“Seven minutes, Bob. We’re looking good on board.”


Am I glad I took my hand off that abort handle,” Cernan declared, referring back to the hold we had at 30 seconds before launch when his left side Thrust Vector Control T-handle functioned as an instant abort trigger if twisted counter-clockwise.

Man!” Evans exclaimed.

So am I! I’ll tell you,” I agreed while we both laughed at the historic irony we would have experienced if Cernan had lost his nerve during the initial uncertainty of the hold on the Pad.

Okay. We got to get through this one [S-II cutoff] and then through staging. Stand by for inboard [J-2] cutoff].

Okay. Inboard [scheduled] at 07:41, Evans responded.

Okay, we’re [at a] g and a half. Stand by.

“We have inboard [S-II engine] cut-off (IECO).”

“Roger, Gene. Inboard [cut-off] on time.” The early termination of thrust on the center engine of the five J-2 engines in the S-II stage was the result of a major vibration (pogo[3]) problem with the inboard J-2 on the Apollo 13 launch and a lesser one on other missions as remedial engineering and operations began to take effect.[4] The structure holding that engine came very close to failing at the end of the Apollo 13 S-II burn. No certain fix of this problem appeared possible so the conservative approach was to shut it down early and to also shutdown the inboard engine of the first stage early as well, just in case. The other four engines would burn to propellant depletion, giving us most of the energy, but not the acceleration, that five engines would have provided.

Okay, and she pitches up just like the simulator,” commented Cernan after inboard J-2 cutoff. Cernan’s comment illustrates how good the simulator models had become by the time we started training for Apollo 17.

Yes, sure does,” confirmed Evans.

As I was trying to reach something, Evans said, “Is that hard to reach, Jack?

Yes. Why don’t you take it out. I can’t quite [reach it at a] g and a half,” I joked, referring back to the problems of lifting an arm at 4 g’s.

“Eight minutes, and we are GO!”

“Roger, Seventeen. You’re looking great!

Stand by for a PU (propellant utilization ratio) shift,” Cernan reminded us.

Yes, I think that was it,” Evans confirmed.

Okay, Ron. Level Sense ARM will be at 36 [8 minutes and 36 seconds].

“Seventeen, Houston. You are GO for staging.” If Mission Control had seen a significant problem in the third stage S-IVB, we would have begun preparations for an abort off that stage and a controlled splashdown in the Atlantic.

“Thank you, Bob. We are GO for staging up here.”

Little over a g,” Evans called out.

Okay. We got to get through this one [staging]. Coming in… We’re Level Sense ARM, now.

“You have Level Sense ARM at this time, Gene.”

“Roger, Bob. Level Sense ARM… Okay, Ron. Our next thing will be stand by for Mode IV, and we’ll have staging – I’ll call it out to you. And little S-IVB – burn, baby, burn!

“Nine minutes, Bob, and Seventeen is GO!”

“Roger, Seventeen. You’re GO here. …Stand by for Mode IV capability.”

“S-II cutoff!

“MARK. Mode IV capability, and we copy cut-off.” Mode IV meant that we would use America’s main rocket, the Service Propulsion System (SPS), to achieve an orbit from which there was time to select an optimum splashdown location.

“Roger. Mode IV. And we do have S-IVB ignition!” In another rapid sequence, outboard engine shutdown and staging of the S-II and ignition of the S-IVB third stage came as planned. Our altitude was actually slightly above the planned orbit of 92.6 nautical miles (about 556,000 feet), but we needed for the S-IVB to add about 2500 feet per second to our velocity. These milestones passed in a space of five seconds around nine minutes and 20 seconds.

“Roger. We see it, and the thrust is looking good on it.”

Jack, did you see that glow go past us! Evans shouted.

Gee! …Yes. We’re right in the flame!

“We saw that one, too, Bob,” Cernan exclaimed. “Yes, that’s what the Titan used to do, used to fly through the flame of that thing. …Let’s press on here. We got a lot to do. We’re Mode IV?

Yes,” I answered, wondering if he had been paying attention to his own and Overmyer’s call-outs.

Cernan continued to state the obvious. “Okay. We’re at a little less than ½ g.

Less than ½ g, sir.

“Seventeen,” Overmyer interrupted, “the [S-IVB and on-board guidance] steering has converged, and the CMC [Command Module Computer] is GO [if needed]. You’re looking great!”

“Roger,” Cernan replied. “The CMC is GO – 10 minutes and Seventeen is GO on board.”

The S-IVB purred quietly away beneath us with every indication that it would serve us well in the long acceleration from 16,560 miles per hour we would have in a 106-mile high orbit around the Earth to the 23,335 miles per hour we would need to escape the Earth and ultimately be captured by the Moon’s gravity. Making “a trip to the Moon” was looking more and more likely.

Okay. …[S-IVB burn] starts a little bit low, but not bad,” Evans observed, watching the altitude readouts on America’s computer and comparing them with the cue card numbers.

“Seventeen, Houston. You are GO for orbit. …GO for orbit,” Overmyer relayed at ten minutes after Mission Control had analyzed the telemetry from the S-IVB. Less than two minutes left on the Saturn, and we now knew that the chances were very good that there would be nothing to keep us from making it to Earth orbit. Orbit insertion approached with increasing anticipation. For Evans and me, this would be our first real exposure to space! We had earned our gold astronaut pins several minutes earlier as an altitude of 50 miles went past on the S-II second stage, however, true space flight would be very different.

“Those are kind words, Robert. We’re GO for orbit, here.”

“Good show, Gene!”

Okay, coming up on [10:]30, Ron. Let’s double check everything.

[At] 30 347 degrees [pitch] – 23.9 [thousands of miles per hour]. Okay. …We’re a little bit high [in altitude], Evans continued to report. The pitch number he called out related to being upside down and nearing level flight of 360/0 degrees.

I couldn’t read (sight on) a star if I had to right now,” Cernan observed, looking out window #4 in front of me.

I couldn’t either,” I agreed.

Velocity is a little high,” Evans noted, meaning that the S-IVB’s J-2 engine thrust was slightly greater than expected.

“Okay. 10:30, and we’re GO,” Cernan reported.

“Roger, Seventeen. You look great,” confirmed Overmyer.

Okay, cut off at VI [insertion velocity] plus 100 [fps],” Cernan told Evans.

Okay, I’ll catch that.

I sure don’t want to hit this handle,” Cernan commented, referring to the hand-controller that could start an abort sequence.

I agree!” I said.

Mode IV right now, Cernan reminded himself, again. “Coming up on eleven minutes.

Okay,” Evans acknowledged. “Eleven minutes and I’m 344 degrees [in pitch].” This pitch readout was relative to 90 degrees pitch up on the launch pad; however, we had rolled 180 degrees to about 270 degrees pitch during the first portion of the S-I burn. “That’s right on the money. …How’s the cabin, Jack?

Cabin’s great,” referring to internal air pressure and no sign of leaks.

Okay. Velocity’s a little bit high and H-dot’s [rate of change in altitude] a little bit negative,” Evans said, monitoring the computer display of altitude rate of change (H-dot) versus altitude.

H-dot’s a little…bit low.” The rocket’s guidance was taking out some of the excess altitude.

Okay, the [manual S-IVB] cut-off is VI [insertion velocity] plus 100 [feet per second], Cernan reminded himself and Evans.

VI plus 100. Okay, I’ll count you out,” replied Evans.

I just want to hit the [button]. …That’s all there is to it.

“Eleven minutes and we are GO,” Cernan reported to Houston.

“Roger, Gene. And cut-off will be at 11 plus 47, 11 plus 47.”

Evans again reported, “H-dot’s a little high. But that’s all right. …500 feet [per second velocity] to go.

“11:30 and we’re GO here. And standing by [for cut-off].”

“Roger, Gene. Cut-off time is still holding good – 11 plus 47.”

There she goes!” Evans could not contain himself as the S-IVB J-2 engine shutdown.

“Cut-off at 42!” Cutoff occurred nine seconds earlier that the normal time indicated in the Launch Checklist, reflecting higher booster performance than expected.

“Understand. Cut-off at 42,” Overmyer replied more calmly than Cernan’s reporting.

Okay, [copy] 25596, Ron.” Cernan read out our orbital insertion velocity (VIO) in feet per second from the Command Module Computer (CMC) display. This was about 100 feet per second less than expected but nothing to be concerned about.

25596. …Okay, KEY RELEASE…” This action on the computer Keyboard gave us its computation of our apogee, perigee and TFF (time from re-entry).

“We’re looking at 93.1 by 89.5 [nautical mile orbit apogee and perigee],” Cernan read off our computer display.

“Roger, Gene. We’re copying the DSKY (Display and Keyboard) [from telemetry],” confirmed Overmyer. “…And the local horizontal maneuver has initiated [by the S-IVB].”

“And Houston…it looks like the [S-IVB] tank pressures are venting [going down].” This relatively small amount of venting keeps the tank pressures within safe limits until we would restart the rocket about three hours later for a trip to the Moon.

“Roger, Gene. The Range Safety [rocket destruct system] is SAFE and…you’re in a GO orbit, nominal.” This destruct system obviously was not needed once we were in a stable orbit.

“Roger. GO orbit, nominal. Thank you!”

Earth Orbit

The S-IVB cut-off five seconds earlier than Houston predicted, giving us a slightly elliptical orbit of 107 by 103 miles. Even though we watched the computer displays and mission timer count us down to S-IVB shutdown, sudden weightlessness came as a complete surprise. No weight! Weightlessness no longer existed as a fleeting memory of a childhood carnival ride or the few tens of seconds during parabolic training flights in a KC-135 “vomit comet”. Now the sensation went on and on!

“Hey, where did that panel screw come from?” Every object not fastened down or stowed floated by, headed eventually for the screen in front of the cabin air intake fan in the Lower Equipment Bay (LEB) to the left of the center couch. Moving from place to place by slight finger or hand pressure on a strut or panel felt like swimming without any water. How could anyone have ever called doing this outside the spacecraft “space walking”? Only cautions concerning motion sickness given by others who had been there before and the demands of the post-insertion checklist kept me from playing with the tumbling abandon of a child. In fact, after some movement around the now much larger useful space of the Command Module cabin, I noticed that I had a slight headache and very slight “stomach awareness” similar to my feelings after an hour or so of heavy aerobatics in a T-38. I found that if I stopped moving for a few minutes, these symptoms would go away, and I could start up again. Repeating this procedure several times over the next few hours seemed to gradually provide some immunity against any significant adaptation discomfort. Cernan and Evans would appear to be not so fortunate.

“And Seventeen, I’ll be unable to update that AOS [Acquisition Of Signal] time, but 52:20 is looking good.” Overmyer referred here to when we would regain communications after we lost sight of the Vanguard communications ship on our way over Africa. Vanguard, stationed in the Atlantic off the coast of Florida, had supported launch communications.

At this point, I asked Overmyer, “Houston, can you confirm MAIN BUS TIE A/C – OFF? …I’ve been carrying very low amps on the BAT BUS, and I did not see a drop. I’m carrying about 2 amps now. Volts are 30.5.”

“Jack, go ahead and take the B/C MOTOR switch OFF.”

“Okay, it’s OFF. And I confirm that one [shows OFF].”

“And we think it’s the EDS POWER switch (Emergency Detection System) and the Fuel Cell…switch that are drawing the current that you’re seeing there.”

“Okay. That could well be,” I replied.

“Okay, Jack, we’re going to lose you in about one minute off of Vanguard here and see you at 52:20.”

“Roger. We’re pressing [with the Checklist items] and thanks, Bob.”

“Okay, Bob,” Cernan inserted. “Everything is looking GO on board. Everything’s stable. We can see the [S-IVB] APS [Auxiliary Propulsion System] firing and our attitudes look good.”

“Geno, everything is in good shape down here. The booster’s in good shape; you’re looking good; and their [confirmed] AOS time is 52:20 as I gave you.”

“We got that, babe. We’ll see you coming around.”

“Good show, babe,” Overmyer repeated. “A little late [liftoff] but a good show!”

“Outstanding ride.”

It is interesting to note that Apollo 17’s launch vehicle, Saturn 512, had no significant departures from its expected performance.[5] The fact that the Apollo Program was near its conclusion makes this nearly perfect performance it made more remarkable. The continued dedication of the thousands of American workers who were still required for this single mission encourages me to this day.

[There have been many descriptions written about the night launch of Apollo 17. One of my favorites is that penned by my good friend and co-editor of this diary, the late author and political humorist William Mellberg.[6] Mellberg remembers the launch of Apollo 17 as follows:

“There was a collective and audible gasp from the crowd as the powerful F-1 engines of the rocket’s first stage suddenly came to life with a blinding light that took one’s breath away. It was an incredible sight.

“The sound finally hit us as the vehicle cleared the tower. First, there was a “boom.” That was the noise from ignition. Then there was a rumble, not a roar, as the Saturn V slowly rose from the pad amidst clouds of steam and smoke produced by the water used to cool the pad as it was blasted by the heat of the engines. I thought I could feel that heat. I certainly felt the ground shaking. And, as Tom Stafford’s neighbor had told us, we could hear the VAB rattling behind us as the sound bounced off its walls.

“As the Moon Rocket picked up speed and altitude, the sky grew even brighter as the light from the engines rose above us like the Sun— a long tongue of flame trailing behind it. What a light and sound show! At the 1-minute mark, the sky was becoming dark again as the Saturn V flew higher and farther away. It now looked more like a comet with its long, bright tail. We could also hear the crew over the loudspeakers. ‘One-thirty and we are go,’ Gene Cernan reported from the spacecraft. When the first stage engines shut down after two and one-half minutes, we could see the nozzles glowing bright red and still trailing smoke. Meanwhile, the second stage engines had ignited, and they produced a steady, white light that grew smaller and less intense as the vehicle picked up speed and distance. Soon, all we could see was a ‘star’ that finally faded out of sight as the Moon Rocket headed out of range.

“Wow! I was awestruck. So was my Dad. So was everyone around us. We were all amazed by what we had just witnessed. Directly in front of us, steam was still rising from Pad A. The thunderous sound of the Moon Rocket had been replaced by the noisy chatter of the crowd— recounting what they had just seen. Most people were too busy talking to hear the ongoing coverage from the public address system. Apollo 17 was approaching the coast of Africa as we headed back toward the buses and the ride back to the Visitors Information Center. No one was going away disappointed that night. It was truly a once-in-a-lifetime experience.”

Another favorite comes from Gunter Wendt[7] who viewed the launch after he had left the White Room with the three of us strapped up inside America.

“…shortly after midnight, the Saturn 5 blasted into the blackness. As the vehicle cleared the tower, the flame seemed much more intense than anything I had ever seen. By the time it was 10 degrees above the horizon, the entire sky lit up in an odd greenish yellow glow. It was like daylight on another planet. …For one last time, I was engulfed in the crackling concussion and felt the ground tremble under my feet. And for one last time, three Americans departed Earth for a trip to the moon.”

Tom Kelley, Grumman Aircraft Corporation’s Chief Engineer for Lunar Module development, provided an engineer’s, manager’s and poet’s impression of the launch.[8]

“The dazzlingly bright yellow-white plume spilled out from beneath the Saturn booster and, as the black-trimmed white cylinder cleared the tower, expanded until it looked like the rocket was riding astride the Sun. The nighttime darkness vanished in the harsh light of a klieg-light white dawn, showing the flat expanse of dunes, wetlands, and tropical scrub growth to the far horizons. I gaped open mouthed at this manmade wonder, and forgot about the oncoming shock of sound until it hit my ears with staccato fury and sent earth tremors up my legs. Then as we stared in wonder, the Sun slowly transformed into a brilliant star and the shrinking rocket became less distinct in its glare. For several minutes our eyes were riveted skyward, until the sound bombardment faded to a distant rumble and the departing moonship was a dimming star. Darkness reclaimed its rightful reign over southern Florida, but the curving trail of fluffy white exhaust cloud, luminous in the light of the target Moon, attested to the reality of the miracle we had all witnessed.”]

My own memories of the daytime Saturn launches for Apollo Missions 8-15 are dominated by the slowly increasing brilliance of the exhaust flames and the pulsating waves of sound that buffeted deeply into my stomach and lungs while my shirt and tie moved back and forth as if a desert wind were blowing – and flocks of water birds rising from the surrounding wetlands and estuaries in temporary response to the passing disturbance. (See Mother’s diary, Appendix I for December 7.)

First Look From Space

“Seventeen, Houston. We’re hanging with you here [with the communications]. Looks like you’re hanging in Vanguard a little longer than we expected.”

About five minutes after cut-off, we began the necessary 36-minute, no-communications period. While now loosely strapped on to my couch, I read through the Insertion and Systems items in the Launch Checklist that served to reconfigure switches and circuit breakers that related to various abort and contingency possibilities during launch while preparing America’s systems for our two orbits of the Earth before beginning to anticipate the TransLunar Insertion burn of the S-IVB. As I read, Cernan and sometimes Evans would confirm the changes from the launch switch and circuit breaker configurations. I kept close watch in order to be sure what I called out was actually done, as Cernan had an Apollo 10 history of switch position confusion and a well-known susceptibility to becoming distracted.

I first turned past the Checklist page that gave the emergency procedures for using small Reaction Control rockets needed to de-orbit if there was an inadvertent separation of America from its Service Module just after orbit insertion and while the abort systems were still armed. Back on the main Checklist, I confirmed that the four SPS Gimble Motors were switched OFF on Panel 1.

SECS PYRO ARM, two, SAFE. These switches arm and safe the Sequential Events Control System, that is, the system that controls the explosive (pyrotechnics) separation events over which the crew had control versus those events related to the Saturn S-IC and S-II stages.

PYRO ARM, two of them are safe. replied Cernan, hesitantly as the adrenaline of the launch faded.


Two LOGIC are OFF.

Circuit Breaker SECS ARM, two, open.

SECS ARM circuit breakers are open. These actions involving the SECS and pyros avoided any unplanned vehicle or S-IVB separations.

Circuit Breaker DIRECT ULLAGE, two, open.

DIRECT ULLAGE breakers are open.

Circuit Breaker ELS/CM-SM SEP[ARATION], two, verify open.

ELS/CM-SM SEP breakers are open.

Circuit Breaker FLT/PL VENT, open. This action removed power from the Flight Pressure Leveling Vent now that cabin pressure had reached flight levels of about 5.7 psi.

FLT/PL VENT breaker is open.

MAIN BUS TIE, two, OFF. …I have turned them OFF, I told Evans and Cernan as these switches were on the panel in front of me.

TVC SERVO POWER, two, OFF.” Power to Thrust Vector Control Servos of the Service Propulsion System was no longer necessary now that the possibility of a launch abort was gone.


EMS FUNCTION, OFF,” I read to Cernan so that the Emergency Management System would be safe and prevented an inadvertent separation from the S-IVB.

Okay, it’s OFF.

TRANS[LATION] CONTROL POWER, OFF,” I continued with the immediate tasks to safe and reconfigure the CSM for orbital flight, prior to preparation for the TransLunar Injection burn of the S-IVB.



They’re OFF.” These actions meant that CSM thrusters would not fire if we accidentally hit the hand controllers when we unstrapped to move around the cabin.


They’re OFF.

BMAG MODE, THREE, [to] RATE 2.” The Body Mounted Attitude Gyros provided control gyros for the backup Stabilization Control System and this action placed them in a normal control rate.

Okay, RATE 2.


CM RCS LOGIC is OFF.” Now, the limited capacity Command Module Reaction Control thrusters were off line and if we needed thrusters for some reason, we would activate the Service Module thrusters.


Okay. Yes, sir. It is OFF!” Cernan said, emphasizing that we certainly did not want to leave behind the S-IVB just yet, with TLI still ahead of us, not to mention that the Lunar Module Challenger was still in it.


They’re LOCKED.


NORMAL and LATCHED,” Cernan reported after having to reach down to the left of his knees for these controls

REPRESS PACKAGE VALVE, OFF.” This valve was located out of our reach from the couches in the Lower Equipment Bay (LEB).

Okay, I’m going to have to loosen up here and get that,” Evans announced as he began to move into the Lower Equipment Bay in order to access the various ECS (Environmental Control System) controls.

Okay,” I acknowledge. “I’ll hold that one. …Circuit Breaker [ECS XDUCER PRESS GRP 2 MNA – CLOSE] That’s me,” I said as I had to twist and reach a circuit breaker panel to my right. “…Okay, let me [twist over to get that]…” This action put power to the Group 2 Transducers of the Environmental Control System on to Main Bus A.

Hoo, Hoo,” Ron exclaimed as he became unrestrained by the couch straps. Here we go [down into the LEB. You said REPRESS PACKAGE…].

Okay. That’s that [ECS transducer] circuit breaker,” I announced, having finally loosened my straps enough to reach down and to my right.

Oh, okay,” responded Cernan. “That’s pushing that in there.

Yes, I’d forgotten all about that,” I admitted. “I should have warned you.

Okay,” my two crew mates responded.

That’s something [that was added]…since the [CSM vacuum] chamber [test], I guess,” I explained, referring to some, now forgotten incident in a test of the CSM environmental and electrical systems some months before. I suspect that I had worked alone with the test engineers for some time to resolve a problem that arose during the test.


Most of these actions changed our spacecraft control authority from what launch aborts might require to what would be needed for orbiting the Earth prior to preparing for the upcoming TransLunar Insertion (TLI) burn of the S-IVB that would send us to the Moon.

Once we had the spacecraft Environmental Control System properly configured, Cernan announced, “Okay, I’m going to loosen up, get out of my helmet here and pick up…” Cernan was interrupted in mid-sentence, as some high delta-P space flatulence escaped into the combined suit oxygen circuit before any helmets could be taken off.

Whoops, excuse me, gang. That was me.” I confessed.

Wow! That’s a good one.

Oh, man!

That is a goodie!” Evans agreed.

Still have to get out of my helmet

Whoo. Whoo!

Still have to get out of my helmet,” Cernan insisted.

Helmets and gloves finally came off and were stowed in their bags ready for use if an emergency so required.

Meanwhile, Public Affairs’ announcements had shifted to Houston:

“This is Apollo Control at 16 minutes 45seconds after liftoff. We’ve confirmed Apollo 17 is in a near nominal orbit. The crew reported an orbit of about 93.5 by 89.5 [miles] based on their onboard [computer] calculations, and computations on the ground show that we’re very close to the nominal ninety-mile nautical mile orbit.

As a result of the late liftoff, the TransLunar Injection will be a little bit earlier than the flight plan ground elapsed time but we don’t have an update on this time yet. We expect that it will be on the order of 8 to l0 minutes early. We’ll update that time as we get a later update. We would expect that the time of arrival at the Moon will be approximately the same as the flight plan time in terms of Greenwich Mean Time. The ground elapsed time will be somewhat earlier, and we expect that there will be clock update – a so-called clock update – at some point where we make the clocks in Mission Control and aboard the spacecraft agree with the ground elapsed time that they would be showing in the flight plan. The net effect will be that we’ll arrive at the Moon in a shorter ground elapsed time – in effect about 2 hours 40 minutes earlier than the flight plan would show, but at the same Greenwich mean time or local time here on Earth, that – that we would have had had we lifted off on time. We are in effect making up the time by speeding up the arrival at the Moon. The spacecraft at Translunar Injection will be going somewhat faster than a nominal liftoff (sic) TransLunar Injection. Consequently, it will arrive at the Moon going slightly faster, and also somewhat earlier, about 2 hours 40 minutes earlier in terms of ground elapsed time. This will also mean that the lunar orbit insertion will require a bit more energy to slow the spacecraft down and get it into lunar orbit. These details of course, will all be worked out in the time that we have before our lunar orbit insertion. This is Apollo Control.”

In addition to dealing with all the Checklist items, we kept an eye on the tank pressure readouts from the S-IVB, as we did not have Mission Control available to alert us if a problem was developing. If the pressure in the liquid oxygen tank became more than 36 psi relative to the liquid hydrogen tank; or the pressure in the liquid hydrogen tank became more 26 psi relative to the liquid oxygen tank; or, if the liquid oxygen tank pressure exceeded 50 psi, an emergency separation from the rocket would have been required.

Just prior to the space flatulence issue, I had called out for Cernan to “…install the COAS.” This Crew Optical Alignment System would be put in Window 2. The COAS was a bore-sighted optical sighting device, aligned to the x-axis of the spacecraft, and would guide Evans’ maneuvers to dock with the Challenger once we had successfully completed TLI.

As Cernan installed the COAS, Evans had gone to work in the Lower Equipment Bay, preparing to conduct star sightings (P52) that would be used for a fine, inertial space alignment of America’s guidance platform.

Hey, you guys care if I turn some lights on down there so I can see?” Evans asked, unnecessarily.

Go ahead. Turn them on,” Cernan answered.

Getting back to the Checklist, I asked myself, “Okay, what do we do down here,” referring to the lower third of the Checklist page.

Okay, Jack, [did you] pick up something [on the Checklist] before the COAS?” Cernan asked.

Before I could answer the question, a Master Alarm occurred, with an accompanying yellow Caution and Warning light. “What is that? I asked as I did not have the C&W panel in my field of view.

O2 HIGH FLOW!” Evans answered, looking at a second C&W panel in the LEB.

O2 FLOW,” repeated Cernan. “Okay, that’s because I’m going to have to pull the [REPRESS PACKAGE valve].” Actually, this was not the problem, as will be explained by Mission Control, later.

Yes, you’ve got to change it (the REPRESS PACKAGE VALVE) [to OFF],” I confirmed.

After this was done, Evans asked us, “You got your helmet off?

Yes,” we both answered.

I’m going to have to pull the REPRESS,” Cernan said, “or the…,”

Yes,” I interrupted before he could finish, wanting him to do what I had called out earlier.

Oh, you cycle the SUIT CIRCUIT RETURN [VALVES],” Evans continued, meaning to take these valves to OPEN, reacting to the fact that we now had our helmets off. This action would be called out later in the Checklist, but was appropriate with the helmets off.

Open it. Open it,” Cernan ordered, to which Evans responded, “I’ll go down and close the…[I mean] purge the cabin pressure.” It is not clear what Evans meant by this, unless he thought at that point that the O2 HIGH FLOW indication might have meant that the cabin pressure was higher than normal.

After all this distraction, Cernan asked me, “Did you give me something before the COAS?


Okay. Let me get REPRESS PACKAGE VALVE, OFF.” Finally, I thought. Then, he added, “Look at those aps… [I mean] that atmosphere.

And let me know when you get [the] COAS, I requested.

Okay. Stand by.

Because I checked it [off] inadvertently here [on the Checklist.

Okay. No problem,” replied Cernan. “I’m not going to get the COAS until I get my helmet out of the way.…We got the major things here. Ron can work on the optics, and I’ll get the…

Evans broke in with, “Couldn’t we get the cabin pressure, [that is], EMERGENCY CABIN PRESSURE at BOTH?

Okay, what did you want to do, Ron?” I responded.


Okay, do that,” I answered after going ahead in the Checklist to where it gave the HELMETS OFF configuration. “Then we’ll take our helmets and gloves off,” quoting the Checklist, facetiously, since we had already done so.

Okay, [do that],” I added, “and SUIT CIRCUIT RETURN VALVE [you have already done].

Evans proceeded to go about his work with a combination of chuckling and singing that we had become use to. Then he observed, “I keep floating up to the top of the tunnel [just above the optics station].

Huh?” This comment seemed to puzzle Cernan.

Yes, that’s because we’re in ORB RATE [attitude control],” I reminded them. “Don’t forget.” This meant that the spacecraft and S-IVB combination were pitching down continuously to maintain a level attitude relative to the Earth’s surface while Evans continued on as a separate object in space without pitching.

What a ride that booster is!” I mused out loud.

Yes,” Cernan agreed, “isn’t that something?

Evans chimed in with, “Man that is a ride!

And the best thing to do, Jack, while you’re in the suit, is to stay in the seat, loosely buckled.” Cernan’s knack for unnecessary advice had arrived in space.

Yes sir. …What’s that?” I asked, startled by the strident sound of a MASTER ALARM. “Okay, I don’t know what that was. That was a spurious alarm. There was no caution and warning with that.

Okay,” Cernan replied.

Let me check my amps [electrical current levels]. Checking amps, gang.


Those are good [normal].

Whoops, Cernan exclaimed.

That was it [spurious ALARM], again,” I said.

What are you seeing?” Cernan asked.

Well, I see nothing. They’re transients,” I responded.

Look at your gages, as if I were not doing that as fast as my scan could move.

They’re [the transients] not triggering the CAUTION AND WARNING [lights], I added.

Maybe we’re getting just a caution and warning transient of some kind, huh? contributed Evans.

Three of them right in [sequence].

In addition to a horn, normal MASTER ALARMs also triggered a rectangular red light on the central instrument panel. That light could be turned off and reset just by pushing it and this was normal procedure so the light was ready to alert us to additional problems. Next to the MASTER ALARM light were columns of yellow CAUTION AND WARNING lights that when lit, would normally remain on to indicate what subsystem problem triggered the MASTER ALARM. In this case, however, the transients, whatever they were, were not illuminating any of these CAUTION AND WARNING lights.

With no more ideas on how to troubleshoot the source of these warning transients until we got more information the next time they occurred, or Houston could analyze the telemetry they would get when we could communicate with the Canarvon antenna north of Perth in Western Australia, we pressed on with getting ready for TLI.

Jack, you don’t want your helmet [bag] back [over there] yet, huh? asked Cernan.

Oh, I can take it any time, Geno,” I replied, “and get it out of the way over here.

Okay, here’s your helmet, Jack.


And, Ron, do you want yours [helmet bag]?

Yes, I may as well get it out of the way, Evans agreed.

Okay, Cernan continued. And…I don’t know when you get into daylight, but your optics [star sightings] is your next…

Next thing here,” Evans completed, “as soon as I get my old helmet and gloves off.

Man,” stated Cernan, “I tell you that booster ride is something to behold.

Gee whiz! Evans continued the thought. “I guess I wasn’t quite prepared for the shaking and vibration until the thing lifted off.

Trying to get the team back on track for TLI, I said, “Let me know when you’re ready for checklist stuff. …Cabin [integrity] still looks good.

Not to be deterred, Cernan continued: “Let me tell you, those people down there must have had something worth waiting for. We saw that light before we left the pad. Did you guys see that? You saw it out your window, Ron? Jack?

Yes,” confirmed Evans. “I saw it out my window [#2]. Not enough to blind anything.

I didn’t see anything,” I admitted, but, then again, the protective cover over America covered the three windows that would have given me light from the first stage booster. I do recall, however, noticing a glow in the cabin. The protective cover did not go over Cernan’s window #2 so that he might see the horizon if required during a launch abort.

Yes, not enough to blind anything, but you could sure see it there,” Cernan added. “Boy, I tell you, I’m sure glad I didn’t have to use any…stars out there. I never would have seen them.” As mentioned earlier, Cernan referred here to that possibility that he would have to fly the Saturn V manually using a visual reference relative to the horizon out Window #2.

Look at that!” Cernan interrupted himself. “Okay, here you go. Your first sight…you’re looking to watch the sunrise. Jack, get out here [from under the couch]. As we approached the sunrise terminator over the South Atlantic, the horizon had begun to glow, catching Cernan’s attention and memory from his two previous flights, Gemini 9 and Apollo 10.

Oh, there it is!” Evans called out. “Wait a minute! I can’t see it!

Get out here, babe!

Look at that!” I exclaimed, as I floated to the hatch window.

Come on out my window over here. …Wait a minute. …Can you see it out Jack’s window? …You’ll see it the next time around. But it’s your first view of the Earth, babe. And it’s going to be your best until you get a quarter million miles away.” As will become apparent later, this was not actually going to be the case.

Holy mackerel!” Evans reacted in good Kansas fashion.

Just keep lookin’. …There’s some lightening out there. See it?

Yes, yes. Right on the horizon,” I replied.

See those big thunderheads on the horizon?” Cernan continued. “Look and the size of those things!

Isn’t that beautiful!” exclaimed Evans.

While Cernan and Evans chatted about the view, I just took as much of it in as I could, as America sped simultaneously over the Earth’s sunrise terminator and the huge cumulonimbus clouds of the Intertropical Convergence Zone. At the same time, I was trying to get a typically distracted Cernan to focus on preparing for TLI (TransLunar Injection).


On the horizon, bands of orange and blue lay below the black of space. Outside, darkness finally had been broken by a spectacular sunrise that had provided what I described a few minutes later as “the biggest rainbow I’d ever seen,” extending along the entire pre-sunrise horizon. (Fig. 5.3) With sunrise, the windows and the first view of Earth from this orbital perspective beckoned in spite of the demands of the flight plan.

Fig. 5.3. Apollo 17 views of the horizon at spacecraft sunrise during its first orbit of the Earth. (top): Sunrise. (middle): first view of the morning terminator off the west coast of Africa. (bottom): Slightly further along, showing the pink cloud patterns of dawn (NASA photos AS17 148-22613 -22614 and -22615, respectively).

Like childhood’s home, we really see the Earth only as we prepare to leave. The years of flying T-38 jets at 40,000 feet above most of Earth’s weather have not prepared us for orbiting at 540,000 feet.


Sunrise [at the surface] has got to be over Africa somewhere,” Evans speculated.

Yes,” Cernan concurred. [But] It may be out in the Atlantic by now.

I think it’s out over the water now,” I added.

Jack, the COAS is in.

Okay. You ready for some more [checklist items]?

Yes. No. Watch the sunrise,” Cernan recommended.

There it comes!” I called to Evans.

I want to watch the sunrise,” demanded Evans.

It’s going to come right into my eyes. …That’s the [problem with looking,]” I said, laughing.

Here it comes…Ka-boom!” shouted Evans.

Take a look at it!” Cernan would repeat several times.



Take a look at it!

Look at that blaze!



Take a look at it!

Dammit, yes!

Ohh, that’s bright!

Yes, sir. Is that nice or not?

Oh, it’s just orange!” Evans began summarize his impressions. “You know. It starts out orange and then…becomes bright; and now it looks like a…

Okay,” Cernan asserted, finally. Now go check your optics out because if they’re no good, I’m going to throw you out the hatch!

On top of Evans’s laughter, I piled on with, “That’s right!

Okay, I got to check the little optics…,” Evans agreed and floated back into the LEB to set up for the P52 star-based alignment of the guidance system.

Okay, I’m ready [to continue the checklist], Jack.

Okay, I want your SM RCS HEATERS, four, to PRIMARY.

Okay. Four HEATERS to PRIMARY. …One…two…three…four. They are PRIMARY. This prepares the hypergolic-fueled thrusters Evans would need to extract the Challenger from the S-IVB.

Okay, I want CAUTION and WARNING to NORMAL. …I’ll get it.” This switch lay within my reach; however, my continued concern about getting through the pre-TLI Checklist items as fast as possible came from wanting to have as much time as possible to handle the unexpected events that might occur, such as our possible problem with the MASTER ALARM. As my Apollo 15 Backup Crew Commander, the late Dick Gordon, often reminded Vance Brand and me, “Time is relentless in space.”

We haven’t had that MASTER ALARM again, huh?” Cernan asked.


Okay. And while you’re talking, I’m going to get the…ORB[BITAL] RATE ball out…or the…

[You mean], ORDEAL?” Evans asked, probably enjoying the fact that he knew the Command and Service Module systems far better than his Commander did.

[ORDEAL (Orbital Rate Drive Electronics for the Apollo Command Module and Lunar Module) was an independent pitch monitoring device for monitoring pitch that could be fed directly into the FDAI (Flight Director Attitude Indicator or “eight-ball”) total-attitude circuits to display spacecraft pitch in either an inertial to a local-vertical reference frame. When in use, ORDEAL’s reference attitude signal comes from either the CMC (Command Module Computer) or the SCS (Stabilization Control System). Once mounted in the socket above Panel 1, ORDEAL received power from the spacecraft’s 115 v AC and 28 v DC buses and became Panel 13.]

[That’s right,] ORDEAL,” admitted Cernan. “Go ahead, Jack; keep talking.

BPC [JETT KNOB, goes 180 degrees from BPC JETT]. Okay, these things [have been done, already]. …It’s (Boost Protective Cover on the Command Module exterior) already JETT.

Evans interrupted again, with “Doggone, I’d like to give them television.

…[so turn] 180 degrees,” I continued. “[Hatch] GN2 valve HANDLE to VENT. …I guess I’m going to have to do what you guys are doing to do that.” I will have to loosen my straps in order to work the hatch controls, but, sense Evans was already out of his couch, I asked, “Hey, Hey, Ron, could you get the hatch stuff, or do you want to check your optics, first?

No, I can get the hatch stuff here if I can get my…helmet [out of the way].

Get the optics, first,” Cernan interjected. This was a good call, and I should not have interrupted Evans in his work in the LEB.

Let me get the optics work, okay?” Evans changed his mind, after Cernan’s order.

Get that [optics] cover off!” Cernan emphasized.

Yes, I’m going to do that; [get that cover] off,” replied a chastised Evan. “Hot diggity dog!’

Misunderstanding this expression from Evans, Cernan asked, “Did it go?

Back in his own world, Evans said, “I can’t believe we’ve made it up here.

Did it go?” Cernan repeated.

Ha, ha!

Did it go?

What?” Evans finally paid attention to the question.

The optics?

I don’t know. I haven’t done it yet,” Evans informed us, laughing. It almost seemed as if Evans was euphoric over this new experience and had lost some of the focus we were used to during mission simulations.

Okay, well, get on that one. That’s one I want to know!” Cernan said in a more relaxed tone.

Okay,” replied Evans. …Let me see… Do-do-do-dooo-do tum,” he sang. “GDC ALIGN…” This last statement concerning the Gyro Display Coupler from Evans indicated that he had jumped ahead in his copy of the Checklist to items ultimately related to performing the P52 (Guidance Platform Alignment) star sightings. Holding in the GDC ALIGN button aligned this backup guidance platform to the Inertial Measuring Unit of America’s primary Guidance and Navigation and Control system.

Geno, …let me know when [you are ready to continue], I requested.


Can you reach the GN2VENT handle?” GN2 refers to the Gaseous Nitrogen that pressurized the rapid-opening mechanism of the hatch. This system came into being as a result of the 204 (Apollo 1) fire that killed Gus Grissom, Ed White and Roger Chaffee in January 1967.

Yes, sir,” he replied.

Right here?” I said, pointing to the handle just out of my reach while still strapped in.

What do you want me to do?

I want you to pull it to VENT.” Venting the pressurized nitrogen from the hatch emergency release mechanism was standard procedure so that the hatch could not open inadvertently – not a good idea in space. This added nitrogen to the spacecraft atmosphere would be replaced slowly by oxygen until we depressurized America for Evans’ space walk on the way home.

Okay, let me get around to this [position].…Okay, one of these things that [are always awkward].

Talking to himself down in the LEB, Evans said, “[Need to get the] state vector here.

Pulling to VENT?” Cernan asked, again.

Pull to VENT,” I repeated.

Then Cernan interrupted Evans to ask, “Ron, it should go to zero, huh? All the way? …Pull to Vent, Okay?

Yes,” I insisted, while Evans ignored Cernan’s question. Chatting away to himself, he seemed to be oblivious when Cernan and I tried to interrupt.

Pull to VENT?

Yes. …All the way.” Cernan had questioned my call-out three times. For some reason, Cernan did not seem to believe the Checklist. This was really a strange uncertainty on his part, as this hatch would not be opened until after splashdown, and then it would be opened from the outside by the UDT swimmers after they had stabilized the Command Module and had a raft ready for our egress. Discomfort due to space adaptation may have been affecting Cernan’s attention span, as he had no challenging task to occupy him at the moment.

Yes, I (you) can vent it all the way, now.” Evans finally joined this strange discussion.

Back in Houston, Mission Control issued another public update:

“This is Apollo Control at 24 minutes. Apollo 17 now in an orbit about 90 miles by 93 miles and everything appears to be nominal aboard the spacecraft and aboard the launch vehicle, Saturn third stage. One additional impact of our late liftoff will be the loss of television coverage for the transposition and docking maneuver. The television coverage will not be possible because the ground track has shifted and we don’t have the site coverage that had been expected for television. The TransLunar Injection burn, [that is] reigniting the Saturn third stage to put the spacecraft on its trajectory to the Moon, is now scheduled to occur at a ground elapsed time of 3 hours 12 minutes 35 seconds, or roughly 9 minutes earlier than the flight plan time. This again is the effect of the late lift off. And we will be reacquiring Apollo 17 through the Carnarvon Tracking Station at a ground elapsed time of about 52 minutes 20 seconds, roughly 27 minutes from now. This is Apollo Control.”

You’re over the Atlantic, guys, looking out your window,” Cernan finally concluded.

Over the Atlantic, huh?” acknowledged Evans.

Best I can tell right now.

Damn, pardon my French.

Yes,” continued Cernan. “Let me tell you. Just because you’ve been in orbit once, that don’t mean you’ve been in orbit all the time.

Hey, by the way, Ron,” I called, “you and I finally qualified.” Here, I was referring to meeting the criterion for having flown in space.

Laughing with uncertainty about what I meant, Evans asked, “We qualified, huh?

I forgot. …I was going to tell you when we went through 50 miles [during launch], but I was too busy.

I forgot all about it.

Okay. …You want this reset?,” Cernan asked me, once again referring to the GN2 VALVE HANDLE.

“No,” I said, trying to be patient with him. “Just pull to VENT. …Just leave it (the valve handle) the way it is.

Okay. It’s going to [be in the way]. We’re going to hit it,” responded Cernan.

It doesn’t say one way or the other [in the Checklist], Geno.

Let me put it back here,” Cernan decided, not knowing if it might affect the operation of the hatch at splashdown. It was a question that we should have asked Mission Control; however, ultimately it did not make any difference.

Meanwhile, down in the LEB, Evans, laughingly, said, “It’s black out there.

Cernan put the GN2 valve handle back in its original position, saying, “There it is.

Just vent it to zero. That’s all that’s important,” I concluded without really knowing.

Okay, that’s good.

…And the hatch [ACTUATOR HANDLE SELECTOR] is neutral?” I asked, having apparently missed a step to verify that the HATCH GEAR BOX was in the LATCH position.

During all of this, Evans’s continued his preparatory work on the navigation optics, singing to himself. As Cernan and I stumbled our way through the Checklist for major systems configuration, in parallel, Evans had finally started to work through his part of the Checklist for OPTICS DUST COVER JETT[ISON]. He had installed the optics eyepieces and then told us, working at Panel 122, “I have the [G/N] OPTICS POWER ON. …Let me see [what’s next.] …OPTICS ZERO to OFF and then ZERO. …OPTICS ZERO [to OFF]. …OPTICS MODE to MANUAL. …OPTICS COUPLING [CONTROL] is DIRECT. …[OPTICS] SPEED is HIGH. …Okay, here goes the old optics.

Let me know if that cover goes,” insisted Cernan.

To add drama, Evans gave himself a countdown: “1001, 1002, 1003, 1004, Evans then put the Optics Hand Controller to MAX RIGHT “Ohhhh! My gosh, there it went!

Beautiful,” Cernan exclaimed, looking out Window 2. “That’s [it] over here.

Hey,” Evans said, excitedly, “it’s floating off. It’s a real bright thing. There’s two pieces of it.

Yes, that’s great!” Cernan exclaimed, again.

Something else is flying all over the place,” Evans added. …Yes, you can see [other fragments].” Removing that cover meant that now he could precisely align our guidance platform for navigating to the Moon as well as backing up guidance for the S-IVB during the TLI burn. Other information, of course, would contribute to this process, such as the Doppler radio tracking from Earth, but being able to make a P52 star sighting made up a critical part of the whole.

[The general Mission Rule for not getting the cover off, that is the loss of the optics subsystem (Rule 15-52), would have required Evans to make backup star alignments using the Crew Optical Alignment Sight (COAS) mounted in Window #2. This problem would not have kept us from going to the Moon; however, the need for accurate sextant sightings of lunar landmarks near our landing site to refine the Challenger’s state vector might have caused consideration of a post-TLI EVA to remove the cover. We were already suited and Evans had his post-TEI (TransEarth Injection) EVA umbilical (Chapter 15). I do not recall, however, this possibility ever being discussed while preparing for either Apollo 15 or Apollo 17.]

While Evans worked to get the optics ready for his P52, I continued to push Cernan through the Checklist. It was important to make sure components of all our essential systems, attitude control, environmental control, and propulsion had not degraded during the launch, particularly during the heavy vibration on the first stage booster. Although America had gone through many ground vibration tests successfully, the real world of flight might have unanticipated effects on plumbing, wiring, pressure vessels, and the like.

Okay, what do you want me to do?” Cernan asked. Back to the checklist, Cernan and I continued to verify that America and its Service Module systems were ready for a long voyage in space.

SM RCS MONITORING CHECK. You got it?” I asked, just to be sure he knew we were beginning to check the status of the Service Module Reaction Control thrusters. …” You got SM RCS Propellant talkback’s, eight [of them are] gray? [9]

They’re all gray.

Okay. …[SM RCS] HELIUM 1 and 2, eight [talkbacks], gray,” I continued.

They’re eight gray.

SM RCS INDICATOR to HELIUM TANK TEMP and check your quads,” I said. “Quads” here referred to the four groups of four thrusters spaced symmetrically around the Service Module. The limits for temperature, helium pressure, manifold pressure, and helium tank temperature for each quad, labeled A, B. C and D, could be checked against the ranges listed in the Checklist and shown in green on the dial Cernan monitored as he went to each rotary switch position.

Okay, helium tanks temp and [pressures]… Okay, all the quads are GO,” Cernan replied.

You want some numbers [for those limits] or you…like them?, I asked.

They’re all nominal.

Okay, [lets do the same for the] CM.” This required verifying that the two Command Module RCS PROPELLENT talkbacks were gray and the helium temperatures and pressures and the Manifold pressures were in limits. In this case, the twelve CM thrusters were not in quads but were distributed in pairs around the cone-shaped spacecraft so as to provide pitch, roll and yaw control during atmospheric entry and descent. They were arranged in two independent systems of six thrusters each so that if one system failed, the other thrusters still could provide full control, albeit somewhat degraded.

Okay,” Cernan reported. “COMMAND MODULE… They’re both nominal.

Just to be absolutely sure Cernan had actually looked, I verified by saying, “You got two gray talkbacks on the propellant – they’re gray. Okay, and you like…the numbers [on the dials].


Okay, [C/W] LAMP TEST. I did [that once].” This was the first thing I did when we had the spurious MASTER ALARMS, but would do it again just to make sure.

Okay, you guys, MASTER ALARM,” I warned. “Stand by…Okay. That’s good,” I said after the two sets of lights had all come on “[They’re] reset,” I reported.

As I reset the lights, we had another transient MASTER ALARM. In this context, a check of the Caution and Warning lamps showed none of them had been triggered. This indicated clearly that all systems were okay but that we had a transient affecting only the Master Alarm circuit.

It tests…almost acts if it’s something to do with the [MASTER ALARM itself],” I speculated, but found little concern amongst my colleagues who were engrossed in the currently higher priority jettisoning of the optics cover.

Earlier, I took care of three items (closing the circuit breakers on Panel 5 for the two WASTE H2O/URINE DUMP (LINE) HEATERS, putting the FUEL CELL REAC[TANT]S VALVE from LATCH to NORMAL, and turning ON the H2 PURGE LINE HEATER.) The heaters, of course, would prevent ice from forming in their respective lines. The FUEL CELL REACTANTS VALVE had been latched prelaunch to prevent launch vibrations from inadvertently shutting off the flow of hydrogen and oxygen to the Fuel Cells, but now would be put in its normal position for routine flight.

Next on the Checklist, we began to reconfigure the cabin for weightless activity within it. Particularly important were the temporary stowage bags (TSBs) that helped provide some discipline in managing all the small items we would use off and on. Also important was gaining access to the drinking water gun. Evans handed us Tool E (a wrench) that we soon would need to activate the glycol cooling system.

With the optics cover jettisoned and the LAMP TEST completed, I once again went back to the Checklist. “STRUT UNLOCK LANYARDS, TWO, STOW,” was the next item. Removing the strut lanyards allowed us to reposition the lower portions of the couches that had been placed in a bent knee position for launch.

I’ll get Ron to do that in a minute,” Cernan replied.

Should I whip into a P52 here…or should I [get the lanyards]? Evans asked.

I interrupted with the next item on the Checklist: “DRINKING WATER SUPPLY VALVE, ON.

Hey, that’s a good idea,” reacted a thirsty Evans.

Check those optics out or you don’t get any [water],” ordered Cernan to laughter in the cabin.

Hey, Ron, …hey, Ron,” I called, “can you CLOSE the COAS/TUNNEL LIGHTING MAIN A circuit breaker down there [on Panel 226]?

Yes, Just a second. Let me… COAS/TUNNEL A and B is CLOSED.

Okay, thank you. …And we got the helmet bags and accessory bags (TSBs) [TSBs were out already] and tool E? Would you get tool E out of L-2, please,” I requested of Evans.

Tool E out of L-2,” Evans repeated. “Is that where that is?

And that’s one thing we’ll need real quick,” emphasized Cernan, thinking ahead, now, to doing leak checks on the cooling system’s radiators.

Meanwhile, Evans was still trying to get to Panel 226. “Oh, you kind of get stuck in these places. …COAS TUNNEL A and B is CLOSED.

Okay, thank you,” I replied.

Want some [water],” Cernan asked me. “You can’t get it [from your couch].

I’ll get it in a minute, Gene. I want to get squared away here [with the Checklist] and then I’ll [un-strap]. It’s just as easy this way…let you guys be at my beck and call…” Reading from the Checklist, I quoted: “If cabin pressure is greater than 5.3, [place] O2 FLOW [at 0.7 pounds per hour].

We got to get to those radiators,” Cernan said, reacting to the slowly increasing temperature in the cabin, but then alerted us that “Here comes Africa”.

Unimpressed, apparently, Evans hummed and said, “Hey, I can still see those dust covers whipping out through there.

Okay, let’s press on and get this [radiator activation] done. It’s getting warm in here.

Yes,” I agreed a little facetiously as I had been trying to get the Commander’s attention to the Checklist for some time. Now, with America in the sun, the cabin became noticeably warmer, requiring that we activate the heat radiators and their associated glycol cooling system.

Main Reg check, Ron – whenever you’re ready…” The main oxygen regulator controls were in the Lower Equipment Bay (LEB) where Evans was working on his optics. “You want to leave that [preparation for a P52]?

We can get the Main Regs later,” Cernan vetoed, finally wanting Evans to get on with the star sightings for the P52 guidance platform alignment.

Okay [Gene], Secondary Rad[iator] Leak Check.

Oh, we can [do that]?

[I’m] Ready [to watch the glycol flow gage], Geno. …Okay, I’m going to SECONDARY. …SECONDARY GLYCOL to RAD valve go NORMAL for 30 seconds.” To do this, Cernan had to use the wrench known as Tool E.

Okay, GLYCOL to RAD, SECONDARY, NORMAL for 30 seconds coming at you,” confirmed Cernan, now rolled to his left to reach the glycol valve next to his couch.

“And then it’s going to BYPASS. Give me a MARK [when you start.”

[Stand by.]

You got it?

Not yet. …[Can’t get the damn tool E]…off here,” mumbled a frustrated Commander.


Okay, you want it NORMAL?” Cernan finally asked.

NORMAL for 30 seconds.

MARK it. It’s [at] NORMAL.

Okay,” and I started monitoring my watch.

In the middle of this, Evans called from the LEB: “Hey, you can see a star!” Evans interjected.

Well, that’s what you’re supposed to, babe,” responded Cernan.

It’s in the daylight too,” I commented.

Yes. …Look at… Did you ever see a blacker sky than that, though?” Cernan added, looking out window 1 as he was rolled left to work the radiator leak check.

Yes, about two minutes ago,” I jabbed, referring to the pre-sunrise night sky – bad habit. Then I reported, “Ten more seconds, Gene,

Okay, is she (the glycol system integrity) looking good to you?

Yes, looks good.

While he waited a few more seconds, Cernan said, “Okay. ORB RATE, by the way, is tracking [our orbital freefall rate].

Okay, you can go to the BYPASS,” I told him.

Okay, it’s back to BYPASS.

That’s good,” I noted, referring to the glycol system plumbing. “Okay, GLYCOL RESERVOIR BYPASS VALVE, OPEN.






PRIMARY ACCUMULATOR…QUANTITY…is up to 40 [percent]…Interesting.” I had expected the accumulator quantity to be much lower.

You want to try…filling it?” Cernan asked.

Yes, we’re going… Let’s put something in it.” Reading from the Checklist, I said, “PRIMARY ACCUM FILL VALVE, ON, until 50-55. I’ll give you a MARK [when it is at that level].

Well, I don’t know whether I [turned] it or not, but it (the FILL VALVE) looked like it was ON,” he replied.

There…Whoa!” I called.

No. Which way?

Turn it off!


Turn it off.


That’s interesting,” I said, noting the accumulator reading had jumped and then gone back down. “Do it [ON], again.

Well,” Cernan replied, “it…looked like it was ON to me.

No, it (the quantity indicator) jumps, Geno, and…I guess I didn’t give you enough time…It’s only [at] 45, now.

Okay, try [again]. It’s ON. …MARK it.


You got that? Cernan asked. “It (Accumulator Valve) was OFF. It was okay.

Now… Turn it OFF,” I ordered as I monitored the quantity gage.

Okay, it’s OFF.

Okay, I got…50 [pounds]. One more time, please,” I requested. “For some reason, there’s a…10 percent bias (delay) on it.

Okay,” Cernan answered as he went to ON, again. “There’s a hysteresis in it (the quantity gage),” he suggested.

Yes…[but] no, it just holds there when it’s (the valve) ON,” I disagreed. “Okay, now turn it OFF.

Okay, it’s OFF.

Good…[it’s] 55,” I reported. “Right in there [where it should be].

“This is Apollo Control, now 32 minutes after the liftoff of Apollo 17 and we have loss of signal with the spacecraft, we will be reacquiring through the Carnarvon Tracking Station in about 20 minutes. And, from the President of the United States, we have the following message to the crew of Apollo 17. The message reads:

‘As you set forth on the final Apollo expedition to the Moon, I want you to have my personal best wishes for a successful mission and safe return. I am sure your voyage, your scientific exploration, will be the crowning achievement in a program which has expanded man’s horizons, brought great credit to your country and lifted the spirits of people all over the world. God speed to you all.’ Signed Richard Nixon.

“The flight Dynamics officer, continuing to process tracking data, following orbital insertions, reports that there is a small amount of out-of-plane error showing up in the orbit. This, [it] is believed, is due to a small error in the instrument unit of the Saturn third stage. However, the orbit is very close to nominal, about 90 nautical miles by 93 nautical miles. And, we look very good, both with respect to the spacecraft and with respect to the Saturn third stage which must perform that burn putting Apollo 17 on its trajectory toward the Moon. At 34 minutes, this is Apollo Control Houston. This is Apollo Control.”

[Author’s Note: Between this point and the next period of communications with Mission Control, a number of activities took place simultaneously. For the sake of clarity, some activities that overlapped have been separated from each other and may not correspond exactly with the sequences indicated in the transcripts of Command Module audio. Also, transcribers of that audio had difficulty at times in distinguishing Cernan’s voice from mine due to the communications system’s clipping of high and low frequencies from our spoken audio. I have attempted to properly identify speakers by the context of what was said.]

Still on his side and looking out window 1, Cernan said, “There’s a little geology for you, Jack.

I hope I can look next time [around], I replied, still trying to get ahead in the Checklist. “…Okay, FLOW CONTROL POWER [to] POWER.” I moved this switch on Panel 2, in front of me. “[Gene,] PRIMARY GLYCOL TO RAD[IATOR] VALVE [to] NORMAL, PUSH! That’s why I want to get going [with the Checklist].” It was getting warm in the cabin.


Okay,” I continued, “ECS RAD HEATER [to] PRIM[ARY] 1.” This switch also was in front of me. “Okay, [check] PRIM OUT (temperature) below PRIM IN. …We’re already there,” I reported, looking at the gage just above the heater switches that showed the INLET and OUTLET temperatures of glycol flowing through the radiators. “That’s beautiful!

That booster ride is just un…just absolutely incredible,” commented Cernan while waiting for my next instruction.

Okay, [I verify] ECS RAD TALKBACK is GRAY.

Then I worked through two more switch changes on Panel 2: “GLYCOL EVAP – TEMP IN, going to AUTO. …POTABLE H2O HEATER going to MAIN A [BUS].

Talking to himself about working with the Sextant in preparation for a star sighting, Evans said, “I guess it’s good to make it focus.

How’s it looking to you, Ron?” Cernan responded.

Well, I can’t get the crazy thing to focus.

Figuring Evans would solve his current problem with the optics, I told Cernan, “Let me know when you can do a MAIN REG check. …Ready, Gene?


Then, I had second thoughts as Evans was working next to the LEB panel with the oxygen controls: “Let’s see…I’m in a Fuel Cell EPS (Electrical Power System) [check]. Let’s see [what is left to be done]. …ECS Monitoring, SPS (Service Propulsion System) [Monitoring Check]…The rest of it is mine. …GDC (Gyro Display Coupler) align is…you got to do.

I’ll take care of that,” Cernan stated.

And then there’s a Sequence Camera [to] unstow and a ‘MOUNT’ your ORDEAL, if you haven’t.

Okay, ORDEAL is mounted and working,” confirmed Cernan, “and I’ll wait for Ron to finish the optics [to align the GDC].

You’ve done the ORDEAL?” I had missed the earlier discussion he and Evans had about this orbital rate-monitoring box.

I’ll wait for him to finish the optics so we can [do the P52],” Cernan repeated.

I guess the rest of it (Checklist) is pretty much mine for a while,” I announced and went to work.

“I need to get to that P52,” Evans mumbled.

Yes,” agreed Cernan. “Why don’t you do it now?

I can’t tell…” Evans started to say something about the focus problem, but then announced, “Hey, that’s not so bad. Ha ha! There we go. Where’s my book (Guidance and Control Checklist).

Right above you,” Cernan said, helpfully, as the G&C Checklist Evans had been using had moved above his head in response to the curvature of our orbit around the Earth.

What’s the cabin temp, Jack?” Cernan asked, as I began to focus on completing the Checklist.

Evans joined in with, “It’s getting hot. Whatever it is, cool it, yes!

Cabin temp. Lets see if we can’t cool it off,” continued Cernan.

Cabin temp is low. Oh, cabin temp? …It’s 65,” I told them.

It’s hot in here,” Cernan insisted. We were still in our suits without interior cooling and he, and certainly Evans, had been moving around more than I had.

Well, let’s see,” I began, “We’re in MANUAL [on the Cabin Temperature control]. INCREASE [on the rotary switch] must be increase temperature.” So, I turned the rotary the opposite direction to get some cooling.

Okay, did you want me to turn the DIRECT O2, OFF, by the way?” Cernan asked. “Did you call that out…?

No, I didn’t call it out…

No, no,” Evans jumped in. “It shouldn’t be [OFF].

No, I didn’t call that,” I repeated.

Okay, conceded Cernan.

Okay, you’re going to see some MASTER ALARMS here, gang,” I alerted my crewmates as I began the Fuel Cell Purge and Electrical Power System Checks. The three Fuel Cells in the Service Module supplied electrical power by converting hydrogen and oxygen to water when passed over a platinum catalyst. This also gives us our necessary water supply. “Any time you get one (alarm) you don’t like, let me know.

I will,” Cernan answered. “We’ve had four spurious ones without anything else [on the C&W display].

There seems to be some association with…working the switches up here on (around) the Caution [and] Warning panel, I noted, “and I’ll check that out later.

I then put the six H2/O2 PURGE switches ON and noted both the expected flow increase and a MASTER ALARM and the appropriate yellow CAUTION light. After resetting the alarm, I placed the H2 PURGE HEATER to OFF. A check of the H2 and O2 pressures showed that the three tanks of each were within limits (225-260 and 865-935 psia, respectively) and H2 SURGE TANK PRESSURE matched that of the main H2 tanks. No stirring by the CRYO[GENIC] FANS in each tank was required. To check the functioning of the Fuel Cells, I first turned on the three Fuel Cell HEATERS, checked that the talkbacks for both the Fuel Cell Radiators and Reactants were all six gray, and then, for each Fuel Cell, checked its H2 FLOW rate (0.03-0.15 lb/hr), O2 FLOW rate (0.25-1.2 lb/hr), reaction MODULE SKIN TEMP (390-440º F), MODULE CONDENSER TEMP (150-175º), and that the FUEL CELL PH HIGH and RADIATOR TEMP LOW talkbacks were gray.

With the Fuel Cells themselves appearing to be in good shape, I proceeded to check their output DC voltage and amperage. This entailed verifying that the two MAIN BUS TIES were OFF and that the talkbacks were gray for MAIN BUS A feeds from Fuel Cells 1 and 2 and the talkback was barber-pole for the feed from the off-line Fuel Cell 3. Similarly, I verified that the talkbacks were barber-pole for MAIN BUS B off-line Fuel Cells 1 and 2 and was gray for the feed from Fuel Cell 3. This arrangement guaranteed that, if we lost either MAIN BUS A or B, power would still be going to the other BUS. Conversely, if we lost two Fuel Cells, one BUS would still be powered by the remaining Fuel Cell. The voltages (26.5-31.0) and amperages of the three Fuel Cells and MAIN BUS A and B were as expected.

Command Module entry BATTERY BUSES A, B AND C, that we would need for power during our return to Earth after separating from the Service Module, showed the required 31.5-38 vdc and an amperage drain of much less than the allowed maximum of 3. If ever necessary, these batteries could be charged off the Fuel Cells. A technique even existed, developed during the Apollo 13 crisis, to charge these batteries from Lunar Module batteries.

PYRO BATTERIES A and B, required for various separations that used pyrotechnics, showed voltages also were within their limits of 36.5 and 37.5 vdc. Also, I changed the DC (direct current) IND[ICATOR] select switch from the launch position on MAIN BUS A to MNB so that bus could be watched for a while. Finally, I checked the AC voltages on all three phases as being between 113 and 117.

One aspect of the battery checks I could not do from my position on the right hand couch was checking the voltage on the BATTERY RELAY BUS. This bus provides power necessary to operate the motor switches that control the Fuel Cell MAIN BUS, RADIATOR, and REACTANTS connections as well as the DC and AC over- and under-voltage sensing units and inverter controls. To check this RELAY BUS voltage, the left hand and right hand SYS[TEM] TEST switches in the LEB needed to be in positions 5 and B, respectively. As Evans appeared to be finished with his P52 IMU alignment when I got to this point in the Checklist, I asked him, “Give me a BATTERY RELAY BUS reading when you turn [the LEB lights back] on.

[SYSTEM TEST SWITCH at] 5 Bravo, do you?” Evans asked. Just for this anticipated test, these switches had been placed at 5 and B before launch.


5 Bravo is about 3.45 [volts], he reported.

Beautiful,” I responded, as this was within its limits of 3.4-4.1 vdc.

Next, occasionally talking my way through the Checklist, I moved on to the checkout of the Environmental Control System (ECS) MONITORING CHECK. The DELTA-P between the cabin and our suits was very low as expected, as we had our helmets off. The O2 SURGE TANK PRESSURE was within its 865-935 psia limits as was the pressure in the REPRESS O2 PACKAGE. The PRIMARY RADIATOR talkback was gray, so no action was required to add glycol to the system.

Cernan interrupted my progress through the Checklist, with, “Jack, the [O2] SURGE TANK there may have [been] hit partly OFF.

Yes, it looks a little low [in pressure], Gene,” I responded. “I was [assuming some bias in the gage reading].

Okay, it’s back ON.


It’s back on,” he repeated. “It was partially OFF. I hit it with my arm.

Okay. Thank you.

[Just] checking [on things].

I won’t assume any [gage] biases anymore,” I told him.

Okay. You know, I must have caught it with my [suit pocket].

Remind me to check that again, if I don’t…remember it,” but I was wondering what Cernan was doing down in the LEB.

Answering my unspoken thought, he said, “That’s why I’m ‘walking’ around the cockpit, so to make sure we got it all.” On the other hand, he wasn’t going through the Checklist so how would he know if “we got it all.” He may have been getting away from the strong light through the window that could have been causing some adaptation symptoms. Over the next few days Cernan would spend a lot of time fighting those symptoms in the LEB.

As I went back to my ECS checkout, I moved the RADIATOR INDICATOR switch on Panel 2 to check inlet and outlet temperatures and another spurious MASTER ALARM occurred. Although these no longer bothered either Cernan or Evans, I told them, “Okay, I did it again. It is switching on Panel 2. I’m sure of it, almost, now.” I again moved the RADIATOR INDICATOR switch. “…It does it in the CAUTION/WARNING NORMAL position…” I moved the switch again, but there was no alarm.

Evans asked, “[What about the] BOOST [postion]?

Well, it (the switch) did it in (with) [CAUTION/WARNING in the] BOOST [position], too. Did it in BOOST, too,” I repeated.

I finally completed the ECS MONITORING CHECK, after noting that the RADIATOR TEMPERATURE PRIMARY INLET and OUTLET temperatures were within their 67-97º F and -20 to +63º respective ranges; the PRIMARY GLYCOL EVAPAPORATOR OUTLET TEMPERATURE was inside its 38-50.5º limits; the SUIT LOOP TEMPERATURE was 45-55º (although we were warmer, wearing the suits without being connected to O2 flow); CABIN PRESSURE was between its normal limits of 4.7 and 5.3; partial pressure of CO2 was well below 7.6 mm Hg; POTABLE H2O QUANTITY was high; and WASTE WATER QUANTITY was low (but not for long!).

While I had worked through checkouts for the Fuel Cell, electrical power, and environmental control systems, Evans quietly followed his G&C procedures to complete a P52 fine alignment of America’s Inertial Measurement Unit (IMU). This complex procedure, that he knew intimately, involved working through the Command Module Computer (CMC) and selecting the IMU ALIGN OPTION. This led to using the Sextant optics to mark on two stars and letting the CMC calculate how much the current alignment of the IMU three gyroscopes should be changed (torqued) to improve its knowledge of our position in inertial space relative to the position of the launch site at the Kennedy Space Center. After TLI, our position would be changed to be relative to our landing site on the Moon.

Evans called out the three torquing angles calculated by the CMC that Cernan recorded in the Checklist. “Plus 1080, [I mean] plus 080, plus 029, …and plus 018.” Evans also recorded the two stars (Noun71) he had used as Gienah and Menkent and the CMC’s calculation of his angular error of 0.01º (Noun 5).

At the completion of this activity, Evans noted the time when the torquing corrections to the gyroscopes were calculated on the computer’s Event Timer as “35:10

It was 35:25 up here, Ron,” Cernan stated.

Oh, really? Evans asked. “I’ve got 35:10 down here.

35:25 on two clocks up here,” countered Cernan.

Hah! Evans exclaimed.

Okay, let me check the [time in] the computer,” decided Cernan.

Well, the event timer’s off a little bit, too,” noted Evans.

The computer is with both of our clocks up here,” reported Cernan.

Okay,” acknowledged Evans. “What time did you say it was [when I torqued]?

It was 35:25 when you torqued.

35:25, then,” agreed Evans. “Okay, somehow the LEB DISKEY Mission Timer doesn’t work…or it’s [running] late.

I don’t understand how that happened,” Cernan mused to laughter from Evans. The cause of this anomaly was never resolved;[10] however, the anomaly resolution team may have confused the Mission Timer in the Command Module Computer (CMC), where the problem occurred, with the digital Mission Timer on LEB Panel 306, to the right of the Sextant eyepiece. Evans reported that the problem was with the CMC timer.

Okay, why don’t you put this (helmet bag) up in the tunnel, if you can,” suggested Cernan.

Yes, I’m going to do that,” agreed Evans, but then changed his mind, saying, “Put it down here [under the couch] where it belongs.

Okay, well, could you put mine down there, too, you suppose? Cernan asked. “Is there room down there to put it…?

Well, you’re going to [have to wedge it in], Evans answered, “if it will stay.

Well, I won’t put it there, then.

Well, I can put it down here for the time being, but…,” said a hesitant Evans.

Well, that’s all right. That’s all right,” concluded Cernan. This discussion illustrates how difficult it was to find storage space in the Command Module’s cabin, particularly since we had not yet unstowed the bungees needed to restrain objects such as the helmets.

At this point, a MASTER ALARM appeared, in response to which, I said, “Okay, that’s spurious,” meaning nothing I was doing should have caused the alarm.

Cernan said, “That’s spurious; nothing with it [on the Caution light panel].

[That’s] number 5 [of those]. I’ll check my amps once more [to be sure nothing is drawing abnormal current.]

You weren’t checking out things and…,” Cernan pressed.

Cutting him off, I said, “No.

A few seconds later, the MASTER ALARM went off again. “Okay, I said, “another one. Seems to be something to do, maybe, with switching up here. I seem to get more of them (alarms) when I’m working on the switches up here. I’ll keep my eye open [more closely].” I was still working through the Checklist items discussed above when these alarms occurred.

Your gages all look good, huh? Cernan asked as I continued to move switches.

Yes, sir. I haven’t found anything [off nominal].

As Cernan moved by Panel 2, another ALARM occurred.

There, you see. You did it, too.

Just bouncing against them. Yes,” responded Cernan.

Thinking about something said in a pre-launch briefing, I mused, “Hey, Ron, what was it that Gordy said about [the SPS] (Service Propulsion System)?

That’s the SPS [you are asking about]?” Evans queried.

That was the SPS [he mentioned], wasn’t it,” I stated.

Yes,” Evans said, now remembering. “[Something to do with] switching.

With that, I continued my checks and asked Evans, still in the LEB, “How about a MAIN REG[ULATOR] check when you get a chance.” These were the regulators that control the flow of oxygen into the cabin, based on cabin pressure, and were located in the LEB.

I caught him in the middle of taking a drink. “Finally got a drink of water.

Congratulations,” Cernan said.

Anybody want a drink,” Evans offered.

Not right now,” I said.


Okay. MAIN REG B [VALVE], CLOSED,” I requested.





Okay, PUSH TO TEST,” responds Evans.

O2 flow [should] increase,” I alert him. “Stand by; you might get a MASTER ALARM. Go ahead [and push].

Okay, it [O2 flow] does [increase]. That’s good.

Whoo! That [feels good].” Evans was feeling a little warm.


Okay, B is going OPEN.

A [is] CLOSED?” I ask, to be sure.

A is CLOSED,” Evans verifies.


Okay, it’s going to 2.


PUSH TO TEST,” repeats Evans.

[O2 flow increased.] Okay, that’s good here. …MAIN REG A VALVE, OPEN.



Okay, EMERGENCY CABIN PRESSURE is in BOTH,” Evans said, and another section of the post-insertion Checklist is done.

There’s the coast of Africa,” noted Cernan, who has not been involved much in the stuff Evans and I were doing once we were in orbit and before TransLunar Insertion.

I’d like to see something,” whines Evans, as he has been in the LEB for the last half an hour.

Oh, you’ll see it,” Cernan responded, totally missing the point of Evan’s remark.

Okay,” I said to Evans, pointing to a STRUT LANYARDS that I had yet to remove and stow.

Get caught up, we’ll [get to look out],” Evans said, wishfully.

…Get this other one (lanyard) over here,” I asked as Evans laughed at my insistence.

Oh, I got it (lanyard),” Cernan volunteered, and then asked Evans to help, anyway.

And then, [Ron], you get a couple of bungees out of there,” I requested, “and I want to trade [cue] cards with you.

Okay,” Evans replied and then began singing again, followed by some addition for an unknown reason: “Okay, 25 and added [to] a 46 [equals] 71. …A couple of bungees coming up. …No, wait a minute, I don’t know where they are. Normally, [they would be over here],” he added with a chuckle.

That GDC ALIGN pushbutton is really hard to push, Ron,” Cernan inserted. “There is a little step in it you got to [overcome].

Oh, it is?


Over the Indian Ocean, we replaced our launch cue cards with those for both a normal and a manual TransLunar Injection (TLI) burn. As every available, irregular space on Panels 1, 2 and 3 was used to velcro cue cards in place, this took some time, requiring matching a cue card shape to its proper spot.

We are coming out over the Indian Ocean,” Cernan announced. “I can’t really tell you where, guys, but…

Hoo,” Evans spoke for the three of us when he added, “I wonder if I could take a leak? Do I have time to take a leak?” We all had decided to not wear the potentially very uncomfortable ‘URINE COLLECTION TRANSFER ASSEMBLIES’ in our suits for launch. (More on the UCTA’s in a later Chapter.)

I am going to have to empty my ‘leak’ when I get out of my suit,” replied Cerrnan.

Stating the obvious, Evans said, “Well, I can’t do that right now,” to laughter in the cabin. Then he added, “Let’s see here. We got to get a camera out, huh?

Yes, get your cameras,” directed Cernan, “that’s the next thing.

Looking at the Checklist, I told Evans, “You need two of them: the 16 [mm Mauer] and the [Hasselbald]. …You want some words on what [magazines] to put on them?

Not yet,” Evans answered.

[Jack,] why don’t you press on [with the Checklist],” Cernan suggested, “and I can work with him on that.

After helping Evans extract the cameras, Cernan inquired about how we were responding to weightlessness. “How you guys doing? Moving slow?” He may have begun to feel uncomfortable at this point.

Yes,” Evans and I responded, relative to “moving slow”.

I feel pretty good.” I replied. “I noted that…,” I started to add but Evans interrupted.

I got a little bit of a [headache]. I know that if I move fast, I’d start to get a headache is all I can say.

Okay, stay where you are and move slow,” Cernan replied.

I’ve been floating around too fast down here…,” Evans admitted.

I think you may have, Ron. You’ve been bouncing around. Just take it easy and go slow. We’re way ahead…and if you feel like you want to get back in the couch, just get back in the couch.

This exchange was a precursor to both Evans and Cernan spending much of the next three days looking and acting, without saying so, like they did not feel well. No one reached the point of throwing up as a few others had in the past; however, America had relatively little internal conversation for the three days after TLI. The exceptions to this occurred during mission critical phases of activity, such as TLI, P52 alignments, etc., when professionalism exerted itself and masked any discomfort.

I had started to say to the others that I had a slight headache and a little stomach awareness, but if I just stopped moving for a few minutes, or stopped looking at the bright Earth scenes against a black background, these motion sickness-like symptoms of space adaptation went away. Later on, I talked to Mission Control on a private communications loop about these physiological observations. The Flight Surgeon in Mission Control, however, interpreted this self-initiated reporting as implying that I was feeling sick and the others were not – just the opposite of what was actually the case.

Getting back to business, I said, “Okay, gang, I’m going to give you a [list of things to do]…well, I’m going to save that, until I get [my pressure suit] unzipped here in a little bit… You got your GDC (Gyro Display Coupler – a backup guidance system) aligned?

GDC is aligned,” Cernan answered.

We’re getting [out] the cameras,” I stated, referring to the next checklist item that included the ORDEAL box Cernan had already mounted on Panel 13 and then initialize. ORDEAL (Orbital Rate Display Earth And Lunar) displayed America’s orbital velocity around both the Earth and Moon.

Cabin pressure looks good to you, huh?” Cernan interrupted, again.

Yes, sir; it’s holding at 6 [psia].” Although this was a bit high, an alarm normally would have alerted us if pressure needed to be reduced.

You got all the hatch configurations we want?

Yes, sir. Very tight. Hatch is good.” Why Cernan seemed to have forgotten that he and I confirmed the pressure integrity of the cabin soon after we entered orbit, I don’t know, unless he felt he was not being “Commander” enough and needed to ask something, or he was feeling guilty about feeling physiological discomfort in weightlessness. On the other hand, in high-risk situations, it is always a good idea to double-check.

Normal and latch[ed]?” Again, he referred to the hatch.

Yes, sir.

Okay, and I’m double-checked here on normal and latched,” Cernan said as he triple-checked.

You want to give me a mark on 48 [seconds] there, Gene? Evans asked from the LEB where he was resetting the computer’s Mission Timer.

Yes. …45 seconds [to go]. I wonder how that clock got off down there?

Okay, I alerted them. “You should have [communications through] Carnarvon in about 5 minutes.

Thirty seconds, Ron.” And then the two of them counted down to a reset of the Timer.

Meanwhile, I was running a check of the SECONDARY GLYCOL LOOP. After selecting SEC on the ECS IND[ICATOR] switch, I put the SECONDARY COOLANT LOOP PUMP to AC1 and verified that the GLYCOL DISCHARGE PRESSURE was between 39 and 51 psia and that the SECONDARY ACCUMULATOR QUANTITY was between 30 and 50 percent. After putting the SECONARY COOLING LOOP to EVAPORATION, I needed to wait five minutes to check the SECONDARY EVAPORATOR TEMPERATURE OUT had reached between 38 and 50.5º. Once that was verified, the SECONDARY COOLING LOOP was RESET for one minute and then turned OFF. Then, the INDICATOR switch was put back to PRIMARY for general monitoring.

As I moved a switch to check the pressures in the SECONDARY GLYCOL LOOP, another spurious MASTER ALARM occurred to which Cernan reacted by saying, “There it went – with that switch.

Sure seems to be it doesn’t it?

Which one…any of the switches?” asked Cernan.

Well, so far it’s at random. Maybe we ought to keep a list,” I replied.

Then, with another ALARM, Evans said, “Was that…I just hit the MISSION TIMER START.

No, I think it was mine, Ron; [I moved] a bat[tery] switch up here,” I assured him. This was starting to look like a problem in some way with Panel 2.

Again, trying to get everyone back on the checklist items, I asked Evans, “You got all the optics stuff [stowed], right, Ron?, …I’ll check that one off. You getting the cameras [out]? …P52 [done]?

After replying in the affirmative to these questions, Evans added, “P52 is completed. [Gyro] torquing angles were small.

Did you copy them [down]?


Okay. SCS (Stabilization Control System) attitude [check]… Can you do that [Gene]?” The SCS provided a backup means of determining the spacecraft’s orientation in inertial space. The gyros (GDC) for the SCS earlier had been aligned with gyros in the Primary Navigation and Guidance System (PNGS) that Evans had just updated with his P52 star sighting.

Yes, I can do the SCS attitude. That’s no problem.

Okay. How about the Docking Probe? Is that [done before] AOS (Acquisition Of Signal)? They (Mission Control) like to have that done [before AOS]…or what’d we decide?

They don’t need it,” Cernan asserted.

Well, they can’t see anything [of much use on the telemetry] anyway. They got their Probe temperature [to tell] whether it’s extended or not,” added Evans.

Then Cernan referred to feeling like he was upside down. “It’s just like [upside down] maneuvers I was doing in the T-38.

[It’s okay] if your oil pressure doesn’t drop,” I joked, stretching an analogy of body fluids to the tendency for some T-38s to perform well upside down and others to lose oil pressure.

Okay, you guys, I said. “Except for one check [on a panel] over here, which I am going to have to unzip [my suit] to do, I think we are done [with the Checklist].

You happy with everything except the MASTER ALARMS?” asked Cernan.

The MASTER ALARMS…Whew!” I interrupted myself.

What was it?

Oh, I got that change in the bias again on that H2 tank, I explained. It’s down to 90 percent. And the surge tank’s coming up, thanks to your little check [of that handle position]. …And the MASTER ALARMS are the only [other] thing that I found anomalous. Okay?” As I then worked out of the harnesses that I had left connected during work with the Checklist, I floated away from my couch and jokingly stated the obvious. “It’s like zero-g!

Just move slow,” Cernan reiterated.…Even if there’s nothing bothering you, you still move slow.” This, of course, was the plan I had already adopted.

Evans then sang, “It’s a lot easier to get out [of the suit than in one g]. Your just take it [off] and let it float up here.

Okay, let me tell you what you want [from stowage],” I continued from the checklist.


Looking out the windows between checks of our systems, the immensity of continental Africa held my eye. The first view of land from over the Atlantic includes the giant sand dunes on the southwestern coast. (Fig. 5.4) A pass over the cloud free inner continent and then Madagascar at midday offers aesthetic and geologic scenery unlike any textbook or travelogue. Geology and botany define ancient, still mysterious patterns of life and soil that, millions of years ago, nurtured our origins as a species. Preceded by long lines of billowing white smoke, range fires sweep before the winds. As they have for millennia, the fires emblaze grasslands of the Kalahari with feathery patterns like ice crystals leave after a breath of winter has passed.

Fig. 5.4. Apollo 17 view of the coast of South Africa, showing the immense sand dunes that have developed there (NASA photo AS17-148-22624).

Speeding silently over the deep blue Indian Ocean and the Intertropical Convergence Zone, we see the dense white tops of hundreds of magnificent afternoon thunderheads break into the stratosphere, forming where tropical air masses converge near the equator. Feeding moisture into air currents that ultimately would drop snow in polar regions, these splendid examples of nature’s inexorable cycles and unstoppable power dominate our crossing of this global band of storms. The sunset shadows of cloud anvils stretch eastward like dark fingers reaching to stop the inevitable advance of night. Without realizing it, I crossed the equator for the first time as we approached the East Indies. After sunset over the Pacific, flashing, blue-white lightning rippled through the cloud tops and across the ocean’s black night. North and south of our orbit, stars rise slowly between the dark horizon and the soft blue airglow in the upper atmosphere.


This is Apollo Control at 51 minutes into the flight of Apollo 17 and we’re standing by to reacquire the spacecraft through the Carnarvon, Australia, Tracking Station. One of the things the booster engineer will be looking for when we reacquire them [will be to] get good log on the data [from] the Saturn 3rd stage instrument unit. Looking at one brief bit of data before we lost signal, it appears that one of the four batteries in the instrument unit had a very high current drain on it. We will be looking closely at that to see if it was simply a telemetry problem or if, in fact, that battery does have some problem. And we should be about 15 seconds from reacquiring.

“Hello, Houston,” I called. “How do you read Seventeen?”

“Seventeen, read you loud and clear,” came Overmyer’s reply precisely at 52:20, transmitting through the Carnarvon antenna station.

“Hey, we’re going real well up here, Bob. Have no significant anomalies as yet; and we’ve just about completed our part of the Insertion Checklist. Gene has his SCS check yet, and Ron’s got some P52 numbers for you. And the only thing I’ve seen so far is…some spurious MASTER ALARMs, without CAUTION AND WARNING [lights], that seem to be associated with moving switches on Panel 2.”

Overmyer seemed a bit confused by this report, so I continued: “So far, it’s (the alarms) been fairly random. Some [switch movement] that I remember are the SECONDARY COOLANT LOOP EVAP switch, the LAMP TEST switch…let’s see, …I think I got one with the TEMP-IN AUTO SWITCH. Gene got one doing something. I can’t remember exactly what it was… Probably random.”

“We copy. Jack, we’re standing by for that P52 data. We’ve only got about a…five-minute [communications] pass here. We’ll take the 52 data, and I got a few updates for you.” Interesting that Houston flight controllers did not seem particularly concerned about my MASTER ALARM anomaly that repeatedly interrupted our initial three-quarters of an hour in orbit. On the other hand, this was a short pass.

Evans then gave the numbers he had come up with for the fine alignment of the guidance platform, all well within the desired limits. “Okay. P52 data is coming. NOUN 71 is 24 and 30 (stars); NOUN 05 is point 01 (—); NOUN 93s are plus point 080, plus point 029, plus point 018; and we torqued at 35:25.”

“Okay. We copy that. Okay, while we’re filling in some here, you might want to know this, Jack. Your sunset and sunrise times in the Launch Checklist are all off [late] by approximately eight minutes and 30 seconds… That’s an approximate number.”

“Okay,” I acknowledged, “we got you.”

“And on page 2-17 of the Launch Checklist, you’re going to want to delete all reference to Honeysuckle [an Australia antenna] AOS (Acquisition Of Signal) and LOS (Loss Of Signal) and delete all reference to Canaries [Islands antenna] AOS and LOS.”


“And we want to add an Ascension pass,” Overmyer continued; AOS at Ascension [will be] 01 plus 54 plus 00 and LOS will be at 02:00:16.”

“Okay, Bob, you’re going to have to repeat that.” Overmyer had caught me without a pen in my hand.

“Okay, stand by. Let me give you a page [in the Launch Checklist]. On 2-17…let’s go Hawaii AOS, first of all. On Hawaii AOS, on page 2-17, AOS is 01 plus 17 plus 24. Hawaii LOS: 01 plus 22 plus 49.

“Roger,” I replied. “Now what about the Ascension?”

“Okay, here, [I’ll] give you Ascension again, now: AOS 01 plus 54 plus 00. Ascension LOS will be 02:00:16. Over.”

I then read back a number of changes from Overmyer in the access times around the world, required as a consequence of our late launch.

“Roger, Jack. Good copy. And the booster’s looking good down here and you’re looking good.”

“Okay, and I’ll do a better job of itemizing those switches,” I said, trying to get their attention on the MASTER ALARM anomaly. “We are pressing pretty hard, and I’ll be able to go back and get most of them, I think. And we’ll keep an eye on…the MASTER ALARMS.”

“Roger, Jack. We understand. And I think we copied most of what you said there, and we’re working on it.”

“Okay, Bob,” broke in Cernan. “Other than that MASTER ALARM, all is well on America, and I understand the booster is looking good to you.”

“That’s affirmative.”

I added: “And, Bob, let me add that…we did get spurious MASTER ALARMS without switch movement, but many came with switch movements. We’ve had about seven [alarms]… That was only after [orbit] insertion.”

“Seven times that your heart doesn’t need, huh?” Overmyer joked.

“Oh, we were paying attention to a sunset that was the biggest…”

“Sunrise,” Cernan inserted.

“…or sunrise or something that we saw,” I continued, undeterred, as it was sunset for the Earth. “It was the biggest rainbow I’d ever seen!”

“Beautiful! We can’t wait to hear what you had to say about…the ignition on the S-II. It sounded pretty spectacular.”

“Bob,” Cernan replied, “just let it be said that that was quite a booster ride! When we get a chance a little later…maybe we’ll be able to tell you something.”

“We’re about ready to lose comm., here. You’re looking great, guys, and we’ll pick you up in Hawaii here shortly.”

“Okay, we’re looking at the deserts of Australia right now,” Cernan said, “and, again, everything’s good on board.”

“Roger. Pick you up at 01:17:24.”

“Gotcha,” I answered.

This is Apollo Control. We’re coming up now one 1 hour after liftoff for Apollo 17. And as you heard CAPCOM Robert Overmyer reporting to the crew that everything looks good including the Saturn 3rd stage. Apparently the indication we had of a possible battery problem in the instrument unit was nothing more than a bad bit of telemetry there. When the booster engineer got a good hard look at the telemetry on this pass, he reported everything looked good.

Continuing to take things out of storage in the LEB and needing to tape something somewhere, a frustrated Evans said, “Well, I’ll tell you…

Okay, 11, 6, …” Cernan responded in gibberish, causing Evans to laugh. “[They’re] pretty stingy with the tape there. [Only gave us a] piece about a foot long.

A foot long?” Evans repeated, incredulously.

Oh, this’ll have to do for now,” Cernan decided. “I’m just going to put this here, if you’ve got any other things…

Evans decided to move from the LEB to where he could see out the hatch window and remarked, “Man, are we moving. Holy mackerel!

Don’t let it out, Ron,” kidded Cernan.

I haven’t had a chance to look out the window, yet,” Evans responded.

That’s all right, get back to work,” Cernan ordered and got another laugh from Evans in return.

Floating the camera toward Evans, Cernan said, “Here it is.

That was as hard as [you could throw it]?” I asked, concerned about the camera lens.

Oh, it didn’t hit it, [did it]?” Evans answered my question with a question.


I hope that [hit] doesn’t mean anything,” a contrite Cernan said, “but it sure could be a pain in the neck, even if it doesn’t.

[What] (singing) he was doing isn’t very loud, is it,” I stated.


Seeing more and more thunderheads below, I said, “[Let me get my] weather map out [of my pocket] and look at it.” The map I referred to was the set of recent satellite photographs given to me as we suited up a few hours ago.

A surprised Cernan asked, “You got [a weather map]? I had not told him of my plan to observe weather patterns on the way to the Moon.

Got the weather map,” I informed him, as I extracted it from my calf pocket.

Okay, we got the SPS REF[ERENCE] CHECK to do yet?” Cernan asked me, changing the subject.

Sure,” I confirmed, having been trying to get that done for sometime, now.

Evans had broken out a map that showed our ground track Xand was trying to identify the land masses below us, to which Cernan, pointing to the map, contradicted Evans’ initial conclusion, saying, “No, we’re not, we’re not doing a darn thing up here [in Asia, but only along the track of the] spacecraft.

Oh, really? Evans responded.

We’re way up here,” insisted Cernan.

There it is,” Evans said, spying an obvious ground feature.

As we approached the East Indies, Evans exclaimed, “Oh, look at the coral reef there, Geno!

Too bad it is not the Bahamas. Well, you’ll see the Bahamas in daylight, as far away as the Moon, but they really get bright.

Fantastic! Coral atolls!

Okay, troops,” Cernan said, “let me get you back and squared away here, I mean checklist-wise.

With the Commander finally deciding to command, but uncertain about how to do the SCS ATT[ITUDE] REF[ERENCE] COMP[ARISON] CHECK, Evans began to walk him through the procedure, having done this many times in training.

VERB 16, NOUN 20,” Ron directed, first. Noun 20 gave a DISKEY display of the roll, pitch and yaw angles of the spacecraft, currently held in the guidance system’s ICDU (Inertial Coupling Data Unit). Verb 16 told the CMC to monitor the Noun 20 data.

I got it,” replied Cernan.

[Next,] select number 1 [on the] FDAI (Flight Director Attitude Indicator).

Okay, got it,” Cernan said, as he moved the FDAI switch.



[Now,] ATTITUDE SET [to] GDC,” continued Evans.


[With the] ATTITUDE SET DIALS, null [FDAI] number 1 error [needles].


Then, key your VERB [16] when they’re (the error needles) nulled,” Evans told Cernan to do this in order to freeze the display on the computer DISKEY.

I interrupted their procedure to say, “…We’ve about 15 minutes to sunset, Gene. …Okay, [actually, it will be] 8 minutes earlier, so we have less than that (15 minutes). …8 minutes earlier.

Okay. Do we call up…” Cernan started to ask a question but then through better of it. “Okay, here’s the numbers, Ron, if you want to write it (them) down.

Okay. Wait just a second [while I get a pen]. Un Poquito. …Okay, [I ready.]

What do you want, NOUN 20 first?


[Roll] 179 point 77

179 point 77.

[Pitch] 118 point 95.

118 point 95.

[Yaw] 359 point 59.

359 point 59.

Okay, Cernan said, “[for comparison, the FDAI] will be [roll] 180 point 3.

180 point 3

[Pitch] 119 point.75.


[Yaw] then [is] 359…point 0.

Evans apparently missed the pitch number, asking, “Degrees of pitch, got that

Okay, that’ll be 114 [and a] half and 115 – about a degree [off]. …degree [of difference].” Cernan apparently misread the FDAI this second time, but got the difference from the computer NOUN 20 number for pitch, right.

Got 8 minutes to Hawaii AOS.” I reminded them.

Cernan commented, relative to the difference between the computer’s reading of the IMU attitude and the FDAI numbers, “Would you believe the GDC drifts just like it…

Like it does in the simulator?” finished Evans.

Can’t believe it does that,” Cernan stated.

Evans laughed and responded, “It’s not supposed to do that!

Well, I discovered one thing,” Cernan said, after perusing the Checklist. “I’m…looking at the time on the Checklist that the [Command Module] tape…” At this point, Evans interrupted, reminding Cernan that what he was looking at related to the next orbit.

While Evans and Cernan worked on the SCS, I went ahead with the SPS (Service Propulsion System) MONITORING CHECK. The big 20,500 pound thrust SPS engine not only would provide the energy needed to go into and out of lunar orbit in a few days, but it was our means of returning home if the S-IVB did not provide a full TLI burn. It also would give Evans the capability to adjust his lunar orbit altitude and orbital plane in preparation for our return from the lunar surface.

I went through the SPS check quietly so as not to disturb Evans and Cernan in their check of the SCS backup guidance. First, I used the SPS PROPELLANT TANK TEMPERATURE INDICATOR to check that the propellant temperatures were between 45º and 75º F. If they had not been within those limits, I could control the temperatures with the SPS LINE HEATERS. Next, I went to the SPS PROPELLANT TANK PRESSURE INDICATOR and checked that helium (He) was less than 3900 psia and that the N2 tanks A and B were less than 2900 psia, leaving the PRESSURE INDICATOR switch on He for general monitoring, as helium diffused much more readily than the larger nitrogen molecule. Then, I checked the redundant FUEL (mixture of unsymmetrical dimethylhydrazine and dimethylhydrazine) and OXIDIZER (nitrogen tetroxide) tank pressures as between 170 and 195 psia, leaving the PRESSURE INDICATOR switches in position 1. The four SPS ENGINE INJECTOR VALVES went to the CLOSED position to check OXIDIZER and FUEL QUANTITIES and the balance between them. The PRIMARY OXIDIZER FLOW VALVE was left in PRIMARY and the two He VALVES were left in AUTO as they were during launch.

Realizing that I was very thirsty, I stated, “I will have a drink of water, though.” We had a gun-like dispenser in the Lower Equipment Bay that allowed us to squirt an ounce of water at a time into our mouths. Drinking water was being added continuously to our tank from the same hydrogen-oxygen Fuel Cells that provided electrical power.

That’s good water now – good water now,” Evans commented as he handed me the water gun.

Aren’t we supposed to use our little thing (measuring bag)?” I asked him.

I don’t know. We’re not…keeping track of it (water consumption) now, so I figure we’ll start tomorrow.

Okay, sports fans. You want to extend the Docking Probe or do you want to wait?

Whoo! I think I might as well do that…” Evans agreed and then, humming to himself, he said, “…try to extend the docking probe…

Before Evans went to work on that, I asked him, “Are you passing out our stowage…bags?

No, not yet. I better get some, hadn’t I. You need some for TLI?” Evans asked.

No. I just thought you’d need some to [control our small items].

Oh, okay. …I got to figure out where to put them.

You want me to read you the checklist [for Probe Extension],” Cernan asked Evans but got no response.

I went back to the main Checklist, asking, “…You guys finished your redundant performance check, didn’t you?” Calling the SCS ATTITUDE REFERENCE COMPARISON check by this name, relates to shorthand used during simulator training.

[Yes.] Except for the…” Looking out the window distracted Cernan from finishing his response. The only step not called out earlier, was to reset the FDAI SELECT switch back to 1 / 2 so that both FDAIs were being fed the same orientation data. [Look at the ocean,] with the clouds with the Sun putting shadows on the [ocean] surface out there.” At this point, we approached sunset on the Pacific as we flew across the Equator north of Samoa and our planned splashdown point on the return trip. The amazing shadow patterns on the Pacific and its thunderheads, and trying to photograph them, took our attention away from TLI preparations for a few minutes.

Hey, we’re pretty close down there, you know,” Evans observed, probably thinking about our relatively low 90 nm orbit.

Yes, we’re getting close to sunset…” Cernan stated.


Good grief! [Look at that!]

What are those bright spots in the clouds there? Evans asked.

Oh, that’s your zero-phase spot [where our shadow would hit the cloud],” I answered.

Cernan noted, “That’s the cloud in the shadow [of another cloud], see, the shadow’s gone a long way.

In fact, it’s a little low-pressure area, see it?” I had noted the counter-clockwise pattern in the clouds. We may have been flying over the tropical storm beginnings of Typhoon Violet south of Guam. I later specifically identified this storm on the way to the Moon. “Why don’t you get our [Earth] orbit chart out when you go into the data file, Ron.

You might take the Flight Plan out,” Cernan added.

There are some pretty lively looking clouds down there, I observed, speaking of the large cumulus build-ups we were seeing.

Yes. Yes, yes!” exclaimed Evans.

Better than [the simulator],” I added.

Evans asked, “Are we going right over the equator…must be.

Yes,” Cernan replied, looking at the orbit chart, “we’re northwest of Samoa.

Evans noted, “We went (launched) on a 91 degree [azimuth].

There’s a good-looking cloud for you – look at that one,” I exclaimed, “…Boy, you could snap a picture of that…(laughing)… I forgot I got the damn camera! After taking a picture so near sunset, I said, “Might be underexposed.

I can get that, Jack; give me that [camera],” Cernan requested.

I got it,” I replied (Fig. 5.5). “There’s some big clouds…

Fig. 5.5. (Upper): Oblique view of the tops of thunderheads near sunset. (Lower); Overhead view of the same larger formation. (NASA photos AS17-148-22659, -22660).

That little round one, you mean?” Cernan asked.


And there’s another one over here on my side, if you’ll give me the camera.” I think the Commander was unhappy with me for not giving him the camera, earlier.

Okay, it’s at 5.6 [f-stop] – might want to open it up more.

I don’t know if I can get it now. It’s going to be hit and miss,” Cernan griped.

That’s the [problem with being in orbit].

Well, I guess it is,” Cernan agreed.

Trying to make it up to him, I said, “How about out your window, Ron?

I can see it, but [can’t get the camera pointed at it].

No, it’s too late,” concluded Cernan.

Too late now. I’m in the dark,” agreed Evans.

Okay, it looks like something [like a cow pad],” I joked.

Now that there was little to see out the windows other than the horizon, Evans offered, “Okay, how about the old docking probe?

With sunset on the Pacific behind us, checking out the Docking Probe constituted a critical event if we were going to take the Challenger with us to the Moon.

Okay, how about the old docking probe circuit breakers, Evans began.

Okay…circuit breakers are in,” Cernan responded.

Okay, let’s go by this checklist and make sure we do it right,” I cautioned.

Evans agreed, saying “DOCKING PROBE circuit breakers, two, closed.

They’re closed.

DOCKING PROBE, EXTEND/RELEASE [push button] – EXTEND/RELEASE until probe extension [complete]. Okay, I’m going to hit it real lightly…[probe position indicator shows] barber pole and then gray [meaning extended]. I thought it went bump, didn’t it?

I couldn’t tell,” I answered.

Cernan admitted, “That was me with the camera.

Go to EXTEND. It’s out. Okay. Go to RETRACT. [Did the two indicators] go gray?

They both popped in a hurry, didn’t they?” I replied.

Yes. That really goes great… Okay, PROBE RETURN,” Evans continued with the checklist.

How did it go again?

RETURN and RETRACT [indicator] is gray. Okay, [now] DOCKING PROBE EXTEND/RELEASE. I don’t know whether [it actually extended]. Okay, …to RETRACT. Okay, we’ll keep it in RETRACT until [just after] TLI [and we] copy the TLI PADs.” I did not call out ‘barber pole’ on the two indicators, but they must have been so, or it would have been an issue.

We got everything on that checklist?” Cernan asked.

To which I responded, “Okay, I’m going to go back through it, then.” Two mission training cycles, combined with T-38 and H-13 training and experience, made me a believer in using checklists and using them twice. I paged through the Checklist to see if I had not checked off some item.

I think we’re in good shape,” stated Evans.

Cernan then asked, “And Hawaii [communications acquisition] is what? …01:17?

Yes,” I said, and then asked Evans just to be sure, “You got the docking probe set?

Yes, that’s [affirmative].

Looking at the modified Flight Plan numbers, I confirmed again, “Hawaii is at 01:17:24, and we leave it at 22:54.

Looking at the upper part of America’s hatch, I suddenly noticed an unofficial decal left by the Support Crew. “What is this stuff. ‘Commander’s Splashdown Speech?’

What’s that? What? Cernan seemed taken aback as Evans chuckled from the LEB.

Commander’s Splashdown…

Evans interrupted with, “Commander’s Splashdown Speech? What’s it say?” He was laughing with me as both of us, and the support crew, had lived with Cernan’s tendency toward being pompous both in private and public.

It says, ‘Commander’s Splashdown Speech’. It’s a decal put on the [hatch] door there with the…

I figured Cernan had had enough kidding, so I interrupted the humor with a review of what we had done to reconfigure the cabin and prepare America’s systems for TLI. “Okay, going backwards [through the checklist], you guys got the SCS attitude reference component check, P52, the optics dust cover, the camera, [I’m] just about finished with the secondary ECS check…

Cernan continued with, “the ORDEAL mounted and initialized. …Do you want the Flight Plan?” he asked.

Well, I don’t need it right now,” I answered. “I’ve got everything I need in here. I want to give you cue cards [for TLI] so tell me when you want them.

I just don’t know where to put them yet.

[Well, give me the ones for launch and I will stow them.]

[I guess we don’t need the] survival kit [for TLI],” Evans mumbled, as he rummaged through a stowage compartment.

Back to the checklist summary, I continued, “Unstow camera, got that; GDC is aligned; SPS is checked except for a couple of items which I’ll do; checked EPS, Fuel Cell purging [done], and the Heaters are ON.

Maps are hard to get out,” Evans told us. “Hey, you want a map?

Yes,” I responded.

Rescue Book – don’t need that,” Evans decided, at least for the time being. I hoped we would not need it after splashdown, either.

You got the EPS configuration [and] MAIN [REG CHECK]…? You guys went through that?” Cernan had not been listening when Evans and I went through the ECS MAIN REGULATOR ECS.

Yes, sir.


Got a map, somewhere?” I asked.

Without answering me, Evans said to Cernan, “Hey, see what’s in there, Gene. I don’t know what’s in there.” Cernan had moved into the LEB, presumably to help Evans see what was in the various storage compartments.

I hope the [Flight Plan is in there]. …Well, it’s the Systems Data [book], Cernan said.

That’s what I hope it is,” I replied, wanting to be sure that book was handy in case any problems developed with the systems I was responsible for monitoring.

…and the Flight Plan, Volume 1, …and Malfunctions [Procedures],” continued Cernan.

Good, that’s good,” Evans said.

Looking into where they were rummaging through the compartments, I commented, “Let’ see [that]. This looks like a LM (Lunar Module) thing here.

What’s that?” Cernan asked and looking at what I had grabbed. “Oh, we don’t need that yet.

We pulled Volume One of the Flight Plan from its launch stowage location and noted the first of many inserts placed there by the Support Crew. This one was quite risqué.

Look at that!” I exclaimed.

Is it in there?” Cernan said, not believing.

Is that in the Flight Plan?” Evans was incredulous.

Oh, those son of a guns!” Cernan said as we all laughed. “Those finks! …Look at those finks!

What did they do?

Everywhere [on the page]. Look at it!

Those finks! Oh, my gosh. That is almost a crime. How can I peel that off [the Flight Plan page]?

Still laughing, Evans declared, “We got to peel that off to get to it (read that part of the Flight Plan).

How could anybody do that? [And] over Hawaii!” exclaimed Cernan.

Gene,” I said, “never saw that one before it was in there.

‘Journey’s Lift-off receipt?’” The support crew had struck, again.

“Hello, Earthlings. We’re back with you,” I called when I heard the communications uplink come to life.

“Roger, Jack. Read you loud and clear [through Hawaii]; how us?”

“You’re loud and clear. And no change, systems-wise, that I’ve seen.”

“Roger, Jack. Any more MASTER ALARMs?”

“We had one when Ron… Looked like his neck ring hit Panel 2.”

“Okay. Sounds like we had something loose in Panel 2, huh?”

“Yes. …It may be annoying, but so far, it doesn’t seem to be a problem.”

“Roger. Just for your information, everything is looking outstanding and no problems. We’re taking a good look at the data here at Hawaii, and we’ll make a GO/NO GO decision about 60 seconds after acquisition at Goldstone [California antenna]. But there’s nothing right now to lead us to believe that Zero Opportunity will be required.” This “Zero Opportunity” referred to the case when the S-IVB could not be used to leave earth orbit.

“Okay, Bob,” I replied, “understand that. We are prepared; however, [the] spacecraft, other than those MASTER ALARMs, is looking very good. We got the Docking Probe extended. The SCS reference attitude check is complete. …Hey, Bob, I just remembered another switch that I think gave us a MASTER ALARM was H2O QUANTITY INDICATOR.”

“Roger. Copy that, Jack. …We’re going to lose you in about 30 seconds. But when you get over the stateside here, we’re going to take the [telemetry] dump on the data, and we’ll read it out real carefully so when you get in TLC (TransLunar Coast) we ought to be able to see where that MASTER ALARM glitch is coming in to (from).”

“Okay, Bob. And yell at me if you want anything done on the comm. With this change in AOS-LOS stuff.” Here, I referred to the antenna configuration that might need to be modified.

“Negative on that right now. We’ll see you at 01:28:59 through Goldstone.”

“Okay, 01:28:59, Bob. We’ll be there.”

“This is Apollo Control. 1 hour 25 minutes after liftoff. During the post-launch press conference at Cape Kennedy, we had a short acquisition with the crew through the Hawaiian tracking station. During that period of conversation, and during that period of monitoring the systems on the spacecraft and the launch vehicle, we found that the situation was essentially unchanged. That is, both vehicles now looking good; the spacecraft and the launch vehicle. And we’re progressing toward a normal TransLunar injection, 1 hour 46 minutes 50 seconds from now.

The crew has discussed one unexplained series of events. It appears that when certain switches are cycled or moved on panel 2 which is the main panel in front of them, the center panel of the spacecraft, they’re getting a Master Caution and Warning signal. A [red] light comes on – a tone comes on. This is to attract the crew’s attention that something may be wrong and the normal procedure is then to look at another matrix of [yellow Caution] lights which would zero them in on the problem. The light… the system or the subsystem or particular area being monitored, or which had the problem would light an individual [yellow Caution] light. However, when they go to this other matrix of lights, they find that none of them are lighted. This is leading the crew and the flight controllers here in mission control to believe that they are getting a [spurious] signal to the Master Caution and Warning, when in fact nothing is wrong. We don’t have any further explanation for the problem at this point. We will continue to look at the data and particularly during the TransLunar Coast, we think we’ll get a good long time to look at things in detail and try to find out precisely what is happening. At this point however, the problem presents no concern and one of the more likely explanations – a possible explanation that’s been advanced is perhaps some contamination in some switches.

Five minutes, we’ll be over the States, guys,” Cernan reminded us. “Let’s turn the lights down a little bit.

You start to see a glow [of West Coast lights],” Evans speculated. “There is a glow. See the horizon?

You got pretty good eyes,” I said. “Oh, yes, there it is. …Guess what I’ve lost…[the] camera. …You see a camera floating around anywhere? …I got it.” Got some laughs out loud at the dialog with myself.

Ron, while you’re down there, Cernan requested, “kick my suit up. I want to bag it up.” He had taken his suit off while I had my brief discussion with Overmyer.

Here it is,” replied Evans, having unstowed the suit bags during his search through the various compartments in the LEB.

See that glow out there, Gene?” Evans asked after he and Cernan had the suit in the bag. “Is that the sunrise?

No, I’m looking out at the north horizon.

That’s what they call a [zodiacal light],” I added… “Boy, did you see us go through that damn S-IVB fire? What was it?

That was the S-II staging,” Cernan explained. “We went through the S-II fireball, because it takes awhile for the S-IV to light up.” Actually, in that interval, we very briefly stopped accelerating and the expanding fireball caught up with us.

Yes, that’s what it was,” I agreed.

…on that [Gemini] Titan, between the S-I and the S-II, you get that because there was a pause [in acceleration] and a fireball would overlap you. And you could fly right through the flash, smoke and flame wall.

Well…we sure enough did it, I tell you. It (S-II fire ball) wasn’t awfully bright, I said.

We saw all three stagings, now, or all three ignitions,” Cernan claimed, although only he had a window out of which he could view these.

Yes, yes,” Evans confirmed, then exclaiming, “There’s the old dipper!

Continuing on the previous theme, I said, “That tower [jettison] was spectacular!

Yes it was,” Cernan had to agree.

Laughing, Evans added, “That tower really went!

Look at the stars,” Cernan said, “Gee, Jack, this is right, you get north, [I mean], you’re always on my north [side in both the] Command Module and in the LM.

We’re looking,” I told him.

Evans commented, having moved back to the LEB, “Ought to look at these optics at nighttime, I guess.

You got to do another P52, by the way,” Cernan reminded him after opening the Flight Plan.

I do it now?

Thing about the “Commander’s Splashdown Speech” decal, again, Cernan said, “I can’t believe that guy did that to me. Not for me, but to me…

Evans and I both laughed at his quasi-concern.

Next P52, Ron, comes at about [one plus] 28 [minutes], Cernan reminded Evans. “Which should be just about 45 [seconds].

Hey, there’s Orion!

AOS Goldstone is [also] at 28,” I added.

28,” Cernan repeated. “We ought to be able to see California in the dark. There’s Baja [California]. Cernan probably had picked up the lights of Ensenada, an area of Baja that I had visited for ten days on a Geology Department field trip during Caltech’s 1954 Spring Break. My mind briefly filled with memories of camping under the stars, listening to the sounds of rocks grinding in nearby surf, hiking though heat and cactus, harvesting abalone from the tide pools, and, regrettably, filling canteens with Santa Tomas Rosé instead of water before a long climb.

I don’t have a good feeling for where our Flight Plan [ground track] is right now; does anybody [else]?” I was anxious to try to see familiar features in Mexico and the southwest U.S.

Yes,” Cernan asserted in answer to my question. Basically, he said, “[our] 90-degree launch azimuth means we’re…[approaching] our launch latitude which is the latitude for the Cape…[actually, a latitude a little bit higher] than the Cape, because [the launch azimuth] actually was 91 and a half.

We’re going across Arizona [on this track], I mused, “and that’s Baja California, probably. …Turn on your lights, San Diego. Boy, it’s [the track] pretty near over my home [in New Mexico], I guess.” The reference to turning on city lights harkened back to John Glenn’s orbit track over Darwin when they turned on the city lights for him.

One hour and 28 minutes after liftoff, Overmyer called again: “Seventeen, Houston. We’re back with you [through Goldstone].”

“Okay, Bob,” Cernan replied. “We’re still same as before and ready when you are for TLI.”


“I can see the lights of southern California, Bob,” as I began the short travel-log across America. “We’re going to be going a little bit south of that area.”

“Right. Your ground track looks like it’s taking you right up over the mid part of Baja California.”

“Yes, sir; I’ll believe that. I’ll bet you I can see Ensenada right now.”

Evans came in from the LEB with, “Bob, I expect he’ll probably be able to see the lights of Silver City, too.”

“Well, I’m sure going to be looking for them, I’ll tell you!”

“Jack,” said Overmyer a minute or so later, “just for your information…when you come up a little farther in this orbit here and get over Mexico, you should be able to see all that bad weather that was giving us so much worry [for the launch] and had Tindall [Air Force Base, Florida] and New Orleans [Naval Air Station] and everything all messed up this morning when I went through there [in a T-38]. They had a pretty bad line of weather along there.”

“I assume it wasn’t too bad. I think you made it didn’t you?” I said a little facetiously.

“Oh, yeah, I made it, but I had to…work at it. But…I was worried about it getting down towards MILA (Merritt Island Launch Annex, tracking station adjacent to Cape Kennedy) there after…if we had to scrub [the launch] and go tomorrow night. Boy, I am sure glad we got you off tonight!”

“Guess who else is!”

“No, I can’t… I wouldn’t believe that…[Bob] Parker can’t make it back [in a T-38]. He’s got to come back on the [NASA Gulfstream]. So you might have to have [John] Young on for a while after we do TLI.”

“Hey,” I broke in, “you just wouldn’t believe, Bob, the lights you can see in the West right now. It must be absolutely clear.”

“Roger, Jack. Sounds spectacular…Jack, people in the room here want to know if you’ve been down your checklist yet.”

“Oh,” I exaggerated, “we got that out of the way in about 5 minutes. Have we missed something?”

“There’s a different checklist here we’re talking about.”

Then I understood what Overmyer referred to and laughed. “If you’re talking about the Flight Plan, yes!”

“Roger.” This last referred one of the traditional pinups, humorous comments, or dumb statements that the Support Crew inserted between or on the pages of various documents we had onboard. One of their most common statements for us was a play on Cernan’s motto for Apollo 17, “The End of the Beginning,” such as, at the end of a checklist section, writing, “This is the End, not the Beginning.” In this case, the insert was probably a Playboy pinup because Evans exclaimed, “What a waste!”

“If I am not mistaken,” continuing my narrative, “we must be just south of Arizona now. Is that right, Bob?”

“That looks real good. Yes, you’re over Mexico, there, and looks like you’re…maybe a hundred miles south of the Border, there.”

“Okay. I was pretty sure I was looking up in the Phoenix-Tucson complex there. …Clear night.”

“Little better than Florida.”

“The West is always that way. I wish it were daylight so we could see Sonora and that country. That’s spectacular, I’ll bet you. …Man’s fields of lights on Earth is competing with the heavens, Bob,” I mused. “Okay, I think we got the Gulf Coast showing up now by the band of lights [I see ahead].”

“Bob,” interjected Cernan, “you’re coming through with a large squeal right now in the background. …Assume the booster is still looking good, and we’ll be GO for a nominal TLI.”

“That’s affirmative.”

“And you’re still coming up with a loud squeal.” For several minutes, Cernan and Overmyer discussed this until Houston found it was a ground problem. As I had not changed anything on the radio control panel, the chances were good that this would be the case.

“Seventeen, how do you read?”

“No, Bob, you still got the loud squeal.”

After some action was taken in Mission Control, Overmyer called, “Seventeen, are you receiving Houston now?”

“All right, Bob. You came up unreadable with the squeal that time.”

A short interval passed, and Overmyer tried again, “Am I still squealing? This is Houston.”

“That’s affirm. You’re very loud, almost unreadable with the squeal. Bob, why don’t you give us the short count.” It is not clear why Cernan felt that “short count” would help solve the problem.

“Would you believe,” I continued in my worst Maxwell Smart impersonation (Get Smart, T.V. comedy series from 1965-1970), “we’re just south of Houston now, Bob? …I’m not sure exactly where we are, but I’m looking out [east] to an awful lot of lights on the horizon out there at 12 o’clock and an awful lot of lightning in the clouds out there.”

“Roger. We show you just about over the middle of the Gulf [of Mexico]. Looking ahead you’re probably south of the very southern tip of Florida there.”

“It looks like almost the entire Florida peninsula has got lights – got lightning on it somewhere.”

“Roger. How does my comm. sound to you now, Geno?”

“Okay, give me a quick short count,” Cernan replied.

“Roger. Short count follows: five, four, three, two, one, one, two, three, four, five. …Short count out.”

“Bob, you’re all right now. …And,” asked Cernan, “can you give us a feel for what the final weather was at the Cape…at launch?”

“Yes, let me get that for you. The reason why we had that problem on the comm is we just handed over from Texas to MILA [in Florida], and you’re going through MILA now. And it’s great. So we have a little problem with our Texas [communications] site. …The television coverage [of launch] had you all the way through [S-I] staging and the S-II ignition. Then, you went right behind a cloud for a while, but they were tracking you pretty well… They also cut in for about a half minute or so and showed a view of the crowd in just the available light from the booster, and it stood out pretty well.”

“Okay, Bob,” I interrupted. “We’re going right over Florida now, looking down at Miami. A beautiful view of the Keys all lit up…and I just saw a shooting star right over Miami! …That’s a very, very fine view of Miami. Hard to believe.”

“I’ll bet they sat there and watched you go.”


The fight plan-generated urgency of preparations for leaving these fascinating scenes of Earth had intervened until I was able to steal a nighttime glance at a cloud-covered Arizona, New Mexico and home. My mother and my sister, Armena, and her family were in Tucson only about 150 miles away. My other sister and her daughters, Janis and Linda, were still in Florida, waiting for their flight back to San Francisco and home. Diffuse glows of the lights of Tucson, Albuquerque and El Paso penetrated late autumn stratus. In fact, clouds covered the entire United States except much of the Southwest and Florida. We knew it would be clear at the Cape because we had left there only an orbit earlier– just an hour and a half ago.

An hour and a half! It hardly seemed real to this space rookie, no matter how much I had heard from others before. I told friends on the airwaves that “a field of stars on Earth is competing with the heavens . . . [We] are going right over Florida now, looking down at Miami. A beautiful view of the Keys all lit up…and I just saw a shooting star [beneath] us right over Miami!” Beneath us! How can you beat that!

Banded sunrises change in a few minutes from deepest black to brilliant blue to desert orange to purest yellow to searing daylight and then back at sunset in never-ending progression. In daylight, the Earth displays tinted oceans and quilted continents with patterns wrought during four and a half billion years of time, dark-shadowed thunderheads and dazzling snows ever varying in their beauty and scientific mysteries. Civilization’s warm fields and patterns of lights by night and farms and roads by day are seen without the inevitable boundaries that stimulated our presence in space.


Second Orbit of Earth

“Looks like we’re right over the Bahamas now, Bob,” I reported.

“Roger. I’ll buy that.”

“Well, I’m not easily impressed, Bob,” I continued. “But I’m certainly impressed by this one!”

“Roger. What’s the CMP doing? We haven’t heard much from him. Is he at the other window?”

“He’s crawling around looking for things down in the LEB,” Evans responded.

Laughing, Overmyer kidded, “They won’t let you have a window tonight, huh, Ron.”

“No, I’ll catch one here pretty quick.”

“Just a reminder, if you haven’t already done it, there is no need to un-stow the TV, because, due to this late launch, there’s just no site available.”

“Okay, Bob,” Cernan acknowledged. “We’re not going to un-stow it.”

“Bob,” I followed up, “I guess there’s no site available for some time, is that correct?”

“That’s affirmative. And if I can pull one of you guys away from a window, I’ve got a TLI plus 90 [minutes] PAD (Preliminary Advisory Data).”

“Oh,” I replied, “I’d love to copy that! …Just a minute.”

“Hello, Houston,” I called a short time later after repeated tries. “Apollo 17. How do you read?”

“Seventeen, Houston. Go ahead.”

“Okay. Lost you there for a minute. We had good signal strength all through that, so I figured it was your problem.”

“Roger. We’re just waiting here… You ready for the PAD?”

“We were calling you, and you missed us. So you might think about that [i.e., why?]. Ready for the PAD.” Overmyer gave me the P30 computer loads we would use if some spacecraft problem forced us to use the SPS to return to Earth without communications after a successful TLI burn . “Okay. It’s a TLI plus 90 (minutes) [PAD]. [Propulsion system and guidance is] SPS/G&N [P30 maneuver], [Weight for NOUN 47] 66953 (pounds); [NOUN 48 trim] minus 0.59 (pitch), plus 1.88 (yaw); ignition time 004:40; 01:48; [XYZ DELTA-Vs] [X is] minus 0351 point 8, [Y is] minus 0000 point 1, [Z is] plus 3378 point 2; [Burn attitude] roll is 180, [pitch] 073, [yaw] 003; NOUN 42 (height of apogee and perigee and total DELTA-V) is HA is not applicable, HP (perigee) is plus 0020 point 1 (nm), 3396 point 4 (feet per second); [burn time] 4:50 (minutes), [DELTA Vc] 3380 point 8 (feet per second); Sextant Star is number 11 (Aldebaran) – that’s one one; [Settings for Sextant Star], [shaft] 342 point 4, [trunnion] 32 point 3. …Stand by, Seventeen, Houston. Are you still reading me?”

“Hey, Houston,” I transmitted, “if you read, we’re reading you. Got you all the way through the trunnion on [the] sextant star.”

“Okay, we’ll have to wait and pick you up at Ascension. We just had a ‘keyhole’ pass at Bermuda and a little bit of a pass at Vanguard.”

“Okay, I’ll wait for you to finish that [PAD] and on the read back.”

“That’s affirmative,” Overmyer continued. “Stand by. …We’ve [still] got Vanguard, [so] I can continue on with…after trunnion, the bore-sight Star is not applicable, Jack. NOUN 61 (splashdown location), [north latitude] plus 13 point 25 (degrees), [west longitude] minus 032 point 00 (degrees); [Range to splashdown point] 1099 point 2 (nm), [Predicted inertial velocity] 34904 (feet per second); GET of point 05g [deceleration at start of entry] 024:38:09. Want to read back that much of the PAD, Jack?”

I proceeded to read back the entire TLI plus 90 PAD that had come in two batches.

“Roger Jack,” responded Overmyer. Good read-back except burn time is 4:50 and not 4:54. And we’ll be losing you here in about a minute, so wait on the rest of that PAD. Just a reminder for Ron, we’ll be standing by at Ascension for the next gyro torquing and we might have a drift update on the IMU there.”

“Okay, he copied that,” I replied. “And we’ll wait for the rest of the PAD. …Burn time was 4:50. I think that was when you started to cut out.”[11]

“This is Apollo Control at 1 hour 51 minutes. We’re getting good telemetry data from Apollo 17 through one of the Apollo Range Instrumented Aircraft out over the Atlantic Ocean. Apollo 17 is moving across the Atlantic now towards Africa. And on the next revolution, at about this point, the spacecraft will be on its way to the Moon during the TransLunar Injection maneuver. Ignition for that burn is scheduled to occur 1 hour 21 minutes from now.

During launch, the Flight Surgeon monitoring heart rates on the 3 crewmen recorded peak heart rates of 130 for the Commander Gene Cernan, also 130 for Command Module Pilot, Ron Evans, and 115 for Lunar Module Pilot, Jack Schmitt. We should be reacquiring the Command Service Module and reestablishing voice communications with the astronauts in about 2 minutes from now through Ascension.”

Once we lost communications with Houston, Evans completed another scheduled P52 star alignment of the IMU. About eight minutes after our last transmission, and after a number of tries through ARIA, Overmyer reached us: “Seventeen, Houston.”

“Go ahead,” I replied.

“Roger. You’re back with us. I’ll finish up that TLI plus 90 PAD so we can talk a little bit here if you want.”

“Go ahead.”

“Okay. Set Stars are Sirius and Rigel; RALIGN (attitude) is [roll] 318, [pitch] 148, [yaw] 358. There’ll be no ullage. Okay, down at the bottom of the PAD we’ve got the P37 (Return to Earth program) for Lift-off plus 9. GET [ignition] is 009:00; [Total] DELTA-VT 4897; [West] longitude minus 175; GET of 400K, 033:49. Over.” The “Lift-off plus 9” term related back to the possible use of a P30 SPS abort maneuver to return to Earth nine hours after lift-off from Florida.

“Okay, Bob,” I called after I read back just the numbers of the remainder of the TLI + 90 minutes PAD. “We had, as usual for up here, a spectacular sunrise…and Gene wants to talk to you.”

“I got some numbers on Ron’s P52 for you, Bob.”

“Okay,” replied Overmyer, “standing by to copy. Go ahead.”

“Okay, NOUN 71 (stars used) were stars 22 (Regulus) and 24 (Gienah); NOUN 05 (Angular error) are all balls (zeros); Noun 93s (Change in gyro angles) are all minus – they’re 00 point 037, 00 point 007, and 00 point 021. That’s minus 37, minus 07, and minus 21; and they were torqued at 01:51:40.” Evans’ star sightings resulted in very small torquing (correction) angles for America’s guidance system’s gyroscopes.

Then I began to insert my first of what would become many weather observations as we flew towards the Moon. “Bob, we’re over…intermediate to low [cloud] strata that have a very strong crenulation pattern – pulling out some geological terms here. I don’t think I’ve ever seen anything like it flying [in a T-38]… (during my many long cross-country flights over the years, I had always made a point to record observations of clouds on my flight plan card clipped to my knee pad.) Looks like about a north-south lineation with a very strong crinkling [running] roughly east-west.”

“Roger, …that’s interesting. You know, you’re just directly over that South Atlantic area. …Your path [this orbit] just kind of kept you going right between…Africa and South America, right dead center all the way.”

“And, Seventeen,” Overmyer added a few moments later, “just for your information, we’ve searched all the data we can, and we cannot find anything wrong with the spacecraft, or the booster, at all. Everything is looking real fine, and the only problem [still] in the air is…those Master Alarms that you have reported. We’re not able to tie in anything common yet to any of those things…”

“Okay, Bob,” Cernan broke in, “we have not had any for quite some time, I think, [at least] since the last time we talked to you about them.”

“Understand. We’ll probably get a good workout on that after TLI and try to track it down one more time.”

“Okay, but we have not really been doing much switching since the Insertion Checklist was complete, either.”

“Understand. It’s got you glued to the windows, I guess, huh?”

“Well, I certainly am, Bob,” I responded, “and again there’s a big, fairly continuous intermediate cloud deck, …and it has patterns comparable to what I have seen on pictures of ice floes…and of pack ice; I should say pictures of pack ice in the Antarctic.”


New patterns suddenly jump into view. Over the South Atlantic, between Africa and South America, a solid layer of morning clouds lies crenulated from one horizon to the other like an old washboard. Jagged breaks in those wrinkled strata give the illusion of polar pack ice fracturing and moving apart (Fig. 5.6).

Fig. 5.6. View of cloud deck over the South Atlantic showing features like ice floes. Note also the thin band of blue at the Earth horizon that constitutes the Earth’s atmosphere. (NASA photo A17-148-22619).


“Seventeen, Houston. We’ve got two questions concerning the Master Alarms. One, do you get the Master Alarm on the LEB (Lower Equipment Bay) also; and, two, do you get the tone with the Master Alarm?”

“We did get the tones,” I answered. “The Master Alarms were on [came with switch movement and bumps against] Panel 1 and Panel 3. I can’t tell you about the LEB right now. Maybe Ron can.” It is not clear why I mentioned Panels 1 and 3 at this point, as previously, I had said that the problem appeared to be with Panel 2. I had begun to think that the problem related to a solder ball moving around, and it had finally permanently lodged somewhere. On the other hand, there should have been no bare connections or wires behind Panel 2 that a solder ball could encounter.

“No, I didn’t pay that much attention,” added Evans.

Cernan continued, “And, Bob, there was something interesting I wanted to get around to tell you. The MISSION TIMER down in the LEB – when Ron went down there to get things squared away – was about 15 seconds or so behind all the other clocks…and we reset it – re-synced it – and it’s been running okay. I don’t know whether that’s a clue to anything or not, but apparently it happened either during launch or somewhere before we got down there right after Insertion.”

“Okay. We’re going to lose you here in about nine seconds. You are GO and looking great, and we’ll work on it. And if you get another Master Alarm, will you check the LEB for us?”

“Yes, sir; sure will do, Bob. We’ll see you. What’s our next AOS?”

“Stand by. … It’s Carnarvon at 02:25.”

This is Apollo Control. Apollo 17 now over the horizon from the Ascension [antenna] site – will be reacquiring in about 25 minutes through Carnarvon. And, as you heard CAPCOM Robert Overmyer advising the crew, we’ve been getting a good look at all the data, and spacecraft and launch vehicles look fine. No discernible problems. Gene Cernan did mention one anomaly and that was the mission timer. One of the numerous clocks aboard the spacecraft, which was running about 15 minutes (seconds) slow, and someone said it appeared that it happened either during the launch phase or shortly before they got down to take a look at it in the Lower Equipment Bay. No explanation for that one at this point. And we show now one minute – 1 hour, rather – 11 minutes until ignition for the TransLunar Injection maneuver; the burn with the Saturn Third stage which will place Apollo 17 on its trajectory toward the Moon. Ignition time and still holding at about 3 hours 12 minutes 35 seconds Ground Elapsed Time; and that burn will be about 5 minutes 45 seconds in duration; but we don’t have the final calculated time from the flight dynamics officer which will undoubtedly vary somewhat from the pre-mission flight plan time. At 2 hours 2 minutes this is Apollo Control Houston.

As I had checked off all the pre-TLI items in the Launch Checklist, we now had about 20 minutes to enjoy the views and take pictures out America’s windows before setting up the switches and displays for the TLI burn that would take us to the Moon. Spurious MASTER ALARMs without any Caution and Warning lights seem to be associated with moving switches on Panel 2. Other than this apparently non-critical issue, possibly due to a migrating solder ball, all the telemetry we were sending back indicated that both the spacecraft and the S-IVB remained in great shape and okay for leaving Earth for the Moon. That burn would begin during our second orbit, about 3 hours and 12 minutes after we left Florida.

This is Apollo Control, 2 hours 25 minutes. Apollo 17 now approaching the west coast of Australia. And we’ll be reacquiring the spacecraft in about 35 seconds. During this pass over Carnarvon we expect to pass up the first set of numbers to the crew that they’ll use in the TransLunar Injection burn to put them on their trajectory toward the Moon. That maneuver is scheduled to begin at 47 minutes from now. And we have acquisition of signal a little bit early.

“Seventeen, Houston. How are you doing?”

“Well,” I responded, “we’re pretty good. …You’re wavering here a little bit on signal strength.”

“Okay. We’ve got a TLI Pad any time you’re ready to copy it, Jack.”

“Goodness! Okay, let me get rid of something here (probably the Checklist). Ron, I’m putting that right underneath you.”

“And, guys,” added Overmyer, “we’d like P00 (always pronounced ‘poo’) and ACCEPT, please.”

“Okay,” I replied.

Apparently not hearing me, Overmyer came back with, “You’ll get a CSM state vector if you’ll give us P00 and ACCEPT.” P00 was the idling program in America’s computer and a switch setting to ACCEPT allowed Mission Control to remotely insert a state vector into the computer based on Evans’ P52 star sightings and the ground tracking of our orbit and velocity. The state vector consists of a time-referenced representation of three parameters (vectors) of our position and three parameters of our velocity in inertial space. This state vector now gave our position and velocity relative to our landing site on the Moon as a result of the earlier change of the computer’s REFSMAT (inertial reference framework) from that of the launch site to the landing site.

“[You] got P00 and ACCEPT,” confirmed Cernan.

“Okay,” I said as I grabbed the TLI PAD form, “let me have my favorite PAD!”

“Okay, here’s the TLI PAD. TIME BASE 6 at 3:02:57; [TLI attitude] 180 [roll], 312 [pitch], 000 [yaw]; [Burn Time] 5:51; DELTA-Vc is 10359.6 (cutoff velocity gained in feet per second); [final velocity] 34482 (feet per second); [separation will be at] 000 [roll], 345 [pitch], 040 [yaw]; [Challenger] extraction will be at 300 [roll], 165 [pitch], 320 [yaw]; [R2 Alignment] 312.0, [R2 Ignition] 306.0; [ORDEAL start time] 57:10; yaw is zero; [Challenger] ejection time 4 plus 39 plus 00.”

After I repeated the PAD back to him, Overmyer said, “Good read-back, Jack; and we would like OMNI Charlie; and it’s your computer (CSM state vector update was complete); and you’ve got your state vector.”

“Okay. You’ve got OMNI Charlie. And, Bob, we had almost a completely weather-free pass over Africa and Madagascar. And the scenery – both aesthetically and geologically – was something like I’ve never seen before, for sure. …We got odds and ends on the tape[12] and quite a bit on the film.”

“Roger; good show. Are you saying that you didn’t have any weather over the southern Africa, there?”

“Not very much. Barely broken clouds in some places. Most of the countryside was clear. …There were patterns like I haven’t seen in textbooks. Maybe I haven’t been looking enough, but some of the desert and grassland patterns…had the appearance of ice crystals almost, except on a mega-scale – if you have ever looked at ice crystals in sand…or better yet, ice crystals on your car windows when you get out early in the morning up in northern areas.” (Fig. 5.7)

Fig. 5.7. (Upper): Apollo 17 view of the savannah of Africa’s Kalahari showing the feather patterns left by range fires. (Lower): detail of white smoke lines from some of the range fires (NASA photo AS17-148-22636).

“Roger. And just be advised, we’ll be standing by for the GO/NO GO for PYRO ARM when we get to Hawaii, and we’ll be giving you a GO for TLI about that time.”

“Okay,” I acknowledged, “and we’ll be ready.”

“And Ron,” Overmyer quickly inserted, “in the Launch Checklist, on [page] 2-25, on the manual and nominal S-IVB TLI-I, add 34 degrees on the Nominal PAD for all the pitch angles; and on the Manual PAD, add 34.5 degrees to all the pitch angles, and you’ll have it right.” These modifications related to the two hour and forty minute delay in our launch that in turn required that TLI take place at a different point in inertial space relative to the Moon’s orbit. “And you’ll want to do that on your cue card also, Ron.”

“Yes, that’s affirm.” Ron immediately made the changes on the cue card while I recorded them in the Launch Checklist.

“And we’re about ready for LOS; we’ll see you at Hawaii.”

“Okay, Bob, we’ll see you…”

“[At] zero two plus 50 at Hawaii,” responded Overmyer.

“Okay, [two plus] 50. And we’ll be into our TLI checklist, and we’ll be ready for that PYRO ARM [check].”


This is Apollo Control. We’ll be reacquiring the spacecraft in about 18 minutes. And during that pass over Carnarvon, and we’ve passed up the numbers to the crew they’ll use in the TransLunar Injection maneuver. The burn is targeted to last 5 minutes 51 seconds with a change in velocity of some 10,359 feet per second. [and] accelerating Apollo 17 to the required speed to get it into an orbit that will intercept the Moon. And the time of ignition [is] 3 hours 12 minutes 35 seconds; and we’re showing an ejection time [for the Lunar Module] of 4 hours 39 minutes. The [time for the] Transposition and Docking maneuver, which precedes ejection, is somewhat fluid in that it’s done when the crew and Mission Control are ready following TransLunar Injection. However, from the projected time for ejection, it would appear that Transposition and Docking will occur about 25 to 30 minutes ahead of the nominal flight plan time. And we’re now 39 minutes away from the scheduled ignition for TransLunar Injection. At 2 hours 34 minutes this is Apollo Control, Houston.

With loss of signal through Canarvon, I began to read through the TLI PREPARATION portion of the Checklist and Cernan and Evans took and confirmed each required action.





“Now you do an EMS (ENTRY MONITOR SYSTEM) DELTA V TEST AND NULL BIAS CHECK.” I told Evans. “Let me turn to page G/2-5 in the G&C (GUIDANDE and CONTROL) Checklist for that.” This check of the Entry Monitor System prepared it for the possibility that TLI would not occur and, for some reason, we needed to re-enter and land.

After finding the G&C Checklist, I began: “EMS MODE switch to STANDBY”

“STANDBY,” repeated Evans.



“SET DELTA V indicator to one…five…eight…six point eight.”

“Got it.”

“Now, EMS MODE goes back to NORMAL and EMS FUNCTION to DELTA V TEST. The SPS THRUST LIGHT should come ON and then OFF in about ten seconds”

“NORMAL and TEST…Light is ON…and OFF”





“Now, SET DELTA V indicator to one hundred point zero.

“One hundred point zero.”

“For this part of the check, put the CMC MODE switch to FREE and leave it there until we finish with the BIAS measurement.”


“Okay, now EMS FUNCTION again goes to DELTA V and we wait five seconds and start the DET (Digital Event Timer).”

“DELTA V. …Timer started.”

“Now we wait for one minute and forty seconds.”

At the indicated time, Evans said, “DELTA V shows less than one foot per second so we do not need to bias readings we may get. Good.” If the reading had been equal to or greater than one but less than ten feet per second, we could use the indicated bias. If it had been greater than 10, the Entry Monitor System would have been “NO-GO.”

“To finish up, put EMS FUNCTION to OFF.”

“It is OFF.”

With the procedure out of the way, I went back to the TLI PREP Checklist.

“Set DELTA V CUTOFF. That’s 10359.6 [feet per second] from our TLI PAD.”

“Okay, that’s ten…zero…three…five…nine point six.”

“Correct. Now, EMS to DELTA V.”


“Set the DIGITAL AUTOPILOT with a Verb 48 ENTER, and enter 31102 and 01111.”

“VERB 48 ENTER, three…one…one…zero…two and zero and four ones.”

“Correct, now, Key VERB 83 ENTER.” This entry provided a DISKEY display of the “rendezvous parameters” of RANGE, RANGE RATE, and THETA which would be helpful during transposition and docking after TLI.

“Set ORDEAL to 90/EARTH.”

This is Apollo Control at 2 hours 49 minutes. We’re standing by now to acquire radio contact with Apollo 17 through Hawaii. During this Hawaiian pass we’re getting another good look at spacecraft and launch vehicle systems. The last look we had through Carnarvon everything looked very good. Flight Director, Gene Kranz, going over the status for these flight controllers observed that there appeared to be no problems that would interfere with TLI and we expect to have a normal TransLunar Injection about 23 minutes from now as Apollo 17 completes its stateside pass and moves out over the Atlantic Ocean at the start of its third revolution [of the Earth].

“Apollo 17, Houston.” Two hours and 50 minutes after launch, and we were back talking to Overmyer in Houston through an antenna in Hawaii.

“Go ahead,” I replied.

“Houston, this is Apollo 17,” Evans also replied, not hearing me. “Go ahead.”

“Hey, Ron, you’re sounding great. Good voice here.”

“Golly, we’ve got things all set up here and we’re kind of standing by for a Logic Check, whenever you guys can give us a GO.” The Logic Check referred to Mission Control looking at the telemetry from the pyrotechnic system that would separate us from the S-IVB either after TLI or in an emergency. This check would see if all the automatic decision logic for such a separation looked to be in order.

“Roger. As soon as we get some TM (telemetry) in here, we’ll give you a GO [for the Logic Check].”

“Seventeen, Houston. We’re ready for the Logic Check.”

“Okay, Bob,” Cernan replied, as the circuit breakers and switches necessary for the Logic Check were on his side of America’s cabin. “Wait one. …Okay, SECS ARM breakers are closed…and LOGIC 1 is ON. …MARK it. …And LOGIC 2 is ON. …MARK it.”

Ten seconds later, Overmyer came back with, “Seventeen, you’re GO for PYRO ARM.”

“Thank you. Understand GO for PYRO ARM.”

This was the cue for me to continue reading the TLI PREPARATION Checklist again:


“TRANSLATIONAL CONTROL POWER – ON, both.” A counter clockwise rotation of this T-handle control by Cernan, of course, would separate us from the S-IVB if it developed a significant problem during the TLI burn.


“Two verified.”


“Two to MAIN A/MAIN B.”

“SPACECRAFT CONTROL – SCS (Stabilization Control System), verify.” This backup RCS control system could be used if S-IVB separation from the S-IVB had been required.

“SCS verified.”



“Circuit Breakers DIRECT ULLAGE, two – close.”

“And finally, for now, set the DIGITAL EVENT TIMER to 51:00.”

“Set at 51:00.”

A few minutes later, with that preparatory sequence taken care of, I added a little more color commentary. “And, Bob, in case you’re interested, all through the night-side pass here, there’s quite a strong – well, stronger than I would have ever expected – horizon glow off to the north. …I think Gene said a while ago that it’s around on his side [of the cabin], also.”

“Roger…Guys, I’ve got the word you wanted to hear – you are GO for TLI – you are GO for the Moon.”

“Okay, Robert,” Cernan acknowledged. “I understand. America and Challenger, with their S-IVB, are GO for TLI.”

“That’s affirmative.”

“You’re a sweet talker.”

“We try to please here, Gene.”

“You know, somehow, Bob, I knew you were going to say that – we were ‘GO’ – and that you try to please.”

“We’ve been working together too long, I guess.”

“Not long enough.”


This banter back and forth between Cernan and Overmyer seems to dilute the enormity of what had just taken place. On the one hand, another trio of Americans had been given the technical blessing to head for the Moon with the objective to actually spend three days exploring a deep valley cut into its surface. On the other hand, this would be the last time for this to take place for a long time. America had reached the conclusion of its most ambitious and successful feat of technical human endeavor, and as remarkable as Apollo had been, the United States would soon walk away from the future benefits that lay within its reach. Indeed, the decisions leading to this end point began four years before, for reasons history will find difficult to justify – Apollo 17 merely was playing out the hand dealt to 450,000 dedicated men and women by a few others of limited vision. These thoughts, however, came at a later time. With TLI looming before us, other issues took precedence.


“Seventeen, Houston. You’re about one minute from LOS, and we’ll pick you up at Goldstone at about three hours and zero zero minutes; and that’s only a couple of minutes prior to Time Base 6 START.”

“Okay, Bob. We’ll be with you.”

At the last minute, I added more on the horizon glow. “Bob, that glow is actually above the horizon, just in case you’re curious. I can see stars below the top (bottom) of the glow [in a dark band] down closer to the Earth.”

“Roger, Jack.”

“Ron, now you need to get into P15 for TLI INITIATE/CUTOFF. That is with a VERB 37 ENTER and a 15 ENTER.” Referring again to the TLI PAD I had copied, I said, “With the flashing 06 33 (time of ignition) load zero three hours…zero two minutes…and five…seven seconds for TIME BASED 6 and PROCEED…”

“With flashing 06 14 (velocity at cutoff), load …1…0…3…5…9…point 6 …and PROCEED…”

“Now, with the flashing 06 95, load …5 minutes…and 5…1 seconds as burn time, all zeros as velocity gained, 3…4…4…8…2 and as final velocity.

Cernan and I verified each entry. These entries in to the computer prepared it to take over in case a problem arose with the S-IVB guidance.

“Finally, verify that LAUNCH VEHICLE GUIDANCE is at IU (Inertial Unit in the S-IVB).” Had the LAUNCH GUIDANCE LIGHT had been ON, showing some problem with the IU in the S-IVB, we would have put GUIDANCE to CMC. At the same time, the two RIGHTHAND CONTROLLER POWER DIRECT switches were placed in OFF to avoid any inadvertent interference with the America’s guidance systems control of the TLI burn. As the S-IVB IU was not going on to the Moon with us, its failure was not mission critical as long as the CMC was fully functional.

America’s cabin became quite as we watched for the coastal lights of California and Mexico and waited for Overmyer’s next call.

“Seventeen, Houston. We’re with you again, and you’re looking good.”

“Okay,” responded Evans, “mighty fine, Bob.”

Cernan followed with, “we’ve got the PYROS ARMED now.”

“Roger. And you can expect some different OMNI calls as we go LOS and AOS again.”

“I always expect that, Bob,” I kidded, as the communications engineer for most of the flight.

“SEP light is ON on time ,” Cernan noted. At nine minutes and 38 seconds before S-IVB ignition, Houston activated TIME BASE 6. In the cabin, both the telemetry UPLINK ACTIVITY LIGHT and the booster SEPARATION LIGHT came on, ten seconds later the UPLINK ACTY LT went out, and 38 seconds later the SEP LT also went out.

“Roger,” acknowledged Overmyer. “And it shows TIME BASE 6 [started] on time, Geno. …We’d like OMNI DELTA, please.”

“Okay, you’ve got it,” I responded. “[When you asked,] I’ll just switch, Bob. I won’t give you a call.”


“SEP light was OUT on time,” reported Cernan.

Ron then set the Event Timer counting up ignition. If guidance had been in CMC, we would have entered VERB 16 NOUN 20 ENTER with a maneuver to the R2 ALIGN pitch attitude of 312.0 after TIME BASE 6 was activated (see below).

This is Apollo Control at 3 hours 4 minutes. We are now some 8 minutes away from ignition. Everything’s looking good for the TransLunar Injection maneuver, the combined S-IVB Saturn third stage and the spacecraft with an orbital weight of three hundred eight thousand, two hundred ninety eight pounds at the start of this maneuver.

After three minutes of quiet, Cernan ask me if we still had communications. I said that all I could tell from signal strength indicated that we did. He then said, “Comm check, Bob.”

“Seventeen, Houston; go ahead.”

“I was just checking with you; you’re so quiet down there, we almost forgot you were there.”

“Roger. Don’t want to forget me. We’re just watching everything; we can’t find anything wrong, so we’re just trying to keep quiet here.”

“Okay, Bob. We’re watching the S-IVB tanks pressurize.”

[At this point, we had the same emergency separation criteria for pressure differentials between liquid oxygen and hydrogen tanks that we had after orbit insertion on the S-IVB, namely, that pressure differentials (psid) between S-IVB oxygen and hydrogen were within certain broad limits: oxygen 36 psid > hydrogen, hydrogen 26 psid > oxygen, or oxygen > 50 psia with normal pressures being 40 psia for oxygen and 31 psia for hydrogen.]

“[Anyway], you ought to look for the good things rather than the bad.” In spite of this statement, Cernan, I am sure, remembered that it is the bad things that cause trouble.

“Well, that’s good when we don’t find anything wrong.”

“Can’t agree more.”

Cernan then switched ORDEAL (Orbital Rate Drive Electronics for the Apollo Command Module and Lunar Module) to drive his FDAI 1 in ORBITAL RATE (local vertical) and Evans’ FDAI 2 in the INERTIAL reference frame. The ORDEAL MODE was switched to HOLD/FAST, and the FUNCTION SELECTOR switch was put at 300/Lunar, the latter in anticipation of leaving Earth orbit. This gave him a secondary means of monitoring the TLI burn pitch orientation.

Meanwhile, in order to be absolutely certain no spurious telemetry commands altered the planned burn, accidental or otherwise, I put both the Command Module and the S-IVB IU UPLINK TELEMETRY switches to BLOCK. Evans also armed his RIGHT HAND CONTROLER as a backup to Cernan’s, in case either had to supply attitude control of the S-IVB burn.

At four minutes before ignition, Cernan slewed FDAI 1 to a pitch of 17º. If the burn needed to be under CMC control, pitch would have been set at 0º and the DISKEY would already be displaying NOUN 20 with R2 ALIGN set at 312.0, as per the TLI PAD.

“Seventeen, the [S-IVB engine] chill-down is in progress, and the tank pressures are looking good.”

“Okay, Bob. Looking good here.”

“Seventeen, Houston. You are GO at three minutes prior to ignition. You’re looking good, and…we’re going to have ARIA coverage all the way through the burn until [acquiring] Ascension.

“Roger, understand, Bob. …57:10, ORDEAL [to] OPERATE. …We’re in average g.”

“Roger. We confirm it,” Overmyer replied. This meant that the sensor that would measure acceleration was in operation.

“SEP light ON at 3:06 [before ignition].” Cernan then verified that the Flight Director Attitude Indicator (FDAI #1), in front of him, generally referred to as the “8-ball,” now showed 12 degrees pitch, the local vertical pitch angle for the S-IVB burn. If the burn were to be under CMC control, he would have maneuvered to the R2 IGNITION pitch attitude of 306.0 given to us in the TLI PAD.

“Roger. …Seventeen, you’re looking great on the final status check here, and you’re GO for TLI. “This meant that Fight Director Griffin had gone around the Mission Operations Control Room (MOCR) and had received a verbal “GO” from each of the console stations of his Gold Flight controllers.

And we’re coming up now on 2 minutes until ignition. This burn, again, will be a 5 minute, 51 second maneuver. The S-IVB engine [will be] delivering about 225,000 pounds of thrust, and it will be increasing the spacecraft velocity in the current state of about 25,000 feet per second up to about 35,585 feet per second.

At one minute and 45 seconds to go, the computer DSKY briefly went blank and then displayed Time From Ignition, Current Velocity Gained, and Insertion Velocity.

“Geno, you need SCS TVC SERVO POWER number one to AC MAIN A.”

“Roger, MAIN A.” This meant that power for a manual takeover for TLI guidance, if necessary, would come from the primary AC electrical circuit connected to the Main A electrical bus being fed by America’s fuel cells.

“Verify that SCS TVC SERVO POWER number two is OFF.”


“I have put the TAPE RECORDER to HIGH BIT RATE, RECORD, FORWARD, and COMMAND RESET.” For unknown reasons, the tape recorder did not record cabin voice during the TLI burn.


“It’s NORMAL.”

At 1:24 before ignition, the S-II SEPARATION LIGHT came on, followed immediately by the beginning of S-IVB ullage. Ullage consisted of the S-IVB’s z-axis attitude control thrusters firing so as to settle the liquid hydrogen and oxygen at the feed ports in the bottom of their tanks.

[If for some reason prior to 18 seconds before ignition, Mission Control decided to forego ignition, we would put the XLUNAR (Translunar) INJECT switch to SAFE which would recycle the booster to TIME BASE 5. If Mission Control called for a TLI inhibit between 18 seconds before and 12 seconds after ignition, we would put the LV (LAUNCH VEHICLE) STAGE switch to S-II/S-IVB, also forcing a recycle to TIME BASE 5. This would give a chance to study whatever problem had arisen, and possible recycle for another try. After 12 seconds, however, putting this LV STAGE switch to S-II/S-IVB would permanently inhibit TLI, and we would not be going to the Moon.]

To the Moon!

“We have S-IVB ullage beginning,” reported Cernan.

At 18 seconds, Cernan reported, “The SEP lights are OUT.” Unsensed by us, at 8 seconds before ignition, ullage was followed by liquid hydrogen fuel being pumped into the engine ahead of the liquid oxygen (LOX). S-IVB ullage stopped at 5 seconds before ignition. Also, at 5 seconds, if GUIDANCE had been by the CMC, the local vertical ORDEAL indication on FDAI 1 in front of Cernan would show zero degrees of pitch.

“…The [engine] light’s on, and we have ignition,” Cernan announced.

“Light’s off, Gene,” Evans noted at 2 seconds after ignition. This indicated full thrust from the S-IVB. At 10 seconds, he again entered VERB 6 NOUN 95 into the DISKEY to get a display of TFC (TIME FROM CUTOFF), VG (VELOCITY GAINED), and VI (VELOCITY INERTIAL).

“Seventeen, Houston. You’re looking good, and the [S-IVB] thrust is GO.”

“Bob, you’re now advised that we’re GO on board at 20 seconds.”

Cernan and Evans both were watching the attitude of the combined spacecraft and S-IVB to be sure that pitch and yaw excursions did not exceed ±45º, pitch and yaw rates did not exceed ±10º per second, and roll rates did not exceed ±20º per second. In fact, the stack seemed steady as a rock to me. I also monitored the S-IVB tank pressures as before.

And telemetry data from the Saturn instrument unit shows the velocity increasing up now to 26 000 feet per second, beginning to climb ever more rapidly. This burn was initiated at an altitude of about 97 nautical miles above Earth, and when finished, the spacecraft will be at about 150 miles above Earth, and on its way to the Moon, some 213,000 miles nautical miles away.

“One minute, Houston, and we’re GO.” Evans and Cernan were comparing what the computer display indicated about the burn with the profile that they had on the TLI cue card. I continued to scan my spacecraft environmental control and power displays more out of habit than concern.

“Roger, Gene. We can barely hear you through ARIA, but you’re GO.”

“[Jack, check your] antenna,” requested Cernan.

“Signal strength is good here, Gene,” I confirmed. “Must be a problem with ARIA transmission back on land.”

“You have reasonable signal strength, but you are unreadable. …Everything’s GO at 1:30. …Confirm a PU (Propellant Utilization ratio) shift and GO at 1:45.”

“Ron, if you want to monitor inertial velocity along with altitude rate, and altitude, enter Verb 16, Noun 62, ENTER, but go back to NOUN 95 with a KEY RELEASE (to freeze the display) at shutdown,” I told Evans, as I still followed the sequence of events in the Checklist. Going back to NOUN 95 in P15 would allow him to monitor time since ignition, inertial velocity, and velocity gained.

“Seventeen, Houston. We can confirm PU shift, and you are GO.”

That was CAPCOM Robert Overmyer confirming to the crew that our data showed the Saturn shifting its Propellant Utilization for a most efficient utilization of the propellant.

“Okay, Houston, 2:30 – [transmitting] in the blind – we’re still GO.”

“Roger, Seventeen. You’re GO; looking great.”

“Okay, Bob. Got that [transmission]. Understand we’re GO from the ground; and it’s a good ride, although it’s rumbling around a little bit. …Three minutes, and we are GO.”

“Roger, Gene.”

“Bob. We’re going to TLI right through sunrise!”

“Roger. Understand.”

Gene Cernan reporting the TLI burn has taken them out of darkness and into sunrise now and we’ re showing a velocity of 30,463 feet per second…

“Okay, 3:30 is GO…”

“Roger, Seventeen.”

“Okay, Bob, Seventeen is GO at 4:30. You’re still unreadable.” It might be that the ionized effluents from the S-IVB interfered with radio reception. Our transmissions, however, were getting through.

Apollo 17 [is] now about 107 nautical miles above Earth and continuing to climb ever more rapidly. 4 minutes and 30 seconds now, and everything continuing to look good. Apollo 17 at a velocity of 32,000 feet per second.

“Roger. How do you read me? You are GO, by the way.”

“Okay, we got you that time. Understand we’re GO on the ground, and we’re still GO here, and we’re TLI-ing right through sunrise!”

“Understand…Seventeen, Houston. Your burn time is nominal.”

“Roger. Understand, burn time [will be] nominal.”

“Coming up on shutdown.”

“Shutdown! At 5:52.” The LV ENGINE LIGHT came on as expected, as the slight acceleration we had felt for almost six minutes, ceased. TIME BASE 7 began at this point, as well.


For 5 minutes and 52 seconds, we accelerated ahead of the S-IVB’s vibrating but soundless rocket engine. I was fascinated both by the marvel of the human and technological event of which we were a part and by the unbelievable beauty of the ribboned sunrise through which we sped.

A perfect burn, and Apollo 17 had stretched the gravitational chains of Earth so eventually they could be exchanged in favor of those of the Moon. Once again, and for the last time in the foreseeable future, humans had left their evolutionary cradle for another potential home in space. This initiated the “end of the beginning”[13] of the movement of civilization into deep space. As a consequence of Apollo and its successful exploration of the Moon, humankind stands on the brink of an indefinite era of exploration, settlement and progress in space beside which even the history of human settlement of the Earth’s continents may ultimately pale. The Apollo explorations became humankind’s first halting but clearly personal look at its universe.

Carried forward in many ways, this adventurous character of humans, particularly Americans, uniquely identifies us among the known species of nature. We have the audacity to try to understand our place in the universe and in its future. We have the further audacity to try to understand, preserve and benefit from the Earth, now with the corrected vision from space. Ultimately, we expect, as a species, to use this understanding to alter the universe and to better our lives within it.[14]


“KEY RELEASE, Ron.” This would freeze the computer display for recording the burn data.

[If the S-IVB had not shut down within one second of the expected burn time, Cernan would have turned his THC (THRUST HAND CONTROLLER) counterclockwise (CCW) and then back to NEUTRAL. That would initiate a MODE IV abort sequence, shutting off the S-IVB and separating us from the booster.]

“That was something, wasn’t it!” The burn into a sunrise and the fact that we actually were headed toward the Moon really had my attention.

“Cut-off at [5:]52,” called Ron to Houston. “Did you read the DSKY?

“We don’t have the DSKY [due to telemetry problems]. You have to read it to us, Ron.”

“Okay. … I got a zero zero and a zero zero [for velocity differences] and NOUN 95 VI is 3…5…5…7…3. [V-delta difference] is a plus 9. And, Bob, the EMS (Energy Monitor System V-delta) is minus one…nine…point four. This was close agreement between the two systems, with the NOUN 95 number being the more reliable.

“Roger, we copy that.”

“…And it was an auto cut-off – auto cut-off on time.”

“Understand – a guided cut-off on time. Looking great,” Overmyer replied.

“…and I am watching tank pressures. …The tanks are venting.”

The S-IVB gave us a near perfect burn, both in amount and direction and the telemetry and tracking data received on Earth soon confirmed this fact. Also as planned, the automatic venting of the S-IVB propellant tanks would prevent any pressure build-up and a possible explosion while we were still on the rocket or in its vicinity.

After a brief communications dropout as we left the inconsistent reach of the ARIA aircraft over the Atlantic, Houston came back up through Ascension. After that, we had continuous contact through the global antenna network of Parkes and Honeysuckle in Australia, Goldstone in California, and Madrid in Spain.

Well, we’re still getting communications through the Apollo Range Instrumented Aircraft. We’ll be picking up through Ascension shortly, at which time we’d expect the communications to improve, the noise to drop off. From Gene Cernan’s report, also from the reports from Ron Evans, it appeared that that TransLunar Injection was extremely close to nominal. The crew read a cut off time of 5 minutes 52 seconds. The pre-maneuver prediction was 5 minutes 51 seconds. And the cutoff velocity appeared to be very, very close to the planned normal. Booster engineer, Frank Van Rensselaer reports the booster cutoff appeared to be exactly normal. And [the] booster engineer [is] now predicting that the maneuver to separation attitude will begin at about 3 hours 33 minutes 27 seconds.

“Gene, are you ready for the post-TLI Checklist items?” I asked.




“PCM BIT RATE to LOW.” I have that one over here.



“SECS PYRO ARM, two, to SAFE.”




“RHC #2 should be locked.”

“LOCKED,” Ron broke in.

“Ron, you need to PROCEED and go to P00. When the CMC ACTIVITY light goes out, ENTER VERB 66, …and Ron, you ready to get us a Challenger?”

Cernan and Evans then changed positions in the cabin so that Evans could prepare for separating from the S-IVB, turning America around, and docking with the Challenger still tucked away in the front end of the rocket. (I had some concern that Cernan might usurp this duty from Evans and was pleased that he did not. Evans had trained for 15 months for this highlight of his duties on the trip to the Moon.) I reconfigured the high gain antenna so that it could begin to serve as our primary mode of operational communications with the various Earth-based antennas of the Deep Space Network and, through them, to Mission Control. This entailed turning the HIGH GAIN ANTENNA POWER switch to OFF and then closing the circuit breakers for the HIGH GAIN ANTENNA FLIGHT BUS and the HIGH GAIN ANTENNA GROUP 2.

“Okay, Houston, how do you read?” I called.

“Seventeen, Houston. We’d like OMNI Delta.”

“Okay. I picked it [your transmission] up a little bit. How do you read now.”

“Read you loud and clear.”

“I hope you got all that [communication through the burn]. It was a beautiful burn – right through a sunrise! …Did you get the numbers?”

“Yes, we copied your VI and your EMS numbers, and we’ve got a number for you. [S-IVB] Maneuver start time will be at 03 plus 33 plus 27.” The S-IVB would be directed by Mission Control to move to an optimum lighting attitude for Evans’ docking and extraction of Challenger.

“Okay, we got you. Maneuver at 03:33:27.” This would be in about ten minutes.

“That’s affirmative, Jack.”

“You guys didn’t tell us we couldn’t see anything going through the sunrise,” I chided Overmyer and received his laughter in return.

“Seventeen, Houston. We’re making plans here for a spacecraft SEP [from the S-IVB] time of 03 plus 43.”

“03 plus 43. Roger,” I confirmed.

“Seventeen, Houston. We’re copying cabin pressure of 5.9 [psi] at this time.” This was a subtle notice that Evans and I had screwed up.

“Roger,” responded Evans. “We just got it, Bob. Thank you [for the heads up]” I earlier had delved back into the Checklist, this time the NORMAL SPACECRAFT/BOOSTER SEPARATIONS section, and had told Evans to open the DIRECT O2 VALVE. He and I both had become distracted by TLI activity and let cabin pressure go beyond the 5.7 psi called for.

This is Apollo Control at 3 hours 30 minutes. The flight dynamics officer has just reported that initial tracking, following the TransLunar Injection burn, shows the spacecraft to be on a very nominal trajectory, and a relatively small midcourse correction indicated at this time. The pre-burn prediction on that first midcourse correction was around 5 feet per second and we expect that that will be up-dated as we get additional tracking following the burn. In about 3 minutes the spacecraft should – the launch vehicle should begin maneuvering to the proper attitude for [Command and Service Module] separation and we’re predicting separation to occur at about 3 hours 43 minutes – or about 13 minutes.

“Frame 65 for the LMP’s [film] mag November November,” I reported, preparing to photograph Evans’ approach and docking with the Challenger. We depended on the Crew Systems personnel in Mission Control to keep track of the film magazine inventory.

First, however, I took several quick photographs of the rapidly changing apparent curvature of Earth’s horizon (Fig. 5.8). At 25,000 miles an hour, these views change very rapidly and foreshadowed the three days of steadily smaller Earth scenes that lay before us.

Fig. 5.8. View of portions of the Earth, including the southwest coast of Africa (upper), taken soon after the TransLunar Injection (TLI) burn that put Apollo 17 on a path to the Moon. The photographs show the rapidly changing aspect of the horizon arc as the spacecraft and booster combination left the Earth at an initial velocity of about 25,000 miles per hour. Note one of the Service Module-LM Adapter (SLA) panels below the limb at center of the lower photo and some debris from the jettison (NASA photos AS17-148-22671, -22679, and -22681, respectively).

“Okay, Ron, lets get you ready for docking with Challenger, I said, going back to Checklist for NORMAL SPACECRAFT activities and for BOOSTER SEPARATION. During this several minutes, Evans carried on a discussion about the bright fragments around the S-IVB while we also worked through the Checklist (e.g., Fig. 5.9 below).

“Okay,” I called as the S-IVB began to move us at the appointed time. “We are maneuvering, Houston.”

At this point, we became aware of “a few very bright particles or fragments that went drifting by as we maneuver,” as Ron put it.

I chimed in with “There’s a whole bunch of big ones in my window down there – [not colored,] just bright. It looks like the Fourth of July out of Ron’s [hatch] window!”

Fig. 5.9. The forward end of the S-IVB immediately after the TransLunar Injection Burn. The Lunar Module Challenger is visible in the Adapter section. A cloud of ice fragments surrounds the booster, dislodged at shutdown from the cold, liquid hydrogen and oxygen tanks (NASA photo AS17-148-22687)

Ron began to add details – “They’re very jagged, angular fragments that are tumbling.”

“Roger. They look like fluid of some sort?” queried Overmyer.

“Not to me,” answered Evans. “The look like pieces of something. …They’re very bright.

“Jack, we’d like OMNI Charlie.”

After complying with this request, I continued with the Checklist. “We have the cabin pressure back under control, thanks to Bob, so I need the two DOCK PROBE circuit breakers verified CLOSED.”



“ON.” The COAS was mounted in the window immediately in front of Evans’ face. He would use the COAS alignment grid to line up with a three-dimensional target on the Challenger as he moved in for docking.



“LOAD the RCS DAP (Digital Auto Pilot) with the following: R1 equal to…, you ready?”


“R1 equal to 1…1…1…zero…three…and R2 equal to zero and four ones. Now a VERB 46 ENTER.

“46 ENTER.”

Referring to the TLI PAD Overmyer had given us before the TLI burn, I said, “LOAD NOUN 17 with the SEPARATION attitude. That is roll zero zero zero, pitch three…four…five…, and yaw zero…four…zero.”

“Okay, now give me the NOUN 22 EXTRACTION attitude.”

I replied with “EXTRACTION attitude is roll three…zero zero, pitch one…six…five… and yaw three… two… zero. Good. …Now, ENTER VERB 63 to monitor the S-IVB maneuver to your SEPARATION attitude.” Evans would now be seeing error needles on his FDAI 2 and, if they were not nulled, he could ENTER VERB 60 to check if the S-IVB attitude control dead-band was the expected ±1.8º.

“Are you ready for the CSM SEPARATION PREP Checklist items, Ron?”

“Go,” he replied, although he probably had the entire list in his memory.



“Verify that RCS TRANSFER is SM (Service Module).” This made sure that we would not deplete the Command Module RCS, unnecessarily.


“Now, verify that the eight SM RCS PROPELLANT talkbacks are all gray.” I had done this before TLI, but it was always good to have another set of eyes make sure that there were no problems with the RCS fuel and oxidizer supplies.

“All gray.”

“The sixteen AUTO RCS SELECT switches should be at MAIN A/MAIN B.” This selection meant that redundant power source would be available to any RCS thruster selected during the separation, docking and extraction maneuvers.

“MAIN A and B,” Evans replied after a few seconds. He had now completed setting up the RCS controls for his separation and docking maneuvers.

Now lets do the old EMS (Entry Monitor System) NULL BIAS CHECK, and I have to go to the G&N Checklist…page G/2-5. Stand by. …”

“Here we go; set DELTA VC to minus 100.”

“Minus 100.”






“RATE COMMAND, three of them.”

“LIMIT CYCLE switch should be verified OFF.”

“It is OFF.”

“Your ATTITUDE DEAD-BAND should be MIN.”


“And the ATTITUDE RATE should be LOW.”


“Verify that TRANSLATION CONTROL POWER is ON, that is, the switch should be up.”

“It is up and ON.”

“Verify that the ROTATIONAL CONTROL POWER switches, two of them, are AC/DC.


“And also verify that the two ROTATIONAL CONTROL DIRECT switches are MAIN A and B.”

“MAIN A and B.”

“Rotate the ATTITUDE SET thumbwheel to show roll zero…pitch 180, and yaw zero.”

“Okay, We’ve got zero one eight [pitch] and zero [roll and yaw] on the old thumbwheels,” Evans replied.

“Unfortunately, the folks at home won’t get to watch your work on TV (This was because of our delayed launch.), so we will move on in the Checklist. …CMC MODE should be verified in FREE.”

“Yeah, that’s a bummer. …Okay, CMC MODE is FREE.”

“SPACECRAFT CONTROL switch goes to CMC (Command Module Computer).”

“Verify the three BMAG MODE switches are in RATE 2.”

“Three in RATE 2.”

“Gene, we need the two RCS LOGIC circuit breakers OPEN.”

“Okay, RCS LOGIC [breakers are OPEN],” Cernan replied.

“Bob,” Evans continued, “for the most part, these fragments…are tumbling at a very slow rate. I tried a couple of pictures of them [at] different settings. You may get an idea of what, at least, the patterns look like.”

“Roger. I got you. We’re all ears on these fragments. Do you think you can figure out what they might be?”

“Well, I don’t know. There are a number of possibilities. …I got the impression maybe they were curved a little bit, as if they might be off the side of the S-IVB. And that’s a wild guess…ice chunks, possibly. Or maybe there’s paint coming off of it.”

“Roger,” acknowledged Overmyer. “I noticed on one trip up the [Launch Umbilical Tower] elevator last week near one of the flags – I thought it was on the S-II, but it might have been on the S-IVB – it looked like it was peeling. Maybe that’s what you’ve got.”

Overmyer broke out of the ongoing discussion about possible ice fragments with, “The S-IVB maneuver is complete.”

“TVC (Trust Vector Control) SERVO POWER number one to AC one/MAIN A.”

“AC one/MAIN A.”

“Set the EVENT TIMER to 59;30.”

“Okay. We’ll set the old clock.”

“Finally, I’ll put the FUEL CELL REACTANTS VALVE to LATCH.” This setting would prevent this valve from closing if there happened to be any unexpected shocks from pyro firings or hard hits during CSM separation from the S-IVB or its docking with and extraction of the Challenger.

Evans briefly returned to the subject of the fragments we could see outside. “…with the [S-IVB] maneuver complete, the fragment field is essentially static, except for very slight tumbling within the fragment [field]. …Every once in a while, a fragment of considerably higher velocity than the others goes across my window. But that is very rare. …Hey, that’s the field of view I saw out my window. Jack, do you see it now?”


“And, Bob,” Evans continued, “At least there’s not apparent relative motion between fragments.” This was an important observation as an explosion of some kind would have created a much more variable set of velocities. At this point, it would appear that there had been a very low energy release of the fragments. Then Evans said, “I’ll take two pictures about a minute apart, if I can. And it’ll be Frame 70.”

“And, Bob. This is Geno. My impression is that they [the fragments] are flat, flake-like particles. Some may be six inches across. And, although there’s no relative motion… Most of them seem to be twinkling. And, I think, for the most part they’re…

Evans then loaded the attitude for Challenger extraction (roll 300, pitch 165, yaw 320) in to the computer through a VERB 49 (Crew Defined Maneuver). So that Mission Control could follow us directly, we went live on voice.




“CONTROLLER number 2 is ARMED.” Evans had already armed RHC #1 which was the one he would use for the maneuver sequence.

“Circuit Breaker SECS LOGIC, two, CLOSED.”

“Okay. SECS LOGIC is CLOSED,” and, anticipating my next call outs, Evans said, “SECS ARM [circuit breakers] are CLOSED [and] LOGIC POWER is ON.”

“Okay.” This preparation included again setting up and verifying the logic train of the Sequential Events Control System (SECS) in case it was necessary to instantly undock with the S-IVB/Challenger combined vehicle. Continued practice for this transposition and docking maneuver, and any contingencies that might arise, had been a major emphasis in Evans’ training regimen.

“Seventeen, Houston. You have a GO for T and D.” (Transposition and Docking).” To which, Cernan replied, “Okay. A GO for T and D.”

“Okay,” Evans continued, “we’ll ARM the PYROS. And we’ll hit the GDC – ALIGN.” The GDC, or Gyro Display Coupler, constituted our backup control system for the spacecraft and now was aligned with the Primary Navigation and Guidance System (PNGS or “pings”).

“Did you put RCS COMMAND to ON?” I asked. Evans, in his excitement, had taken off on his own while I set up the Tape Recorder, but I wanted to be sure we covered all the Checklist items.

“Yes, I did that.” Then he continued on his own, talking more to himself than to us. “And the maneuver’s complete…and 0, 180, and 0 [set]…on the GDC? No, [on the Attitude Indicator].”

“Ron, are you okay?”

“It’s just…it’s just kind of diddling…Okay. [EMS FUNCTION is DELTA-V…and [EMS Mode] NORMAL…S-IVB’s okay…Okay, switches are all set.” It was clear that excitement permeated Evans really as he approached his first major operation on the mission and knew what needed to be done by heart. I got a kick out of his enthusiasm, but still watched the Checklist, closely. That was our lunar lander out there he was about to dock with.

“Ron, you need VERB 62 ENTER,” I reminded him.


“Okay, [we have] 59:30 [set],” I noted, relative to the Digital Event Timer.

“Okay,” Evans replied, “lets start the DET.”

“Tickity-tick-tickity, Houston,” Evans transmitted. “We’re running at 59:30.

“Roger,” replied the waiting Overmyer.

“Okay, Ron, thrust plus X and hold,” I told Evans. “Stop thrusting after three seconds, Ron.” This had us moving away from the S-IVB at about half a foot per second.

“Okay…okay, that’s LAUNCH VEHICLE SEP, push button [and hold then release].

The cabin indication of LAUNCH VEHICLE tank pressures immediately went to zero, as pyro cutters severed the umbilical between the S-IVB and America, prompting Cernan to call, “Separation, Houston.”

“Okay, check the covers,” Evans said, referring to the four SLA (Service Module/Lunar Module Adapter, pronounced “slaw”) panels that had protected Challenger up to now. Our SEPARATION command also had triggered the ejection of these panels. “And check the other ones off.” (See third photograph in Fig. 5.8)

“They’re all [off],” I told him, looking back from window 5 at the SLA panels moving rapidly away from the S-IVB as it continued to hold a stable attitude, waiting for us to turn around and come back for the Challenger.

I quickly read through the items we needed to check as unchanged after separation and Cernan took care of them while Evans watched the SLA panels tumble through space.

“Check the SERVICE MODULE RCS PROPELLANT talkbacks, eight of them, as being gray.”

“They are gray.”

“Same for the eight SERVICE MODULE RCS Helium talkbacks.”


“SERVICE MODULE RCS PROPELENT FUEL PRESSURE switches, four of them, should go to CLOSED, and the FUEL CONTROL REACTANTS valve should go to NORMAL.


“And I have verified that the OXYGEN TANK #3 ISOLATION VALVE talkback is gray.”

It looked like no adverse events in the attitude control and fuel cell systems accompanied separation from the S-IVB.

“Okay,” Evans continued, “I’m going to start the… My gosh! Look at the junk! …Okay, there’s 15 seconds. Pitch her up. Okay, we’ll PROCEED on the [computer display].”

At half a degree per second, it would take about a minute and a half to pitch the full 180 degrees so that we were pointed directly back at the front end of the S-IVB. As we did so, Cernan reported, “Houston, we’re right in the middle of a snowstorm! (Figs. 5.9 and 5.10 upper)”

Fig. 5.10. (Upper): View of more of the ice fragments surrounding the S-IVB after separation of the Command and Service Module from it and the ejection of the protective Service Module LM Adapter (SLA) panels. The Lunar Module Challenger is housed in the visible end of the S-IVB. (Lower): The photo shows the changing aspect of the Challenger as it was approached during the Transposition and Docking maneuver by Ron Evans. The small, circular, black and white 3D target Evans used to guide the docking is visible just to the upper left of the central tunnel opening (NASA photos AS17-148-22691, -22695, respectively).

“Roger, and we’d like OMNI Delta.” I complied immediately.

“Hey, look at that burst!” Evans exclaimed. “It is going to be bright as all get out.”

“And there goes one of the SLA panels,” Cernan added.

“Yes,” agreed Evans. “We’re not there yet,” referring to the pitch maneuver. “Long ways to go yet. It’s on the other side of the Earth, if the simulator’s any good. …Oh, man!” I think Evans referred here to the fact that he would be facing the Earth when the 180 degree pitch up was completed. Evans clearly was in his zone, having practiced this part of the mission hundreds of times.

“There goes another SLA panel, Houston, going the other way.”

“Hey, there’s the booster!” I shouted, feigning surprise (Fig. 5.10).

“Roger,” returned Overmyer. “Bet you never saw the SLA panels on the simulator.”

“No, but we’ve got the booster and is she pretty,” I replied. “Challenger’s just sitting in her nest.”

“Roger. We’d like OMNI Bravo, now Jack.” The Flight Controllers watching the communications quality were searching for the right antenna while the spacecraft changed orientation relative to the Earth.

As Evans completed his maneuver and the pitch change stopped with our X-axis pointed at the S-IVB, he said, “Okay, we’ll plus-X it. Well see the [target on the Challenger]. …Oh, you can’t see. …Oh, I can’t see [through] my COAS [yet because of the particles].”

“And, Houston,” Cernan observed, “some of the particles going by the window…were fairly obvious to me…as paint.”

“Okay. We’ll buy that,” Overmyer said, prematurely.

“Okay. There it is [zero degrees in pitch],” Evans said to himself. With the small end of our spacecraft cone now pointed directly at the Challenger’s overhead hatch and docking port, and America’s engine bell pointed directly away, Evans used four quads of small rocket thrusters on America’s Service Module to move the spacecraft forward so that the probe and drogue of docking system were positioned to capture the Challenger. Then he asked me, “did you change the Data Acquisition Camera (DAC) settings.” The 8-16 frame per second Mauer film camera normally was mounted in a bracket in window #4, above my head. It pointed along the x-axis, and it understandably meant a lot to Evans to film his docking with Challenger.

Evans, now in the left hand couch and with access to the main hand controllers and the switches for selecting the most sensitive attitude control mode, maintained a slow approach to the Challenger’s docking port and hatch, using alignment of a three dimensional target on the Challenger as his guide. This alignment method resembled flying close (three feet wing separation) formation in a T-38 by keeping the tip of the lead aircraft’s wing on the NASA logo painted on the fuselage ahead of Lead’s wing root. The attitude control system of the S-IVB held the Challenger in a stable inertial position as it rested in its “nest.”

“Okay, Ron, are you ready for your TRANSPOSITION Checklist?” I asked.

“Go ahead.”


“It is there.”

“Pitch UP at point five degrees per second.”

“Point five – we’re pitching UP.”

“So now, PROCEED [on the DISKEY], and you should have a flashing 50 18.”


“PROCEED again to a flashing 06 18. …Now, MANUAL ATTITUDE for pitch goes to RATE COMMAND.”


“When you stop at the docking attitude, the DISKEY will show a flashing 50 18 and you should ENTER on that display.”


“Now the big moment! Thrust plus X for four seconds. That should give us a velocity of about point 7 feet per second.”

“Thrusting four seconds.”

“For some reason, you need to reach down and OPEN the two DIRECT ULLAGE circuit breakers.” This item may have appeared as a result of an event in test when an electrical interference was noted when those breakers were closed during a Service Module RCS maneuver.

“I can do that. …They are OPEN.”

“Now, you need to load the RCS DAP (Digital Auto Pilot) with three ones…zero…two …and zero and four ones.” This process involved entering a VERB 48 in the DISKEY, giving a flashing 04 46 with two registers for entering the desired DAP load in octal format. Evans, of course, knew how to do this by heart.

“DAP is loaded.”

“Okay, …[I] got ATTITUDE 1/RATE 2,” Evans stated as he set up his preferred control sensitivity.

“Okay, Houston,” I queried, looking at the Checklist, “you want the high gain?

“Roger. We’re standing by for it, and the [slew] angles as published on [Checklist page] L/3-3 should be good.”

Talking to myself, I said, “HIGH GAIN ANTENNA TRACKING to MANUAL – HIGH GAIN ANTENNA POWER to POWER – slew to verify operation – set angles at PITCH 42 degrees and YAW at plus 293 degrees – S-BAND ANTENNA OMNI to HIGH GAIN – HIGH GAIN ANTENNA TRACKING now to REACQUISITION – we are not going to do TV so that stays in STANDBY – DAC has been started.”

Then I reported to Overmyer: “Okay, it’s [the antenna] flying pretty good. …We’re in REACQ here. …Houston how do you read? We don’t have a very good lock-on here in REACQ.” I was referring to the level of signal strength I was reading on my indicator.

“Roger, Jack. We’re reading you pretty good in voice.”

“Okay. It looks like it’s improving. …Signal strength dropped off, and now it’s picking up again.”

“Roger. We’re getting good signal now, Jack. …Jack, the high gain is looking good.”

“That’s good news. It seemed to slew very smoothly, so it looks all right.” Exchanges like the preceding took place every time we maneuvered America. Good voice and telemetry communications always remained high on the priority list for everyone. At this point, the ground needed to monitor all our systems during Ron’s critical docking activities in case a spacecraft problem started to manifest itself while our attention was on capturing the Challenger.

“How far away from the booster are we, Ron,” asked Gene.

“I’m guessing. I don’t know…about a hundred [meters, maybe].”

“What does the Checklist want for the BMAG MODE?” Ron asked. BMAG referred to the three Body Mounted Attitude Gyros that the backup SCS control system used as an attitude reference.

“ATTITUDE 1/RATE 2 [for all three BMAG switches].” Evans had already selected this BMAG MODE earlier.

“I can’t tell you too much, Bob,” Cernan volunteered, “from the center seat, other than Captain America is very intent on getting Challenger at the moment.”

“Roger. I can believe that.”

“I’m coming in a little slow, but we’ve got plenty of time,” Evans said to no one in particular. This slow approach gave me a chance to observe more closely the few remaining particles around the Challenger.

“Okay, Houston, while we’re moving in here, I can see a few chunks of that platy material, possibly paint down in the SLA [and] sort of bouncing around between the S-IVB and the LM. …But, so far, LM looks very clean. Can’t see anything abnormal from the view, yet.”

“Can you believe the stability of the S-IVB?” Cernan asked.

“Isn’t it, though? That thing is really stable out there.”

“Do you have a clear view?”

“Yes. Can you see it at all, Gene? …Got one little chunk coming out…it just came out of the SLA, and it’s spinning along the long axis, and it looks very stable. …Every once in a while, a small particle flies off of it though.” This observation suggested that the fragment, indeed, was ice frost and, as it warmed up, small pieces were going off as it spun.

“How big a chuck are you talking about, Jack?”

“…Referenced to the thrusters, about the same diameter as the thruster on the LM…That’s how long it was, and about a fifth that thick or that wide. …And I don’t think it’s more than a quarter of an inch or maybe even less, thick.”

Cernan, looking out the large, round hatch window, added, “That same particle, Bob, came by and as it went spinning, it was throwing off pieces of itself – radially out[wards]. …There’s a small one…floating by and it looked like flakes. …And I think I caught three of the four SLA panels going as we were maneuvering. I’ve got one out the hatch window now. It’s quite a ways out. …It’s tumbling in all three axes.”

“And I saw the fourth one out my side,” I reported, “so we saw them all…The area around the two spacecraft has cleaned up pretty well by now. There are just a few fragments moving around.”

“Now she’s coming in,” Evans interjected.

The crew of Apollo 17 [have been] describing what appeared to be paint or possibly ice flaking off the Saturn Third stage. But somewhat puzzling at this point is just exactly what the flakes or particles that they’re describing might be. Apollo 17 [is] in the process of docking with the lunar module, preparatory to extracting the LM from the Saturn 3rd stage. This [is] occurring at some 5300 nautical miles from Earth. And we’re watching the spacecraft velocity drop off rapidly as the altitude increases rapidly. The velocity, which at the TransLunar Injection cutoff was around 35,000 feet per second, [is] down to about 22,000.

As we moved closer to the Challenger nestled in the end of the S-IVB (Figs. 5.9-5.11), I could see two of the Descent Stage storage bays (QUADS 1 and 4) on either side of the ladder (ladder is under the porch at upper right at ca. 2 o’clock in photo 148-22695 of Fig. 5.10). QUAD 1 contained the Lunar Rover and QUAD 4 housed the Modular Equipment Storage Assembly (MESA).

“Rover [stowage area] looks in good shape, so far.”

Fig. 5.11. View of the S-IVB from Command Module America during the Transposition and Docking maneuver. The Lunar Module Challenger remains attached to the S-IVB within the Service Module/Lunar Module Adapter (SLA) (NASA photo AS17-148-22698).

“Roger, Jack. Can you see down on that quad [of the Challenger]. Is that what you’re looking at?”

“Yes, I’m looking right at it. And I got a good view of the MESA [quad] anyway. It’s pretty well covered [by the edge of the Command Module], but it looks all right, also. …All the antennas look good. Thruster quads all look great. I could see all four of them a minute ago.”

Through all this discussion, Evans intently kept the three dimensional target on the Challenger in alignment, finally stating, “Okay, about 10 feet there, Gene. Stand by for a…barber pole [on the PROBE EXTEND/RETRACT talk-back indicator].”


“All right; in good shape. …It’s in now!”

“Capture, Houston.”

“Roger. We copy.”

“Okay, we’re [in CMC MODE] FREE; rates look pretty good. Let’s lock it together.”

“Okay. You ready [for RETRACT]?” I asked as a double check before placing the DOCKING PROBE RETRACT switch to PRIMARY 1.

“Ready. She’s lined up not bad,” replied Evans.

“Okay,” confirmed Cernan.

“PRIM 1,” I said and moved the RETRACT switch.

“MARK it,” said Cernan. “Stand by.”

“Here she comes,” observed Evans as the docking mechanism drew America toward Challenger’s docking hatch. “Ka-chunk! My gosh!” Evans reacted to the loud sound of the spring-loaded docking latches firing, automatically. Three hours and fifty-seven minutes after launch and we were connected to Challenger.

“Okay, Houston, ripple fire [on the latches]; but we still have number A barber pole,” Cernan reported. This meant that at least one of the three opposing latches had not fully closed. “And we have a MASTER ALARM.”


“We got most of the latches, but A is barber pole, and B is gray.” Indicator A related to sensors on latches 1, 5, and 9 and indicator B related similarly to latches 3, 7 and 11. The remaining latches did not have sensors. At least three, alternating B latches apparently had fully closed. From the “ripple fire” sounds we heard, the chances were good that most of the latches had closed.

“Okay,” Evans began, “check circuit breakers; they’re IN. …We had one clear fire, maybe one or two latches and then a ripple fire on the rest,” recalling what he had heard. “And, by the way, I had a good view into the AOT (Apollo Optical Telescope on the Challenger], and I can still look in there, and its very clean.”

“Ron and Gene, we saw your MASTER ALARM. Did you have anything on the [CAUTION AND WARNING] matrix light up.”

“No, not a thing. I looked,” answered Cernan.


That appeared to be a repeat of the Master Alarm [that] has been reported several times previously by the crew. They get the alarm light and tone, but when they look for the exact location or precise indication of what’s wrong it’s not there, indicating some sort spurious response by the master alarm to a problem that doesn’t exist.

“Okay, Bob,” Cernan said while I grabbed the Malfunction Procedures book, “we’re going to go ahead and take a look at that docking malfunction before we press on here further and check this barber pole [indication] out.”

“Roger. We’re working some words up here. We’ll be back with you in a second on that, Gene.”

Meanwhile, I was going through the “After dock latches have engaged” portion of the Checklist with Evans so that both the automatic sequential events system and the docking mechanism were in a safe configuration.







“Okay,” Cernan reported to Overmyer, “we’re down on the checklist through the EDS POWER breakers, OPEN. …And, Houston, in case we didn’t tell you, it’s Talkback A that’s barber pole.”

“Understand. We have it. …After pausing for a few minutes to check out this indicator anomaly, Overmyer relayed Houston’s consensus: “Say, Gene, we don’t think it’s a problem. We’ll find out what it is when you get in [the tunnel].” We think we should just press right on with the Flight Plan checklist and keep going.”

Mission Control probably was worried about the limited time they had to control and maneuver the S-IVB using its remaining battery power. The final S-IVB maneuver would target it for a lunar impact within the net of seismometers deployed by previous landing missions.

At this point, I continued to read through the post-docking latches checklist.

“Circuit Breakers EDS, three, open.”

“Three are OPEN.”

“DOCKING PROBE EXTEND/RELEASE switch to OFF…I have that one, and the next one – two DOCKING PROBE RETRACT switches to OFF.”

As Cernan preformed these switch position changes, the previous anomaly concerning spurious MASTER ALARMS reoccurred. “Okay, Bob,” Cernan said. “We just got a MASTER ALARM when I went to the RETRACT PRIM, from 1 to OFF.”

“Roger. We copy that. Looks like Panel 2 is jinxed up there, huh?”

“Circuit Breakers DOCKING PROBE, two, OPEN.” This completed the removal of any possible power from the docking system now that America appeared to be firmly attached to Challenger.

“Okay, check both circuit breakers – they’re IN. Yes. Okay,” Evans said, but misspoke and meant they were OPEN.

Next, I guided Evans through the Checklist items that would reconfigure the spacecraft control system for coasting flight rather than maneuvering.


“ATTITUDE DEADBAND to MAXIMUM.” This change would minimize the automatic firing of the Service Module attitude control thrusters and thus save fuel for future planned and possible unplanned maneuvers. Flight philosophy always sought to preserve all consumables, that is, fuel, hydrogen and oxygen, just in case of some unanticipated future need.

“COAS (Crew Optical Alignment System) POWER to OFF.”

“OFF.” Evans had become more subdued as the excitement of Transposition and Docking wore off.

“Circuit Breakers REACTION CONTROL SYSTEM, two, verify open.”





“It’s LOCKED.”





“Verify that three BMAG switches are RATE 2.”

“They are now RATE 2.”

“Finally, O2 HEATER number 3, to AUTO, and I got that one.”

“O2 HEATER number 3 went to AUTO,” I reported.

“Roger. We copy that.”

After configuring the three couches so as to maximize room in the Lower Equipment Bay (LEB), we verified that there was no power going to the Lunar Module umbilical Cernan would soon connect in the tunnel between America and Challenger. Of course, while in the tunnel, Cernan also would inspect the docking latches to see if there were any indications of malfunctions.

A few minutes later, Cernan floated to the apex of the cabin to begin work in the tunnel. Decals in appropriate places gave the checklist procedures for this activity.

“Okay,” Cernan said, beginning the decal checklist for pressure equalization between the two spacecraft.

“Ron, I need CRYO PRESS INDICATOR to SURGE 3. …You should read between 865 and 935 psi.”

“It’s there,” Ron replied, from the Lower Equipment Bay.





“DIRECT O2 VALVE to CLOSE. And you should see a CAUTION AND WARNING light.”

“CLOSED and a light.”

“Okay, I’m putting the TUNNEL VENT VALVE indicator to LM/CM.”

“Okay, Bob. We’re reading a DELTA-P (difference in pressure) of greater than 4, and I’m going to open the PRESSURE EQUALIZATION VALVE, now. …Okay, the DELTA-P is coming down, Bob.”

“Roger. …Gene, while you’re watching that, I just thought you’d be interested. We talked to some of our friends down at the Cape who watched the launch, and they said you were aglow all the way until you faded into [a point where] you couldn’t tell you from a star. They saw staging, and they could just see you as a star way off in the distance until you faded out. Not a cloud in the way at all.”

“Beautiful! …Okay, we’re at 2 [psi DELTA-P] and we’re monitoring it for three minutes… Jack, I closed the PRESSURE EQUALIZATION VALVE so give me a countdown to 3 minutes on the event timer and we will see how tight the tunnel is.”


“And Houston,” I called after taking more Earth photos, “while we’re checking the [tunnel] integrity here, on Mag Alfa Alfa, [I have] 50%.

“Geno, now 30 seconds…20…10, 9, 8, 7, 6, 5, 4, 3, 2, MARK.

“…Okay, Bob,” Cernan reported. “That’s three minutes. DELTA-P change (difference) is less than zero point 1.”

“Three minutes and less than 0.1,” acknowledged Overmyer.

“…We are pressing on [with the decal checklist].”




“Okay, now OPEN the REPRESS O2 VALVE and cycle between 4.0 and 5.7 until you see zero on the REPRESS O2 PRESSURE INDICATOR.”

“REPRESS O2 VALVE is OPEN and I’m cycling.”

“Okay,” Evans began talking to himself on an open mike. “… Cabin’s at 4.8 now; REPRESS is about empty. …No, not yet, it’s still getting a little bit. …That REPRESS PACKAGE VALVE is kind of noisy. …That’s all the REPRESS O2. We’ll turn that OFF.

“Okay, Ron, DELTA-P is about zero point two,” Cernan called from the tunnel.

“Okay, Houston, the REPRESS PACKAGE is empty now,” Evans relayed, “and we are down to a DELTA-P of zero point two.”

“Roger. We copy that. …And, Seventeen, just be advised, you’re going to have an S-IVB non-propulsive vent start at 04:18:27. You’ve got about three minutes on that.”

“Okay,” Cernan laughed. “Thank you.”

“Can you reach [the valves] there?” I asked Evans.

“Yes, I’ll get them.”

“Ron, did you CLOSE the REPRESS O2 VALVE?” Cernan asked.


“Okay, Bob,” an impatient Cernan called. “We seem to be holding [LM/CM] DELTA-P at about zero point two. I suspect that’s probably zero [pressure difference]. …And the cabin pressure’s about 4.5. You want us to wait until 5 psi [in the cabin] for EMERGENCY CABIN PRESSURE SELECT [to BOTH]?” This procedure would be the fastest way to get America’s pressure back to normal.

“Negative on that. Let’s just go ahead and let’s press on [at this pressure].”

“Okay,” Cernan continued, speaking to Evans. “They (the valves) should be [to] BOTH.”

“Okay, EMERGENCY REPRESS [is] working. …[Delta-P] coming down, though, Gene. Let’s wait until it gets down a little ways. …Yes, straight up and down as well. …Up one [point] one…”

Looking out the window at the S-IVB, Ron kidded, “Must be the non-propulsive vent that’s banging. Here comes all the [material from the S-IVB]. Look at all the stuff going [out] again. It’s really glowing.”

“Your ‘non-propulsive vent’ gives quite a glow,” I said, pulling the leg of my booster Flight Controller friends.

“Roger, Jack.”

“Looks like a rainbow. A dark one,” added Evans and then went back to work. “Okay, REPRESS PAKAGE to FILL. …That ought to take the [oxygen] surge tank down a little bit…to about, what? About 400 [psi]? [I mean,] 500. 500 on the surge [tank].” Ron was looking at the CRYO O2 PRESSURE INDICATOR.

“Do we leave the REPRESS PACKAGE valves open?” asked Evans.

“No, they ought to be closed off by now, I think. Yes, close them,” answered Cernan, referring to the hatch decal checklist.

“Ron, You should see the cryo tank pressure go to above 835. …Okay, back to the decal – TUNNEL VENT VALVE to OFF. … Ron, we need the WASTE STOWAGE VALVE to VENT.” It will stay there until Houston reminds us to close it after the cabin has been purged.

“Seventeen, Houston. …Be advised, you don’t have to wait until 5 psi cabin to go ahead and open the hatch.”

“Okay, we’re not [waiting], Bob. We’re pressing on with it now. …Okay, it looks like we’re going to maintain about 400 [psi] on the surge [tank]. …Okay, Houston. The hatch is coming out.” To do this, Cernan needed to un-stow and then stow the hatch’s actuator handle.

Evans started laughing. “I don’t know what you’re going to do with it!”

“Put it up here…on the couch. …There we go. …Hey, that’s a lot lighter than it used to be. …There’s going to be a lot of happy people down there, Bob. I haven’t checked them all (the docking latches), but visually, they’re all locked, …Let me give them a good check.”

“Yes,” cautioned Evans. “You’d better check them, because we got a barber pole on that one [set].”

“Okay, here’s one that [is only partially] over.”

“What is the position of it?”

“7 and 9 are not fully locked.”

“7 and 9?”

“Hey, Bob,” Cernan reported to Houston. “Maybe we aren’t all going to be so happy…Okay, [for latches] 7, 9, and 10: the handle is flush; the bungee is vertical, but the handle is not locked down, and the red [caution] button is showing. And I can pull each one of them back slowly. I haven’t done anything [else] with them. That’s 7, 9 and 10.”

“Roger. We copy that.” Overmyer repeated back Cernan’s report.

“That’s affirm. …Okay, Bob…I just pushed the handle on 10 a little bit and it did lock. And the red button is flush. So that leaves me 9 and 7.”

“Roger; understand. …Geno, go ahead and try the handle on 9 and 7; and, if that doesn’t work, cock them and re-fire them starting with 9, please.”

“Okay. The handle doesn’t work. I’ll have to re-cock them.”

“When you trip it with your [finger],” asked Evans who knew the docking system backwards and forwards and probably should have been doing the trouble shooting, “did you cock it twice?”

“Yes.” It is not clear that Cernan had actually had done what Evans said he should.

“And it took two cocks to make it go?” Evans asked.

“Yes. …Okay, 9 cocked twice – it tripped. It is over-center and locked.”

“Roger. How about the barber pole now,” Overmyer enquired.

“Wait a minute.” Evans had to reverse some of the changes we made, post-docking, in order to get power to the indicators. “I’ve got DOCKING PROBE MAIN A circuit breaker’s IN and [I’ve] gone to [DOCKING PROBE] RETRACT [ON], and it’s gray.”

“Okay, Bob. Cocked 7 twice and tripped it, and it’s over-center and locked. …I think that takes care of them all.”

“Good show!” Left unexplained was why the B system, which had a sensor on latch 7, did not identify a problem, that is, showed gray on its indicator.

“Okay, DOCKING PROBE circuit breakers are OUT and EXTEND/RETRACT is OFF,” reported Evans.

“Why is this thing on the probe painted yellow,” Cernan asked Evans.

“Because it belongs on the probe. …Its painted yellow [because] it belongs on the probe.”

“Okay, Bob. The umbilicals [to the Challenger] are connected,” said Cernan. These umbilical lines between the two spacecraft allowed America’s electrical power to go to some heaters on critical equipment in the Challenger and to give me a readout on the voltage of one LM battery– a capability, used in reverse with LM battery power to the heaters, that had allowed Apollo 13 to trickle charge its Command Module entry batteries, removing the last hurdle to the crew’s safe return to Earth[15]. A LM PWR toggle switch on one of the main panels in America controlled whether CSM current went to the heaters, based on thermal management decisions by the Lunar Module flight control team in Mission Control.

Handing the hatch back to Cernan, I said to myself, “There we go. …There, we’re going up in the tunnel.”

Out of the recesses of the Lower Equipment Bay, Evans said, “Pretty good ham sandwich.” This was the sandwich we had put in our suit pockets when suiting up for launch.

“Okay, Bob, the hatch is back in.”

Our next activity involved separating and ejecting Challenger from the S-IVB. This required firing the pyrotechnic charges in the clamps holding Challenger to the booster so that mechanical springs could push the two docked spacecraft away at about one foot per second. I began my checklist reading again with Cernan and Evans responding.

“Circuit breakers S-IVB/LM SEPARATION, two, verify closed, and I’ll do that over here. …Verified.”


“LM/CSM on CG.”



“Slew DELTA V indicator to +100.0 [feet per second].

“Plus 100.0.”




“I have the TAPE RECORDER in HIGH BIT RATE / RECORD / FORWARD / COMMAND RESET and the Sequence Camera (DATA ACQISITION CAMERA) to six frames per second.

At this point, Overmyer called, “We’ve got some new angles here for you.”

As the duty recorder, I said, “Stand by a minute, and let me find a place to copy them.”

“What kind of angles are they, Bob?” queried Evans.

“They’re your NOUN 22 attitude maneuver for the [S-IVB] APS (Auxiliary Propulsion System) burn out of the hatch window. They’re in the middle of the page L/3-5…Instead of 270, we want 274 [for roll]…”

“Wait one,” Evans interrupted. “We’re not quite with you…” He had seen me scrambling for a pen.

“Okay, I think I’m with you at page 3-7; GO,” I said, since I had the Checklist.

“It’s on 3-5, Jack,” Overmyer corrected, “middle of the page, there. Those NOUN 22s.”

“Okay, I take it back; 3-5, middle of the page.”

“Okay, you notice there’s rhree angles there…270, make that 274.”

“That’s the only change?” I asked.

“…and the next one [pitch], the 129.8, change that to 164. And 4.3 on the yaw, change that to zero. It’s close enough; zero on the yaw.”

“Okay,” I replied. “We got them at 274, 164 [and] 000.”

“Roger, and the high-gain [antenna] angles that you’ve got on the Flight Plan are close enough and should do it.”

“Very good.”

“Before that NOUN 22 load, Ron, give me a V48…and load the DAP with two…one…one…zero…one in Register One…and four ones after the X in Register Two. …Now do your NOUN 22 thing…and load roll with two…seven…four…, pitch with one… six…four…, and yaw with all zeros.” This attitude would give us a good hatch window view of the S-IVB maneuver.

“Now, I want a VERB 60, followed by a VERB 63.


Working with the DAC camera, I mused to myself, “I’ll leave it at ten feet and about an f/8. …Okay, all set [in its bracket]”

“Okay, Bob,” Gene said, “we’re aligning our GDC (Gyro Display Coupler) and the next thing we’ll pick up will be SECS ARM circuit breakers. And we will give you a call on the [SECS] LOGIC.”

“Okay, Bob,” I interjected. “While we’re waiting, does the balance on the H2 and O2 flow into Fuel Cell 3…actually, into all three Fuel Cells, look pretty good to you?”

“Jack, the flows look just right for the current.” This was a comparison that Mission Control could make better than I.

“Okay. [I’m] used to seeing them more or less lined up, and I hadn’t calculated any further than that. …O2 seems a little higher than H2, relatively speaking.”

Back to the preparation for separation from the S-IVB, Evans verified closure of the circuit breakers for the SEQUENCIAL EVENTS CONTROL SYSTEM. “Okay, Houston, we’re ready to come up with the LOGIC [switches to ON].” Mission Control always wanted to watch this system as we switched power to it. “Okay, Houston,” continued Evans, “LOGIC 1 is coming ON now and LOGIC 2.’


“…And, Houston,” Evans continued, “just to keep track of [the] ENTRY MONITOR SYSTEM null bias (system drift) check, that time [it] went from 100 to 100.7 in 100 seconds.” He had done another quick NULL BIAS CHECK.

“Seventeen, we’d like to just verify on that top line [of the checklist] S-IVB/LM SEP circuit breakers – both of them are CLOSED?”

“Okay,” Evans replied, “we’ll verify them again. We double checked them [earlier].”

“Okay, we just didn’t hear your call, and we want to make sure of that. Didn’t want to miss anything, here.” Actually, I had not read that part of the checklist on the air-to-ground loop.

“Okay. They are verified CLOSED,” Evans replied. “and Jack just checked them again.”

“Okay,” Overmyer said. Then, “you are go for PYRO ARM and GO for [LM] extraction.”

“Okay, GO for PYRO ARM; GO for PYRO extraction…” With Cernan and me laughing, Evans corrected himself, “or LM extraction.”

With the GO from Mission Control, I went back to the checklist and said, “Okay, PYRO ARM.”

To which Evans replied, “Okay, we’ll ARM the old PYROs. There’s PYRO A…PYRO B.

“[TVC] SERVO POWER number 1 to AC1/MAIN A [power],” I continued.


“TRANS CONTROL POWER, up and ON [verify].”


“Okay, ROTATIONAL CONTROLLERS are ARMED. Okay, I’ll wait just a little bit on that. …EMS to NORMAL. …Get DELTA V changes by going to VERB 37 ENTER 47 ENTER. You should have a flashing 16 83 showing DELTA V for X, Y, and Z.”

“Okay, EMS to NORMAL. Push right there. Yes.”

“DAC is started,” I told them.

“Okay,” said Cernan, entering the conversation. “On my mark. [Remember] the S-IVB/LM SEP [light] will come on.”

“Okay,” Evans responded, “and then I’ll back it off to…okay?

“Okay, on my mark, S-IVB/LM SEP: three, two, one, MARK it. Okay, we got it!”

“Oh, ho! Man, did we!” exclaimed our Kansan. “There she goes. Yes; LM came with us! …Okay, we’re [in] CMC AUTO. All right. We’ve got 0.6 [feet per second]. It’s all right [for separation velocity]. Okay, whoopee-dee-do!”

15 thousand miles from Earth and four hours and forty-five minutes after launch from the Kennedy Space Center, America and Challenger left the Saturn V and proceeded to the Moon on their own.

“PROCEED [on the DISKEY].” This took the computer to P00 [idle].

“Gene, when the CMC Activity light is out, ENTER VERB 66.”

“Okay, VERB 66 ENTER.”

“SECS PYRO ARM, two, to SAFE,” I read, now off line.

“Safe the PYROS,” confirmed Evans.


“Okay, LOGIC’s OFF.”

“Circuit breaker SECS ARM, two, OPEN.”

“SECS ARM breakers are OPEN. …Now, I think we ought to go to the maneuver pretty quick. Otherwise, the S-IVB will be so far away you can’t see it. Okay, you ready to maneuver [to viewing attitude]?”

“Go ahead,” confirmed Cernan.

“Okay,” Evans said, talking to himself as he initiated the maneuver. “CMC’s in AUTO. Away we go. …That [bump] wasn’t as bad as the original [separation].”

“Yes,” I agreed.

“Came right out, though.”

“Two SIVB/LM SEPARATION circuit breakers, OPEN.”


“O2 TANK 3 ISOLATION valve talkback, gray. I verify that. …MAPPING CAMERA ON switch to OFF. PANORAMIC CAMERA POWER switch to OFF.” These last two items were part of their normal power cycling requirement.


I kept moving down the Post-LM EJECTION Checklist items with Evans sporadically taking the various actions due to his wonder about seeing the Earth. I was impressed by the view, but a combination of my geological expectations that this is what I would see and my desire to make sure we made it to the Moon made me more focused on the immediate tasks at hand.


“Okay. POWER’s OFF. Hey, Jack. Hand me the Hasselblad [camera]. I think we’re going in the right direction. Yes, the Moon is there. The Earth is…that’s the Earth!”

“Let’s finish this, Ron. LAUNCH VEHICLE/SERVICE PROPULSION SYSTEM INDICATOR switch to GPI and I will do that.”

“TVC SERVO POWER, two, to OFF, Ron.”

“[THRUST VECTOR CONTROL] SERVO POWER’s OFF, yes?” Cernan had taken up the Post-LM Ejection Checklist run through while Evans took pictures of parts of the Earth visible outside the hatch window.

“The Earth just fills up window 5.” Not paying any attention to me, Evans was looking out the square window on my right. I gave him the camera and he said, “Okay, f [-stop], [focus at] infinity, about a 250th [of a second shutter speed]…”

“Ron, do you want the viewing attitude numbers, now?” I asked.

“What? What do you have [for viewing attitude]?”

“274 for roll, 164 for pitch [and] 000 for yaw.”

“…[That] a zero in there [for yaw]? …Hey, I lost my watch!”

“EMS MODE switch to STANDBY.”


“EMD FUNCTION switch to OFF.”


“TAPE RECORDER, OFF, and I got that…and PCM BIT RATE to LOW…and STOP the DAC.”

“Now, Ron, I need you to put the four AUTO RCS SELECT switches to OFF.”

“Yes, [AUTO REACTION CONTROL SYSTEM] AC is OFF. …Whoo, what a beauty! What a beauty!”

“Now, I will put three O2 HEATER switches to OFF, …and we can watch the S-IVB.”

When we finished the last few items on the checklist, and then it was time to go to the right attitude for viewing the S-IVB as it made its evasive maneuver so as to move on a slightly different trajectory to the Moon. Eventually, the S-IVB would be targeted to a lunar impact about 12.5 degrees west and 4.2 degrees south of the center of the Moon.[16] This impact point would provide a new set of seismic signals from a known location southwest of the existing seismometer net set out by Apollos 12, 14, 15 and 16.

“I can’t see the S-IVB,” Cernan interjected.

“Look at that!” an amazed CMP continued.

“Yes,” I replied. “Madagascar and Africa (Fig. 5.12) Got to be. …Hey, there’s Antarctica. It’s all full of snow!” as if no one knew that. “You want to look?” I asked Evans.

Fig. 5.12. Apollo 17 view of the western Indian Ocean (far right), Madagascar, the southern part of Africa and the Atlantic Ocean (left) (NASA photo AS17-148-22717).


“Can you see the S-IVB, Jack?” Cernan asked me.

“Yes. Oh, there it goes…there!” I replied. Looks kind of empty down there without the LM.” (Fig. 5.13)

“Okay, Bob,” Cernan reported, “we’re looking right up the dome of the S-IVB.”

Fig. 5.13. Three views of the S-IVB from the CM looking past the top of the LM Challenger now docked to America. (top): The empty “nest” where the LM had been stowed at the end of the S-IVB above the O2 tank. (middle): Maneuvering into a position that will take the S-IVB on an independent trajectory to impact on the Moon. (bottom): Closer view of the same (NASA photos AS17-148-22705, -22711, and -22714, respectively).

“Roger. We copy that. We’re standing by for your GO for [S-IVB] yaw maneuver.”

“We can give them a GO for yaw, can’t we?” Evans asked. “We can see it now.” Having the S-IVB in sight from America before any maneuvering of the unattached S-IVB was a constraint put on by the Astronaut Office.

“Yes, we can see it,” said Cernan. “You’ve got a GO for the yaw. …Looks like she came out of there clean as a whistle.”

“Seventeen, Houston. The yaw maneuver will be starting in about 4 plus 52 [ground elapsed time since launch], a little less than two minutes from now.”


“Sounds like you are taking a picture of that old dome out there, huh?” Overmyer interjected.

We would leave America’s thrusters and their control systems activated until after the evasive burn in case the S-IVB failed to perform that burn. In that event, Evans would thrust along our +x axis for six seconds to provide the desired separation but at the cost of using some of his precious “Volkswagen” reserve of RCS propellant.

“Hey,” I cried. “There it goes. Look at the aft fire of the thing!”

“Yes, we can see it fire, now,” Cernan added.

“Roger, Seventeen. Yaw maneuver started.”

“The old S-IVB had a flare for the dramatic,” I replied, referring to the hold on the launch pad that involved its liquid oxygen tank, “but it certainly did its job for us.”

“Roger, Jack. Preliminary data indicate that you are about as nominal [on the trajectory to the Moon] as you can be.”

“That’s the way we’d like to keep it, Bob,” agreed Cernan.

“You’d better believe it!”

As we watched the booster maneuver, the whole of the rocket became visible from the dome of the liquid oxygen tank below the Challenger’s former home, to the guidance section (the Inertial Unit or IU), to the J-2 engine bell at the aft end. Everything we could see of the booster looked normal with no sign of any paint having come off its sides, possibly suggesting that all the particles we had seen were ice.

“…As we’re looking at it,” Cernan described, “she’s pitching up. She was looking right at us – we were looking right at the dome – and now she’s pitching up. The shroud around the IU seems to be totally intact. It looked like a super clean separation. I can’t really see where there’s any paint or anything externally chipped off the booster from here. We’re beginning to pick up the [engine] bell. It’s really a shame you don’t have this whole thing on TV – it’s really quite a sight. …The Mylar and the gold coating on the inside of the shroud that’s now visible is also intact. It looks like you could use it again, if you could get it back.”

“Well,” Overmyer reminded, its got a job to do when it hits the Moon, yet.”

Okay, Bob. We’re almost looking at it broadside now. …She’s spitting a little – looks like the yaw maneuver may be complete.” Cernan then repeated how clean the entire booster looked.

“If you’re happy, we’d like a GO from you for the evasive burn.” With the yaw maneuver complete, a short burn by its Auxiliary Propulsion System would add 10 feet per second along the S-IVB’s x-axis. This would put it on a trajectory to the Moon that would not interfere with the remainder of our flight.

“Let’s get a picture or two here yet, and we’ll give you a GO.” (Fig. 5.14)

Fig. 5.14. Longitudinal view of the S-IVB, third stage of the Saturn V, just before its evasive burn to set it on a trajectory to the Moon different from that of America. Upon impact, it would provide a seismic signal of known energy to be sensed by Apollo’s net of seismometers deployed on Apollos 12, 14, 15, and 16 (NASA Photo AS17-148-22724).

“And, Gene, it’ll be about seven minutes until the [planned] evasive burn [at] 5 plus 30.”

“Okay,” Cernan said after we had some photographs of the S-IVB. “You have a GO.”

“And for your reference,” I reported, “at frame 105, I started a few 250 millimeter pictures of the S-IVB.”

“Roger, Jack.”

“And, Bob,” commented Cernan, “the entire sky, as far as I can make it out through the hatch window, is completely filled with our twinkling flakes.”

To which I added, “I saw a couple particles go by the window awhile back, and it looked a little bit like insulation in this particular case – styro-foam insulation, but in flat flakes…That was right after we separated [Challenger] from the S-IVB.”

“Roger. Understand.” Overmyer had an inclination to follow “Roger”, which means “understand” in pilot language, with the redundant word, “understand.” He might have wanted to be sure he was clear to all the non-pilots listening in on the transmissions.

[Later, we concluded that the fragments were pieces of the frosty ice sheath that had accumulated on the very cold sides of the Saturn during our delayed launch in the humid Florida air. Such a frost layer would not have the dense appearance of solid ice, but might look relatively incoherent like insulation. Most of the frost sheath on the external skin around the cold LOX and H2 tanks had come off quickly during the heavy vibration of the S-IC first stage; however, some of it on the S-IVB third stage apparently survived until the shock of shutdown at the end of the TLI burn. As a consequence, the fragments had more or less the same velocity toward the Moon as did America and Challenger. No formal post-mission investigation as to the source of these fragments, however, is included in the Apollo 17 Mission Report on anomalies.]

“Sure is round, isn’t it.”

“Bob,” Cernan called, “I know we’re not the first to discover this, but we’d like to confirm, from the crew of America, that the world is round.”

“Roger. That’s a good data point. Have you gotten a good look at any of that weather down there on the Antarctic?”

“You know,” broke in Evans,” it’s real funny there in Antarctica. …You can see the snow, but there isn’t any weather at all in it. All the weather’s around it in the water.”

“That’s where the moisture is,” I suggested.

“Seventeen, Houston. Look’s like you’ve got a super conservative CMP up there. We’ve run off some numbers. Looks like you used about 40 pounds of RCS [Reaction Control System propellants] on the T&D (Transposition and Docking), and you’ve used about a total of 42 pounds RCS total; so we’re hanging right in there [on the fuel budget]. Beautiful!”

“…velvet touch,” Evans responded. “Still a little bit too much, but that’s not bad.”

Cernan added, “We’ll be glad to leave all that extra, I hope, in the Service Module when we get home.”

“It’s in the Volkswagen pouch down there,” said Evans.

During this back and forth, I was beginning my three and a half day campaign of observing and photographing Earth’s weather, using the 60mm Hasselblad camera and Ectachrome 360 color film. This was the first time this new Kodak film had been used in space.

“Seventeen, Houston. It’s about 30 seconds from the evasive maneuver burn [by the S-IVB]”

“Here Jack, “can you see him good [out your window]?” Evans asked, as he floated the cameral over to me. “Check the settings there [on the camera]. I took [it earlier] at an f/22 stop.”

At five hours, three minutes, and 19 seconds, Cernan reported, “There it goes, Bob!”

“There it goes…, finally,” I repeated, happy to have that phase of the flight under our belts.

“Seventeen, Houston. The evasive burn is complete, and the LOX dump will be a 5 plus 24 plus 20.”

“It’s going to be gone, I think, before we see it,” I commented, thinking that 20 minutes (1200 seconds) at 10 feet per second relative velocity change would put the S-IVB over two miles away when the oxygen dump occurred. I had not taken into account the huge oxygen cloud that would ensue. The dump would add a further 28 feet per second to the separation velocity.

The success of the S-IVB evasive maneuver meant that we could reconfigure some control switches that had been left active in case we might have to move farther from the booster. I quickly went through those items and Evans took care of them.

“Okay, Ron, lets verify that the two DIRECT ULLAGE circuit breakers are OPEN.”

“They’re OPEN.”


“It’s OFF.”


“Two are OFF.”

“LOCK the two hand controllers.”

“Gene, you get yours and I’ll get the one over here.”

“Now, Ron, you have to go down to the LEB and put the REPRESS PACKAGE VALVE to OFF.”

“Okay. …It is OFF.”

“Finally, while you are down there, the O2 ISOLATION/AUXILLARY BATTERY circuit breaker should be OPEN.”

“And, Bob,” Cernan declared, “you can tell Frank [van Rensselaer] to forget returning the phone call I made to him a couple of days ago. …All my questions are answered.”

“Think you’ve had enough booster briefings, huh?” responded Overmyer.

“Yes. I figure this is probably the best one of all.”

“Frank said [from across the MOCR] he’d guarantee all those S-IVBs would just as good as that one.”

“Okay. That’s fair enough. The S-IC and the S-II didn’t put on a bad show either.”

“Houston, magazine November November is on about 123 right now.” I reported.

“…And, Bob,” Cernan said, “we’re on page 3-9 of the Flight Plan now. We’ll check the LM/CM DELTA-P [and] get the Cabin Fan Filter in. We’ll go over the Systems Checklist, get [deactivate] the Primary Evaporator, and a few odds and ends, and start doffing our PGAs (Pressure Garment Assembly, that is, Apollo-speak for ‘spacesuit’). How’s that sound?”

“Sounds like a winner, Gene.”

And so, the three and a half day flight to the Moon had begun.

(to be continued . . .)



    1. In the quoted dialog and annotations directly related to the Apollo 17 Mission, black = normal mission activity and commentary with quotes from the NASA transcript of air to ground communications; red = spacecraft anomaly discussions; blue = Earth observations; brown = Lunar Module Challenger discussions; green = Public Affairs Office transcripts or news updates from Mission Control; and purple = lunar observations. Other than their use in the names of spacecraft, italics = onboard recorder transcripts (Data Storage Equipment or Command Module DSE and Data Storage Electronics Assembly or Lunar Module DSEA), and turquoise = probable dialog derived from the author’s memory.

      In addition, parentheses (-) in the text are used to clarify the meaning of a preceding word or phrase. The use of text inside brackets [-] provides completion of an unspoken transcript thought. Brackets [-] enclosing letters or words quoted from a checklist complete abbreviated words to clarify what the word in question means. They are also used for parenthetical emphasis of explanatory paragraphs set off from regular text.

      The CMC (Command Module Computer) commands are referred to occasionally in text as Pxx (Program i.d. number), Nounxx (data specification), or Verbxx (action number) to be carried out by the CMC when entered by hand.

    2. For a 3D Virtual Reality online tour of the interior of the Apollo 11 Command Module (CM), which will give the reader an idea of the design layout associated with the sequence of events described in the following pages, see the digitization model provided by the Smithsonian Institute by clicking here. It may take a couple of minutes for all components of the interior scene to appear, depending on the speed of the web connection and user computer, but once fully loaded, the controls are at the upper left of the display screen. The main controls are the right-left arrowheads followed by “[1 of 27]start”, etc. Later mission CMs differ, among other things, by having some switch/light combinations in different locations on the instrument panels.

    3. Sutton, George P. and Biblarz, Oscar, 2001, Rocket Propulsion Elements. 7th ed. Wiley and Sons, p. 350.

    4. Clavius, Space Vehicles – Pogo and the Saturn V, Definition given here.

    5. Marshall Space Flight Center, 1973, Saturn V Launch Vehicle flight Evaluation Report-AS-512 – Apollo 17 Mission, MPR-SAT-FE-73-1, click here for a PDF copy.

    6. Mellberg, W. F., 2012, The Apollo 17 Launch: An Eyewitness Account, a 1.5 Mb PDF file published on this website. Download a copy by clicking here.

    7. Wendt, G., 2001, The Unbroken Chain, Apogee, Burlington, Ontario, p. 158.

    8. Kelly, T. J., 2001, Moon Lander, Smithsonian, Washington, pp. 251-252.

    9. Talkbacks are small, square visual indicators that show either barber pole and gray depending on the status of certain critical mechanisms, e.g., valves and latches. Position sensors on the mechanisms are tied to the talkbacks by independent electrical circuits. If the window shows yellow diagonal stripes (barber pole), then the condition indicates an abnormal or temporary status. If the window shows a solid gray appearance, then the condition of the mechanism is normal or as commanded.

    10. Apollo Mission Evaluation Team, (1973) Apollo 17 Mission Report, 15.1.2 Mission Timer Slow, Johnson Space Center, JSC-07904, p. 15-3, March, 1973. PDF available by clicking here.

    11. No transcripts or audio from onboard tapes have been located from this point through TLI.

    12. Unfortunately, no tape record of these descriptions prior to 2:25 GET have been located.

    13. Motto of the Apollo 17 Mission.

    14. Adapted in part from Schmitt, H. H., 1994, A Trip to the Moon, in V. Neal, editor, Where Next, Columbus? Oxford University Press, New York, pp. 41-76.

    15. Lybergot, S., 2001, Apollo EECOM, Apogee, Books, Burlingame, Ontario, p. 145; Kranz, G., 2000, Failure Is Not An Option, Berkeley, New York, p. 329-330.

    16. Latham, G. V., et al., 1973, Passive seismic experiment, Apollo 17 Preliminary Science Report, NASA-SP 330, p. 11-1 to 11-9.

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