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Copyright © 2007 by the Editors of Working on the Moon.
Last revised 13 October 2010.

"(John) was sleeping so great that I just woke him up a second ago ...  I couldn't stand it any longer (and wanted to get him up and get going)." - Charlie Duke, Apollo 16, in the LM prior to EVA-1.

1. Summary

The crews of the first two Apollo missions - the checkout flight of the Command and Service Modules (CSM) in Earth orbit on Apollo 7 and the CSM flight to lunar orbit on Apollo 8 - did not get adequate sleep primarily because it was deemed necessary on these pioneering missions that at least one crewmember be awake at all times.  Along with other factors, the need to fit two sleep periods into each day produced large disruptions to the crews' circadian work/sleep cycles.  Although the crews - particularly on Apollo 8 - were able to fulfill mission goals, it was clear that careful attention would have to be paid to work-sleep schedules on subsequent missions to ensure adequate rest.

During the next two flights - checkout of the LM in Earth orbit on Apollo 9 and the final landing-mission rehearsal in lunar orbit on Apollo 10 - all three crewmembers slept simultaneously and were able to get good rest.  On Apollo 10, the crew had a 14-hour rest period prior to lunar orbit insertion and a shorter rest period prior to LM operations.  Unlike the first two crews, they did not show any signs of post-flight fatigue.

Generally, the subsequent crews arrived in lunar orbit well rested.  Whenever possible, flight plans were organized to minimize shifts of the sleep cycle.  The only notable exception was Apollo 14.  That crew had to deal with the largest sleep-cycle shift in Apollo and got relatively poor sleep.

The first three LM crews did not obtain adequate sleep on the lunar surface because they did not remove their suits for the single rest period scheduled for each crew.  In part, the lunar stays were too short to allow the crews to doff their suits before the rest period and don them again afterwards.  In addition, NASA and the crews weren't confident that the zippers would seal properly if the suits were taken off and put on again.

On Apollo 11, Armstrong and Aldrin did not have hammocks and tried to make themselves comfortable on the floor (Aldrin) and the ascent engine cover (Armstrong) for a four-hour rest.  Neither was able to sleep because of (1) the suits were uncomfortable, (2) the cabin was cold, (3) there was noise from a glycol pump in the Environmental Control System, and (4) sunlight was leaking into the cabin around the window shades and through the Alignment Optical Telescope.

On Apollo 12, Conrad and Bean had hammocks but obtained only about 3 hours fitful sleep.  Conrad experienced significant shoulder pain due to improper suit fit and had to wake up Bean to let out the laces on Conrad's lower legs.

On Apollo 14, Shepard and Mitchell got very little sleep because of suit discomfort and because of a sensation that the LM was about to tip over.  Inadequate sleep obtained on the trip out to the Moon may have been a contributing factor.

The last three mission each included a lunar-surface stay of roughly 72 hours and three rest periods.  From the experiences of the prior crews, it was clear that they would be unable to complete the ambitious schedule of lunar surface activities they had planned unless they got adequate rest.  Doffing the suits for the rest periods was essential and, generally, all three crews slept well.

Some of the astronauts took Seconal (Eli Lilly branded Secobarbital, a barbituate) sleeping tablets on occasion during their missions.

2. Lessons

Adequate sleep in the small volumes available in the Apollo Command Module and Lunar Module was most easily achieved if (1) there was minimum disruption to the pre-flight circadian rhythm of the crew members; (2) all crewmembers in the spacecraft slept at the same time; (3) crewmembers were able to doff their suits before sleeping; (4) work schedules were organized  - and revised as needed - to provide an undisturbed (radio quiet) 6-8 hour rest period during each 24-hour period; (5) in zero-gravity, loose restraints were provided to keep the crewmen from drifting; (6) on the lunar surface, a hammock or other form of bed was provide; (7) there was an adequate combination of cabin temperature and sleepwear for comfort; (8) the crew could dim instrument lights and either cover their eyes or exclude sunlight from the cabin; and (9) equipment such as pumps were adequately muffled.

The last three LM crews -  those that spent three days on the Moon and were able to doff their suits for the rest periods -  reported that they slept very well.  On Apollo 15, Jim Irwin said that his first sleep on the Moon was his best sleep of the mission, despite being awakened an hour early to investigate a water leak in the cabin.

3. Non-Landing Missions

3.1 Apollo 7

Launch: 15:02:45 GMT, 11 October 1968
Splashdown: Ground Elapsed Time 260 hr 09 min 03 sec

CDR - Wally Schirra
CMP-Donn Eisele
LMP-Walt Cunningham

Apollo 7 has been described as Apollo's 'shakedown cruise' in Earth orbit, the first flight of the Command and Service Modules (CSM) with a crew onboard.  Because NASA had only 13 1/2 months to complete the task of completing a successful landing mission "before this decade is out", the flight plan was full.  If at all possible, NASA wanted to be able to next fly the CSM on a far more ambitious mission. Because this was the first crew to fly a CSM, at least one of them would be awake at all times; the need to fit two sleep periods into each 24 hours made the flight plan even tighter.  And, finally, all three crewmembers developed head colds early in the flight, which didn't help their productivity and probably contributed to the bad relations that developed during the flight between Apollo 7 Commander Schirra and Houston.

The crew removed their suits not long after reaching Earth orbit and these were stowed under one of the couches.  Sleeping bags were secured under the other two couches with straps and the sleeping crewmembers slept in the bags, floating in zero-gravity.  The crew did not have to cover the spacecraft windows during sleep but, rather, covered their heads with sleeping bag fabric and were not bothered by the sunlight.  Biomedical data, including heart rate, were available from only one crewman at any one time.  A switch on the instrument console could be set at one of three positions.  The crew made regular reports on water consumption and any medication taken.  Reports on the amount and quality of sleep were made occasionally.  Crew status reports became more formalized, starting with Apollo 9 and becoming part of the daily routine with Apollo 11.

(Adapted from the Apollo 7 Mission Report) Like prior (Mercury/Gemini) crews, all three crewmembers experienced a sensation of fullness of the head shortly after achieving orbit.  After the flight, the Commander stated that he became aware of head cold symptoms within an hour of launch, but did not report his cold to Houston until about 15 hours.  Twenty-four hours later, the other two crewmembers reported having head colds.  "The crew reported poor sleep for about the first three day of the flight and experienced both restful and poor sleep after that period."  Late in the mission, at 214 hr 40 min.  Apollo 7 Commander Schirra recommended that Apollo 8 Commander Frank Borman immediately begin a review of his mission's timeline from liftoff onward "for sleep (and) work cycles, and for food periods."

Mission Report Figure 7-1 gives an approximation to the rest periods.  See, also, Sleep Notes derived from the Apollo 7 Technical Air-to-Ground transcript ( 26 Mb PDF ).  There seem to be only minor differences between the figure and the information gleaned from the transcript.  There is no mention that any of the crew took any sleeping tablets.

3.2  Apollo 8

Launch, 12:51:00 GMT, 21 December 1968
Lunar Orbit Insertion,  Ground Elapsed Time of 69:08:20
Ten revolutions were completed in lunar orbit in 20 hours 11 minutes.
Transearth Injection, 89:19:17
Splashdown, 146:46:14

CDR - Frank Borman
CMP - Jim Lovell
LMP - Bill Anders

Apollo 8 was a circumlunar mission flown out of the planned Apollo sequence because of intelligence information that the Soviet Union was preparing send a crew of its own on a circumlunar flight.  The success of such a mission would diminish the geopolitical impact of the first lunar landing; and, confident that the Soviets were not in a position to make a landing in 1969, NASA wanted to make sure that an American crew was the first to fly around the moon.  Although planning for what became Apollo 8 first focused on a flight that would go out to the Moon, circle around the farside and return to Earth without entering lunar orbit, the final plan included ten lunar orbits.  The twenty hours spent in lunar orbit would be the most challenging of the mission and the flight plan was designed to get a well-rested crew into lunar orbit.  Once the crew was circling the Moon, there would be much opportunity for sleep until they were on their way home.

As with Apollo 7, the pioneering nature of the mission meant that at least one crew member would be awake at all times.

The following is an extract from the Apollo 8 Mission Report: "Work/rest cycles.- The very busy flight schedule precluded simultaneous sleep and resulted in large departures from normal circadian periodicity, thus causing fatigue. The wide dispersions of the work/rest cycles are given in figure 8-2.   A 'practical shift' of 3 hours before or 8 hours after the start of the usual Cape Kennedy sleep period is shown for the Command Module Pilot and Lunar Module Pilot. The Commander experienced a 'practical shift' of 11 hours before to 2.5 hours later than his assumed Cape Kennedy sleep time."

Rest periods

Apollo 8 Mission Report Figure 8-2 showing the large variations in the times of planned sleep periods relative to a 'normal' start of sleep at 2300 at the Cape.  These variations were due to the work load of this first voyage to lunar orbit.

From the Apollo 8 Mission Report: "The scheduled sleep and that actually obtained are compared in figure 8-3. Real-time changes to the flight plan were required because of crew fatigue, particularly during the last few (lunar) orbits before the transearth injection maneuver."  As can be seen in Sleep Notes derived from the Apollo 8 Technical Air-to-Ground transcript ( 39 Mb ) , at 31:40:49 Apollo 8 Commander Frank Broman told Houston "We would like to see, in looking over the flight plan - perhaps we ought to put the rest periods a little bit shorter and more frequent.  It seems it might work out better.  We got all out of kilter on it yesterday.  We are sort of trying to get back in a normal cycle."  As can be seen in the following comparison of the planned and actual sleep periods, by and large the crew did switch to a pattern of shorter, more frequent sleep periods. 

planned and actual sleep periods

Apollo 8 Mission Report Figure 8-3 compares planned and actual sleep periods for the three crewmembers.

During the 20 hours spent in lunar orbit, the crew had planned only short naps and, except for timing variations, this is what they got.  In addition to engine burns, tests of navigation/guidance/landmark tracking procedures that would be used by later crews, preparations for the engine burn that would take them back to Earth, and general spacecraft operations, the crew spent a lot of time taking photographs and providing television broadcasts for a global television audience.  On this landmark voyage, with support from Houston, the crew was ready to find a way to get sufficient rest within the context of mission requirements.  CDR Frank Borman took a 100-mg sleeping tablet before the first rest period.

3.3 Apollo 9

Launch: 16:00:00 GMT, 3 March 1969
Splashdown:  241:00:54

CDR - Jim McDivitt
CMP - Dave Scott
LMP - Rusty Scheickart

Apollo 9 was flown in earth orbit primarily to allow two members of the crew to fly the LM as an independant spacecraft and check out systems and procedures that would be used during the early stages of descent from lunar orbit and during the final stage of the return to orbit on landing missions.  For the first time in Apollo, all three crewmen had the same rest periods.  They reported getting 6-8 hours of sleep per period, except for the fourth.  Prior to that rest period they had fallen behind in preparations for the LM flight.  They shortened the rest period so that they would be able to start LM operations at the scheduled time, primarily in the interest of preserving the schedule of planned passes over ground stations.

The launch was postponed 3 days to let the crew recover from head colds. Launch at 11:00:00 a.m. EST on 3 March 1969.  Splashdown at a Ground Elapsed Time of 241:00:54.  Initial fullness of the head, that was "of short duration".  CMP and LMP both had problems adapting to weightlessness, especially the LMP who vomited "after donning his pressure suit for transfer to the lunar module" and, again, four hours later "shortly after transfer to the lunar module".  "Until the sixth day...he subsisted exclusively on liquids and freeze-dehydrated fruits."

 Extract from the Apollo 9 Mission Report ( 16 Mb ): " Work/rest cycles.- This mission was the first in which all three crewmen slept simultaneously. A definite improvement over the previous two flights was observed in the estimated quantity and quality of sleep. The lack of postflight fatigue was correspondingly evident during the physical examination on recovery day. It should be further recognized, however, that crew work load during the last 5 days of flight was significantly lighter than on previous missions. The flight plan activities for the first half of the mission resulted in excessively long work periods for the crew, and the time allocated for eating and sleeping was inadequate. Crew performance, nonetheless, was outstanding. Departures from the crew's normal circadian periodicity also contributed to some loss of sleep during this time. The crew experienced a shift in their sleep periods, which varied from 3 to 6 hours from their assumed Cape Kennedy sleep time."

A table from the Mission report summarizes crew sleep reports.  Apparently, the LMP was able to sleep despite his difficulty adapting to weightlessness.  He took a Seconal for the Flight Day 4 sleep, one for Day 5, one for Day 6, one for Day 10; he had generally good sleep.

Details in  Sleep Notes derived from the Apollo 9 Technical Air-to-Ground transcript ( 27 Mb ). LMP Rusty Schweikart took one Seconal sleeping tablet before seven of the rest periods.

3.4 Apollo 10

Launch, 16:49:00 GMT, 18 May 1969 
Lunar Orbit Insertion, 75:55:54
CSM/LM undocking, 98:11:57.
Rendezvous docking, 106:22:02
Transearth injection, 137:36:29
Splashdown, 192:03:23

CDR- Tom Stafford
CMP - John Young
LMP - Gene Cernan

Apollo 10 was a final test of procedures and equipment prior to the first landing mission.  Once in lunar orbit, the two-man LM crew entered their spacecraft and flew the descent profile down to 50,000 feet (15,000 meters), jettisoned the LM Descent Stage, and then performed a rendevous and docking with the CSM.

From the Apollo 10 Mission Report ( 10 Mb ):  "The three crewmen were scheduled to sleep simultaneously, and in general, they slept very well during the nine periods. Estimates of the quality and quantity of sleep were based entirely on subjective reporting by the crew. In postflight debriefings, the Commander commented that the sleep stations and sleeping bags were satisfactory."

During the last day of the translunar coast, Houston scheduled a 14-hour rest period for the crew in preparation for lunar orbit insertion and, then, after another, relatively-short rest period, the LM flight.

Details in Sleep Notes derived from the Apollo 10 Technical Air-to-Ground Transcript ( 27 Mb ).  No sleeping tablets were taken.

3.5 Apollo 13

Launch, 19:13:00 GMT, 11 April 1970
SM Accident, 56 hours
Splashdown, 142:54:41

CDR - Jim Lovell
CMP - Jack Swigert
LMP - Fred Haise

The landing planned for this mission had to be abandoned because of an explosion in an oxygen tank in the Service Module that made the crew totally dependant on the limited resouces of the LM prior to re-entry into Earth's atmosphere.

From the Apollo 13 Mission Report ( 8 Mb ), "The crew reported sleeping well the first 2 days of the mission.  They all slept about 5-1/2 hours during the first sleep period. During  the second period, the Commander, Command Module Pilot, and Lunar Module  Pilot slept 5, 6, and 9 hours, respectively. The third sleep period was  scheduled for 61 hours, but the orygen tank incident at 56 hours precluded sleep by any of the crew until approximately 80 hours. After the incident, the command module was used as sleeping quarters  until the cabin temperature became too cold. The crew then attempted to  sleep in the lunar module or the docking tunnel, but the temperature in  these areas also dropped too low for prolonged, sound sleep. In addition,  coolant pump noise from the lunar module and frequent communications with  the ground further hindered sleep. The total sleep obtained by each crewman during the remainder of the mission  after the incident  (about 87 hours from the incident to splashdown) is estimated to have been 11, 12, and 19 hours for the Commander, Command Module Pilot, and Lunar Module Pilot, respectively."

4. Landing Missions

4.1  Apollo 11

Launch, 13:32:00 GMT, 16 July 1969
Lunar Orbit Insertion, 75:49:50
Lunar Landing, 102:45:40
Lunar Liftoff, 124:22:01
Transearth Injection, 135:23:42
Splashdown, 195:18:35

CDR - Neil Armstrong
CMP - Mike Collins
LMP - Buzz Aldrin

From the Apollo 11 Mission Report ( 12 Mb ): "It is interesting to note that the crewmen's subjective estimates of amount of sleep were less than those based upon telemetered biomedical data, as shown in Table 12-I. By either count, the crewmen slept well in the command module. The simultaneous sleep periods during the translunar coast were carefully monitored, and the crew arrived on the
lunar surface well rested. Therefore, it was not necessary to wait until after the first planned 4-hour sleep period before conducting the extravehicular activity. The crewmen slept very little in the lunar module following the lunar surface activity. However, the crewmen slept well during all three transearth sleep periods."

Details in Sleep Notes derived from the Apollo 11 Technical Air-to-Ground transcript ( 16 Mb ).

From the Apollo 11 Mission Report, Pilots' Report (Section 4.12.6): "The rest period was almost a complete loss. The helmet and gloves were worn to relieve any subconcious anxiety about a loss of cabin pressure and presented no problem. But noise, lighting, and a lower-than-desired temperature were annoying. It was uncomfortably cool in the suits, even with water-flow disconnected. Oxygen flow was finally cut off, and the helmets were removed, but the noise from the glycol pumps was then loud enough to interrupt sleep. The window shades did not completely block out light, and the cabin was illuminated by a combination of light through the shades, warning lights, and display lighting. The Commander was resting on the ascent engine cover and was bothered by the light entering through the telescope (Alignment Optical Telescope, AOT). The Lunar Module Pilot estimated he slept fitfully for perhaps 2 hours and the Commander did not sleep at all, even though body positioning was not a problem. Because of the reduced gravity, the positions on the floor and on the engine cover were both quite comfortable."

There was never much spare room in the LM cabin and, after the EVA, two rock boxes added to the clutter.  After taking photographs out the windows to further document their EVA, Armstrong and Aldrin had a meal and then jettisoned the PLSSs and other gear, primarily in the interest of reducing the LM weight for the return to orbit, but also to give them more elbow room.  Lunar gravity is weak enough that there is no discomfort in standing for hours at a stretch but, for their rest period, Aldrin tried to make himself comfortable on the floor across the front of the cabin and Armstrong got up on the engine cover farther aft.  Later crews had hammocks, which made sleeping much more comfortable; and the last three crews were able to remove their suits for the rest periods, which allowed them to sleep well.

LMP Buzz Aldrin took aspirin on occasion to help him sleep. No other sleeping tablets were taken.

Sleep Comments in the Apollo 11 Lunar Surface Journal

Ground Elapsed Time (hh:mm:ss)
Armstrong, from the 1969 Technical Debrief - "There was still a full truckload of equipment inside that cockpit at the end of the EVA.  It's just a bunch of stuff, and I was glad that we were able to get rid of a lot of it and finish the jettison before we started our sleep period.  With all that stuff in the cockpit, there's really no place left for people to relax."
CapCom wishes the crew a "good night".  At 115:50, NASA's Public Affairss commentator reports that the Surgeon doesn't believe that Neil is closer to sleep than 'dozing'.  Output from Buzz's biomedical sensors are not being monitored during the rest period.

Armstrong - "I think it was my position (that) was bothered by the noise (of the glycol pump) more than yours, because you were on the floor - right? - and I was on the engine cover with a loop that'd I rigged up (using a waist tether) to hold my legs, hanging from (the AOT guard) up there (at the front of the cabin).  And my head was back to the rear of the cabin and there was a glycol pump or a water pump or something very close to where my head was. But the temperature control was probably the most troublesome."

[A muffler was installed in the glycol pump for subsequent missions. It reduced pump noise to acceptable levels.]

Armstrong - "(The quality of the rest) was poor in my case."

Aldrin - "I'd say the same thing."] <p>

[Armstrong - "And for a lot of physical reasons that I mention (in the tech debrief extract, next); and also, I'm sure, just the (problem of) getting unwound from the excitement of that day was contributing, too."
Tech. Debrief Extract
Armstrong - "We cleaned up the cockpit and got things pretty well in shape.  This took us a while, and we planned to sleep with our helmets and gloves on for a couple of reasons.  One is that it's a lot quieter with your helmets and gloves on, and then we wouldn't have any mental concern about the ECS and so on having two loops working for us there."

Aldrin - "We wouldn't be breathing all that dust."

Armstrong - "That was another concern.  Our cockpit was so dirty with soot, that we thought the suit loop (filtered oxygen going directly from the ECS to the suit and then back again) would be a lot cleaner."

Armstrong - "A couple of comments with respect to going to sleep in the LM.  One is that it's noisy; and two is that it's illuminated.  We had the window shades up (that is, covering the windows) and light came through those window shades like crazy.  They're like (photographic) negatives and a lot of light will shine through."

[There is no discussion of the window shades in the Apollo 11 Mission Report.  However, the fact that none of the other crews reported problems with light coming in suggests that the shade design was modified to use a more opaque material.]

Armstrong - "The next thing is that there are several warning lights that are very bright and can't be dimmed.  The next thing is that there are all those radioactive illuminated display switches in there. Third, after I got into my sleep stage and all settled down, I realized that there was something else shining in my eye.  It turned out to be that the Earth was shining through the AOT (Alignment Optical Telescope) right into my eye. It was just like a light bulb.  If I had thought of that ahead of time, we could have put the Sun filter on or something that would have cut that light out. The next problem we had was temperature.  We were very comfortable when we completed our activities and were bedded down. Buzz was on the floor and I was on the ascent engine cover.  We were reasonably comfortable in term of temperature. We had the (LM cooling) water flowing and the suit (oxygen) loop running.  We had to have the suit loop running because our helmets were closed. After a while, I started to get awfully cold, so I reached in front of the fan and turned the water temperature to full up - Max increase.  It still got colder and colder. Finally, Buzz suggested that we disconnect the water (flow into the suits), which I did. I still got colder.  Then, I guess, Buzz changed the temperature of the air flow in the suit."

[The cabin temperature through the rest period was in the range of 61 to 62 degrees Fahrenheit or about 16 degrees Celsius.  During the EVA prep at 108:38:36, Public Affairs reported to the press that the cabin temperature at that time was 61 degrees Fahrenheit, a comfortable temperature while they were working in the suits, but not when they were trying to sleep.  For subsequent missions, ECS operating procedures were modified to produce a comfortable cabin temperature of about 71-72 degrees Fahrenheit.]

Aldrin - "Yes.  We fell victim to a time constant.  Once we noticed it going bad, there wasn't anything we could do about it. In addition, because we were trying to minimize our activities and stay in some state of drowsiness, we didn't want to get up and start stirring around, because it would be that much harder to get back to that same state again.  So we tried to minimize our activity.  We underestimated how much light was coming in through the windows.  There must have been a significant amount of light and heat coming in and just being reflected off the surface. We had no feel for what gas-flow setting we should have had, because we'd been on the cooling all the time up to that point while moving around I'm not sure that there's much control over that anyway.  We finally disconnected the oxygen flow."

Armstrong - "But that requires that you take your helmet off, so that you can breathe when you turn the suit disconnects (that is, shut off the flow from the ECS into the suits). This means that it gets noisy again, and all you hear is a glycol pump and stuff like that. This was a never-ending battle to obtain just a minimum level of sleeping conditions, and we never did.  Even if we would have, I'm not sure I would have gone to sleep."

Aldrin - "I don't know who was on Biomed at the time (it was Neil), but I feel that I did get a couple of hours maybe mentally fitful drowsing.  I'll have to say that I think I had the better sleeping place.  I found that it was relatively comfortable on the floor, either on my back with feet up against the side, or with my knees bent (and his feet on the floor, the cabin width being insufficient for him to stretch out).  Also, I could roll over on one side or the other.  I had the two OPSs stacked up at the front of the hatch, so there was ample room on the floor for one.  But there wasn't room for two."

Aldrin - "To cut down on the light level, we're just going to have to do something with the window shades to make them more effective.  I think sleeping with the helmet on will keep the cooling down and is probably a good, reasonable way to go as long as you're going to keep the suit on. Unless some change is made, we'd never even think about taking the suits off."

Collins - "Apollo 12 is planning to take their suits off.  With the longer stay-time and a couple of EVAs, they're planning to take their suits off."

Aldrin - "I think they ought to think a little more about it.  I don't know what the temperature would be in there. I got the impression that it was a lot cooler outside the suit than it would have been inside.  I don't feel that having the suit on in one-sixth g is that much of a bother.
It's fairly comfortable.  You have your own little snug sleeping bag, unless you have some pressure point somewhere.  Your head in the helmet (which has a pad at the back of the head) assumes a very comfortable position. Even out of the helmet, you don't have to worry about what you're leaning against.  Your head doesn't weigh that much, and will very comfortably pick just about any position.  I just don't see the real need for taking the helmets off."

Armstrong - "I didn't mind sleeping on the engine cover.  I didn't find it that bad.  I made a hammock out of a waist tether - which I attached to some structure handholds - to hold my feet up in the air and in the middle of the cockpit. This kept my feet up about level with or a little higher than my torso."

Aldrin - "Well, you were back out of the mainstream of the light, except for the AOT.  I think we could fix that up and obtain a more horizontal position or the capability to roll from one side to the other. That's just something that has to be worked out.  It wasn't satisfactory.  If we had known then what we know now, we could have preconditioned the cabin a little bit better (in terms of temperature).  We needed to start at a warmer level by turning the water off, thereby storing a small amount of heat."

Armstrong - "That's just one of those areas that didn't occur to us.  It clearly needs some more work."

[Ultimately, the Apollo 12 crew decided not to take their suits off between the two EVAs.  However, they took their helmets off, kept the flow of cooling water off, connected the hose bringing oxygen from the ECS to the suit O2 outflow connector (which put warm oxygen from the ECS into the suit at the feet and wrists) and the outflow hose to the inflow connector (which returned air to the ECD from the neckring),  and strung up hammocks to sleep in. They did not report any problems with noise, excess light, or cold temperatures keeping them from sleep.  Neither of them slept more than three hours, but the brief sleep was due to a poor fit of Pete Conrad's suit that was causing him sufficient discomfort that he and Al Bean had to get up early to fix it. The Apollo 14 crew had the same sort of arrangements as the 12 crew but found that they had trouble getting their heads into comfortable positions, perhaps because of the rigid neckrings. In addition, their spacecraft had landed with a significant tilt and, when they were in a drowzy state, the tilt produced a sensation that the LM was about to tip over.  That sensation kept them both awake. Starting with Apollo 15, the astronauts got out of their suits after each EVA and it made a world of difference. They were able to get comfortable in the hammocks and, on the whole, they slept soundly.  Some of them felt more excitement about the situation than the others did and had trouble falling asleep but, all of them slept soundly for at least a few hours each rest period, and woke up refreshed and ready to go back to work. Neil and Buzz and the other early crews demonstrated the obvious - that it was possible to accomplish a great deal with limited rest.  And the later crews demonstrated that simple additions to the equipment list - and confidence in the suit that let them take it off and put it back on three times - made it possible to get adequate rest at a small cost in lunar surface stay time.]

4.2 Apollo 12

Launch, 16:22:00 GMT, 14 November 1969
Lunar Orbit Insertion, 83:25:23
Lunar Landing, 110:32:36
Lunar Liftoff, 142:03:48
Tranearth Injection, 172:27:17
Splashdown, 244:36:25

CDR - Pete Conrad
CMP - Dick Gordon
LMP - Al Bean

This was the first mission with two scheduled EVAs and the first use of hammocks during the rest period between the EVAs.  In preparing for the rest period, the crew put the Commander's hammock up fore-and aft about halfway between the top of the ascent engine cover and the ceiling.

Deployed LM hammocks

View aft of the deployed LM hammocks.

From the Apollo 12 Mission Report ( 13 Mb ):  "Sleep periods during translunar coast began approximately 7 to 9 hours after the crew's normal bedtime of 11 p.m. The crew reported that they had no particular trouble in adapting to the shifted sleep periods.  However, the first flight day was extremely long, and the crew was thoroughly fatigued by the time the first sleep period began 17 hours after lift-off. The crewmen slept well in the command module during the translunar and transearth coast phases, and the Lunar Module Pilot took at least two unscheduled naps during transearth coast. However, they reported their sleep periods were longer than necessary, since they would invariably awaken about 1 hour ahead of time and would usually remain in their sleep stations until time for radio contact. The lunar module crew slept only about 3 hours on the lunar surface prior to the second extravehicular activity period. In the next sleep period, following rendezvous and docking, all three crewmen in the command module slept only 3 or 4 hours, which was less than desirable.  Biomedical monitoring during sleep periods was very limited. The crew complained that it was inconvenient to hook up to the biomedical harness while in the sleeping bags ; hence, very little data were received."

The short sleep the LM crew had between their two EVAs was due to signifcant pain Apollo 12 Commander Pete Conrad had in his shoulders because the suit was too short.  After about 3 hours of fitful sleep, Conrad woke LMP Alan Bean so that Al could undo the laces on Pete's lower legs, let it out to relieve Conrad's pain, and re-lace them.  A full discussion can be found in the Apollo 12 Lunar Surface Journal after 122:37:27.

The short sleep after rendezvous and docking was due to the need to control the large quantity of lunar dust the LM crew brought up on their suits and gear that was to be transferred to the Command Module for the trip back to Earth.  They also had to prepare for and perform the Transearth injection burn.  They made up for the two short sleeps with a 12-hour marathon once they were on the way home.

Details in Sleep Notes derived from the Apollo 12 Technical Air-to-Ground transcripts ( 28 Mb ).  LMP Alan Bean took a Seconal tablet before each rest period "throughout most of the mission".

Sleep Comments in the Apollo 12 Lunar Surface Journal

Ground Elapsed Time
During the EVA-1 close-out, Pete says that, because of the long day (17.5 awake at that point), he's "not going to have any trouble sleeping tonight."
Capcom asks how they are going to configure their suit hoses for sleep.  Pete says Al feels hot and will leave his air hose connected.  Pete thinks he'll probably leave his disconnected.
Pete indicates that he is eager to start the second EVA as early as possible that they may get up early and call Houston.
In 1991, Al believed that using hammocks has always been part of the Apollo 12 planning.  Hammock discussion.
Discussion of the hammocks, the value and problems of sleeping tablets, and the importance of a good sleep.  Extensive extract from the Technical Debrief about Pete's shoulder discomfort due to poor suit fit, for which he takes responsibility, and the re-lacing Al had to do to relieve Pete's discomfort.  During the Technical Debriefing, Pete mentions that "the cabin temperature remained good all night.  He did notice his lower legs getting warm and wet  inside the suit and, episodically hooked up the hoses to circulate dry air to remove any collection of perspiration.
NASA Public Affairs reports that the Flight Surgeon has indications that the crew is awake.  During the post-flight Techical Debriefing, Pete said that he slept for 4 1/2 hours, woke Al, and that the suit adjustment took about an hour.  It seems likely that they finished the adjustment at about the time they make their first call to Houston, at 129:01:50.
There are subtle differences between Al's performance on the second EVA compared with the first. "I'm not surprised.  I think I'm more tired on this EVA, because of the lack of sleep."
About 1 hour 40 minutes into the second EVA, Pete says "I've got the decided feeling I'm going to sleep tonight."  Part of his tiredness is due to the difficulty of bending the suit so he can run, but most is probably due to the lack of sleep.
During the lead up to LM liftoff, Pete mentions that the cabin has been warmer than Neil's. ECS (Environmental Control System) operation procedures were changed to raise the temperature from 61-62 F (16.1 - 16.6 C ) on Apollo 11 to "the low 70s" (about 22 C) on Apollo 12.

         4.3  Apollo 14

Launch, 21:03:02 GMT, 31 January 1971
Lunar Orbit Insertion, 81:56:41
Lunar Landing, 108:15:09
Lunar Liftoff, 141:45:40
Transearth Injection, 148:36:02
Splashdown, 216:01:58

CDR - Al Shepard
CMP - Stu Roosa
LMP - Ed Mitchell

This mission was similar to Apollo 12 in that the crew did two EVAs with a rest period between them.  The Apollo 14 crew spent two hours (one Command Module orbit) more than the Apollo 12 crew on the Moon.

From the Apollo 14 Mission Report ( 9 Mb ): "The shift of the crew's normal terrestrial sleep cycle during the first four days of flight was the largest experienced so far in the Apollo series. The displacement ranged from 7 hours on the first mission day to 11-1/2 hours on the fourth. The crew reported some difficulty sleeping in the zero-g environment, particularly during the first two sleep periods. They attributed the problem principally to a lack of kinesthetic sensations and to muscle soreness in the legs and lower back. Throughout the mission, sleep was intermittent; i.e., never more than 2 to 3 hours of deep and continuous sleep. The lunar module crewmen received little, if any, sleep between their two extravehicular activity periods. The lack of an adequate place to rest the head, discomfort of the pressure suit, and the 7-degree starboard list of the lunar module caused by the lunar terrain were believed responsible for this insomnia. The crewmen looked out the window several times during the sleep period for reassurance that the lunar module was not starting to tip over. Following transearth injection, the crew slept better than they had previously. The lunar module crewmen required one additional sleep period to make up the sleep deficit that was incurred while on the lunar surface.  The crewmen reported during postflight discussions that they were definitely operating on their physiological reserves because of inadequate sleep. This lack of sleep caused them some concern; however, all tasks were performed satisfactorily."

The suit contributed to the lack of sleep in the Apollo 14 LM because the neckring made it difficult to position the head comfortably.  The last three crews removed their suits for each rest period, which eliminated this problem.

It is interesting to note that the Apollo 15 LM sat on the lunar surface with a larger tilt but that the crew did not report any feeling that the LM was about to tip over.  The Apollo 14 tilt was 7 degrees to the right (LMP's side of the cabin down), the Apollo 15 LM was tilted back 6.9 degrees and left 8.6 degrees, with a total tilt of 11.0 degrees. 

In a 9-day mission, CDR Al Shepard only got about 41 hours of sleep, LMP Ed Mitchell got about 46, and CMP Stu Roosa got 44 hours.  In contrast, during the ten days of Apollo 12, each crew member got about 70 hours of sleep.  Although none of the first three crews who landed on the Moon got much sleep while they were on the surface, the Apollo 14 crew was the only crew - since the adoption of all-crew rest periods for Apollo 9 - to get inadequate sleep in the Command Module.

Details in Sleep Notes derived from the Apollo 14 Technical Air-to-Ground transcript ( 26 Mb ).  No sleeping tablets were taken.

Sleep Comments from the Apollo 14 Lunar Surface Journal

Transcript Time*
During the EVA-1 Close-out, Ed Mitchell wants to get as much dust as possible off Shepard's suit  because Al was going to be in the hammock over Ed's and Ed didn't want dust raining down on him during the rest period.  Al's feet were going to be over Ed's sleep station, they removed his overboots - and Ed's - because of all the dust that had collected in them.  As Alan Bean discovered at the end of the first Apollo 12 EVA, stomping your feet on the ladder rungs on the way up to the cabin helped remove dust from the legs and boots.
Because they are already 1 hr 15 min past the planned start of the rest period and still have about a half hour of tasks to accomplish before getting in the hammocks, Houston shortens the planned EVA debriefing.  Houston won't wake them early, but if the crew wants to start the EVA early, Houston will support them.  Shepard says "Okay, that sounds good.  We'd like to plan on an early egress anyway, so that we'll be in a position to get the full EVA-2 and still get back in at the regularly scheduled timeline.
Shepard requests wake-up an hour earlier than planned "so that we'll be able to get in a 30-minute  (EVA) extension and still have time after we get back in (the LM) to have a leisurely re-stowage." Houston tells him they will support an even earlier start, so they agree on wakeup 1 1/2 hours early, which is transcript time of 128:20.  Shepard says, "I don't think we're going to sleep more than 6 hours anyway.  And we'll be in bed so that we have 6 1/2 hours."  Last comm from the LM is at 121:34:52.  During the rest period, the Flight surgeon had indication that Shepard was alseep by about 121:58.  Mitchell was not being monitored.
In 1991, Ed Mitchell talked about getting the hammocks up and getting into them.  They slept without helmets, gloves, or EVA boots.  Getting the hammocks properly routed thru the various suits hoses was tricky; they had rehearsed the procedure a few times.  They did not use earplugs.  A muffler had been installed in the ECS pump to reduce to an acceptable level the noise that had disturbed Neil's sleep.  They woke several times because they both had a feeling that the LM was about to tip over.  Ed describes the hammocks as being uncomfortable and realized that it was the suits that were causing the discomfort.  There wasn't time in a 32-hour lunar stay to doff and don them between EVAs; and, perhaps more importantly, there was concern about jeopardizing suit integrity.  Removing the suits for comfort during the 3-EVA misisons was imperative to avoid crew exhaustion, which Ed thinks was a bigger risk to the mission than the possibility that loss of suit integrity would force cancellation of one or more EVAs and an early return to orbit.  Experience with the suits gained from Apollos 11, 12, and 14 made it possible to decide to remove the suits for the Apollo 15, 16, and 17 rest periods.
Shepard reports, "Okay.  We're up and running this morning.  We're assuming we have a Stay for EVA-2 and our crew status report is we've had no medication."  CapCom requests a sleep report a few minutes later.  Although they both report 4 to 4 1/2 hours, in Shepard's case, the mission report statement above, that they got "little or no sleep", may reflect the view of the Surgeon, who was monitoring Shepard's biomed data.
Debrief discussion of the problem of finding a comfortable position for the head.  Neckring part of the problem.  Also, a pillow would have helped.  There is no mention of pillows in the A15-A17 LSJ.  Nor any significant weight difference between hammocks listed in the Apollo 14 stowage lists and those of the later mission that could be ascribed to a pillow.

*There was a 40-minute delay in the Apollo 14 launch.  Mission clocks in Houston and onboard the spacecraft are relative to the planned time of launch.  Times in the transcript are relative to the actual time of launch.  Similar problems arise for Apollo 17 because of a launch delay.

4.4 Apollo 15

Launch, 13:34:01 GMT, 26 July 1971
Lunar Orbit Insertion, 78:32
Lunar Landing, 104:42:29
LM Liftoff, 171:37:23
TransEarth Injection, 223:49
Splashdown, 295:11:53

CDR - Dave Scott
CMP - Al Worden
LMP - Jim Irwin

This was the first of three missions during which the crews each spent 67 or more hours on the Moon and performed three EVAs.  Because of confidence in the suits gained during prior missions, a decision was made the the LM crew would doff their suits before each rest period so that they would have a better chance of getting adequate rest.  They were the first crew to use earplugs during the sleep periods;  to make sure they would hear any calls from Houston, Dave Scott wore an earpiece during the rest period.

From the Apollo 15 Mission Report ( 15 Mb ):  "Very little shift of the crew’s normal terrestrial sleep cycle occurred during the translunar and transearth coast phases of this mission. As a result, all crewmen received an adequate amount of sleep during these periods. Displacement of the terrestrial sleep cycle during the three lunar surface sleep periods ranged from 2 hours for the first sleep period to 7 hours for the third sleep period. This shift in the sleep cycle, in addition to the difference between the command module and lunar module sleep facilities, no doubt contributed to the lunar module crewmen receiving less  sleep on the lunar surface than was scheduled in the flight plan. However, the most significant factors causing loss of crew sleep were operational problems. These included hardware malfunctions as well as insufficient time in the flight plan to accomplish assigned tasks. During the first sleep period, the crewmen went to sleep one hour later than planned and had to arise one hour early to fix a cabin oxygen leak. The crewmen again were an hour late in getting to sleep for the second lunar surface sleep period. The final sleep period was changed so that the beginning of the period was 2 1/2 hours later than originally planned. The period, which had been planned to last 7 hours, was terminated after 6 1/2 hours to begin preparations for the final extravehicular activity. Lengthening the work days and reducing the planned sleep periods on the lunar surface coupled with a significant alteration of the lunar module crewmen's circadian rhythm produced a sufficient fatigue level to cause them to operate on their physiological reserves until they returned to the command module."

As indicated in the table (below) of Sleep Comments from the ALSJ, the crew decided early in the planning processes that they were going to build the mission on a 24-hour Houston day.  Despite the Mission comments quoted above, Dave and Jim believed that they'd gotten adequate sleep.  Certainly, they got more quality sleep on the lunar surface than any prior crew.

From the Pilot's Report in the Apollo 15 Mission Report: "The crew was able to sleep fairly well. Noise was minimized by configuring the environmental control system in accordance with the checklist and by using earplugs. The temperature was ideal for sleeping in the constant-wear garment and sleeping bag, or in the constant-wear garment and coveralls. A wider hammock would improve the conditions for sleeping. A slight light leak through the stitching on the window shades interfered with getting to sleep."

Details in Sleep Notes derived from the Apollo 15 Technical Air-to-Ground transcript ( 38 Mb ).  No sleeping tablets were taken.

Sleep Comments from the Apollo 15 Lunar Surface Journal

Ground Elapsed Time (hh:mm:ss)


Full discussion of reasons for doing the Stand-up EVA (SEVA), including the value of not disturbing their circadian rhythm.
During the post-mission debriefing, Dave said that one advantage of doing the SEVA and then sleeping before going out for the first EVA is that their first sleep was in a clean cabin.
In 1992, Dave did not remember that the LM tilt was a problem.  In 1989, Jim remembered that the hammocks "were adjustable to a certain degree ...  I didn't notice any problem at all."  During the post-mission debriefing, Dave said "I was afraid I would be feeling like I was sleeping heads down with that pitch angling there, but I didn't at all. "  Dave and Jim suggested modifications to the feet end of the two hammocks to improve comfort and prevent accidental contact with switches.
Discussion about the quality of the sleep and the pre-flight decision to doff the suits for the rest period.  In 1989, Jim said that he thought the sleeping arrangements in the LM were better than what they had in the Command Module.  He also thought that the familiarity gained by sleeping in the simulators was very valuable.  He said that he had the best sleep of the flight that first night on the Moon, in part because "it was kind of an exciting day, a satisfying day."  Dave took an alarm clock along on the flight, just in case. (One scenario that comes to mind is losing comm while they were asleep.)

First Lunar Surface Rest Period

Houston wakes the crew an hour early to have them locate and close an oxygen leak.  The cause was the urine transfer valve and was found quickly.  At 115:50, Parker notes that Jim's biomed data indicated he was sleeping well.  Jim replies, "best sleep of the flight".  Dave comments that he, too, was "way down in sleep when you gave us a call."
Debrief extract in which Jim says the cabin temperature was very comfortable for sleeping. He slept in his "Constant Wear Garment in the sleeping bag and did not use the coveralls."  Dave slept in his coveralls "without a sleeping bag.  So I guess we each had two layers on, and it was very comfortable."  They used earplugs, "so noise was no problem".  Dave wore an earpiece, too, in case Houston needed to wake them.  Commented on the value of a pre-flight vacuum chamber run in the LM to find-tune the ECS configuration for noise reduction.  Some light leakage through the stitching around the window covers.
Houston tells the crew they are convinced that the urine valve was the only leak source and is now tight.  Dave says they'll sleep better knowing that Houston will wake them to take care of any other problems that arise." 
Discussion of the earpiece.  Dave says that there never any problems with the earpiece used in Apollo coming out of the ear.  CapCom then offers them to option of going back to sleep for the remaining 22 minutes of the rest period.  Dave and Jim decide to use the time to get organized for the EVA.  There was a pre-flight agreement to start the EVAs on time, perhaps because of the fatigue problems on Apollo 14.
They both got about 5 hours sleep and took no medication.
Before the second rest period, CapCom says Houston will try not to wake them early, as happened in previous rest period because of the oxygen leak.  CDR replied, "Well, if you see something that you'd like to look at, we'd rather have you wake us up."
Jim's biomedical data indicates that he is sound asleep.  At 134:53, NASA tells the press the cabin temperature is 56 degrees Fahrenheit (13.3 C). During the post-flight debrief, Dave was briefly awakened by a call from Houston to the Command Module.  He was wearing the earpiece, but the fact that he heard the call was due to a mistake in Houston; someone keyed the wrong comm channel.

Second Lunar Surface Rest Period

Wake-up call from Houston.  The wake-up was scheduled at 137:55.  At 138:53:40, Jim reports that "we both slept for the full time".
Dave describes a simulated rest period he and Jim did in one of the LM simulators before the flight. They "got a lousy night's sleep.  When you get to one-sixth g, it's just terrific; but you try to sleep in those hammocks in one g: not terrific."  They did the session in part because they were the first crew who were going to doff the suits and they wanted to do that in the confines of a LM cabin.
Dave comments on building the mission around the circadian rhythm and the value of having the crew all resting at the same time.  He also comments on the value of the Flight Directors and other managers  observe training, so they could make better real-time decisions that influenced the timeline.  Dave and Jim are currently about an hour late in starting EVA-2.
Dave and Jim are running late - about 1 1/2 hours behind the timeline - and Houston is anxious to get them to bed.  At 151:35:06, CapCom tells them that the EVA debrief won't be done to help make up some time.  During the rest period, Houston will assess the tasks for EVA-3.
Dave tells Houston, "I'll tell you, the secret to living up here is getting out of these suits.  It really makes the difference."  Dave discusses the need to get the suits off to get some good rest between EVAs.
CapCom re-inforces early statement about the importance of rest.  Houston will insist on a 7-hour rest period starting when they get into the hammocks.  However, there is an unstated understanding between CapCom and the crew that the 7-hour clock will start when the crew calls to say they are in their hammocks, whether they really are or not.  In 1992, Dave thought they did get in the hammocks about the time they said they were getting in them.
Dave calls Houston to "Start your clock" for the rest period.  They were planned to start the rest period at 151:25, so they are 1 hr 50 min behind.  the Surgeon is monitoring Jim's biomedical data and, at 154:04, reports that, although is heart rate is beginning to fall, he is not yet soundly asleep.  At 155:03 Jim was dozing.  At 156:00, Jim was not sound asleep.

Third Lunar Surface Rest Period

During the post-mission debriefing, Dave and Jim remembered getting sleep on the third night as good as on the second and that they were both well rested. Discussion about the value of the biomed data.

4.5 Apollo 16

Launch, 17:54:00 GMT, 16 April 1972
Lunar Orbit Insertion, 74:28:28
Lunar Landing, 104:29:35
LM LIftoff, 175:31:48
TransEarth Injection, 200:21:33
Splashdown, 265:51:05

CDR - John Young
CMP - Ken Mattingly
LMP - Charlie Duke

From the Apollo 16 Mission Report ( 8 Mb ): "In contrast to the Commander's Apollo 10 experience, he slept well during all the scheduled sleep periods. Typically, the Commander's sleep was uninterrupted for 4 to 5 hours after which he would awaken, get a drink of water, and return to sleep for the rest of the night. The Lunar Module Pilot slept well during all sleep periods except the first. However, the Command Module Pilot reported that he slept uninterrupted only two nights of the mission and, characteristically, would awaken about once every hour. He also stated that he never felt physically tired nor had a desire for sleep. On this mission, displacement of the terrestrial sleep cycle ranged from 30 minutes to 5 hours during translunar coast, and from 3 1/2 hours to 7 hours during the three lunar-surface sleep periods. This shift in the sleep cycle on the lunar surface contributed to some loss of sleep; however, this was the first mission in which the lunar module crewmen obtained an adequate amount of good sleep while on the lunar surface. This assessment of the amount of sleep is based on a correlation of heart rate during the mission sleep periods with preflight sleep electroencephalograms and heart rates. The estimates of sleep duration made by ground personnel were in general agreement with the crew's subjective evaluations."

From the Pilot's Report : "The crew slept exceptionally well although the cabin temperature varied. The ear plugs were not used; it was felt that they were unnecessary. For the first sleep period on the lunar surface, the Commander donned only his sleeping bag, whereas the Lunar Module Pilot wore his liquid cooled garment while in his sleeping bag. For the second and third sleep periods, both crewmen wore their liquid cooled garments while in the sleeping bags. The intravehicular garments were never used. There was some light leakage into the cockpit ; however, it did not prevent the crew from sleeping. The Lunar Module Pilot aided his first sleep period by taking Seconal; however, he was awakened three times - the first two times by master alarms caused by the reaction control system 'A' problem, and the third time by an apparent loss of communications lock during a handover which produced noise in his earphones. The first sleep period lasted about 8 hours. In general, the cabin configuration is acceptable to get a good night 's sleep."

Details in Sleep Notes derived from the Apollo 16 Air-to-Ground transcript ( 50 Mb ). Charlie took one Seconal for the rest period before the lunar landing and one before each of the first two lunar surface rest periods.

Sleep Comments from the Apollo 16 Lunar Surface Journal

Ground Elapsed Time
Landing Delay
A technical problem in the Comand Module resulted in a 6-hour delay in landing.  John and Charlie had awakened at about 91:30 and had planned planned to do an EVA before their first rest period.  They would have started that first rest period at about 113 hours, after a 21 1/2 hour day.  If they had tried to do an EVA after the delayed landing, they would have had a 27 1/2 hours day and, in Houston, Flight Director Gerry Griffin was unwilling to test their endurance to that extent.
After the landing, CapCom tells them that he has extensive changes to the Surface Checklist, which he can read up when it's convenient.  Charlie sums up the general feeling in both the LM and Houston, "Jim, I feel exactly like I thought I was (going to feel).  I really want to get out, but I think that discretion is the better part of valor, here."  John adds, "Man, it's really tempting, though.  It really looks nice out there."  By the early 1990s, Charlie had changed his mind.  He said he was so pumped up with adrenalin and enthusiasm, that "I had a tough time getting to sleep."  The Apollo 17 crew decided to do an EVA after landing, planning to wake up in lunar orbit at 105 hour 45 minutes and, after landing and doing an EVA, starting their first lunar surface rest period at about 128 hours, after a bit more than a 22-hour day, similar to what the Apollo 16 crew had planned.  Except for some timing differences, that's what they did.
CapCom gives them some Surface Checklist changes including wake-up at 115:53 and suit donning at 117:03.
CapCom tells them they will see an RCS warning light at about 108 hours, which is when they should be starting to sleep.  They should do a reset.  And, then, just before they wake up, they will get a different warning and will need to change a control setting.  John complains that they're going to have to wake up at least twice and wants to know, "How much sleep from the time when we start to bed do you want us to get?"  He is told "eight hours".
Charlie is disappointed that the surgeons will monitor him.  Discusses the problems the cable biomed cable caused in trying to get comfortable.
Charlie comments about the light leaking into the cabin.  CapCom Tony England wishes them a good night a couple of minutes later.  However, three minutes after that, Charlie wants to share an observation about the thickness of the soil he will drill into during EVA-1.  John calls Houston at 108:00 to say that the warning light had come on.

First Lunar Surface Rest Period

Charlie calls Houston to confirm that an alarm he's just heard is the second one Houston was expecting.  Comments about the shock of the noise and that he "almost jumped out of my skin".  Comments about sleeping in the hammock.  The only problem with getting to sleep was "to get your mind in idle."
The Public Affairs commentator gives the press start time for what are hoped to be three 7-hour EVAs:  EVA-1 start, 119:28; EVA-2 start, 141:43; EVA-3 start, 165:30; and liftoff at 177:28, which nearly six hours later then the original time of 171:45.
Charlie calls Houston and tells them, "We're up."  Charlie was awakened by a burst of static  in the earpiece, "and that's why I pegged out the EKG about 20 minutes ago."  (Confirmed to CapCom by the Surgeon.) During the post-flight debrief, John mentioned that the suits piled on the engine cover "were up into the hammock about three inches"and the support under his back made it feel like he was "sleeping on a bed".  Charlie took a Seconal tablet before each of the first two rest periods to help him overcome his excitement..  John said he was 'warm' at the start of the rest period, took everything off and "slept in the sleeping bag with nothing on.  I woke up in the middle of the night and my feet were freezing. So I turned around (putting his feet toward the back of the cabin) and put the ISA (Interim Stowage Assembly, a set of cloth bags) over my feet and went right back to sleep.  Worked like a charm.  But the next couple of nights, I slept in the LCG (Liquid Cooled Garment, but without water flow) because it was really cold at night."  Charlie agreed that they needed to wear the LCGs and use the sleeping bags, because it was "chilly at night".  He, too, didn't use the bag when he first went to sleep, but used it later after he cooled down.  Because of the 6 hour landing delay, they needed to conserve battery power, so Houston had them power down more equipment than would have normally been the case.  This may have contributed to the cool conditions.
Charlie reports that he slept 6 1/2 to 7 hours and that, John "was sleeping so great that I just woke him up just a second ago ...  I couldn't stand it any longer (and wanted to get him up and get going)." John slept 7 1/2 hours.
CapCom reads up some checklist updates.  The rest period after EVA-1 will start at 130:15 and is scheduled to last 8 hours.  "Tomorrow is pretty relaxed; we encourage you to get a lot of sleep tonight. You've got plenty of time; no need to feel like you've got to press (meaning 'hurry') in the morning."
Deke Slayton tells them that EVA-2 will be seven hours, EVA-3 five hours, launch and rendezvous after EVA-3, but postpone the LM jettison till after a rest period so they'll only  have an 18-hour work day. Re-iterates that Houston wants them to get a good sleep before EVA-2
The Surgeon wants to watch Charlie's biomed during the rest period.  John says he is going to wear the earpiece: "I'm going to get Charlie some good sleep."  Charlie says, "Couldn't ever believe we'd go to sleep (because of the excitement of being on the Moon), Deke;  but, man, this guy John sleeps like a baby up here.  I've never seen it."  Although they are slightly behind schedule, Deke reads up some checklist changes to save time in the morning.
They are about to configure the Environmental Control System (ECS) for sleep.

Second Lunar Surface Rest Period

John calls to ask "What time are we supposed to get up?"  CapCom says they are 3 1/2 minutes early.  Fifteen minutes later, before giving his estimate of how much sleep he got, Charlie asks Houston how much the surgeons think he got.  The surgeons say six hours; Charlie says his estimate was 7 hours.  John got 7 1/4 hours.  Charlie provides a description of the sleeping bag, which he had to use when he got cold in the middle of the night.
About eight minutes after what was to have been the final 'good night', John calls to ask if they can change the Alignment Optical Telescope (AOT) pointing because they've got sunlight streaming in.  Houston tells them to put it in any position that solves the problem.  Comments follow about sleepwear, the urine collection system, noise.  No problems.
Late in EVA-2, during the drive back to the LM, Charlie asks in they still have adequate supplies of consumables: oxygen, cooling water, and PLSS battery power.  CapCom tells them they have enough "to go on a long time;  We just feel you've put in a good day."  John says "Well, why don't we stay out here and set a new world's outdoor record?", meaning that he wants to take the record for the longest lunar EVA away from the Apollo 15 crew."  CapCom replies that they should leave something for Apollo 17 and that, "We're going to set a new sleep record."
John and Charlie ask for a ten-minute extension, still eager to to have the longest EVA.  The Flight Director understands their interest but is reluctant, with the surgeon telling the Flight Director that he doesn't want to shorten the sleep period.  At 149:00:00, Charlie begs for an extension.  It is granted.
After EVA-2, Houston tells them "we're not pushing, John, but we would like to stay fairly close to the timeline so you can get plenty of sleep tonight.  You're going to have a hard day tomorrow." An hour and a half later, CapCom tells them that the rest period is to begin at 154:35 and will last 8 hours.
In 1996, EVA CapCom Tony England provided some comments about making sure that he had adequate rest during the mission.  On the J missions, the EVA Capcoms were on duty well before the EVA started and, in Tony's case, virtually until the start of the rest period.
Tony apologizes to John and Charlie about letting them get behind in the EVA.  A late end to the EVA means a late start to the rest period and, because everyone appreciates how important adequate rest is in the long missions, a late start to the rest period means a short final EVA.
Last comm before the rest period.  John says they are about  1/2 hour away from getting in the hammocks.  The surgeons will be looking at John's biomed data.

Third Lunar Surface Rest Period

Charlie responds to the wake-up call sounding like he's emerging from deep sleep.  Today, it's John's turn to ask the surgeons how long they thought he slept.  6 1/2 to 7 hours.  John was going to say 7.
Back in the LM after EVA-3, while John and Charlie have a meal, CapCom gives them some checklist changes for post-docking.  They will defer some of the transfer of samples and other items till after they have some sleep.  Jim says they've got water and electricity for another 18 hours on the Moon and, jokingly, asks if they'd like to do a fourth EVA.  Charlie replies "If you'd let me sleep, I wouldn't mind."

4.6 Apollo 17

Launch, 05:33:00 GMT, 7 December 1972
Lunar Orbit Insertion, 86:14:23
Lunar Landing, 110:21:58
Lunar Liftoff, 185:21:37
TransEarth Injection, 234:02:09
Splashdown, 301:51:59

CDR - Gene Cernan
CMP - Ron Evans
LMP - Jack Schmitt

From the Apollo 17 Mission Report ( 26 Mb ) Biomedical Evaluation: "As on previous missions, displacement of the terrestrial sleep cycle contributed to some loss of sleep. In addition, changes to the flight plan occasionally impacted previously planned crew sleep periods.  In general, however, an adequate amount of good sleep was obtained by all crewmembers. The estimates of sleep duration made by ground personnel were in general agreement with the crew's subjective evaluations.  All three crewmen averaged approximately six hours of sleep per day throughout the mission. Only during the first sleep period was the amount of sleep obtained (approximately three hours) inadequate from a medical point of view. The crew reported that the Seconal effectively induced sound and undisturbed sleep for a period of four to five hours.  Sleep restraints were used for every sleep period by all three crewmen. The Commander also emphasized the importance of programming an eight-hour sleep period each day."

From the the Mission Report's Pilots' Report: "The planning to include a short sleep period in the first day allowed the crew to return to a normal work-rest cycle ... (On the lunar surface) the liquid cooling garments were doffed at the end of each extravehicular activity and the constant wear garment was donned for sleep. The crew believed that their sleep was much more comfortable in the constant wear garment partly because it was cleaner than the liquid cooling garment. Also, the constant wear garment removed the general level of pressure that a tight-fitting liquid cooling garment exerts on the body."

Details in the Sleep Notes derived from the Apollo 17 Air-to-Ground Transcript ( 58 Mb ).  CDR Gene Cernan took four Seconal tablets, one each before the first two 8-hour rest periods during TransLunar Coast, one for the rest period in lunar orbit prior to the landing, and once for the second lunar surface rest period.  LMP Jack Schmitt took six Seconal tablets; one each for the three TLC rest periods, one in lunar orbit before landing, one in lunar orbit after rendezvous and docking, and one for the last night before splashdown.  CMP Ron Evans took six Seconal tablets, three during TLC and three in lunar orbit.

Sleep Notes from the Apollo 17 Lunar Surface Journal
After confirming with Houston that the Surgeons will be monitoring Jack, Gene asks permission to remove his sensors for the first rest period. "The sensors itched, and it was just generally irritating to have them on.  We had learned to put them on ourselves, so that we could take them off when we could."  The Apollo 15 crew fought pre-flight to get approval and training for sensor removal and re-application.  See discussion in the A15LSJ at 109:58:36, 141:00:09, and  152:35:44.
CapCom Joe Allen asks if they'd like a 30-minute extension of the rest period (from 7 1/2 to 8 hours).  Cernan replies, "Yeah, I'd like to try to get the full amount (of sleep).  As I recall, tomorrow's a little bit flexible.  If we get out 30 minutes late, it doesn't really hurt us." 
Discussion of sleepwear and sleeping bags.  In January 2004, they disagreed as to whether they wore the LCGs or the CWGs and whether they did or did not have sleeping bags.  The Apollo 15 and 16 LM crews used sleeping bags. Their LM stowage list shows two "sleep restraint assemblies", each weighing 2.3 pounds. The Apollo 17 LM stowage list shows the same items with the same weights, suggesting that Gene and Jack did have sleeping bags, whether or not they chose to use them.
Gene said in the early 1990s that "sleeping on the Moon is the greatest waste of time a human being can conceive" meaning that they were on the Moon for only 72 hours and slept for 24 of those. "But you had to sleep; we were just so tired that we didn't have any choice but to sleep."  Discussion of the decision to do the EVA before the rest period, rather than the other way around.  Comments from Jack about the necessity of sleep, about doing the EVA first, and about getting better sleep on the Moon than in orbit and, in some ways, than on Earth.

First Lunar Surface Rest Period

Jack was connected to comm through the rest period and was only awakened once by comm noise.
Jack describes the forearm fatigue he experienced during EVA-1 and the fact that there was no residual soreness after the rest period.  Perhaps there had been  more efficient removal of lactic acid and other metabolic products in 1/6th gravity than on Earth.
At the end of the EVA debriefing, Jack wants to continue; but CapCom Joe Allen indicates they should finish eating and get ready for sleep.  Making allowances for some padding in the timeline, they are about an hour behind.  Gene tells Joe "We're working as fast as we can.  Best place in the world to make it up is tomorrow night.", meaning that he doesn't want to cut EVA-3 short and would rather have a short second rest period, a full EVA, and catch up on sleep during the final rest period before LM launch.  More discussion about the need for rest.
Fatigue can be heard in Gene's voice. He and Jack have been awake since 136:55:05 and, in those 14 3/4 hours, have been very active.  Last comm at 152:24:15, followed by more comments about sleep.
Second Lunar Surface Rest Period
Gene wakes up sounding groggy.  Comments about the difference between the first day and the third, physically and psychologically.  Houston wants them stay on the timeline.  They are an hour behind.  That isn't a problem, but they shouldn't get an farther behind.  they will actually gain back about 8 minutes in a smooth EVA prep.  Jack had six good hours of sleep.  Gene had  3 hours good and 3 intermittent.  He'd taken a Seconal sleeping tablet.
Last comm before the third rest period.
Third Lunar Rest Period
Jack was awakened during the night by some comm noise and got himself back to sleep by composing a variation on "The Night before Christmas" suitable to Apollo 17.  He gave a rendition after wake-up.
Gene got 5 hours of good sleep; Jack got "my usual 6".  Neither took any medication.

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