EASEP Deployment and Close-out

The Return to Orbit

 

Trying to Rest

Corrected Transcript and Commentary Copyright © 1995 by Eric M. Jones.
All rights reserved.
Scan credits in the Image Library.
Video credits in the Video Library.
Last revised 28 October 2017.

MP3 Audio Clip (46 min 59 sec; 43 Mb) from the Public Affairs loop starting at about 111:56:00. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.

Restored Video Clip 3 minutes 15 seconds ( 4.3 Mb FLV or 4.9 Mb MPEG). May require VLC for playback.

111:56:08 Armstrong: (Garbled) read? (Pause) A, receive. B, off.

111:56:25 McCandless: Neil, this is Houston. We seem to be reading you now. How do you read us? Over.

111:56:32 Armstrong: ICS, push to talk. (Pause) Houston, this is Tranquility. How do you read?

111:56:47 McCandless: Tranquility Base, this is Houston. Loud and clear. How us?

111:56:53 Armstrong: Loud and clear. We're in the process of switching over to LM Comm here.

111:56:56 McCandless: Roger.

[Comm Break]

111:59:41 McCandless: Tranquility Base, this is Houston. We'd like to verify your steerable antenna in track mode Slew. We're going to do a communications handover here on Earth. Over.

111:59:55 Aldrin: Roger. That's affirmative. We're in track mode slew.

112:00:00 McCandless: Roger. Out.

[The Moon is about to set at the Goldstone tracking station in California and there will be a handover of uplink responsibilities to the Honeysuckle Station outside Canberra, Australia.]

[Mike Dinn, Deputy Director at Honeysuckle during Apollo recalls "'Handover' basically means handover from one ground station to another of 'uplink' voice, command and ranging. 'Downlink' signals can be taken from any station in view and configured, regardless of uplink. And, of course, telemetry, voice, and TV could all be selected from different sites. Also bear in mind that there could be three uplinks - CSM, LM and EASEP/ALSEP. The 9m stations (CRO, HAW, GWM on this longitude) were generally used for the EASEP/ALSEP support."]

[As indicated on page 14 of the Honeysuckle Creek station log kept by John Saxon, a signal from the LM was obtained in the main beam of the receiver at 01:18 GMT (GET 107:46) and it was the Honeysuckle TV downlink that was used at the time of Neil's "one small step" at 109:24:48. Much of the TV downlink for the rest of the EVA was received thru the radio astronomy dish at Parkes, Australia. Goldstone continued to handle uplink responsibilities until the present handover.]

[As shown on page 16 in the HSK station log, the GDS-to-HSK uplink handover was done at 05:42 GMT/UTC (21 July 1969), which corresponds to a Ground Elapsed Time (GET) of 112:10. At that time, the Moon was low in the west at Goldstone, at an elevation of 6.2 degrees and and azimuth of 256.5 degrees.]

[Long Comm Break]

Restored Video Clip 3 minutes 32 seconds ( 4.7 Mb FLV or 5.3 Mb MPEG). May require VLC for playback.

112:06:00 Collins: (Calling at AOS) Houston, Columbia. Omni C-Charlie. How do you read?

112:06:06 McCandless: (Apparently not have heard Mike's call) Columbia. Columbia. This is Houston. Over.

112:06:12 Collins: Roger, Columbia on (Omni) C-Charlie. How do you read?

112:06:16 McCandless: Roger, Columbia. This is Houston. Reading you loud and clear on Omni Charlie. The crew of Tranquility Base is back inside their base, repressurized, and they're in the process of doffing the PLSSs. Everything went beautifully. Over.

112:06:36 Collins: Hallelujah.

112:06:38 McCandless: And we'd like to get P00 and Accept from you. We have a state vector uplink. And, after that, we'd like you to re-align your platform to the new REFSMMAT that we sent up a rev or two ago. Over.

[See Charlie Duke's discussion of the Reference to Stable Member Matrix at 104:47:55 in the Apollo 16 Lunar Surface Journal.]

[Comm break. Houston promises new information of the landing site location.]

112:09:11 Collins: P52.

[Long Comm Break.]

Restored Video Clip 4 minutes 00 seconds ( 5.3 Mb FLV or 5.9 Mb MPEG). May require VLC for playback.

112:14:44 McCandless: Columbia, this is Houston. Do you read? Over.

112:14:53 Collins: Roger, Houston. Columbia's reading you.

112:14:56 McCandless: Okay, Columbia. We've completed the uplink; the computer is yours. You can go Block; however, we'd like you to hold off on the P52 option 1 align until after you've passed landing site 2; and we're requesting that you perform another P22 and attempt to find the LM this pass. I've got some numbers for you when you're ready to copy. Over.

112:15:22 Collins: Roger. Stand by. (Long Pause) Ready to copy.

112:15:51 McCandless: Roger, Columbia. P22 landmark ID is lunar module... (correcting himself) make that Tranquility Base; T1, 112 25 08; T2, 112 30 17, 4 nautical miles south. Time of closest approach, 112 31 52; shaft 357.051, trunnion 047.432, roll zero, pitch 250, yaw zero. Readback. Over. (Long Pause)

Restored Video Clip 2 minutes 38 seconds ( 3.5 Mb FLV or 4.1 Mb MPEG). May require VLC for playback.

112:17:06 McCandless: Columbia, this is Houston. Did you copy my P22 update? Over.

112:17:39 Collins: Houston, Columbia.

112:17:45 McCandless: Columbia, this is Houston. Did you copy my P22 PAD?

112:18:03 McCandless: Columbia, this is Houston. Do you copy my PAD? Over.

112:18:09 Collins: Negative, Bruce. Just give me the latitude and longitude over 2, altitude, and the grid squares. Never mind the other. You're broken up.

112:18:21 McCandless: Stand by.

112:18:30 Collins: Well, that is, if you have new information. Otherwise, I'll just use the old numbers.

112:18 34 McCandless: No, wait a minute. We've got new information.

112:18 39 Collins: Okay. (Long Pause)

Restored Video Clip 2 minutes 52 seconds ( 3.7 Mb FLV or 4.4 Mb MPEG). May require VLC for playback.

112:20:42 McCandless: Tranquility Base, this is Houston. Can you give us some idea of how you're progressing on the PLSS doffing and preparation for Depress?

[Once they have doffed the PLSSs and have gotten unnecessary gear packed away in a trash bag, they will depressurize the cabin and jettison the PLSSs and the trash.]

[They are finishing up magazines 37/R, taking AS11-37-5460 to 5555, and 39/Q, taking AS11-39-5792 to 5843. Journal Contributor Bob Farwell has selected frames from Magazine 37/R for a pan covering both windows. Note that Farwell's construction involves a certain amount of artistic license because neither Neil or Buzz actually had an unrestricted view from side to side, as shown by pans assembled from Magazine 39/Q images for the CDR window and the LMP window. Exercising a bit more artistic license, Farwell has created an enhanced version by using pre-EVA image AS11-37-5452 to fill the a gap in the post-EVA coverage below Neil's window. Finally, Farwell, modified Figure 10.12 from the Lunar Sourcebook to provided a rough comparison with the assembled pan. Farwell has provided a fuller discussion of the assembled pan and related items.]

[The current time is about 0553 on 21 July 1969 (UTC/GMT). From the bottom of the footpads to the top of the rendezvus radar, the LM is 7.04 meters tall (23 feet, 1 inch). The solar elevation is about 15.8 degrees and the shadow length on level ground would be about 25 meters. Yuri Krasilnikov has created an animated GIF ( 0.3 Mb or 2.7 Mb ) from 5477 and photo AS11-37-5454, which Buzz took at about 2132 UTC/GMT on the 20th, not long after the landing. the animation shows, among other things, the change in shadow length. At the earlier time, the shadow length on level ground would have been about 34 meters.]

[Frames 5466 to 5468 show the flag. During the technical debriefing, Neil said, "The flagstaff was pushed into the ground at a slight angle such that the c.g. (center of gravity) of the overall unit would tend to be somewhat above the point at which the flagstaff was inserted in the lunar surface. (That is, they tilted the flag so that it would balance.) That seemed to hold alright, but I noted later, after getting back into the LM, that the weight of the flag had rotated the entire unit about the flagpole axis such that the flag was no longer pointed in the same direction as it was originally. I suspect that the weight of the flagpole probably had shifted its position in the sand a little bit from the position where it had originally been installed."] [In 5467, the flag still appears to be in its deployed orientation, a fact confirmed by comparison of TV taken during the PLSS jettison after 114:10:37 with TV taken during the EVA, such as a clip starting at 1105858. Clearly the re-orientation Neil noticed has not yet happened. The next images of the flag we have are in a DAC pan Buzz took about an hour after the RCS hot-fire check. Thomas Schwagmeier has compared 5467 with a frame from Buzz’s post-hot-fire DAC sequence, showing roughly a 90 degree change in orientation. Although the re-orientation Neil mentions clearly happened sometime after the PLSS jettison and before the hot-fire, we have no way of knowing how much of a change Neil noticed. That change would have been overwhelmed by the effects of the hot-fire.]

[Frame 5480 shows the view out Buzz's window, including the flag and the TV camera. Note the cluster of boulders in the background. These may have been ejected from West Crater.]

[All the photos taken at this time are out the forward windows except AS11-37-5506 to 5509 which are photos of Earth taken out the rendezvous window over Neil's head. These may be the Earth photos that Neil remembers taking - rather than AS11-40-5923 and 5924, the two taken out on the surface, probably by Buzz. Note that none of these photos have reseau crosses, indicating that they were taken with the IVA Hasselblad. The EVA Hasselblad was purposefully left outside.]

[Aldrin, from the 1969 Technical Debrief - "This period was prolonged a bit to try to make as much use of the film remaining. I think we probably took more pictures than we should have in an effort to make sure that we covered each particular window as thoroughly as possible and with as wide a range of settings as we could before we proceeded to jettison the camera."]

[During the 1991 mission review, we talked a little about the post-EVA window pan.]

[Aldrin - "Look at how the dust kicked up around here (near the flag and the TV camera beyond). It makes it really darker, as viewed from this angle which is sort of out to the front and the right (that is, northwest out Buzz's window)."]

[Jack Schmitt has hypothesized that, during the landing, the LM engines sweep away a lot of the very fine dust and leave behind a surface with a disproportionate number of small rock fragments sticking up. These reflect more sunlight than the normal surface would, making it look brighter than normal. Certainly, from orbit, the areas around the landed LM's are brighter than the surrounding countryside. Then, when the crew walks around near the LM, they stir up the soil and return it to something closer to its normal condition. Against the abnormally bright background, then, the disturbed soil looks dark. In support of his contention, Jack notes that, at geology stations far from the LM, disturbed soil doesn't look dark.]

[I asked how the horizon looked.]

[Armstrong - "The horizon looks close. But, because it's hilly you're probably not seeing all the horizon you could see. An intermediate hill is probably cutting it out. It wasn't mountainous in our area; it was flat. But there were still crater rims and so on that probably affected how far out the observable horizon was."]

112:21:31 Aldrin: Roger. We're planning on doing that. I was just wondering how much longer we want to wait, though. We've probably got another half an hour's worth of picture taking, and I guess we could run through an eat cycle and then change the canister, and then Depress. Over.

112:21:56 McCandless: Roger. That sounds fine to us.

112:22:02 Aldrin: Well, it'll be a little crowded in here for a while.

112:22:06 McCandless: Oh, we don't mind a bit! (Pause)

[If they eat before they do the depress and equipment ejection, they will have to take their helmets off. There is little spare room in the cabin and, with two rock boxes, the LEVAs, the helmets, and the PLSSs in the cabin with them, they will be cramped for space. Of course, on the last three missions, the crews took their suits off between EVAs and the cabin was even more crowded. Fortunately, lunar gravity is weak enough that there is no discomfort in standing for hours at a stretch and, consequently, much of the gear can be piled - more or less out of the way - on the engine cover.]

[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."]

[Crews on the later missions had hammocks which helped with the crowding problem during the rest period. However, on the last three missions, the crews took their suits off and piled them on the ascent engine cover. See a composite image (2.5 Mb) made by Ed Hengeveld from Apollo 17 post-EVA photos AS17-134-20522 and 25, giving a wide view of the cabin from the LMP's station.]

[Armstrong, from the 1969 Technical Debrief - "The post-EVA checklist went very well. It was well planned, and we went precisely by the pre-planned route with possibly a few exceptions. They...probably took about the same or a little more time than we expected. Of course, the time period that we took while we were waiting for the canister (replacement) before starting the depressurization was comparably long. We had to put an eat period in there, as I remember, and took a lot of pictures."]

[In the published version of the Technical Debriefing, Neil is quoted as saying "Of course, the time period that we took while we were waiting for the canister (replacement) before starting the repressurization was comparably long." Journal Contributor Thomas Schwagmeier notes that, because they wanted to wait and do the canister replacement just before they got ready to depressurize the cabin for the jettison - the used canister would be one of the things jettisoned - 'repressurization' should be 'depressurization'.]

[Aldrin, from the 1969 Technical Debrief, discussing the LiOH canister change - "We elected to leave the helmets on because, at this point, there was so much stuff rattling around inside the cabin that they would have added just one more bulky item. The primary canister change proceeded quite well to the point of inserting the new canister. I ran into a minor problem in getting it to rotate fully so that I could get the cover on. When it finally did seat itself properly, I can't for sure identify what I did differently from the times it didn't seem to rotate. That seemed to be what was stopping the cover from going on completely - the fact that, when the canister was inserted, I couldn't seem to rotate it as much as I thought it should have been rotated."]

[The LiOH canisters go into the inboard face of the ECS unit behind Buzz. The replacement cannister was stowed behind the ascent engine cover, below the back corner ot the ECS. Buzz had to face the rear of the spacecraft to do the change, but could do it with his right hand. It is not clear when, exactly, Buzz did the canister change. He and Neil did eat prior to doing the depress and jettison and did, of course, take their helmets off for at least a little while. They reported that they were finished eating at 113:17:52. At some point, Buzz takes AS11-37-5528, which is an excellent portrait of Neil in his Snoopy cap. Neil also took some photos of Buzz - AS11-37-5530 to 5534, unfortunately all dominated by the bright window behind Buzz. Bob Farwell and Kipp Teague have digitally enhanced 5534. Note the 16-mm DAC at the upper right. Clearly, they took their helmets off while they were taking pictures out the windows and of each other.]

112:22:27 McCandless: Columbia. This is Houston. Go ahead.

112:22:34 Collins: Roger. Have you got the new coordinates for me?

112:22:37 McCandless: Roger. Latitude 00 decimal 691...That would be plus 00.691. And longitude over 2 is plus 11.713. The altitude is minus 1.44 nautical miles. Over.

112:23:15 Collins: Roger. Thank you. (Long Pause)

112:23:31 McCandless: Columbia, this is Houston. On latitude, make that plus 00.692, rounding off. Over.

112:23:45 Collins: Okay. (Long Pause) Okay. I read back plus 00692, plus 11713, and minus 00144. And do you have a grid square for me?

112:24:10 McCandless: Roger. Standby. (Long Pause) Columbia. This is Houston. Grid coordinates: Kilo 0.9, 6.3, on LAM-2. Over.

[The actual landing site is Juliett 0.65, 7.52 and, as can be seen in Figure 5-14 in the Apollo 11 Mission Report, the landing site will be just outside the field-of-view of the CSM sextant on this pass. In the figure, each of the small squares is 1 kilometer on a side and the circles, which represent the approximate sextant field-of-view, are each about 3.2 km (2 miles) in diameter. Mike reports a negative result at 112:33:59.]

112:24:48 McCandless: Roger. (Long Pause)

[The sextant field-of-view covers an area equivalent to about seven squares.]

112:25:40 Collins: Roger.

[Because Mike is orbiting the Moon at about 100 kilometers altitude, he is above the horizon at Tranquility for about 13 minutes and, in principle, could talk to the surface crew on the VHF system.]

112:25:53 Collins: Okay.

[Long Comm Break]

112:34:06 McCandless: This is Houston. Go ahead. Over.

112:34:12 Collins: Roger. I can't see them.

112:34:17 McCandless: Roger. I guess that takes care of the news for today, Mike.

112:34:23 Collins: Rog. (Garbled)

112:34:29 McCandless: You might be interested in knowing, Mike, that we have gotten reflections back from the laser reflector array they deployed, and we may be able to get some information out of that a little later.

[Information from the laser returns can be used to refine estimates of the landing site location made, so far, from tracking data and LM guidance telemetry.]

[MIke seems to be estimating the number of square in the area that includes possible LM locations Houston has mentioned since the landing: ten squares or more; twenty or more; thirty or more. Certainly a lot of squares when he can only scan one on each pass over the landing site. Certainly a lot of squares when he can only scan one on each pass over the landing site.]

[In order to maintain sextant pointing, Mike must expend a small amount of maneuvering fuel.]

[At 123:55:23, about a half hour before LM liftoff, Ron Evans will give Mike a location only 200 meters from the actual landing site.

112:35:18 McCandless: Roger. There's no problem fuel-wise. It's just that there seems to be a limit to the number of P22's and the number of grid squares you can search. Over.

112:35:32 Collins: Rog. Well, I'll continue this maneuver, then, to roll 82, pitch 218, yaw zero, if that's okay with you, and do a P52 in that attitude. And that'll be the sleep attitude.

[As the Command Module - or the LM, for that matter - orbits the Moon, it remains in an fixed inertial attitude. That is, the spacecraft axis remains fixed relative to the stars, but not to the lunar surface. David Woods tells us that, "while Mike is using P22 to search for the LM, he commands the CSM to make a slow, pitching motion to keep the aim point within the range over which the sextant can move it's line-of-sight. After he finishes P22, he will maneuver to attitude 082, 218, 000 so he can do a P52 realignment of the inertial platform. After finishing P52, he will leave the CSM in that attitude for his upcoming sleep period." Because the Moon doesn't move terribly far in its orbit around Earth during a rest period, the spacecraft attitude relative to Earth doesn't change very much either; and, if need be, Houston can wake Mike from his sleep during any of the front side passes.]

[Thomas Schwagmeier had produced an illustration showing a spacecraft in inertial attitude and another in a very slow, contant pitch maneuver to maintain an attitude relative to the lunar surface. Thomas used a NASA/GSFC/Arizona State University mosaic showing the Moon's north pole. The Mosaic was made tom multiple images taken with the LROC Wide Angle Camera as was released on 16 March 2011.

[Very Long Comm Break]

[Either Bruce has misspoken or has misunderstood Mike's "And that'll be the sleep attitude." and thinks Mike will go to a different sleep attitude - presumably one in the flight plan. There is no further discussion of the sleep attitude after Mike completes the P52 at 112:53:16.]

112:43:46 McCandless: Tranquility Base, this is Houston. Over.

112:43:52 Aldrin: Houston, Tranquility Base. Go ahead.

112:43:55 McCandless: Roger. When you all have a free moment, I have your T8 through T12 block data. Over.

112:44:08 Aldrin: Roger. Stand by one.

[Comm Break. These are lift-off times for upcoming launch opportunities, each corresponding to a CSM pass over the landing site. T13, at about 124:22 is the planned launch time. Note that the successive times differ by 118 minutes 13 seconds, the current period of the CSM orbit.]

112:45:29 McCandless: Roger, Tranquility. T8, 114:30:57; T9, 116:29:10; T10, 118:27:23; T11, 120:25:36; T12, 122:23:49. Readback. Over.

112:46:14 Aldrin: Roger. T8, 114:30:57; T9, 116:29:10; T10, 118:27:23; T11, 120:25:36; T12, 122:23:49. Over.

112:46:45 McCandless: Readback correct. Houston out. (Long Pause)

112:47:26 Collins: Houston, Columbia. (No answer; Long Pause) Houston, Columbia...

112:47:50 Armstrong: Houston, Tranquility Base.

112:47:50 Collins: ...on high gain.

112:47:54 McCandless: Columbia. Columbia. This is Houston. Over.

112:48:04 Collins: Columbia on the high gain.

112:48:06 McCandless: Roger. Reading you loud and clear on the high gain, Columbia.

112:48:13 Collins: Roger. Maneuvering to P52 attitude. You want a crew status report?

112:48:21 McCandless: Say again, Columbia?

112:48:27 Collins: I say again, I am maneuvering to the P52 attitude, and do you want a crew status report?

112:48:34 McCandless: Roger. And go ahead with your crew status report.

112:48:40 Collins: Roger. No medication. Radiation 100 point 16.

112:48:46 McCandless: Houston. We copy. (Long Pause)

112:49:15 Armstrong: Houston, Tranquility Base.

112:49:17 McCandless: Go ahead, Tranquility.

112:49:23 Armstrong: Roger. The weight of the RCU was 12 ounces. That was by itself without the bag, and the weight of the water from the CDR's PLSS was 12-1/2 ounces. (Pause) That's reading zero with the bag on.

[They've weighed an RCU to calibrate the scale, then weighed the residual feedwater. The zero on the scale could be adjusted and, here, they zeroed the scale with nothing on it, weighed the RCU to give a calibration point, and then put the empty water bag on and re-zeroed the scale before weighing the full bag.]

[Armstrong - "And the intent, here, was to begin a data base for coordinating your water usage with your metabolic rates. I think there was a plastic bag that we put the water in when we drained the PLSSs."]

[Note that Neil sounds a little congested. On Apollo 17, Jack Schmitt had a dramatic nasal reaction to lunar dust after his first EVA and, then, lesser reactions after the other EVAs. However, see the discussion following 114:31:38.]

112:50:11 Armstrong: Okay. 10837.

[Comm Break. They will enter this number in the computer during final preparations for launch.]

112:53:30 McCandless: Columbia, this is Houston. Affirmative.

112:53:39 Collins: Okay.

[Comm Break]

112:55:49 Aldrin: Houston, Tranquility. Say again which one should be closed?

112:55:54 McCandless: Roger. Panel 16, row 2, Stab control ATCA, that is A-T-C-A, and it should be open at this time. Over.

112:56:06 Aldrin: Roger. Coming open.

112:56:12 McCandless: Roger. Out. (Pause)

112:56:28 Aldrin: Houston, Tranquility. Do you have a way of showing the configuration of the engine arm circuit breaker? Over. (Pause) The reason I'm asking is because the end of it appears to be broken off. I think we can push it back in again. I'm not sure we could pull it out if we pushed it in, though. Over.

112:56:56 McCandless: Roger. We copy. Stand by please. (Long Pause)

[With space limited in the cabin, a person wearing a PLSS has ample opportunity to hit a circuit breaker without being aware of it. The engine arm circuit breaker is seventh from the left in second row of Panel 16, which is on Buzz's side. Because Neil was never on that side of the spacecraft, it has to have been Buzz who hit it.]

[Aldrin - "There weren't guards over any of the circuit breakers. One got pushed in and one got broken off. So I must have pushed one in and broke one off (with his PLSS prior to doffing)."]

112:57:41 Aldrin: Roger. Copy.

[Comm Break. As shown on Surface checklist page Sur-20 this circuit breaker was put in the 'open' position after powerdown and is supposed to remain open until about two and a half hours before launch, as indicated on Sur-45 and Sur-47. According to the Apollo 11 Mission Report, "The engine arm circuit breaker was successfully closed when it was required for ascent, but loss of the knob would not allow manual opening of the breaker." See, also, a high-quality image of the Apollo 12 Controls and Displays.]

[In his book, Men from Earth Buzz elaborates, "We discovered during a long checklist recitation that the ascent engine's arming circuit breaker was broken off on the panel. The little plastic pin (or knob) simply wasn't there. This circuit would send electrical power to the engine that would lift us off the moon...We looked around for something to punch in this circuit breaker. Luckily, a felt-tipped pen fit into the slot."]

[To prevent a recurrence of this problem, NASA decided that guards would be placed over the breakers for future flights. Furthermore, additional checks of the circuit breaker configuration were added to the checklist. Buzz will close the circuit breaker at some point after the rest period and, at 123:20:43, about an hour before lift-off, Houston will tell the crew that telemetry indicates that the circuit breaker is in its proper, closed position.]

112:59:51 McCandless: Roger. 11014 for the CDR.

113:00:01 Aldrin: Roger. LMP reads 09018. Over.

113:00:06 McCandless: Roger. 09018.

[Long Comm Break. Buzz reported a reading of 09017 - and, jokingly, three quarters - prior to the EVA. Neither reading has changed since landing. The last digit in the PRD readout indicates 0.01 rad. Total, uncorrected dosages received by the crew during the mission was about 0.25 rad. Post-mission corrections gave true readings of 0.18 rad, most of which was received during passage through the Van Allen Belts on the way out and on the way back. In comparison, the Apollo 14 crew received an average dose of 1.14 rad, in part because their trajectory took them closer to the center of the Belts than any of the other crews. Doses at these levels do not present significant medical risks - certainly not in comparison with other risks that are inherent to a lunar mission.]

113:04:43 McCandless: Columbia, this is Houston. Go ahead.

113:04:48 Collins: Roger, Bruce. When you get a few minutes could you give me some words on tomorrow's activities; (that is), when they're going to start?

113:04:57 McCandless: Roger.

[Long Comm Break]

113:12:03 Collins: Go ahead.

113:12:05 McCandless: Roger, Mike. Couple of quick flight plan updates here. First off, we'd like to get an O₂ fuel cell purge at time 113:30. Are you copying? Over.

113:12:23 Collins: Rog; I'm copying.

113:12:26 McCandless: Secondly, we will return to the nominal timeline with your scheduled wake-up of 121 hours and 12 minutes. We sort of slipped by lithium hydroxide canister change number 9 during the EVA and EVA Prep. We'd like you to accomplish that now. The Comm for sleep will be the normal lunar Comm configuration. (For) the RCS configuration, we're requesting you use quads Alpha and Bravo. A DAP data load for R2 should be 01111. Readback. Over.

113:13:28 Collins: Roger. Oxygen fuel cell purge at 113:30. Return to the nominal timeline at 121 hours wake-up. Lithium hydroxide change number 9 right now. Normal lunar comm sleep configuration, I'm in that now. On the RCS, I understood before (that) you wanted to load the DAP register to 01100 which made sense on panel eight to pitch only on quad A, enable all on quad B, and C and D off. But you don't want to do that any more, huh? (No immediate answer)

[Comm Break. The actual wake-up call will be at 120:59.]

113:15:34 Collins: Okay. (Pause)

113:15:38 McCandless: And you'll...

113:15:39 Collins: Load's going in right now.

113:15:41 McCandless: Roger. And you'll be enabling quads Alpha and Bravo on the Auto RCS select switches. Disable Charlie and Delta.

113:15:51 Collins: All right. (Pause)

113:15:59 McCandless: And we have a little less than 2 minutes to LOS. If you're still up, AOS next time around will be 114:04. Over.

113:16:18 Collins: Roger. (Pause)

113:16:27 McCandless: And, Columbia, if it's agreeable with you, we'd like you to stay awake until we have one successful re-acquisition on the high-gain antenna. And I guess you can plan on turning in shortly after AOS on this next pass. Over.

113:16:47 Collins: Okay.

113:16:49 McCandless: Roger. Out. (Long Pause) Tranquility Base. Tranquility Base. This is Houston. Radio check. Over.

113:17:42 Armstrong: Go ahead. Houston.

113:17:44 McCandless: Roger. Reading you loud and clear. Just wanted to make sure we still had Comm.

113:17:52 Armstrong: Roger. We just finished up...We're just finishing up our eat period. Be ready to go back into Prep for Depress.

113:17:59 McCandless: Roger.

[Very Long Comm Break. The following audio sequences were accumulated during a press briefing.]

113:46:23 McCandless: Tranquility Base, this is Houston. Over.

113:46:29 Armstrong: Roger. Go ahead, Houston.

113:46:32 McCandless: Roger. On your next depressurization, it's acceptable to use the overhead hatch dump valve in addition to or instead of the forward hatch dump valve to speed up the depressurization of the cabin. I have a T13 update for you. And if you could, sometime here, give us P00 and Data: we'll uplink you a new CSM state vector. Over.

[The overhead valve has about twice the flow rate of the forward dump valve because it isn't equipped with a bacterial filter. However, they now have samples in the rock box so the filter is less important. The photograph of LTA-1 at the Cradle of Aviation Museum shows the forward dump valve without a bacterial filter.]

[Aldrin - "I think they just wanted to speed it up."]

113:47:19 Aldrin: You've got the DSKY.

113:47:22 McCandless: Roger. Your T13 time (the planned lift-off) is 124:22:02. Over.

113:47:40 Aldrin: Roger. T13, 124:22...Is that 'zero two'? Over.

113:47:49 McCandless: That's affirmative. That is zero two. And do you have a time estimate for us until you're ready to start cabin Depress? Over.

113:48:05 Aldrin: Fifteen minutes, maybe?

113:48:10 McCandless: Roger.

[Comm Break]

[Aldrin, from the 1969 Technical Debrief - "There's no getting around it, it's another EVA Prep exercise. It's easier (because they stay on LM systems rather than having to hook up the PLSSs), but you still have to go through the same exercises such as pressure-integrity check, bleeding the cabin down, and configuring the ECS (Environmental Control System). I guess if you have two EVAs, it probably would be nicer to jettison your equipment at the beginning of the second one, rather than (getting in after the first EVA, repressurizing, hooking up to the LM ECS and) having to add another Depress (to do a jettison before starting the rest period). I'm not sure how they're planning to do this."]

[On the other missions, the crews did what Buzz suggested. At the start of each EVA, they took the trash out with them. The only extra jettison was done sometime between the end of the final EVA and the launch. This final jettison was done primarily to get rid of the PLSSs.]

113:50:39 Armstrong: Roger.

[Comm Break]

[Former Mercury Astronaut Deke Slayton, the Director of Flight Crew Operations who has primary responsibility for crew selection, joins the conversation. Alan Shepard works for Slayton and is Head of the Astronaut Office.]

113:59:59 Armstrong: Go ahead. Tranquility Base, here.

114:00:02 Slayton: Roger. Just want to let you guys know that, since you're an hour and a half over your timeline and we're all taking a day off tomorrow, we're going to leave you. See you later.

114:00:13 Armstrong: I don't blame you a bit.

114:00:16 Slayton: That's a real great day, guys. I really enjoyed it.

114:00:23 Armstrong: Thank you. You couldn't have enjoyed it as much as we did.

114:00:26 Slayton: Roger.

114:00:28 Aldrin: It was great.

114:00:30 Slayton: Sure wish you'd hurry up and get that trash out of there, though.

114:00:34 Armstrong: Yes. We're just about to do it.

114:00:36 Slayton: Okay.

[Comm Break. The press briefing is over and normal taping of the mission audio resumes.]

[Comm Break]

114:05:33 Collins: Houston, Columbia. Go ahead.

114:05:35 McCandless: Roger. We've successfully re-acquired high-gain antenna. Unless you have some other traffic with us, I guess we'll bid you a good night and let you get some sleep, Mike. Over.

114:05:48 Collins: Okay. Sounds fine.

114:05:50 McCandless: And we're going to power down the voice subcarrier part of our uplink to you in order that we don't disturb you while we're talking to Tranquility Base. If you need us, just give us a call, and we can respond with a time lag of about a minute to a minute and a half in getting reconfigured. Over.

114:06:13 Collins: Okay. Thank you.

114:06:15 McCandless: Roger. And good night.

114:06:20 Collins: Good night, Bruce. Thanks a lot.

[Comm Break]

[The LM crew starts depress procedures for the jettison at about 114:07, doing a suit integrity check at 3.5 psi.]

114:09:46 Collins: Okay. Bravo 1 and Bravo 2 Enable.

114:09:49 McCandless: Roger. Out. (Long Pause; LM pressure starts toward zero) Tranquility, this is Houston. For a reference, which dump valve are you using? Over.

114:10:28 Armstrong: We used the forward dump valve until about 2 psi, and we're using the overhead now.

114:10:34 McCandless: Roger. Out.

114:10:37 Armstrong: They're both open now.

Restored Video Clip, PLSS Jettison 1 minutes 24 seconds ( 1.9 Mb FLV or 2.2 Mb MPEG). May require VLC for playback.

[Long Comm Break]

[Because Neil and Buzz are both right-handed, it was probably Neil, standing on the left side of the cabin, who opened the overhead valve.]

[The PLSS jettison comes at about 114:14. Both PLSSs could be seen on the TV as they tumbled out of the hatch, albeit not on the tape compilation available to us in 1991, which ends about about 112:24.]

[Ed von Renouard was a Video Tech at Honeysuckle Creek during Apollo and brought his Super-8 movie camera to work during some of his Apollo shifts and filmed his colleagues and, sometimes, the TV monitor. Fortunately, Ed filmed the PLSS jettisons. Journal Contributor David Woods organized digitization of the films after Ed rediscovered them in 2005; and Journal Contributor Colin Mackellar has provided a file combining the two clips ( 4.3 Mb mp4 ).]

[Returning to the 1991 Apollo 11 mission review. I asked Neil and Buzz how they got the PLSSs out.]

[Aldrin - (Chuckling) "We didn't seem to talk about it very much, did we? I don't think we got down on our hands and knees and pushed them out."]

[Armstrong - "I think we could probably get down far enough (in the pressurized suit) to reach them with our gloves. I think you could get down there. I think that's more likely what we did (than kick them out as some later crews did)."]

[Aldrin - "I'd have to have reached over the door, so you (Neil) had to push 'em or kick 'em."]

[Aldrin, from the 1969 Technical Debrief - "The (replacement LiOH) canister container behind the ascent engine removed very easily, and we were able to jettison it without any problems. We didn't have any problems; I didn't notice you (Neil) had any difficulty giving the packages the heave-ho. I think each PLSS bounced once on the porch before it went down."]

[Armstrong, from the 1969 Technical Debrief - "Only one thing stayed on the porch. That was a small part of the left-hand-side storage container that did not make it off the porch onto the surface. That was the last item jettisoned."]

[Neil thinks they were on LM intercom, so they could talk to each other, and used the PTT trigger if they wanted to talk to Houston. Houston can monitor the proceedings through telemetry.]

114:18:47 Armstrong: (Joking) You can't get away with anything anymore, can you?

114:18:51 McCandless: No, indeed.

[Comm Break]

[Locally-produced signals such as the PLSS impacts provided insights into the depth of the regolith and its seismic properties.]

[I asked about assignment to specialties after getting accepted into the Astronaut Corps.]

[Armstrong - "It was true for a long period of time there that individuals got assigned to particular areas. Mine happened to be training and simulation. That was predominantly to make sure that crew interests were represented in all the meetings and discussions. So, if there was a meeting on simulators or simulator requirements or something, and the person who was assigned to be simulators would be the obvious guy to go track that and it wouldn't take some master scheduler to be figuring out where people should be going all the time. That let people then decide on their own where they needed to be, covering the various issues and decisions. It was more of a convenience than anything. In some cases, I suppose, people were assigned because of educational or experience strengths in that area, so that they'd have a running start. But not always."]

[I then asked if they had any comments on the geology training. I mentioned Jack Schmitt's efforts to tailor things so that it was useful in the sense of "what do I need to know to be a good observer?", as opposed to an academic approach to geology.]

[Armstrong - "I think that was the intent, (that is) in a relatively short period of time, to bring non-geologists up to the level so that they would be adequate observers and be able to pick out those things which deserved attention or would be of interest to real geologists. And, I think they achieved that at least to some degree."]

[In his excellent book, To a Rocky Moon, Don Wilhelms discusses the training in some detail and, among other things, notes that both Neil and Buzz were good enough students to warrant special attention from the geology instructors.]

114:21:34 Armstrong: Go ahead, Houston.

114:21:36 McCandless: Roger. When you get back into your surface checklist and come over to the Comm reconfiguration on page Surface-45, we'd like you to enable the ranging feature on your S-band. That is, when you come down to S-band configuration, instead of "Caution-and-Warning Electronics, Enable TV", we'd like you to go into the Range position and leave it there for as long as you conveniently can until you get ready to commence your rest period; and we'll try to get a little more ranging data on you. Over.

114:22:20 Armstrong: Roger. Copy.

[Houston is still trying to figure out exactly where they are.]

[In the copy of Surface-45 in the ALSJ, the S-Band configuration line reads "S-BAND: PM, PRIM, PRIM, VOICE, PSM, CWEA ENABLE, LEFT, HI" where the last two items have been added by hand. The handprinted addition is quite tidy, suggesting that it was added pre-flight. These settings refer to the S-Band section of Panel 12 (detail from Apollo 11 LM-5 "Eagle" poster by Mark Gray. Used with permission.) The first six items refer to the top row of switches: (1) Modulate switch to PM(FM); (2) XMTR/RCVR (Transmitter/Receiver) to Prim(ary); (3) PWR AMP (Power Amplifier) to Prim(ary); (4) first function switch to Voice; (5) second function switch to PSM(PCM); (6) third function switch to TV/CWLR (CWEA) Enable. The handprinted addition refers to the two telemetry switches at the right end of the second row: MonoMed to Left (Neil) and PCM to Hi. Bruce is telling them to set the third function switch to Range, rather than TV/CWLR (CWEA) Enable.]

114:22:46 Armstrong: Thank you very much.

114:22:48 Aldrin: It's been a long day.

114:22:51 McCandless: Yes, indeed. Get some rest there and have at it tomorrow.

[Comm Break]

114:24:27 McCandless: Stand by, Tranquility. We'll be back with you in just a minute. (Long Pause)

[Post-mission analysis indicated that the most likely cause of the timer failure was a cracked solder joint caused by differential thermal expansion within the unit. By the time Neil and Buzz turn it back on - in about 5 minutes - it will have been off for about 11 hours. The resulting cool down has reversed the differential expansion and, at least temporarily, has closed the solder crack. The timer will work properly during the rest of the mission. For subsequent missions, NASA subjected the units to longer periods of vibrational, thermal, and operational testing. The LM timer and an identical unit in the Command Module were supplied by the Bulova Watch Company. The Apollo 12 CM mission timer had intermittent problems, ascribed to a cracked solder joint. According to the Apollo 12 Mission Report, modifications to the timer design were going to be made prior to Apollo 13 to reduce the chance of such problems. Further, intermittent problems were experienced with the Apollo 15 CM timer. Post-mission inspection of the unit did not reveal the cause of the problem and, since the intermittent failures were no more than a 'nuisance' to the crew, no further action was taken. Colin Fries, Frank O'Brien, and Phill Parker contributed to this discussion.]

114:25:37 McCandless: Tranquility, this is Houston. Yes, indeed. It's been a mighty fine presentation there.

114:25:43 Aldrin: Okay. Signing off. See you again tomorrow.

114:25:46 McCandless: Roger.

[Comm Break. They have turned the TV off to conserve power. Although there is plenty of power remaining in the batteries, there is no reason to continue powering the TV camera. The scene is not going to change prior to liftoff and, at the moment of staging, the circuit that provides power to the camera will be severed along with all other connections between the two LM stages.]

114:27:00 Collins: Go ahead, Houston.

114:27:02 McCandless: Roger. Sorry to bother you, Columbia. Two things: we request that you select 10-degrees deadband in your DAP in accordance with the procedures on Foxtrot 9-7 in your checklist; and secondly, we'd like to leave a display on the DSKY that is not one that's cycling, being continuously updated. What you have when you get through widening the deadband will be a static display, and that'll be satisfactory. Over.

114:27:41 Collins: Okay.

114:27:42 McCandless: Roger. Goodnight again. (Long Pause) Tranquility Base, this is Houston. Over.

114:28:16 Aldrin: Roger. Go ahead.

114:28:19 McCandless: Roger. On your mission timer, we wanted to pull the circuit breaker and let it cool down for an hour and a half to 2 hours. I believe the breaker is currently open. It has been off, so go ahead and reset the mission timer circuit breaker. Put the timer control to Reset and hold it in Reset for three-zero (30) seconds, and then slew it to your desired settings left to right, and place the timer control to Start. Over.

114:29:04 Aldrin: Okay. We'll try it. (Long Pause)

[I asked about the need to get the timer working again, since they have at least one watch.]

[Aldrin - "There are rapid-paced things that happen during the rendezvous and we like to have something that's a little easier to look at than an Omega (watch)."]

[Armstrong - "(Resetting the timer) was a matter of adjusting the numbers in the register to the current mission elapsed time and, then, on some kind of a mark from someplace, to engage the timer. It's not on (that is, driven by) any registers of the LGC; it's an independent unit."]

114:30:52 Armstrong: Okay. (Garbled)

114:30:52 McCandless: ...at 114:31. (Pause) Stand by. (Pause) Mark. (Pause) Tranquility, this is Houston. Did you copy my Mark at 114:31?

114:31:22 Armstrong: Roger. Thank you, and our mission timer is running now.

114:31:27 McCandless: Roger. Very good. And, I've got a consumables update for you if you're ready to copy or listen. Over.

114:31:38 Armstrong: Stand by. (Pause)

[I asked if they could hear any stuffiness in their voices, thinking of Jack Schmitt's allergic reaction to lunar dust.]

[Aldrin - "It wasn't a very restful evening. How long have we been up?"]

[They were awakened at 93:40 and, so, have been up for nearly 21 hours.]

[Armstrong - "And temperature control was a bit of a problem for us and it could be that cabin temperature was contributing to something."]

[I then told them about Jack Schmitt's apparent allergic reaction to lunar dust after the first Apollo 17 EVA - but not after the later ones.]

[Armstrong - "I can't say that I recall it."]

[Aldrin - "There wasn't any particular odor."]

[Armstrong - "Yeah, I remember commenting that we had the scent of wet ashes. Something like that."]

[Aldrin - "There was a hint of something. A slight metallic...That's hard to remember. But it wasn't a real objectionable one."]

[Armstrong - "Yeah."]

[Aldrin - "Like it was going to catch fire."]

[Other crews described the smell as being similar to expended gunpowder. I asked if the dirt they tracked in settled to the floor pretty quickly.]

[Armstrong - "There wasn't a whole lot floating around in the cabin. Although we did tromp some in. There's no question about that."]

[I asked if they'd noticed any film of dust on the instruments. And neither of them remembered any.]

[Armstrong - "When we got back up to zero-g, some of the stuff did come up."]

[Colin Mackellar has provided the following audio clip, recorded at Honeysuckle Creek, which was the prime station for LM audio after the handover from Goldstone at 112:00:00. Colin notes that the quality is much better than the NASA archives copies and that, in the HSK recording, the voices of the people working near McCandless in the MOCR are very clear.]

114:31:45 McCandless: Okay. RCS (Reaction Control System, the steering jets) Alpha is 81 percent; RCS Bravo, 75 percent. Coming up on 115 hours GET, descent oxygen is 31.8 pounds or 59 percent; descent amp hours 858 (remaining), and ascent amp hours 574. Over. (Pause)

114:32:28 Aldrin: Roger. Copy. Thank you very much.

114:32:32 McCandless: Roger. Out. (Long Pause) Tranquility, this is Houston. We also have a set of about 10 questions relating to observations you made, things you may have seen during the EVA. You can either discuss a little later on this evening or sometime later in the mission at your option. How do you feel? Over.

114:33:35 Armstrong: I guess we can take a couple of them up now.

114:33:39 McCandless: Okay. And your friendly Green Team here has pretty well been relieved by your friendly Maroon Team, and I'll put Owen on with the questions. (Pause)

[Astronaut Owen Garriott takes over as CapCom for the EVA debriefing.]

114:33:53 Armstrong: Okay. Thank you, Bruce. If you...(Listens) Go ahead.

114:33:59 Garriott: Tranquility, Houston. First question here is how your best estimate of the yaw of the LM as compared to the nominal pre-flight plan. Over.

114:34:16 Armstrong: (Sounding congested) We're yawed 13 degrees left on the ball, and I think that's probably about right. Looking at the shadow and so on, we're probably about 13 degrees left of the shadow.

114:34:31 Garriott: Roger. That's 13 degrees left of the shadow.

[That is, the spacecraft is facing about 13 degrees south of west.]

[Aldrin, from the 1969 Technical Debrief - "I want to inject a thought about spacecraft location (probably means 'orientation') in respect to lunar surface working conditions. Putting the area of the MESA in shadow also put the (TV) cable in the shadow. The white cable, being covered with a little bit of this powdery stuff and being in the shadow, was very difficult to observe. Consideration should be given to keeping any cable or small object out in sunlight whenever possible. It leads one to think that, if you're going to yaw one way or the other, it's preferable to put your working areas out into the sunlight."]

[The unintended left yaw put the MESA farther into the LM shadow than it would have been otherwise.]

[Armstrong, from the 1969 Technical Debrief - "We discussed - pre-launch, on a number of occasions - whether we wanted to yaw specifically for lighting at touchdown. There are obviously a lot of advantages, but I was very reluctant to do any fancy maneuvering on the first lunar touchdown for selected yaw for lighting considerations. I figured we'd just take what we got; and we paid for that later, because we had a lot of operations in the shadow during the EVA that would have been easier had we had better lighting."]

[Readers should note that this quote differs from the one originally transcribed by NASA. Neil provided the correction in 1995.]

114:35:02 Armstrong: I'm not sure I understand that question, but we got a good bit of the ground mass in the bulk sample plus a sizable number of selected rock fragments of different types. (Pause)

114:35:22 Garriott: Roger, Neil. One of the implications here is the depth from which the bulk sample was collected. Did you manage to get down there several inches or nearer the surface? Over.

114:35:37 Armstrong: We've got some down from as much as 3 inches. In the area where I was looking at variation with depth in the bulk sample, there really wasn't appreciable difference, and I didn't run into any hard pan. Later on, or at some other times and other areas, why, I'd get down just a short distance, an inch or two, and couldn't go any further.

114:36:06 Garriott: Roger. Believe we understand down as deep as 3 inches, did not hit any hard bed, and no significant changes in composition to that depth. Next question. The second SRC was packed rather hurriedly due to the time limitation, and wonder if you would be able to provide any more detailed description of the samples which were included in the second SRC. Over.

114:36:40 Armstrong: We got two core tubes and the solar wind and about half of a big sample bag full of assorted rocks which I picked up hurriedly from around the area. I tried to get as many representative types as I could.

114:37:09 Garriott: Roger, Neil. Next topic here relates to the rays which emanate from the DPS (Descent Propulsion System) engine burning area. We're wondering if the rays emanating from beneath the engine are any darker or lighter than the surrounding surface. Over. (Pause)

114:37:42 Aldrin: The ones that I saw back in the aft end of the spacecraft appeared to be a good bit darker. Of course, as viewed from the aft end, why, they did have the Sun shining directly on them. It seemed as though the material had been baked somewhat and also scattered in a radially-outward direction, but in that particular area, this feature didn't extend more than about 2, maybe 3 feet, from the skirt of the engine. Over.

114:38:24 Garriott: Roger. Understand that near the aft end - out to the east - that the rays did appear darker. I understand, Buzz, that these were... (that) this was the appearance of the material which had been uncovered by the rays that appeared darker for 2 or 3 feet extending outward. Is that correct?

114:38:49 Aldrin: No. I wouldn't say it was necessarily material that had been uncovered. I think some of the material might have been baked or in some way caused to be more cohesive and perhaps flow together in some way. I don't know. Now, in other areas, before we started trampling around out front, why, we could see that (some) small erosion had taken place in a radially-outward direction; but it had left no significant mark on the surface other than just having eroded it away. Now, it was different right under the skirt itself. It seems as though the surface had been baked in a streak fashion, and I think a couple of pictures on film will show this. But that didn't extend out very far. Over.

114:39:48 Garriott: Roger, Tranquility. And this baked appearance that you described, at least the suggestion is that it was due to the heat of the engine at any rate. Next subject, did...

114:40:01 Aldrin: I believe so.

114:40:02 Garriott: Roger. Next subject, did either of the solar panels on the PSE touch the surface of the Moon during deployment? Over.

114:40:19 Aldrin: I think that two corners did touch since, when it was deployed, both of them didn't come out at the same time. It unfolded a little unevenly, and of course, the terrain that it was on was a little bit...(was) not quite as level as I would like to have it. And I think that two corners did touch to about 1 inch, no, three-quarters to a half an inch deep; and maybe along the bottom, it might have been maybe 3 inches, leaving a small triangular coating on two of the corners; and I think these are on the western ones. Over.

114:41:06 Garriott: Roger. Understand the description there. And the next subject, on the two core tubes which you collected, how did the driving force required to collect these tubes compare? Was there any difference? Over

114:41:27 Aldrin: Not significantly. I could get down about the first 2 inches without much of a problem, and then as I would pound it in about as hard as I could do it, and the second one took two hands on the hammer, and I was putting pretty good dents in the top of the extension rod, and it just wouldn't go much more than... I think the total depth might have been about 8 or 9 inches. But even there, for some reason it didn't seem to want to stand up straight. In other words, I'd keep driving it in and it would dig some sort of a hole but it just wouldn't penetrate in a way that would support it and keep it from falling over, if that makes any sense at all. It didn't really to me. Over.

[Buzz's troubles with the core tubes were caused by the design of the tube. The top few centimeters of the lunar soil - consisting of relatively recent ejecta from craters near and far - can be quite loose and, in anticipation that the soil would be loose to considerable depth, the core tubes were designed with an internal bevel which compacted the soil entering the tube as Buzz hammered it into the ground. However, the in-place soil actually becomes quite compact at only a few inches depth because of shaking induced by countless small impacts. Consequently, once Buzz had pushed the tubes in a short way, he encountered soil which was already at near maximum density and the entrance to the tube quickly became blocked. Other designs - a small diameter tube with an exterior bevel and a large diameter, thin-walled tube with no bevel - worked beautifully on the other missions.]

114:42:59 Aldrin: Yeah. That's about it. It wasn't a rapid change in resistive force. And, also, I noticed when I took the bit off that the material was quite well packed, a good bit darker, and the way it adhered to the core tube gave me the distinct impression of being moist. Over.

[I suggested that by "moist" Buzz might have been referring to the fact that lunar dust clings to almost anything it comes in contact with.]

[Aldrin - "That plus maybe a little more perception of the color, because you're looking at particles rather than a surface. Maybe that makes it look darker. When it's a surface, maybe the reflection tends to lighten it up, in the Sun. 'Moist' was about the best I could grab hold of."]

[Armstrong - "It didn't imply any moisture. It had to do with the reflective characteristics and, also, maybe the slumping...Actually, I don't think we've mentioned earlier that you could have fairly steep walls."]

[Small trenches dug by later crews would retain virtually vertical walls.]

[I asked if the tongs or the scoop retained a coating of dust after they scraped it through the surface]

[Armstrong -(After much thought) "I don't remember. Certainly the boots did."]

[Aldrin - "Yeah, if there's anything that it can grab a hold of, the stuff seems to stay there."]

114:44:01 Armstrong: Yeah, let's...We'll postpone our answer to that one until tomorrow. Okay?

[Neil answers the question at 123:10:32.]

[Aldrin - "I'm just kind of wondering about that kind of question because, once you've taken panorama pictures, (the question) makes me feel a little inadequate trying to describe something in a subjective way when you've got very objective data. So, is the question, do you suppose, in case the photos and you don't make it back? That they want to know what your subjective description is?"]

[Armstrong - "They had TV panoramas."]

[Aldrin - "I feel imposed on, I'll tell ya, by those questions. I like to be an expert in an area before I get put on the spot."]

[Armstrong - "I don't think there's anything sinister. (Animated) I just think those geology guys just couldn't wait to get more detail and just wanted more information!"]

114:44:31 Armstrong: Well, I can do it like this, Owen. About all the struts are about equally stroked, and the height from the ground to the first step is about 3 feet or maybe 3 and 1/2 feet, huh?

[I asked if they saw any distinct evidence of stroking.]

[Aldrin - "They weren't going to bounce back, I don't think. Weren't they crushable?"]

[Armstrong - "They weren't springs. They were honeycomb inside and they took a permanent set. We probably knew what the unstroked length was, but we probably had seen that someplace in time. I think that what I said here was the best way to put it. We touched so gently that we sure didn't do much."]

[I mentioned that there is a lot of bantering on other missions about possible landing gear stroking and that it's impossible to tell how much is banter and how much is fact. Neil did not reply.]

114:45:32 Aldrin: No. I don't believe so. I think that it's about as level as any other areas that we chose.

114:45:46 Garriott: Roger. I...

114:45:47 Aldrin: There's nothing large, anyway, that's going to get in the way.

114:45:50 Garriott: Roger. Copy. That's also the way it appeared from the television, I think. And now the final question. You commented, Neil, that on your approach to the landing spot, you had passed over a football-field-sized crater containing rather large blocks of solid rock perhaps 10 to 15 feet in size. Can you estimate the distance to this football(-field)-sized crater from your present position? Over.

114:46:25 Armstrong: I thought we'd be close enough so that when we got outside we could see it's rim back there; but I couldn't. But I don't think we're more than a half mile beyond it. That is, a half mile west of it.

114:46:45 Garriott: Roger. So you estimate your present position less than half a mile approximately west of this large crater. Over.

114:46:56 Armstrong: That's correct.

[The distance back to West Crater is about 500 meters or about 0.3 miles, rather than 0.5 miles.]

[During the following discussion, we were looking at Figure 3-3 from the Preliminary Science Report, a high-resolution mosaic of Lunar Orbiter photos of the site. Figure 5-8 in the Mission Report is a grainier version of the same image.]

[Armstrong - "That (West Crater) was a big dude! See, Buzz could not see it, because he was on the right side. On the LM, between the right and left crew positions, there's a panel that goes out so that either crew member can only see forward and out his side, but not to the other side. So we came over the (north side of) big West Crater, which looked enormous, humongous...To me it looked like a football stadium - you know, a circular football stadium - about that size. And he couldn't see it! (Chuckling) He couldn't appreciate that at all! We were coming right into the northeast slopes of it. And there were a lot of big boulders on that slope. A generally undesirable landing area for the first one. Geologically interesting, but not a good place to land."]

[I asked if West Crater had been named prior to the mission.]

[Armstrong - "I don't think so. I was considerably west of where we were intending to land, so it wasn't one of the those craters that we'd been looking for in the approach path."]

[Aldrin - "It's east of where we landed, so why did it get the name West Crater? Who named it West Crater?"]

[Armstrong - "I don't know."]

[I noted that the landing ellipse (about 19 km by 5 km) contains perhaps two or three dozen craters bigger than West Crater, although it's one of the largest in the southwest quadrant of the ellipse.]

[Armstrong - "You can see from this picture (meaning figure 5-8), it does look like it's a somewhat more sharp-edged crater than this one, which is more weathered."]

[Aldrin - "Now, where's the Cat's Paw? Wasn't it out in front of us? 'Cause we saw it on lift-off."]

[The Cat's Paw is a cluster of craters directly west of the landing ellipse. The eastern most point is at L.0/2.0 on the far left on map LAM-2 and is about 5.6 km from the landing site at about J.65/7.52. It is also shown in a labeled version of overhead photo AS11-37-5447. Finally, in the post-landing panorama taken out Buzz's window (123k), the hill on the horizon beyond the tip of the LM shadow and the similarly-sized hill farther to the right are part of the Cat's Paw rim, as can be seen in a comparison of a detail from 5447 with portions of frames AS11-40-5882 and 5882a from Buzz's plus-Z pan. The sector encompassed by the yellow lines in each image is about 25 degrees. I have not attempted to correlate the 'hills' seen from the landing site with specific features in Cat's Paw rim as seen in the overhead view.]

[Armstrong - "I don't think we ever knew this one (meaning West Crater) was here."]

[At at 123:55:23, about a half hour before LM liftoff, Ron Evans tells Mike that the LM is "just west of West Crater, Juliett 0.5, 7.7. Over." This suggests that the crater had been named before the flight; but I am unaware of any pre-flight map that would provide confirmation.]

[Finally, we have the following from the Crew Observations chapter of the Apollo 11 Preliminary Science Report - "This crater was later identified as one we had informally called West Crater during our prelaunch training."]

114:47:12 Armstrong: Okay. Thank you.

[Comm Break]

114:49:14 Aldrin: Roger. Will do.

[Comm Break]

114:52:27 Armstrong: Go ahead, Houston.

114:52:28 Garriott: Roger. Two more verifications, here. Will you verify that the disk with messages was placed on the surface as planned, and also that the items listed in the flight plan - all of those listed there - were jettisoned. Over.

114:52:48 Armstrong: All that's verified.

114:52:51 Garriott: Roger. Thank you, and I hope this will be a final good night.

114:52:57 Armstrong: Okay.

[Armstrong - "I think what he (Garriott) was referring to was the silicon disks that had the replicas of all the messages to the United States from various world leaders."]

[Aldrin - "That was in the pocket."]

[At 115:50, Public Affairs reports that the Surgeon doesn't believe that Neil is closer to sleep than "dozing". Buzz is not being monitored. In orbit, Collins is sound asleep.]

[At 116:50, Public Affairs reports that the Surgeon says Neil is 'resting' but not asleep. This recording includes a detailed status of consumables.]

[At 117:50, Public Affairs reports that the Surgeon says Neil may be 'dozing' but is not sleeping soundly or well. His heart rate drops into the 50s, but not for long.]

[At 118:50, Public Affairs reports that Mike Collins is sleeping soundly; Neil may be sleeping fitfully, if at all. Cabin temperature is 61F (16C)]

[At 119:51, Public Affairs reports that Neil has not been sleeping. His heart rate occasionally drops into the 50s - the "sleep range" - but does not stay low.]

[I asked if there were any comments they wanted to make about the sleep period.]

[Armstrong - "We had one pump..."]

[Aldrin - "I don't remember being troubled too much by the noise."]

[Armstrong - "I think it was my position (that) was bothered by the noise 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 of some kind to hold my legs, hanging from something up there. 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."]

[I speculated that the back of the cabin was small enough that Neil's legs would have hung over the front, then we found Buzz's statement at 121:41:02 indicating that Neil had used one of the waist tethers to keep his legs suspended. See the discussion following 121:41:02.]

[Armstrong - "Yeah, I suspended them. I rigged up a loop to hold my legs. And the other thing was (that) the Earth was coming through the AOT (Alignment Optical Telescope). (Chuckling) We had blinds over the windows and so on, but the Earth was coming through the AOT. We were all settled down and we realized that we still had a light source coming from something. We rigged up something to hang something over the top of the AOT to cut that out."]

[The accompanying photo by Stacey O'Brien shows her husband, Journal Contributor Frank O'Brien, lying on the floor of a LM simulator on display at the Cradle of Aviation Museum.]

[I asked about pressure points.]

[Aldrin - "We tried it with the helmets off, at first, but that didn't...We thought we might, somehow, be warmer with the helmets on and we probably ended up that way."]

[Armstrong - "I don't remember a pressure point problem."]

[Aldrin - "If there was, you'd move some way to avoid it."]

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

[Aldrin - "I'd say the same thing."]

[Armstrong - "And for a lot of physical reasons that I mention (in the tech debrief, see below); and also, I'm sure, just the (problem of) getting unwound from the excitement of that day was contributing, too."]

[Aldrin - "I guess I may have mentioned it before but, maybe again, it seems almost inconceivable that you can't afford to monitor two people. It seems a little hokey for a nation to be sending people to the Moon..."]

[The following is a section of the Technical Debrief subtitled 'General Lunar Surface Fatigue'.]

[Armstrong, from the 1969 Technical Debrief - "I wasn't tired at all. I worked real hard at a high workload right there near the conclusion (of the EVA) when I was pulling the rock boxes up. We knew that was going to be hard, plus the fact that we were racing around a little bit towards the end, trying to get everything thrown into boxes and getting all the pieces put together. I expect my heart rate ran up pretty good right there (it peaked just below 160 beats per minute), but I had a lot of energy and reserve at that point, because we had been sort of taking it easy all through the EVA."]

[Prior to the final burst of activity, neither Neil nor Buzz had a workload comparable with those regularly undertaken by later crews. The purpose of the Apollo 11 EVA was to demonstrate that useful work could be done and grab a few samples; but, with the landing accomplished, their main job was to get home safely and there was no point in pushing limits and risking fatigue for the all-important launch and rendezvous.]

[Armstrong, from the 1969 Technical Debrief - "Everything was, with a few exceptions, accomplished with a comfortable workload. We didn't have to work hard throughout the whole timeline, and I knew I could afford to race around there for 5 or 10 minutes without jeopardizing the operation at all. They called for a status check (a veiled request that he slow down) and I gave them one and we proceeded, but there wasn't a problem with respect to available energy and reserve."]

[Aldrin, from the 1969 Technical Debrief - "I think that the fact that you're well cooled off enables you to absorb a fair amount in an increase of activity before it manifests itself. The oxygen flow rate concerned me a little bit pre-flight because I found, in doing some fairly strenuous exercise in the thermal vacuum chamber, that the first indication I got was that there was not quite enough circulation of oxygen to breathe. It tended to get a little stuffy in the helmet. (Here, Buzz changes the subject to the workload involved in launch and rendezvous) I think all of us who have been through this business (in the simulators) know a good bit about the pace of activities following insertion (into lunar orbit), which is rather leisurely taken. However, you can get wrapped around the axle doing a lot of different things that aren't required (in a normal launch and rendezvous) - many of them are doing things just to say you can add more and more solutions. Therefore, to carry out a minimum-rendezvous effort is not, as I would see it, a very tiring task to look forward to after descent and a prolonged EVA. I think we would have been fully capable of carrying out a lift-off and rendezvous (right after the EVA, had one been required)."]

[Armstrong, from the 1969 Technical Debrief - "We handled one."]

[Aldrin, from the 1969 Technical Debrief - "You just are not going to get any sleep while you're waiting for it to be completed, but you're certainly not going to be completely bushed chasing yourself around the cockpit. With the automatic radar, lift-off and rendezvous are fairly leisurely exercises. I guess I'd have more concern about Mike's ability to continue, because he's quite active moving back and forth and doing a lot of manual tasks with the sextant that we didn't have to do."]

[Armstrong, from the 1969 Technical Debrief - "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, from the 1969 Technical Debrief - "We wouldn't be breathing all that dust."]

[Armstrong, from the 1969 Technical Debrief - "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."]

[Aldrin, from the 1969 Technical Debrief - "I guess the question is: can you keep it cleaner? I guess you could keep it a little cleaner, but there are so many things going in and out that it's almost impossible to avoid getting a significant amount of lunar material in there."]

[The Apollo 12 crew had an even worse problem with dust and, for the remaining missions, the solutions that seemed to help were (1) dusting each other off as thoroughly as possible with a house-paint-sized brush before going up the ladder; (2) stomping their feet on the ladder to get more dust off the boots and lower legs; and (3) putting the suit legs into spare jettison bags between the EVAs.]

[Armstrong, from the 1969 Technical Debrief - "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."]

[Aldrin, from the 1969 Technical Debrief - "You can't see what's going on outside, but you can come quite close to it."]

[Armstrong, from the 1969 Technical Debrief - "For example, you can see the horizon out there through the window shades. There's that much light that comes 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, from the 1969 Technical Debrief - "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."]

[As detailed on pages 9 and 10 in Apollo Experience Report - Protection from Radiation, the tips of the toggle switches in the LM cabin contained "microspheres of promethium-147 (2.6-year half-life) bound with a phosphor that produces light by interaction with the short-range promethium-147 beta radiation." The switch tips were made of Kel-F plastic. The microspheres were encapsulated in glass and then sealed with epoxy into a cylindrical hole the Kel-F switch tip. Paul Fjeld calls attention to a 1968 Grumman photo showing a LM panel with the tips in place. The tips were removed from all the remaining LMs and simulators long before this paragraph was written in April 2011. Harald Kucharek calls attention to a 2009 briefing by Michael Interbartolo (NASA JSC), indicating that the docking targets were also radioluminiscent.]

Armstrong, from the 1969 Technical Debrief - "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, 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.]

[Aldrin, from the 1969 Technical Debrief - "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 (before the rest period) - I'm not sure that there's much (quick) control over that (meaning the temperature in the suit) anyway. We finally disconnected the oxygen flow."]

[Armstrong, from the 1969 Technical Debrief - "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."]

[The following is from Section 9.10 in the Apollo 11 Mission Report: &quot:During the sleep period on the lunar surface, the crew reported that they were too cold to sleep. Analysis of the conditions experienced indicated that once the crew were in a cold condition, there was not enough heat available in the environmental control system to return them to a comfortable condition. Ground tests have indicated that in addition to the required procedural changes which are designed to maintain heat in the suit circuit, blankets will be provided and the crew will sleep in hammocks."]

[Aldrin, from the 1969 Technical Debrief - "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, from the 1969 Technical Debrief - "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, from the 1969 Technical Debrief - "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, from the 1969 Technical Debrief - "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, from the 1969 Technical Debrief - "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, from the 1969 Technical Debrief - "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, from the 1969 Technical Debrief - "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 and gloves off, kept the flow of cooling water off, and slept in hammocks.]

[The Apollo 12 crew 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 and 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.]