Trying to Rest

Rendezvous and Docking (AFJ)

 

The Return to Orbit

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.
Except where noted, audio clips by Gordon Roxburgh.
Last revised 5 October 2017.

MP3 Audio Clip (50 min 59 sec; 47 Mb) from the Public Affairs loop starting at about 120:59:00. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.

[Astronaut Ron Evans takes over as CapCom and makes the wakeup call to Mike.]

120:59:04 Evans: Columbia, Columbia; good morning from Houston.

120:59:12 Collins: Morning, Ron.

120:59:14 Evans: Hey, Mike, how's it going this morning?

120:59:17 Collins: (Not having heard Evans yet) How goes it?

120:59:18 Evans: Hey, real fine. While you're...

120:59:20 Collins: (Answering Evans' "how's it going?") I don't know yet, how's it going with you?

120:59:23 Evans: (Chuckles) Real fine here. (Pause) Columbia, request P00 and Accept. We'll shove the state vector in for you right away. (No answer; Long Pause) Okay. It's coming up now, Columbia. We're going to keep you a little busy here. As soon as we get the state vector in, we'd like you to go ahead and do a P52 option 3 on this night pass, and then when you come on around the other side there, we'll give you some landmark tracking information on prime 130.

121:00:29 Collins: Okay.

121:00:34 Evans: And for your information, we're also going to have Tranquility Base do a P52 (means P22, tracking the CSM with the LM's rendezvous radar) when you come around the other (means 'next') time. And I have the P22 (landmark tracking from the CSM) information if you're ready to copy. (Pause)

[In a 2010 book, From the Trench of Mission Control to the Craters of the Moon, H. David Reed, who was Flight Dynamics Officer (FIDO) for the Apollo 11 LM liftoff, details the story behind this unscheduled request for a P22 one orbit before liftoff. Briefly, he and his support team needed an accurate LM position so they could pick a liftoff time that would minimize propellant usage. The various estimates available at that time were scattered over a considerable area. They needed something better. After extensive discussions within the team, Reed choose a method suggested by Pete Williams, the COMPUTER DYNAMICS officer: they would track the CSM with the LM's rendezvous radar and, then, using a separate, accurate determination of the CSM's orbital track over the landing site (as discussed at 121:07:37), work backwards to find the LM.]

[In a June 2011 e-mail, Reed adds: "For Apollo 12 (and subsequent), as you know, we wanted to do a 'pin point' landing, which we had discovered would be impossible without a real fix in LM position before landing. This was accomplished by implementing a post DOI (Descent Orbit Insertion), doppler-tracking scheme devised by Emil Scheisser of MPAD (Mission Planning and Analysis division). The ground would compute the predicted downrange error and send that correction to the crew prior to powered descent ignition. It allowed us to land within a few hundred feet or less of the desired landing site."]

121:00:56 Evans: Okay. Track landmark 130 prime using P22; and for information, this will properly position your rendezvous radar transponder. T1 is 122 plus 16 plus 05...Whoops, okay. Stand by. (Long Pause)

121:02:04 Evans: Columbia, Houston. The computer is yours. (Pause)

121:02:12 Collins: Okay. And I'd like the grid square of this crater 130 prime. Over. (Pause)

121:02:24 Evans: Columbia, Houston. Say again about 130 prime.

121:02:31 Collins: I'd like its grid square, please.

121:02:35 Evans: Roger. Stand by.

[Comm Break]

121:05:08 Collins: Go ahead.

121:05:09 Evans: Roger. I have the T1 and T2 times and also the lat-longitude of the 130 prime. We're working on the grid squares and we'll get them shortly.

121:05:26 Collins: Okay. Ready to copy.

121:05:28 Evans: Okay. T1: 122 plus 16 plus 05. Tango 2 (that is, T2) is 122 plus 21 plus 11, and 6 miles north of track. And do you want your Noun 89 values?

121:05:58 Collins: Yes, please.

121:06:00 Evans: Roger. Latitude: plus 01.243. Longitude over 2: plus 11.844. Altitude: minus 001.46. Over.

121:06:32 Collins: Copy T1: 122:16:05. T2: 122:21:11, 6 miles north, Noun 89 is plus 01243, plus 11844, minus 00146.

121:06:51 Evans: Columbia, affirmative. And at the T1 time, put your rendezvous radar transponder switch to Operate.

121:07:05 Collins: All right.

121:07:06 Evans: And this 130 prime is the same one that you tracked prior to descent. Over. (Pause)

121:07:23 Collins: Okay. (Pause) You've updated your information as to the LM's position and this is your best estimate of where the LM is, is that correct?

121:07:37 Evans: Columbia, that's a negative. This 130 is the little bitty crater there that you tracked - John Young's crater - that you tracked prior to descent. (Pause) And we want that...

[John Young used this crater for tracking purposes during Apollo 10.]

121:07:53 Evans: Affirmative. We want this for one last fix on your (orbital) plane.

[That is, Houston wants to be sure that they know Columbia's orbit in as much detail as possible. Tracking data from the Command Module on John Young's crater will help refine solutions to the Earth-based tracking data they have on the CSM. With an accurate CSM orbit in hand, the FIDO team will be able to determine the LM location with sufficient accuracy. At 122:24:51, Mike reports that he got five good marks (location determinations) on the crater.]

121:08:05 Evans: And when the LM does his P22 on your transponder, well then, that'll be our last shot at the LM's position.

121:08:14 Collins: Rog. Understand. (Pause)

[The LM crew will track the Command Module as it passes over the landing site for the last time prior to launch and, with the Command Module orbit well known, in principle the tracking data will help pin down the landing site. At 123:55:23, about a half hour before liftoff, Ron gives Mike a final LM location of J.5/7.7, which is only about 200 meters from the actual landing site at J.65/7.54. Mike will be too busy during that pass over the landing site to look for the LM.]

121:08:35 Evans: Rog. It'll be on Warm-up prior to that time, and you can go to Operate anywhere around that time.

121:08:44 Collins: Yeah. I got it on its 24-minute warm-up now.

121:08:47 Evans: Roger. (Pause) And (Columbia), Houston. The computer is yours, you can go to Block anytime.

121:08:59 Collins: Roger. Block, going P52, option 3.

121:09:02 Evans: Roger. And we'll see you coming around the other side. About 1 minute to go, and all your systems are looking good.

121:09:11 Collins: Thank you, Ron.

[Very Long Comm Break. Evans now makes the wake-up call to Neil and Buzz.]

121:40:45 Armstrong: Good morning, Houston. Tranquility Base. Over.

RealAudio Clip ( 10 min 20 sec )

121:40:49 Evans: Roger. Loud and clear. And how is the resting standing up there? Did you get a chance to curl up on the engine can?

121:41:02 Aldrin: Roger. Neil has rigged himself a really good hammock with a waist tether, and he's been lying on the ascent engine cover, and I curled up on the floor. Over.

[There were two waist tethers in the LEC-Waist Tether Kit. The tethers were primarily intended for use during an EVA transfer to the CM, should that be necessary. The one Neil used to suspend his legs was not the one Buzz took outside and hooked to the porch rail for possible use as a lanyard. See a labeled detail from AS11-40-5868, one of Neil's shots of Buzz coming down the ladder.]

[As it turns out, the waist tether that was among a number of Eagle artifacts Neil returned to Earth in the Apollo 11 Purse is the one Neil used to suspended his legs from the AOT guard during the rest period. A full discussion includes the discovery of yellow paint flecks on the inside surface of the large hook on the returned tether that provides convincing evidence that the returned tether was the one Neil attached to the AOT guard. Ulli Lotzmann has done a sketch showing a waist tether attached to the AOT guard.]

[See a discussion at 121:00:34.]

[See Fred Martin's discussion of this issue. He was a real time participant in the effort to understand the program alarms that occurred during the descent.]

121:42:14 Evans: Tranquility Base, Houston. I missed that. Say again.

[Aldrin - "I was just arguing with him."]

[P22 is the program that uses the rendezvous radar to track the Command Module. P57 is the platform alignment program. Readers should note that, although some of the detail was a little fuzzy after 22 years, neither Neil nor Buzz hesitated in remembering the basic purpose of these programs.]

[Armstrong - "My guess is that (P57) was the gravity align plus a star alignment."]

121:42:33 Evans: Roger. We copy that. But there's a greater duty cycle on...There's a good 15-percent duty cycle on the ascent program there, so just go ahead and leave it off. And I have the changes there if you want to get out your surface checklist, and I can go ahead and start giving them to you.

121:42:59 Aldrin: All right. Go ahead. I've got it out.

121:43:01 Evans: Okay. Before we start here, request P00 and Data, and we'll give you some vectors. (Long Pause)

[While Neil and Buzz get themselves ready for the morning's activities, Houston will send up a new state vector. They are at the top of checklist page Sur-48.]

121:43:25 Evans: Okay. And on Surface (checklist page) 50 will be the first change there. (Pause)

121:43:35 Aldrin: Okay. And I understand you want us to do a P57 option 3 and then a P22, is that the general idea? Over.

[Neil and Buzz know the procedures and the likely variations that Houston could give them quite well and, knowing what Houston wants to do, can check to make sure that the changes make sense.]

121:44:21 Aldrin: Roger. Understand that's 122:15, "Do P22 as per PGNS-20, G&N dictionary."

121:44:29 Evans: Roger. Okay. Let's skip on over to Surface-59. (Long Pause)

[I asked about writing implements.]

[Aldrin - "The one I liked to use was sort of a...It wasn't exactly a felt tip, but it was a composite. It seemed to flow out with a bit more ink than the Fisher (Space Pen). It just gave a bolder stroke."]

[The following changes refer to circuit breakers.]

[In response to a question from Journal Contributor Thomas Schwagmeier about the acronym AELD, Frank O'Brien writes, "The Ascent Engine Latching Device was the electronics assembly that controlled the sequencing of the explosive bolts for staging, and then ascent stage engine ignition. Because the need for reliability in the Ascent engine is so high (consider the bad day you would have if it shut down early and couldn't be restarted) the 'engine on' signal was 'latched'. The manual says it was a 'memory circuit' that maintained the engine-on signal in the event the automatic 'on' signal was lost. Engine shutdown was accomplished only by an explicit 'engine off' command by either an automatic (I'll assume this to be the PGNCS/AGS) shutdown command or a manual shutdown command." O'Brien suggests that the "memory circuit' "didn't look like any memory we think of today - most likely a flip-flop circuit."]

[Journal Contributor Phil Karn suggests that it may have been a "a good old-fashioned electromechanical relay. It'd be easy to wire the contacts to keep its own coil energized once it had been pulled in with a momentary 'on' pulse. I've actually been somewhat surprised at the number of electromechanical relays in Apollo systems given the inherent limits on their reliability. Perhaps at the time they were still considered more reliable than the early semiconductor ICs (Integrated Circuits) of the day."]

[O'Brien agrees that the 'memory circuit' could have been a relay but adds, "My only argument for a non-electromechanical implementation was that the manuals are *usually* careful about stating that a relay is used. Also, remember that, by the mid-1960's, transistors were being made by the 100's of thousands, if not millions, and had made it through most of their early teething problems. This is in contrast with the early IC's used in the AGC (Apollo Guidance Computer) in the 1961-1962 time frame. Major advances in fabrication were needed to bring reliability up to acceptable levels."

[Aldrin - "The reason for that query may be that there are a lot of switches and a lot of circuit breakers with names which are the same. So what we did in the checklist was, wherever it came to a circuit breaker, we put 'CB(11)'. That meant it was on one side or the other (Neil's in the case of panel 11). So we knew what was going to happen afterwards, and that it was a circuit breaker. Because if it didn't say that (CB(11) or CB(16)), then it was a switch. And we knew where the switch was on the panel. We got to that point through sufficient amount of confusion and 'Well, are we talking about the circuit breaker or the switch'? And it would have eased that if he (Evans) had said 'Circuit breaker such and such.' But, you know, that's kind of nitpicking."]

[A discussion of the use of circuit breakers versus switches is linked here

121:47:02 Aldrin: Roger. I have those two.

121:47:04 Evans: Okay. Let's go over to Surface-60, and then down the middle of the page, after "Launch guidance system recommendation from MSFN", then I add the switches there. (Pause)

121:47:37 Aldrin: Rog. Go ahead there.

121:47:38 Evans: Okay. After "Launch guidance system recommendation from MSFN", add (reading slowly) "Descent Propulsion Fuel Vent, Open"; add "Descent Propulsion Oxidizer Vent, Open"; add "Verify Talkback, Gray". Over. (Pause)

[Aldrin - "That's like a window flag. You got to know the name of the game. Talkback is one or two indicators behind a window. In some cases they were red and in some cases they were striped; and, if it was neutral, usually it was gray."]

[That is, the window would show red or a red-stripe pattern to show a positive indication, and gray for a neutral indication.]

121:48:29 Evans: Roger. You got that one, so that'll be the last vent and it will continue venting. Skip over to Surface-61 down there at "TIG minus 17". (Long Pause)

121:49:10 Aldrin: Roger. I'm there. Go ahead.

121:49:12 Evans: Okay. At TIG minus 17, delete "CB(11), AC BUS A: Rendezvous Radar, Close, wait 30 seconds"; delete "PGNS: Rendezvous Radar, Close"; and then add "Up-Data Link switch to Voice Backup". Over

121:49:47 Aldrin: Roger. I have that. We'll leave those two circuit breakers open, and have the Up-Data Link to Voice Backup; and we'll make the appropriate changes on the following circuit breaker status card.

[The circuit breaker cards in the checklist show the desired status of the panels. A white dot on the card indicates that a breaker is supposed to be open, while a black dot indicates a breaker that is supposed to be closed.]

[Aldrin - "We came up with this (idea of the circuit breaker cards). I don't think it was done on previous (flights)...maybe it was. But in all the damn things that were happening, occasionally you want a summary of where things are. So we printed a map of these and colored them in black or white, so you can just look along it. (If) you tried to use a (written) summary of where things ought to be and read 'em off while you're looking (at the panel), and looking and reading and...God, it's a mess! But, if you've got something like this, you can just look at it and see where the open ones are and go right along the row. But, when he (Evans) was reading up these changes of things, that was in the text, so you've got to correct the text and the card, too. Which just points out how updating checklists is a difficult thing to do. One of these days, I'm sure - if we're not there already - you get it done by a computer, or the computer will do both."]

[Aldrin - "And, in retrospect, there are a lot of valves for which the switch (setting) is 'closed' or 'open'. It seems to me there are not too many that are 'in' and 'out'. So, a nomenclature of 'In' and 'Out' on circuit breakers might have been a little better description (than 'Open' or 'Closed'). Less confusion."]

121:50:35 Aldrin: Okay. We'll put it in AGS.

[During the ascent, the tapemeter could show range and range rate based on data from either the PGNS (Primary Guidance and Navigation System) or the AGS (Abort Guidance System).]

[Armstrong - "The same meter can show you altitude and altitude rate if it's on the landing radar."]

[In an effort to prevent a re-occurrence of the computer alarms that were experienced during the landing, Houston is reducing the PGNS workload by using the AGS to drive the tapemeter.]

121:51:08 Aldrin: Okay. Then it looks to me like we ought to get hopping on this P57.

121:51:21 Evans: Roger. We agree wholeheartedly. And while you're starting on that, I'll just read these notes on P22. Call P22 possible program alarm 526, range greater than 400 nautical miles, and then use the P22 as described on PGNS-20. Take option 1 in Noun 06, and use the no-update mode. The rendezvous radar will lock on at about 25 degrees elevation above the horizon. If 503 alarm occurs, designate Fail. Key a Proceed and allow the rendezvous radar to search for the CSM. And place the range altitude monitor switch in altitude/altitude rate to prevent the tape meter from driving into the stops. And press on.

121:52:29 Aldrin: Roger. I think I have that.

[Long Comm Break]

[Ron calls Mike at Command Module AOS.]

121:58:18 Evans: Columbia, Columbia, Houston. Over. (No answer; Long Pause) Columbia. Columbia. Houston. Over.

121:59:33 Collins: Houston, Columbia.

121:59:35 Evans: Roger, Columbia. We'd like a Cryo(genics tanks) stir - all four tanks - and the standard 1 minute. Over.

121:59:47 Collins: In work.

[Mike will activate small fans in the tanks to stir the contents. According to Gerry Griffin, as the tanks emptied in zero-g, the contents tended toward a "slush", a mixture of liquid oxygen (or hydrogen, depending on the tank in question) and gas. With the content in the slush state, Houston could not be sure of uniform flow out of the tank or of accurate measurements of the amount of oxygen remaining. By stirring the contents with a fan, they homogenized the mixture and got both more uniform flow and better gauge readings.]

121:59:55 Collins: Roger. Stand by one. (Long Pause)

122:00:12 Evans: Tranquility, Houston. Request Error Reset at this time. Over.

122:00:21 Aldrin: Roger. Error Reset, and would you tell me when you're satisfied with the LGC self-test? (Pause)

[The self-test is a routine that checks to see that memory in the LM Guidance computer is in the proper configuration for launch.]

122:00:36 Aldrin: Roger.

[They are on checklist page Sur-48, near the middle of the page.]

122:00:41 Evans: Columbia, Houston. Go ahead.

122:00:51 Collins: Roger. Stars 25 and 42; star angle difference 5 balls (meaning five zeros); Noun 93, plus 00165, plus 00186, minus 00039, time of torquing 121:15. Over.

122:01:12 Evans: Columbia, Houston. We copy. Thank you. (Pause)

122:01:26 Collins: And Cryo stir complete.

122:01:29 Evans: Roger. Thank you, Columbia.

[Long Comm Break.]

[Frank O'Brien writes, "At this point, Buzz is performing an alignment of the LM's inertial platform. Rather than the traditional Program 52, which requires sighting two stars through the AOT, Program 57 is used. All platform alignments require determining the exact position of two references is space, which is all that is necessary to determine the platforms orientation to any reference. Normally, stars are used as the references, as they combine the necessary quality of being in fixed, well-defined locations in the sky. Program 57 does use one star for its orientation, but the fact the LM is on the surface allows the platform to use another well understood reference: the gravity field of the moon. Thus, performing a fix on a star, and sensing the gravity vector for its second directional reference supplies all the information necessary for the computer to align the platform to a known orientation."]

["Using gravity to help align the platform is not a radical concept, and a variation known as gyrocompassing is used on the Command Module before launch. Because this is the first lunar landing, engineers are especially eager to see how well gravity alignments perform on the Moon. The procedure Buzz uses requires him to enter a Verb 32 to 'recycle' Program 57, allowing him to preserve some of the data previously entered, and start the program from the beginning. Recycling saves time, and allows the engineers on the ground time to observe the performance of the alignment. If the data shows something is amiss in Program 57, it can be terminated, and the familiar Program 52 alignment is used."]

["In his next transmission, Buzz's 'Verb 604' is a informal contraction of the sequence Verb 06 Noun 04 (appearing as the line '06 04 +____ Gravity Err(or) Angle' near the top of page Surf-50), which is a request to show the difference between the platforms orientation and that which was calculated by the gravity alignment." ]

122:05:47 Evans: Tranquility, Houston. We copy. Stand by one. (Pause) Tranquility, Houston. Request recycle.

[Long Comm Break.]

[Aldrin, from the 1969 Technical Debrief - "On P57 before lift-off, the Sun moved up in the field-of-view, as did all the rest of the stars. The Earth stayed the same. The Earth obscured the forward detent and the right detent. The Sun was now in the rear detent, and for some reason, it also obscured the left-rear detent, which was the one I was counting on using with Rigel. This was the one we had used before. I was quite surprised to discover this. The Sun was not within more than 15 degrees of the total field-of-view. It completely obscured the left-rear detent. It effectively left us two out of the six detents to pick stars from. Looking at those two detents, there weren't any stars near the center. The closer to the center you get (that is, the closer to the center the star you sight on is), the greater the accuracy is. The day before, we had used Navi, and it wasn't particularly bright. So I went back, and now used Capella, but it was fairly close to the edge of the field-of-view."]

[The star known as Navi was named for Virgil Ivan "Gus" Grissom. Navi is Ivan spelled backwards.]

[Aldrin, from the 1969 Technical Debrief - "So we did a gravity, one-star alignment and that first gravity alignment came up with 00010. Verb 32 gave us 00001. We used a sequence of markings that involved an onboard averaging of five successive cursor readings, followed by depressing the Mark button, and then five successive spiral readings that Neil would log down as I would read them off. Then he would average these up and we would put them in. We'd use either spiral or cursor first, which ever appeared to be convenient. I think this averaging technique worked out better than letting the computer do it, because it would have amounted to a considerable rotating of the spiral-and-cursor reticle field back and forth to make one spiral, then a cursor, then a spiral, and do a recycle. There is the option, however, to do one or the other. This was a REFSMMAT alignment. The torquing angles were fairly large (that is, the indicated change in orientation of the inertial platform). The star-angle difference was 00007 (0.7 degrees difference between the measured position of the star and the location expected based on the platform alignment) which, pre-flight, was the expected value of a two-star alignment. Torquing angles were very close to 0.7 in all three axes, which indicated that the platform did drift a fair amount during that time period (since the last alignment performed prior to EVA Prep)."]

122:11:52 Evans: Spacecraft calling Houston, say again.

122:11:57 Collins: This is Columbia saying the rendezvous radar transponder is operating.

122:12:02 Evans: Roger. Copy, Columbia.

[Comm Break]

[Comm Break. Houston's request that they close the rendezvous radar circuit breaker is in preparation for doing the P22 procedures on page PGNS-20 in the Apollo 11 Guidance and Navigation Dictionary, as per the handwritten note near the bottom of Sur-50 that they added at 121:43:44.. For Apollo 12, P22 procedures are shown on pages PGNS-21 and PGNS-22 in the Apollo 12 LM G&N Dictionary. The Apollo 12 procedures are likely to be the same to those in the Apollo 11 Dictionary.]

122:15:56 Armstrong: Roger.

[Comm Break]

122:17:01 Evans: Tranquility, affirmative. Go.

122:17:07 Aldrin: Roger. We're going to a torque.

122:17:10 Evans: Houston. Roger. (Long Pause)

[They are in the middle of checklist page Sur-51 at the step "PRO (Monitor Gyro Torquing)". Having completed the measurements of star positions and gravity direction which gives the new inertial platform alignment, they will now command the computer to move the platform to that new alignment.]

122:18:21 Aldrin: Roger.

[Comm Break]

RealAudio Clip ( 7 min 37 sec )

122:20:35 Aldrin: Houston, we'd like to check this on the tapemeter against the AGS. We'll go back to altitude-altitude rate as soon as the rate starts to build up. Over.

122:20:50 Evans: Tranquility, Houston. Roger.

[The NASA Public Affairs commentator reports that the LM rendezvous radar (LM-9 photo by Randy Attwood) has picked up the CSM transponder.]

122:21:31 Evans: Roger. Stand by one. (Pause) Tranquility, affirmative. Proceed. (Pause)

[They seem to be on checklist page Sur-52.]

122:22:04 Evans: Tranquility, affirmative, and we're saving it. (Pause) We've got four (data) points so far, and it's looking good.

122:22:18 Aldrin: Okay. What do you people think about calling up a Verb 83? (Long Pause)

[Verb 83 is not a step listed in the Surface Checklist. Buzz did his Ph.D. Thesis on orbital rendezvous and was extremely knowledgeable about the guidance programs and procedures. This suggestion to Houston is an indication of the depth of his knowledge.]

122:22:50 Aldrin: And we expect that we may lose lock when it passes overhead because of the Max rate that the radar has. (Pause)

122:23:05 Evans: Tranquility, Houston. Negative on Verb 83.

122:23:11 Aldrin: Understand. (Long Pause)

122:24:09 Aldrin: We just lost (radar) lock.

122:24:12 Evans: Tranquility, Houston. Go. (Pause)

122:24:23 Armstrong: We've just lost lock, Ron.

122:24:25 Evans: Roger. We had about twenty-some points before you did that. And for your information, the reason the AGS is a little different is because the K-factor is a little bit wrong.

122:24:40 Aldrin: Has he already gone...(Listens). Okay. Okay. Has he already gone overhead, or do you want to try and get it lock on again?

122:24:51 Collins: Houston, Columbia. You got Noun 49. Five good marks (on John Young's crater).

122:24:57 Evans: Tranquility, affirmative. Try to lock on again, and you'll lose him at about 29 minutes and 35 seconds.

122:25:09 Aldrin: Okay. Do you have a real quick procedure how to do that? (Pause)

122:25:21 Evans: Columbia, Houston. Say again about your Noun 49.

122:25:28 Collins: I say I got five good marks. You got Noun 49. When you get everything you need off the downlink, let me know and I'll proceed.

122:25:36 Evans: Columbia, Houston. Stand by one. (Long Pause)

122:25:56 Armstrong: Ron, did you say on the 526 alarm to proceed or do a Verb 32? (Pause)

122:26:03 Evans: Roger...

122:26:03 Aldrin: (Garbled) radar thinks the range is greater than 400 miles now.

122:26:13 Evans: Tranquility Base, Houston. Recommend you terminate P22. Over.

122:26:22 Aldrin: Roger. Will do.

[Houston has enough good radar tracking data and doesn't need any more.]

[Aldrin, from the 1969 Technical Debrief - "I had hoped (during the P22) to use the AGS to tell me where the Command Module was; but, unfortunately, we didn't update the AGS with the latest PGNS state vector, so it wasn't giving us good range and range rate. I would recommend doing that, if anyone does a P22 in the future, because you can't use the PGNS to tell you what the range and the range rate are. And you can't use the radar because it's not going to lock on until it gets to 400 miles (possibly because of a too-weak return). But the AGS gives you very good indications as you are approaching that range. So we were a little misled and I thought we were still out of range when we finally got the lock-on. You call up the program before the Command Module gets to 400 miles. It sits and waits; and, when it gets less than 400, it locks on automatically, and you see the signal strength grow and it starts to track. But it's in mode 2, so you don't see the needles doing anything; the cross-pointers move, indicating it's got rate drive going as it's trying to keep up with it. Because we didn't want to run the tapemeter into the stops, we left it in Altitude/Altitude Rate. We really didn't have much of an indication that any good information was coming in, other than signal strength. I guess the ground got the data on the downlink. When it broke lock, I thought the Command Module was overhead and (that) it had broken lock because of a maximum rate drive. The radar representative from RCA had indicated that the spec (that is, the radar system specifications) said it might break lock, but he didn't think it would as it went over the zenith. But, because of the AGS indications, I thought that was what had caused the break-lock. Evidently, it had gone out the front field-of-view. (Here, Buzz is mistaken. As Evans indicated at 122:24:57, they shouldn't have lost lock because of range until 122:29:35. For some other reason, they lost lock at 122:24:09.) It broke lock just a short time after the time given us by the ground for the zenith passage, so I was fully expecting to acquire it again. I don't think we had our AGS configured (properly) and the ground was not as helpful as they might have been had we run this sort of thing previously in simulations and had a bit more training on it."]

122:26:34 Collins: I have. I'm running fast.

122:26:36 Evans: Roger. (Long Pause)

122:27:14 Collins: I'm staying in P22 here a second just to record the Noun 89 and then I'll Verb 34.

122:27:21 Evans: Columbia, Houston. Roger. We copy, and that's good. (Long Pause)

122:27:57 Evans: Tranquility, Houston.

122:28:07 Aldrin: Roger. Go ahead.

122:28:09 Evans: Roger. Request S-Band Function Switch to Range. We're going to do some ranging on you. Also, I have an updated AGS K-factor when you are ready to copy. Over.

122:28:24 Aldrin: Roger. Go ahead with the K-factor.

122:28:27 Evans: Roger. 119 plus 59 plus 59 point 92. Over.

122:28:44 Aldrin: Rog. A little closer this time.

122:28:46 Evans: Yeah. It sure is.

122:28:47 Aldrin: 119:59:5992. Over.

122:28:52 Evans: Tranquility, Houston. Readback correct.

[Comm Break]

122:30:10 Evans: Columbia, Houston...

122:30:11 Aldrin: Houston, Tranquility. I see what you mean now about the K-factor.

122:30:15 Evans: Roger. (Pause)

122:30:23 Collins: This is Columbia. Go ahead. And I'd like to know about this P52 coming up. Is that the one I just completed or do you want a pair of them back to back?

122:30:36 Evans: Columbia, Houston. You do not need to do another P52 unless you want to. Break. And also, Columbia, when you get a chance, request Batt C and the Pyro(technics) readouts. Over. (Pause)

[The "Pyro readings" are voltage readouts on the batteries powering various explosive devices used later in the mission to jettison the LM and, just prior to re-entry into Earth's atmosphere, to jettison the Service Module.]

122:31:20 Evans: Columbia, Houston. Roger. We copy. Thank you.

122:31:28 Collins: Batt bus B is 37. Batt bus A is 36, or I'd think the gauge was stuck.

122:31:35 Evans: Roger. And you're looking good to us, Columbia.

122:31:43 Collins: Yes sir. Keep it that way. (Long Pause) Columbia is coming up on a Verb 45, Enter to reset the surface flag.

[Frank O'Brien writes, "The Surface Flag is essentially that - whether the LM is on the surface or not. I don't have time to go through the code, but I suspect it is used to see whether the LM state vector needs to be updated or not - or is updated only with the rotation of the moon." Verb 44 sets the surface flag, presumably to indicate that the LM is on the lunar surface. Verb 45 resets the flag to indicate that the LM is in flight. Presumably, once Mike has a fully updated LM state vector, he can do Verb 45 in preparation for the upcoming launch.]

122:32:22 Collins: Roger that. (Long Pause) And a crew status report from Columbia. I figure I got about 5 hours' good sleep, although you guys probably know better than I do.

122:32:52 Evans: Columbia. Roger. We copy. (Long Pause) Columbia, Houston. We've got a couple more vectors to send up to you. They'll be coming up shortly and then you can do the Verb 45 after you get those in. Over.

122:33:44 Collins: Okay. That's fine. Just wanted to make sure that we're both in Sync on the order (in which the procedures are done).

122:33:54 Evans: Roger.

[Comm Break]

122:35:44 Collins: (Static) Columbia. Rog. (Pause)

122:35:54 Aldrin: Houston, Tranquility. Be advised we've got...

122:35:57 Collins: (Garbled) on schedule.

122:36:01 Aldrin: ...(garbled under Mike) flags showing red right now. We just put a Verb 77 in. I believe that this is (garbled) (Pause)

122:36:20 Evans: Tranquility Base, Houston. We've got a lot of static down here. Could you say again?

122:36:31 Aldrin: Roger. We have four out of eight (garbled) talkbacks indicating red. We still have the circuit breakers out as of right now. I believe this is normal. We have just entered Verb 77 on page Surface-52 and are ready to proceed with the hot fire. Is it normal to have these four red flags? Over. (Pause)

[Talkbacks are little windows over the switches that show status. The window would contain either a grey square indicating normal status or a pattern of diagonal red stripes - called the barber pole - indicated abnormal or temporary status. A photo by Frank O'Brien shows RCS switches and talkbacks in a LM simulator. The three windows at the upper right clearly show the barber pole pattern]

[Verb 77, Enter ("V77E") is at the middle of the page. They are about to test fire the RCS thrusters to make sure those are all working normally. During the 1991 mission review, I asked if the hot fire rocked and/or shook the LM. Did they check the thrusters individually or all together?]

[Aldrin - "We exercised the controller so that it would give a command for each of them to fire. I don't think that we were verifying that they fired. But the ground was getting something. I'm pretty vague on that. Maybe we got the noise but it sure didn't rock any, or physically jolt."]

[Armstrong - "I don't think it moved much."]

122:37:28 Aldrin: Roger. They are reset.

[Aldrin, from the 1969 Technical Debrief - "We did an abbreviated RCS check. Because one of them was a cold-fire check, we got all the red flags coming on."]

122:37:44 Collins: Okay; going P00 and Accept.

[Long Comm Break; static clears. Buzz is about to start the final P57 on checklist page Sur-55.]

122:41:58 Aldrin: Houston, Tranquility. I used Capella in the last sighting (that is, for the P57 he did prior to 122:17:10), and it's a good ways near the edge. A good ways away from the center of detent 4. I'm wondering if it would pay any to use Alpheratz, star number 1. It might be a little closer. However, it would delay things a little, since I'd have to designate the radar out of the way. Over. (Pause)

[Buzz is indicating that the rendezvous radar is partially blocking the AOT detent he would use to observe Alpheratz and wants to know if Houston thinks it would be advisable to move the radar out of the way and make the observation. The alternative would be to use Capella, despite its relatively poor position in detent 4.]

122:43:19 Aldrin: Roger. (Pause)

122:43:30 Evans: And, Tranquility, Houston. The RCS check looked mighty fine to us.

122:43:37 Armstrong: It looked good up here. (Pause)

122:43:48 Evans: Columbia; Columbia; Houston. Over. (No answer; long pause) Columbia, Houston. Over. (Long Pause) Columbia, Houston in the blind. High gain: pitch minus 20, yaw plus 150. (Long Pause)

122:45:52 Aldrin: Houston, Tranquility. Could you give me the TIG portion of the ascent Pad so I can load it in for a P57? Over.

122:46:02 Evans: Tranquility. Roger. Stand by one. We want to wait on that P57 until about TIG minus 50 minutes. Over.

122:46:19 Aldrin: Roger. (Long Pause)

[Aldrin, from the 1969 Technical Debrief - "We started to do the (final) P57 (on Sur-55) and realized that this would be too soon before lift-off (TIG = Time of Ignition). It seems to me (that) we had a time period in which we were essentially standing by."]

[The P57 is scheduled for launch minus 45 minutes or 123:38 and, apparently, Houston has no interest in getting an hour ahead of the timeline. They will read up the Ascent Pad in about 5 minutes, as per checklist.]

[Comm Break]

122:50:39 Evans: Tranquility Base, Houston. Roger. (Long Pause) Columbia, Houston. Over. (Long Pause) Tranquility, Houston. I have your LM ascent and CSI data Pads when you are ready to copy.

122:51:33 Aldrin: We're ready to copy.

[They are at the middle of checklist page Sur-54. Because Buzz is busy with the AOT, Neil will copy the LM ascent pad. However, to do so, he has the Data Card Book in one hand and a felt-tipped pen in the other. Neil's not on Vox, so Buzz makes the call to Houston for him.]

[If, for some reason, they miss the planned launch opportunity, T14 would be the launch opportunity for the next CSM pass over the landing site. ]

122:53:26 Evans: Roger. Your crossrange for Noun 76...By the way, we may update this later, but now it is plus 0017. Over.

122:53:47 Armstrong: Roger. Readback follows. TIG 124:22:0000, 55349, 00322, plus 0017, plus 37104, minus 70470, plus 58604, plus 56936. LM weight 10837. T14, 126:20:12. Go.

122:54:30 Evans: Tranquility, Houston. Roger. Your readback correct. Now I have your CSI Pad.

122:54:50 Armstrong: Going to CSI Pad.

122:54:52 Evans: Roger. CSI Pad. TIG of CSI 125:19:3470; TIG of TPI 126:57:0000; Noun 81, 0532 plus 0000; FDAI, NA; DEDA 373, 03196; DEDA 275, 04170; Noun 86 plus 0532, plus 0000, plus 0012. Tranquility, readback.

122:56:21 Armstrong: CSI Apollo Pad follows. TIG 125:19:3470; TIG of TPI 126:57:0000; Noun 81, 0532, plus all zeroes; 373, 03196; 275, 04170; Noun 86 plus 0532, plus 0000, plus 0012. Go.

122:57:10 Evans: Tranquility Base, Houston. Your readback is correct. (Pause) And, Tranquility, no need for any Gyro compensation. It's Go.

122:57:26 Aldrin: Roger. Understand. (Pause)

[The Gyro Compensation step is just above "122:53" on checklist page Sur-54.]

122:57:34 Evans: Columbia, Houston. Over. (Pause) Columbia, Houston in the blind. Request high gain. Pitch minus 30, yaw plus 170. Over. (Long Pause)

122:58:35 Collins: Houston, Columbia on the high gain. Over.

122:58:38 Evans: Ah! Roger, Columbia. We still need to finish your (state vector) uplink there, and then I have your CSI and TPI times and also the lift-off.

122:58:53 Collins: Go ahead. Ready to copy.

122:58:57 Evans: Roger. LM ascent lift-off time: 124:22:0000. Your CSI TIG, (I) say again CSI TIG: 125:19:3470. Your TIG of TPI: 126:57 0000. And the LM's Noun 81 values for CSI: 0532 - that's 53.2 for Delta VX; Delta VY all zeros. Columbia, Houston. Over.

123:00:12 Collins: Roger. I readback lift-off TIG 124:22 even, CSI 125:19:3470; TPI 126:57 even; the LM's Noun 81 for CSI, 53.2 Delta VX. Over.

123:00:35 Evans: Columbia, Houston. Roger. Your readback correct. (Long Pause) Columbia, Houston. We're coming up with your second load now.

123:01:12 Collins: Roger that. (Long Pause)

123:01:49 Evans: Columbia, Houston. The computer is yours, and you can do your Verb 45 Enter now.

123:01:58 Collins: Roger. Going to Block and Verb 45 Enter.

123:02:02 Evans: Roger. (Pause)

123:02:11 Collins: How's the Black Team today? All primed and raring to go?

123:02:14 Evans: You bet you there, Mike.

123:02:20 Collins: Good (garbled).

[Long Comm Break]

123:05:43 Evans: Columbia, Houston. About 3 minutes to LOS, and I have your consumables update.

123:05:52 Collins: Ready to copy.

123:05:53 Evans: Roger. At 123 plus 00, RCS total minus 7 percent, Alpha minus 12 percent, Bravo plus 4.5, Charlie minus 7, Delta minus 6.5. Your hydrogen total minus 1.4 pounds; oxygen plus 1.7. Over.

123:06:40 Collins: Whoever figured those hydrogens and oxygens out a couple of days ago must have known what he was doing.

123:06:46 Evans: Okay. I think I read that oxygen (wrong), it's a plus seventeen pounds.

123:06:54 Collins: Roger. Still close.

123:06:56 Evans: Roger. (Long Pause)

[Unlike the reports on LM consumables, which are given in terms of percentage remaining, this CSM report seems to be in terms of deviations from the expected quantities remaining (or used) at this point in the mission. Jim Lovell, the commander of the backup crew joins the conversation.]

123:08:04 Armstrong: Thank you, Jim.

123:08:06 Aldrin: Thank you, Jim.

123:08:10 Collins: Glad to have all you big-room-full-of-people looking over our shoulders.

123:08:15 Armstrong: We had a lot of help down there, Jim.

[Comm Break]

123:10:32 Armstrong: And, Houston, Tranquility Base is going to give you a few comments with regard to the geology question of last night. We are landed in a relatively smooth crater field of elongate secondary...(correcting himself) circular secondary craters, most of which have raised rims irrespective of their size. That's not universally true. There are a few of the smaller craters around which do not have a discernible rim. The ground mass throughout the area is a very fine sand to a silt. I'd say the thing that would be most like it on Earth is powdered graphite. Immersed in this ground mass are a wide variety of rock shapes, sizes, textures - rounded and angular - many with varying consistencies. As I said, I've seen what looked to be plain basalt and vesicular basalt. Others with no crystals, some with small white phenocrysts, maybe one to less than 5 percent. And we are in a boulder field where the boulders range generally up to 2 feet with a few larger than that. Now, some of the boulders are lying on top of the surface, some are partially exposed, and some are just barely exposed. And in our traverse around on the surface - and particularly working with the scoop - we've run into boulders below the surface; it was probably buried under several inches of the ground mass.

123:12:55 Evans: Tranquility, Houston. Roger. Very fine description.

[Neil and Buzz probably do not realize just how compact the soil can be below a few inches depth and are mistaking the resistance of that very compact soil for buried rocks.]

[Aldrin - "A fine description. I would have been at a loss to describe it that well."]

[Houston's Astrodome has an outer diameter of about 420 meters. Inside, the area at playing-field level inside the permanent seating has a diameter of about 180 meters. The diameter of West Crater is about 165 meters.]

123:14:42 Armstrong: Roger.

123:14:45 Evans: And, Tranquility, I have a LM consumables update for you.

123:14:53 Aldrin: Roger. Ready to copy.

123:14:55 Evans: Okay. At plus 123 plus 00, RCS Alpha 78, (repeating) seventy eight percent, PQMD; Bravo is 76 percent PQMD; descent O₂ is 62, sixty-two percent. Descent ampere hours are 590...590 remaining; ascent ampere hours are 574, 574 remaining. Over.

123:15:41 Aldrin: Roger. Copy. Sounds very good. Thank you.

123:15:44 Evans: Roger.

[Comm Break]

[Journal Contributor Henry Spencer provides the following description of the Propellant Quantity Measuring Device (PQMD) that was part of the Reaction Control System (RCS): "The PQMD system is actually a bit complex, which may be why it got this acronym. What's sensed is the pressure/temperature ratio of the helium tank used to pressurize the propellants, which is directly proportional to the mass of the gas remaining in the helium tank. Knowing how much helium was in the system to start with, that gives the mass of helium in the propellant tanks. The propellant-tank pressure is regulated, so that gives helium volume in the propellant tanks. Finally, knowing the tank volume, that gives remaining propellant volume, shown as a percentage."]

123:18:41 Armstrong: Go ahead, Houston.

123:18:43 Evans: Roger. For your P57 here, we did a little looking around, and it looks like Sirius and Rigel out at detent 6 would be real good on that. The Sun angle on Sirius is about 43 degrees, and on Rigel, it's about 55 degrees. Over.

123:19:08 Aldrin: Roger, Houston. The only trouble is that the Sun is in number 5, the closed one. And it appears to also be close enough to detent 6 to shine on the far side of the cone. And it completely obscures detent 6. I'm unable to use that at all.

123:19:37 Evans: Okay. We understand it now. Thank you.

[Comm Break]

123:20:54 Aldrin: Roger. I don't think I could get it out now if I wanted to.

123:21:00 Evans: Roger. We copy.

[This is the breaker seventh from the left in second row of Buzz's circuit breaker panel (CB(16)), that he broke with his PLSS and reported at 112:56:28. Buzz undoubtedly closed the breaker while performing the configuration changes indicated on Sur-47, reporting after the mission that he used a felt-tipped pen to do so. See, also, a high-quality image of the Apollo 12 Controls and Displays.]

123:21:15 Evans: Roger. (Long Pause)

123:21:33 Armstrong: And by the way, Houston, our EVA antenna did retract.

123:21:37 Evans: Ah; roger. Mighty fine. Thank you.

[Comm Break. The EVA antenna provided a radio link with the PLSS antennas. It was located on the top of the spacecraft and was raised and lowered with a T-handle mounted in the cabin ceiling.]

[Armstrong - "It seems to me that it interfered with the docking. It was in the docking geometry volume."]

[Aldrin - "But how would we know it was retracted - if it's up there in the top somewhere? Oh, well. We're not going to build another one of those (LM's again), I don't think."]

[Although the antenna is on the top of the LM, it is at the back and would not have been visible in the LM shadow. See page 97 from the Apollo 11 Press Kit ( 8.9 Mb ). AS11-37-5451 is a down-Sun photo Neil took out his window after the landing. The rendezvous radar antenna is at the top of the shadow, one of the VHF antennas is next left pointing diagonally off the the upper left, and the RCS cluster outside Neil's window can be seen on the lefthand side of the shadow. ]

123:22:52 Aldrin: Roger. Go ahead.

123:22:54 Evans: Roger. It looks like you're going to have to re-position the radar here (to do the star sighting for the final P57 platform alignment). We suggest you may want to start your TIG-minus-45 minute point in the checklist at about TIG minus 50. Over.

123:23:10 Aldrin: Roger. Why do you think I need to move the radar?

123:23:14 Evans: Well, we thought that you probably wouldn't be able to get the star there. (Pause)

123:23:36 Aldrin: On the rear detents, the radar can be pointing plus-X, and I'll be using right-rear detent. That's okay.

123:23:44 Evans: Roger. That's fine then.

[Comm Break. Plus-X is straight up and the right-rear detent points northeast.]

123:26:00 Aldrin: Roger. Go ahead.

123:26:01 Evans: Okay. On Surface-57 there on your Verb 21 Noun 73 trunnion, leave it 180; the shaft we'd like 335. Over.

123:26:25 Aldrin: Roger. Understand. Shaft 335.

123:26:29 Evans: Roger. And if the steerable (high-gain antenna) doesn't quite hack it on lift-off, looks like the forward Omni is good for about 30 to 60 seconds after lift-off. And then the aft Omni antenna is good for the rest of the ascent. Over.

123:26:52 Aldrin: Roger. Copy. (Long Pause) Houston, we've got two angles here at 3 minutes in ascent. Would you confirm those? Pitch 134 and yaw minus 32. Over. (Pause)

123:27:25 Evans: Tranquility Base. Roger. We verify; those are correct.

[Comm Break]

123:30:46 Armstrong: Go ahead.

123:30:48 Evans: Roger. Eagle's looking real fine to us down here. We have a fairly high confidence that we know the position of the LM. However, it is possible that we may have a plane change; but, in the worst case, it would be up to 30 feet per second. And, of course, we don't expect that at all.

123:31:15 Armstrong: Okay. (Pause)

[Houston will get tracking data starting at lift-off and, if they decide that the LM is significantly north or south of the Command Module ground track, they would have to correct the LM orbit appropriately. A 30 fps velocity change is small compared with the 5000 fps speed they must achieve to reach orbit.]

123:31:24 Aldrin: Houston, Tranquility Base. Since we've still got plenty of time I think I'll go ahead and recycle on this 604.

123:31:38 Evans: Tranquility. Roger. That's okay with us, and we assume that the primary canister is still aboard. Is this correct?

123:31:52 Aldrin: We have one primary canister on board and one secondary. The other primary is, oh, out in front of the plus-Z pad. Over.

123:32:06 Evans: Rog. We copy. Thank you.

[Comm Break]

123:33:44 Aldrin: (To Houston) The PGNS looks consistent today.

123:33:47 Evans: Hey, that's affirmative, by gosh. Looking great.

[Very Long Comm Break. Buzz's next transmission may relate to the step "06 05" which is just below center on Sur-56. With telemetry, Houston has been able to follow along through the procedures.]

123:44:21 Evans: Tranquility Base. It's beautiful.

123:44:28 Aldrin: Okay. We'll proceed.

[Journal Contributor Thomas Schwagmeier suggests that means that he will push the Pro(ceed) button on the DSKY to start the 'gyro torquing' that comes at the end of the 06 93 lines on Sur-56.]

123:44:35 Aldrin: I know where the star is; I'm not sure the PGNS knows where gravity is.

123:44:39 Evans: (Chuckles) Okay.

[Long Comm Break. Buzz's next transmission may be related to the changed radar pointing angles on page Sur-57.]

123:48:04 Aldrin: Houston, these are your angles, not ours.

123:48:12 Evans: Roger, Tranquility.

123:48:13 Aldrin: And I'm standing by for some change or modification in the angles.

123:48:23 Evans: Tranquility Base, Houston. Recommend 334, and that should just keep it out of the limit.

123:48:32 Aldrin: Okay.

[Long Comm Break]

[Apparently, a shaft setting of 335 exceeded some limit and the computer rejected the setting. If so, Ron's phrase "keep it out of the limit" really means "keep it away from the limit."]

Post-EVA 16-mm film 2 min 16 sec (74Mb mpg) clip prepared by Ken Glover from material provided by Mark Gray. Mac users may need VLC for viewing.

[During this comm break, as per the last instructions at the bottom of Sur-57, Buzz gets the 16-mm DAC ready to film the ascent. He loads 16-mm magazine L into the camera (see the Apollo 11 Photography Index: 70mm and 16mm). He and Neil shot five sequences lasting a total of 2 minutes 17 seconds. Buzz shot the first two segments out the LMP window; Neil shot the third out his own window; and Buzz shot the remaining two. We can determine that these sequences were shot several hours after Buzz took the last Hasselblad photos; namely, a comparison of the locations of features in the LM shadow relative to a pattern of rocks, footprints, and disturbed soil just north of the shadow shows that the shadow features are much closer to the LM in the DAC film than in Hasselblad images such as AS11-37-5465. The Hasselblad images were taken at about 112:20:56 (0553 UTC on 21 July 1969), about eleven hours before now (1720 UTC on 21 July 1969). During that interval, the Sun rose from 15.6 degrees above the eastern horizon to 21.4 degrees. The LM is 7.1 meters tall, so the tip of the shadow moved from about 21 m west of the front of the LM to 18 meters. This change is consistent with the differences in shadow location between the DAC film and the post-EVA Haselblad images.]

[As discussed after 112:20:56, after the PLSS jettison at 114:10:37 but before the hot-fire check, Neil noticed that the orientation of the flag had changed, possibily because they hadn't been able to get the staff firmly planted, leaving the flag precariously balanced and prone to shift because of its own weight. Buzz took the DAC sequence linked above about an hour after the hot-fire check and, in the DAC sequence, we see the flag pointing north, perhaps having moved for a second time because of the hot-fire.]

[After Buzz finishes with the DAC, Neil and Buzz don their helmets and IVA (Intravehicular Activity) gloves and attach their waist restraints, as per Sur-58.]

[The accompanying photo by Mike Poliszuk shows Neil's and Buzz's IVA gloves on display at the Kansas Cosmosphere, Hutchinson, Kansas.]

[Mike calls Houston at AOS.]

123:55:23 Evans: Columbia, Houston. Roger. Loud and clear. And if you would like to take it down, we have the latest position of Tranquility Base. Over.

123:55:33 Collins: Go ahead.

123:55:36 Evans: Roger. It's just west of West Crater, Juliett 0.5, 7.7. Over.

[Details from Figure 5-8 (top) from the Apollo 11 Mission Report and from the flown copy of LAM-2 (bottom) show the area immediately around the LM. The center of West Crater is at about Juliett 0.54, 8.03, Little West Crater is at about Juliett 0.64, 7.58 and the actual landing site is at about Juliett 0.65, 7.52. Mike plotted the J.5/7.7 location on the flown copy of LAM-2, with the notation 'Last Bst Pos Prior L/O', where 'L/O' is (LM) 'lift-off'. The distance from the LM's actual location to J.5/7.7 is about 230 meters. This location is almost certainly from P22 data from use of the Rendezvous Radar to track the CSM. With the CSM orbit well know from tracking a certain small crater with the CSM sextant, the calculation was run backwards to determine the LM location. See the discussions following 121:00:34 and 121:07:37.]

123:56:01 Evans: Columbia, Houston. That is correct.

[Using a precision of 0.1, the center of West Crater is at J0.5/8.0 so J0.5/7.7 is about 300 m west from there. Ron Evans' answer to Mike's question isn't strictly correct, but it is impossible to know if this contributed to Mike's lack of success in spotting the LM shadow.]

[Aldrin - "He's talking to Collins about West Crater, so it must have been named that way prior (to the mission)."]

[I haven't found a map Mike would have had with the name on it.]

123:56:20 Armstrong: Go ahead.

123:56:21 Evans: Roger. Because of the lower load with the rendezvous radar off, we'd like to have battery 5 and 6 on the line now, 1 and 3 off. Over.

123:56:53 Armstrong: In work.

123:56:55 Evans: Roger. Thank you. (Long Pause) Columbia, Houston. You're still looking mighty fine to us.

123:57:43 Collins: Thank you. (Long Pause) Columbia is holding inertially at lift-off attitude, my DAP is configured as per my procedures at a time of 124:02.

123:58:19 Evans: Columbia, Houston. Roger. We copy you. (Pause)

123:58:36 Collins: I'm using B and D roll.

123:58:41 Evans: Tranquility, Houston. Say again.

123:58:51 Aldrin: Houston, we were not calling.

123:58:54 Evans: Roger. Columbia, was that Bravo and Delta roll? Over.

123:59:00 Collins: Columbia, affirmative.

123:59:03 Evans: Roger.

[Comm Break. During this Comm Break, Neil and Buzz are reconfiguring the LM switches, as per Sur-59 and continuing on to Sur-60.]

124:01:27 Evans: Columbia and Tranquility, I'll give you a Mark at 20 minutes to go, and that's in about 20 seconds. (Long Pause) Stand by.

124:01:59 Evans: Mark. 20 minutes.

124:02:06 Collins: Columbia. Rog.

[Comm Break]

124:03:26 Evans: Tranquility Base, Houston.

124:03:31 Armstrong: Go ahead.

124:03:32 Evans: Roger. Just a reminder here, we want to make sure you leave the rendezvous radar circuit breakers pulled (that is, open, to avoid a computer overload). However, we want the rendezvous radar mode switch in LGC, just as it is on Surface-59.

124:03:48 Armstrong: Okay. (Long Pause)

124:04:43 Evans: Tranquility Base, Houston.

124:04:49 Aldrin: Roger. Go ahead.

124:04:51 Evans: Roger. Our guidance recommendation is PGNS, and you're cleared for takeoff.

124:05:00 Aldrin: Roger. Understand. We're number 1 on the runway.

124:05:04 Evans: Roger. (Long Pause)

124:05:47 Aldrin: Houston, Tranquility. We're not sure that we got number 2 tank to fire. It's still showing a high pressure.

[They are pressurizing the fuel tanks in the ascent stage, as per the steps near the middle of Sur-60. The valves connecting the helium and propellant tanks are opened with small explosive charges. Apparently, they are getting a high reading of the pressure in the helium tank, which should have decreased when they opened the valve to let helium flow into the propellant tank. In the checklist, "ASC" is Ascent, and "SOV" is Shut-Off Valve.]

124:06:12 Aldrin: Okay. We'll go to number 2 this time.

124:06:15 Evans: Roger. We concur. (Pause)

124:06:24 Aldrin: Roger. No fire.

[Comm Break]

124:08:53 Aldrin: Houston, looks like there's very little difference between the two (tanks).

124:09:00 Evans: Roger.

124:09:02 Aldrin: We've got number 2 reading 3050 (psi) and number 1 is reading, oh, 3000 and it drops down to 2990. So I'm not sure that it's really indicative that it (the tank 2 valve) didn't go. Over.

124:09:17 Evans: Roger. We copy and we agree. (Long Pause)

[Everybody wants to be sure that the tanks pressurized properly before Neil and Buzz proceed with the step "SYS A ASC Feed 2-Open" which provides fuel from the Ascent Propulsion System tank 2 to the Reaction Control System A. They will use APS fuel until well into the lift-off to conserve the separate RCS supply. "SYS A Main SOV (Shut-Off Valve) - Close" prevents use of the RCS supply.]

124:10:02 Evans: Roger. That's correct, and we'll go ahead and watch tank 2. If it doesn't...(If) tank 2 doesn't decrease, we'll tell you to close the ascent feeds and open the shutoffs. Over.

[Although there is no mention in the LM Lunar Surface Checklist (pages 60-64) of getting a Go from Flight Director Gene Kranz, Buzz is asking for confirmation that the Flight Controllers on Kranz's White Team of Flight Directors aren't seeing any problems.]

124:10:31 Evans: Roger.

124:10:32 Aldrin: And I've got the cross feed on.

[Comm Break. The crossfeed valve, presumably between RCS systems A and B, is "CRSFD" near the bottom of Sur-60.]

124:12:06 Evans: Tranquility Base, little less than 10 minutes here. Everything looks good and we assume the steerable (high gain antenna)'s in track mode Auto.

124:12:20 Aldrin: Roger. It is in track mode Auto.

124:12:24 Evans: Roger. (Long Pause)

[This step is just prior to "124:13" on Sur-61.]

[That is, they are ready to fire the explosive devices that will separate the Ascent stage from the Descent stage.]

[Comm Break. Neil and Buzz are verifying circuit breakers as per Sur-62 and Sur-63. In the following, Neil and Buzz do a VHF voice check with Mike, as per Sur-61. Houston does not receive the LM transmissions.]

124:14:44 Collins: Neil, I'm reading you on VHF. You sound good. (Pause) Yes, sir. Couldn't be better. It's just purring along.

[Comm Break. In the following, Neil is on Push-to-Talk and his voice is only occasionally picked up by Buzz's microphones]

124:17:17 Aldrin: (Clears throat) Rate scale, 25?

124:17:18 Armstrong: (via Buzz's microphones) 25.

124:17:19 Aldrin: ATT translation, four jets. Balance couple, On.

124:17:23 Armstrong: (via Buzz's microphones) Balance couple, On.

124:17:24 Aldrin: TTCA (Thrust/Translation Controller Assembly) jets. (Pause) Prop Pushbutton Reset. (Pause) Abort, Abort Stage Reset.

124:17:32 Armstrong: (via Buzz's microphones) Reset.

124:17:34 Aldrin: Deadband, Minimum.

124:17:35 Armstrong: (via Buzz's microphones) Min.

124:17:36 Aldrin: ATT Control to Mode Control. (Pause) Mode Control, Auto, both.

124:17:42 Armstrong: (via Buzz's microphones) Auto, Auto. (Pause)

124:17:49 Aldrin: Okay. We're standing by for 2 minutes to - for the guidance steering in the AGS. (Long Pause) (Garbled) (Pause)

[On Sur-64, they have just finished checking the APS Configuration Card and, being a little ahead, are waiting for the two-minute mark so that they can do the step "*400 + 1E Guid Steering".]

[At about 124:18:00, Flight Director Glynn Lunney polls his Black Team of Flight Controllers for Status. Audio is available at http://honeysucklecreek.net/msfn_missions/MSFN/Network_A11_lunar_ascent.html .]

124:19:26 Aldrin: (To Neil) 76.5 doesn't look too (garbled)? (Long Pause)

124:19:59 Evans: Mark. TIG minus 2.

124:20:05 Aldrin: Roger. Guidance steering in the AGS. (Long Pause)

Onboard Audio Clip (12 Mb mp3) 12 min 34 seconds, starts at 124:20:35. Downloaded from NASA's Apollo 11 40th Anniversary page. Transcription by Colin Mackellar.

Onboard Audio Clip (right channel) and Flight Director Loop with air-to-ground (left channel) (7 Mb mp3) 6 min 55 seconds, starts at 124:20:01. Assembled by Colin Mackellar.

124:20:58 Aldrin: Okay. Master Arm, On.

124:21:01 Armstrong (onboard): Master Arm is On. (Long Pause)

[As shown in a detail from Sur-64, At one minute before ignition, Neil turns on the Master Arm switch and Buzz goes into the DEDA to display the contents of address 500, which is the velocity to be gained along the thrust axis (plus-X).]

124:21:19 Aldrin (onboard): Right.

124:21:21 Armstrong (onboard): (Emphatically) And that's all. (Pause)

124:21:28 Aldrin (onboard): (Garbled)

RealAudio Clip by Derek Henderson ( 2 min 59 sec )

[As noted above, Neil is not on VOX and, in the recording made in Houston, can be heard only occasionally when his voice is picked up by Buzz's microphone.]

[On Sur-58, they started LM Guidance Computer Program 12: Powered Ascent. Since then, the DSKY has been displaying the time to ignition. In a 2004 paper, Tales from the Lunar Module Guidance Computer, Don Eyles wrote, "At 35 seconds the display went blank, and at 30 seconds reappeared. This was a signal that Average-G (which integrated acceleration over a two-second interval for a smoother guidance solution) had started."]

124:21:46 Armstrong (onboard): This one?

124:21:48 Armstrong (onboard): (Is this the) place to put it?

124:21:51 Aldrin: Yeah.

124:21:54 Aldrin: 9, 8, 7, 6, 5, Abort Stage, Engine Arm, Ascent, Proceed.

[They launch at 124:22:00. Note that, now that they have launched, the LM call sign is once again "Eagle"]

[Buzz gets the 16-mm camera started about 6 seconds after liftoff.]

[Voice communications with Eagle is lost momentarily. The following is only heard on the onboard recording.]

[Comm was restored just before Buzz said "shadow".]

124:22:09 Aldrin: 26, 36 feet per second up.

124:22:11 Armstrong (onboard): The Eagle has wings.

124:22:12 Aldrin: (Under static) Standby for the pitchover.

124:22:13 LM Crew: Pitchover.

124:22:14 Armstrong (onboard): Pitching over. Balance couple, Off.

124:22:15 Aldrin: Very smooth. Balance couple, Off. (Pause) (To Houston) Very quiet ride. (To Neil) There's that one crater down there. (Pause)

[Journal Contributor Markus Mehring suggests that this may be a crater associated with the hills on the western horizon visible from the LM windows. He also suggests that sometime while they were on the surface, Neil and Buzz suspected that the hills were associated with one or more crater rims and, knowing that they had landed long, may have tried to identify a candidate crater on the Lunar Orbiter maps they had with them. One prominent candidate is a multi-crater feature named before the flight as the Cat's Paw. See section 4.5.4 in the 2011 photogrammetric analysis of the Apollo 11 site for a discussion of these western horizon features and their identification with a crater 200 m in diameter and its near rim 200 m from the LM. This crater nearly fills the the first frame of the DAC film, which Buzz finally got going about 6 seconds after ignition. The near rim of the Cat's Paw doesn't appear in the film until about 52 seconds after ignition.]

[Neil seems to be saying that he can see mountains downtrack from their current location. However, that interpretation doesn't seem consistent with their current location and altitude. Apollo 11 photo AS11-41-6121 shows a view more or less along the ascent ground track but taken from much higher altitude. The two prominent craters of the right are Sabine (right center) and Ritter (right). Both have diameters of about 30 km and depths of about 1.3 km. Two parallel rilles run WNW from the lower left toward the center of the image and end just south of Sabine. The rilles point toward toward Schmidt Crater (AS10-34-5162), which has a diameter of 11 km and a depth of 2.3 km. As can be seen in a composite made from the Ascent Monitoring Chart, Sheet 3, Parts 1 and 2 and the LROC WMS Image Map, the nearest 'mountains' west of the landing site are some elevations at about longitude 19.7 E south of Sabine, and some substantial peaks and ridges at about 16.5 E. The landing site is at about 23.5 E.]

[PAO tells us that Eagle is currently at an altitude of 0.3 km (1000 feet). From that height, the horizon is about 1.0 degree west of the LM or a longitude of 22.5 E. Any feature beyond that point will be visible only if it is higher than a minimum altitude which increases with distance west. The hills south of Sabine are 2.8 degrees west of the current horizon and would be visible only if they were taller than 2.8 km; the substantial peaks near 16.5 E, would have to be about twice the height of the most prominent mountains elsewhwere on the Moon. Neither seems plausible. Comparing the shadowing of the features south of Sabine with the shadows in both Ritter and Sabine, the features south of Sabine aren't tall enough to be visible from the LM at 0.3 km altitude. Clearly, Neil isn't seeing any 'mountains' out in front from an altitude of 0.3 km. However, within a minute, they will be up to 2.7 km (9000 feet) and, even neglecting their forward motion, will have a horizon about 3 degrees out in front. By that time, Neil might be able to see the hills south of Sabine peeking over the horizon.]

124:22:47 Aldrin: Roger. (Pause)

124:22:52 Aldrin (onboard): (To Neil) Didn't see it.

124:22:53 Armstrong (onboard): See the Cat's Paw?

124:22:54 Aldrin (onboard): No. (Long Pause) This might be it here.

124:23:04 Evans: Eagle, Houston. One minute and you're looking good.

124:23:10 Aldrin: Roger. (Pause)

124:23:17 Armstrong (onboard): Yeah I think it is (Cat's Paw), isn't it.

124:23:19 Aldrin: (To Houston) A very quiet ride, just a little bit of slow wallowing back and forth. Not very much thruster activity.

124:23:31 Evans: Roger. Mighty fine.

124:23:37 Aldrin: 700 (feet per second horizontal velocity), 150 (feet per second vertical velocity) up. Beautiful. 9000 (feet altitude). (Pause) (PGNS and) AGS agrees within a foot per second. (Pause)

124:23:59 Evans: Eagle, Houston. You're looking good at 2 (minutes). PGNS, AGS, and MSFN all agree.

124:24:00 Armstrong (onboard): Pressures are good.

124:24:06 Aldrin: And that's 1000 (feet per second horizontal velocity), 170 up, beautiful. 14,000. And a foot per second again, AGS to PGNS. (Pause)

[Buzz has a chart in front of him that gives the desired relationships between time, horizontal velocity, vertical velocity, and, less importantly, altitude. As long as they gain sufficient horizontal velocity and get high enough to clear the highest lunar mountains, they will achieve lunar orbit. If they are a bit higher or lower than planned, the orbit can be adjusted with a short burn of the RCS at an appropriate time to ensure rendezvous.]

124:24:32 Aldrin: S-band looks like it's holding good, Houston.

124:24:36 Evans: Roger. We concur. It's great.

124:24:38 Aldrin: 1500 (horizontal velocity), 185 (vertical velocity). (Long Pause)

124:25:01 Evans: Eagle, Houston. You're Go at 3 minutes. Everything's looking good.

124:25:07 Armstrong: Roger. (Pause)

124:25:17 Aldrin: Right on H-dot (meaning that their vertical velocity is exactly as expected).. Coming up to...This is H-dot Max now. (Pause)

[H-dot is the vertical velocity, the time derivative of altitude. At this point, they achieve their maximum climb rate. The planned initial orbit is a 10 mile by 45 mile ellipse and, at engine shutoff, lunar gravity will have slowed H-Dot to about 30 feet per second.]

124:25:35 Armstrong: (To Houston) We're going right down U.S. 1.

[Prior to construction of the Interstate Highway System, U.S. 1 was the main north-south route along the east coast of the United States. In his book, Men from Earth, Buzz makes the following comment concerning the flight of Apollo 10. "The glaring Sun was behind Tom (Stafford) and Gene (Cernan) as they flew backwards (landing legs first) above the lunar equator towards the west. With their windows parallel to the surface, they could photograph landmarks along the approach to the Sea of Tranquility landing site." One of these landmarks is a pair of east-west rilles - Rimae Hypatia - just to the left (south) of the ascent ground track. Sometime before Apollo 11, the astronauts started calling the longer, more southerly of the pair "U.S. 1" and the shorter, more northerly rille "Wagon Road". See a labelled version of AS11-41-6121, taken from the Command Module sometime after the LM returned to lunar orbit.]

124:26:01 Evans: Eagle, Houston. Four minutes; you're going right down the track. Everything's great.

124:26:03 Armstrong (onboard): Okay, there's four minutes. (Pause) (garbled) fast. (garbled) altitude rate (garbled).

124:26:12 Aldrin: Now we've got Sabine (Crater) off to our right now.

124:26:18 Evans: Roger. (Long Pause)

124:26:29 Armstrong (onboard): Coming up on Schmidt (garbled).

[When they pass Schmidt Crater, they will have two minutes left in the burn. AFJ Editor David Woods has provided a brief, noise-reduced audio clip and suggested changing my original transcription to "Coming up on Schmidt (garbled)."]

124:26:53 Armstrong (onboard): (garbled)

124:26:56 Aldrin: Okay. (Looking for Schmidt Crater) There's Ritter out there. There it is, right there; there's Schmidt. Man, that's impressive looking, isn't it?

124:27:04 Armstrong (onboard): I can't see it (meaning Schmidt).

124:27:07 Armstrong (onboard): Oh yeah, now I just see the edge of it.

[Neil's view to the right is blocked by LM structure over the forward hatch. We get a good view into Schmidt in the DAC film shot out Buzz's window.]

124:27:10 Evans: Eagle, Houston. You're looking good.

124:27:13 Aldrin: ...155. (Pause)

124:27:17 Armstrong: Looking good here. It's a pretty spectacular ride. (Long Pause)

124:27:40 Aldrin: Dionysius (Crater) is off to the right. (Long Pause)

124:28:02 Evans: Eagle, Houston. You're still looking mighty fine.

124:28:02 Armstrong (onboard): (inaudible under Evans)

124:28:09 Aldrin: Roger. Good agreement in Delta-V-to-go in both AGS and PGNS.

124:28:13 Evans: Roger.

[The computers agree on the velocity left to be gained before they are in the desired orbit.]

124:28:31 Armstrong (onboard): (inaudible)

124:28:34 Aldrin: Got 800 (feet per second) to go. (Pause) 700 to go. (Pause) Okay, I'm going to open up the main shutoffs.

124:28:37 Armstrong (onboard): Okay.

[Buzz will shut off the feed of Ascent fuel to the RCS systems.]

124:29:00 Armstrong (onboard): 350 to go, right?

124:29:01 Aldrin: 350 to go. (Pause)

124:29:11 Aldrin: Stand by on the engine arm. 90, okay, Off, 50.

124:29:17 LM Crew: Shutdown. (Pause)

124:29:23 Aldrin: We got 5337.3 (feet per second horizontal velocity), 32.8 feet per second (vertical velocity), 60,666 (feet altitude).

124:29:33 Evans: Eagle. Roger. We copy. It's great. Go.

124:29:34 Armstrong (onboard): (inaudible)

124:29:35 Aldrin: And we got our residuals (showing on the computer). (Pause)

124:29:40 Armstrong (onboard): Okay. Take those out, right?

124:29:45 Aldrin: Yeah (Pause)

124:29:50 Evans: Eagle, Houston. Trim residuals.

124:29:53 Aldrin: (Garbled) (Long Pause)

[They will use the RCS to refine their orbit by making three-axis velocity corrections to exactly the desired values. Public Affairs reports that they are in a 9.1 by 47.2 nautical-mile orbit.]

124:30:33 Evans: Eagle, Houston. Trim looks good. (Pause)

124:30:40 Armstrong (onboard): (Garbled) check that residual.

124:30:43 Aldrin: That's good.

124:30:45 Collins: Eagle, Columbia. You got a solid lock on in VHF ranging and a fresh estimate of R-dot (rate of change in range, the rate of approach) is 480 feet per second.

124:30:53 Armstrong: Okay. That sounds a little on the high side.

124:30:57 Collins: Yeah. I'll update it here shortly.

124:30:59 Armstrong: Okay.

124:31:00 Aldrin: Okay, Houston. We show 47.3 by 9.5 (nautical miles for the high and low points of their present orbit).

124:31:07 Evans: Roger. 47.2 by 9.5.