MP3 Audio Clip (30 min 05 sec; 29Mb) from the Public Affairs loop starting at about 107:30:41. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.
107:31:00 Armstrong: Houston, Tranquility Base.
107:31:03 McCandless: Go ahead Tranquility Base.
107:31:09 Armstrong: Okay. We are on about the middle of page 28, Surface (checklist page) 28.
107:31:20 McCandless: Roger, Tranquility. We copy.
[Very Long Comm Break with occasional unintentional keys.]107:54:00 McCandless: Tranquility Base, this is Houston. Over.
[They are getting Buzz into his PLSS. NASA Public Affairs informs the press that the crew is running about 30 minutes behind schedule.]
[Armstrong, from the 1969 Technical Debrief - "Now, a preliminary comment (on the EVA Preps) has to do with the longer time that it took than during our simulations. It is attributable to the fact that, when you do simulations of EVA Prep, you have a clean cockpit and you have all the things that you're going to use there in the cockpit and nothing else. In reality, you have a lot of checklists, data, food packages, stowage places filled with odds and ends, binoculars, stop watches, and assorted things, each of which you feel obliged to evaluate as to whether its stowage position is satisfactory for EVA, and whether you might want to change anything from the pre-flight plans. For example, our mission timer was out, and we decided we had better leave one wristwatch inside in case it (the one taken outside) got damaged. We would have at least one working watch to back up the mission timer or to use in place of the mission timer, in case we could not get it going again."]
[The astronauts each had an Omega Speedmaster Professional. Neil's can be seen on his right forearm in training photo S69-32234.]
[Journal Contributor Ulli Lotzmann notes that, contrary to Neil's statement above, "there were no binoculars onboard. They had a 10x40 monocular manufactured by Leitz, Germany, and modified by NASA's Manned Spacecraft Center (MSC) Houston. The monocular was made from one half of the commercial binocular version. Contrary to the stowage list the monocular was transferred from the CM to the LM prior to undocking and was used on the moon both before and after the EVA. Later missions had a monocular stowed in the LM. Thus the Leitz-monocular used on the Apollo 11 mission was the first telescopic viewing device used on another celestial body. It is interesting to note that, unlike Omega and Hasselblad, the Leitz Company never really used their Apollo role in their advertising."]
[Armstrong, from the 1969 Technical Debrief - "All these items took a little bit of time, a little bit of discussion - which never showed up in any of our EVA Preps on the ground - really accounted for the better part of an hour of additional time. Our view of EVA Prep was that we were not trying to meet a time schedule. We were just trying to do each item and do it right sequentially and not worry about the time. Well, the result was, a lot of additional time was used there. I don't think that's wrong. I just think in future planning, you are probably better off adding time for these kinds of things."]
[Aldrin, from the 1969 Technical Debrief - "No matter how many times you run through an EVA Prep, to the best of the instructor's ability to put things in a logical sequence, when you're faced with doing these things, there is a natural tendency to deviate somewhat from the printed sequence that you have. It's a rather complex operation. Nobody writes a checklist to tell you in the morning when you get up all the sequences you go through to put your clothes on, brush your teeth, shave, and all that. If you had one (that is, a morning checklist) setting there, you wouldn't follow it the same every day. You would make small deviations just based on what seems appropriate at that time. It is a very difficult thing to build a checklist for."]
[The EVA checklists for later missions were much less detailed, partly because crews had more time in training to become familiar with the necessary procedures, and partly to allow for a certain amount of flexibility. Certainly, the critical steps were always included but, otherwise, trivial steps like "Turn right and back into PLSS" (see page Sur-28, near the middle) were eliminated.]
[Armstrong, from the 1969 Technical Debrief - "We shouldn't imply that the EVA preparation checklist wasn't good and adequate. We did, in fact, follow it pretty much to the letter, just the way we had done during training exercises. That is, the hook ups, and where we put the equipment, and the checks were done precisely as per our checklist. And it was very good. I don't have any complaints about that at all. It's these other little things that you don't think about and didn't consider that took more time than we thought."]
[Armstrong, from the 1969 Technical Debrief - "There was one control on the PLSS that surprised us. I don't know if it was different from the trainers or the flight PLSSs at the time we were looking at them or not, but there was a press-to-test knob of some sort that neither of us could correctly identify as to function. At this time, we aren't really quite sure what it does."]
[Aldrin, from the 1969 Technical Debrief - "It was a thumb depress button that seemed to go in somewhere as if it was relieving some pressure from something. I can't remember ever having seen that before. It protruded out toward your back and looked as if it might come fairly close to riding on the back of the suit."]
[Armstrong, from the 1969 Technical Debrief - "We both thought we knew the EMU (Extravehicular Mobility Unit, consisting of the suit, the backpack, the Oxygen Purge System, etc.) very well and knew every function and how it operated. But it turned out we were wrong. It was something that we hadn't learned there, and if it had been there before, somehow it escaped us. It took a little time to discuss that, and we proceeded."]
107:54:09 Armstrong: Roger. Go ahead, Houston.
107:54:11 McCandless: Roger, Tranquility. We're coming up in about 6 minutes on GET of 108. If you'd like to start your event timer, we can give you a hack at 108:00. Over.
107:54:27 Armstrong: Wilco (meaning "Will comply").
[Long Comm Break. During either this comm break or the prior one, Neil and Buzz installed the electrical fitting that connected the PLSS to the RCU.]MP3 Audio Clip (24 min 06 sec; 23Mb) from the Public Affairs loop starting at about 108:00:53. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.
[Aldrin, from the 1969 Technical Debrief - "We had problems with this one particular electrical connector, the one that joins the RCU to the PLSS, ever since the first time we'd ever seen it."]
[Armstrong, from the 1969 Technical Debrief - "It's about a 50-pin Bendix connector."]
[Aldrin, from the 1969 Technical Debrief - "It's just very difficult to get the thing positioned properly so that the three pins on the outside, the three little protuberances, will engage in the ramp so that, when you then twist, it'll cinch in. That must have taken at least 10 minutes. The problem was not with mine, but in hooking up Neil's. I can't say that there was much difference in the many times I tried it unsuccessfully and the one time it did go in correctly. It appeared to be squared away each time."]
[Armstrong, from the 1969 Technical Debrief - "This is not because we didn't understand the problem. We had had trouble with that connector for 2 years or more. We'd always complained about it. It had never been re-designed, and it was usually ascribed to that fact that all the training models were old and gouged, and so on. But when we looked at the flight units during CCFF (Crew Compartment Fit and Function) on the EMU (Extravehicular Mobility Unit, the suit, backpack, etc.), it turned out they were still difficult. We accepted the fact that, by being very careful with that connector, we could, in fact, connect and disconnect it satisfactorily. We did that in the lab at the Cape. We had a little bit of difficulty with it there.]
[The EMU CCFF was done in a large room at the Cape on 25 June 1969 ( 3 Mb PDF ). No one is wearing hair coverings or gloves, but the room is clean, as can be seen in NASA photo S69-38488. Photo S69-38497 shows Neil being fitted with a strap-on thigh pocket. He is wearing the flight units of the suit and PLSS. A counter-weighted suspension device is bearing the weight of the PLSS although, evidently, a cable has come off its pulley. A training version of the electrical connector is seen in a side view and a front view photographed by Ulli Lotzmann at the Smithsonian Institution's Garber facility in 2005.]
[Armstrong, from the 1969 Technical Debrief - "When we got to the lunar surface, it was the same problem. It took us at least 10 minutes each to mate those connectors. It's the big electrical cable from the RCU to the PLSS. It attaches at the PLSS end. It's our recommendation that it's a sufficiently serious problem that we can't afford to jeopardize the success of an EVA on that connector. And that's, right now (on the day of the briefing), what we're betting. It began to look like we never would get those connectors mated on the surface. We just have to improve that."]
[As a result of the Apollo 11 experience, the connector was successfully re-designed. The following is taken from the Apollo 11 Mission Report. "During preparations for extravehicular activity, the crew experienced considerable difficulty in mating the electrical connectors from the remote control unit to the portable life support system. For rotational polarization alignment, it was necessary to grasp the cable insulation because the coupling lock ring was free for unlimited rotation on the connector shell (see figure 16-22). For future missions, the male half of the connector has been replaced with one which has a coupling ring with a positive rotation position with the connector shell and can be grasped for firm alignment of the two halves. The ring is then rotated 90 degrees to capture and lock. In addition, easier insertion has been attained with conical tipped contact pins in place of hemispherical tipped pins."]
108:01:03 Aldrin: Houston, Tranquility. We're ready to start with the electrical checkout. We're going to S-band modulate FM. Over.
[Journal Contributor Phil Karn writes, "The normal S-band mode, PM (phase modulation), carried voice, telemetry and ranging but could not support TV. Switching to FM (frequency modulation) enabled television. It also disabled ranging but this was not needed on the lunar surface. Switching to FM also meant that the large 210-foot dishes at Goldstone and Parkes were now necessary even to receive voice from Eagle; in the PM mode the smaller 85-foot antennas sufficed for voice. Needless to say, the Apollo 11 mission had unquestioned priority for all ground station resources."]108:01:14 McCandless: Roger. Tranquility, this is Houston. We copy. Go ahead with the FM. And we missed the mark at 108. Do you want us to try and give you one at 108:05? Over.
108:01:27 Aldrin: I think we've got the timer going. We've got 1 minute and 30 seconds. Mark.
108:01:34 McCandless: Roger. We copy, and you're in sync with us.
[Long Comm Break with occasional accidental triggers of the microphones.]
[Armstrong - "Someone asked me if I had left my wristwatch in the Lunar Module during the EVA as a backup to the mission timer; and I couldn't remember. But that seemed like a logical suggestion."]
[Aldrin - "That jibes with what I remember: your electing not to take it out on the surface was because of (the mission timer)."]
[Journal Contributor Ulli Lotzmann notes that, according to an Omega brochure, Neil mentioned leaving his watch in the LM to NASA Historian Alan A. Nelson.]
[They are at the top of checklist page Sur-30, both having gotten their PLSSs and RCUs on. Next, they will make sure that they have good comm from both PLSSs and will check to make sure that various sensors and warning flags and tones are operational.]
108:06:49 Aldrin: That's got it. (Long Pause)
108:07:30 Armstrong: Fastest VOX in the west. (Pause)
[The VOX is the voice-activated comm system.]108:07:37 Aldrin: (Garbled).
108:07:44 Armstrong: Well, we've got antennas down and (garbled) not real good (garbled)
108:07:54 Aldrin: (Garbled) We'll put my (PLSS) antenna up. (Pause)
108:08:11 Armstrong: Okay.
108:08:14 Aldrin: Okay; how do you read now?
108:08:15 Armstrong: Okay.
108:08:18 Aldrin: Okay. I think that's going to be better. (Pause) You read me all right now?
108:08:28 Armstrong: Yeah.
108:08:30 Aldrin: Okay. That sounds pretty good. I guess it's a combination of the volume and the antenna. May have been just the volume that was way up too high. Why don't you try stowing it again; see if that makes any (difference). (Pause)
108:08:52 Armstrong: Okay.
108:08:53 Aldrin: All right. 1, 2, 3, 4, 5, 5, 4, 3, 2, 1. That sounds pretty good.
108:08:58 Armstrong: That's okay.
[They are in the middle of Sur-31. Each of them has a foot-long flat-wire antenna on the top of the backpack. When not in use, it is held down by a loop of fabric velcroed to the top surface of the OPS. Nominally, in the interest of not breaking it off as they move around inside the LM and crawl through the hatch, they would leave the antenna lying flat until they were outside; but, as here, if comm is poor, the checklist suggests raising the antenna.]108:08:59 Aldrin: Better keep it (the microphone) pretty close to your mouth, though. Okay. (Reading from the checklist) Open up your audio circuit breaker, and disconnect the LM Comm cable. (Long Pause)
[Houston has re-acquired Columbia as it came into view around the eastern limb of the Moon.]108:09:44 McCandless: Columbia, Columbia, this is Houston. Over.
108:09:53 Collins: Houston, Columbia on the high gain. How do you read?
108:09:55 McCandless: Roger, Columbia. Reading you loud and clear on the high gain. We have enabled the one-way MSFN relay that you requested. The crew of Tranquility Base is currently donning PLSSs. The LMP has his PLSS on, Comm checks out, and the CDR is checking his Comm out now. Over.
108:10:23 Collins: Sounds good. Thank you kindly. (Long Pause)
108:10:50 Collins: Houston, Columbia. I tweaked the (inertial) platform up on the back side. I have a P52 option 3 when you're ready to copy the data.
108:10:58 McCandless: Go ahead, Columbia.
108:11:03 Collins: Roger. Stars 43 and 44: star angle difference four balls one, Noun 93 plus 000...
108:11:14 Aldrin: Audio circuit breaker Closed.
108:11:16 Collins: ...57, plus...
108:11:17 Aldrin: All right, on your panel, VHF A, Off; VHF B, Off.
108:11:22 Collins: ...00166, minus 00022, and the...
108:11:26 Aldrin: All right, RCU PTT to Main.
108:11:27 Collins: ...time (is) 107:30:38. Over.
108:11:32 McCandless: Columbia, this is Houston. Copy star angle difference of 4 balls 1; Noun 93, plus 00057...
108:11:42 Aldrin: PLSS mode switch to B.
108:11:43 McCandless: ...plus 00166, minus 00022...
108:11:50 Aldrin: Got a warning tone?
108:11:51 McCandless: ...time of 107:30:38. Over.
108:12:00 Collins: You got it.
108:12:02 McCandless: Roger. ...
108:12:02 Aldrin: (Garbled under Bruce).
108:12:03 McCandless: ...Are you reading Tranquility Base now?
108:12:05 Aldrin: Okay. You've got an O and a P.
[These warning flags are on the top of the Remote Control Unit (RCU) and indicate that there is no oxygen flow and that the suit isn't pressurized. At this point in the EVA preps, Neil and Buzz are merely checking to see that the warning system is working properly.]108:12:06 Armstrong: What is your O2 quantity, by the way?
108:12:11 Aldrin: O2 quantity is about 91 (percent).
108:12:15 Armstrong: I've got 92.
108:12:21 Aldrin: Okay. Now I'm going to Mode Select B. (Long Pause) Warning tone. (Pause) That where you want to be?
108:12:44 Armstrong: I'm in B.
108:12:45 Aldrin: (Garbled) A.
108:12:47 Armstrong: Going to A. I'm in A.
108:12:51 Aldrin: Okay. How do you read me?
108:12:53 Armstrong: I read you.
108:12:55 Aldrin: You're loud and clear.
108:12:58 Armstrong: I got another warning tone. (Pause) (Garbled)
108:13:04 Aldrin: Out now? Okay?
[They have just finished Sur-31.]108:13:06 Aldrin: Both. PLSS mode select AR.
108:13:11 Armstrong: AR. How do you read?
108:13:16 Aldrin: Didn't get a warning tone.
108:13:17 Armstrong: I got one.
108:13:18 Aldrin: Got it? (Pause) Okay, warning tone is out. Verify PLSS O2 bottle pressure greater than 85.
108:13:33 Armstrong: It is.
108:13:35 Aldrin: Do you have voice with "each other".
108:13:38 Armstrong: Yup.
108:13:39 Aldrin: Houston, Tranquility. How do you read? Over.
108:13:43 McCandless: Neil. Neil. This is Houston through Tranquility. Radio check. Over.
[Now that they are on PLSS comm, the path is from Houston through the LM to the PLSS antennas, then back through the LM EVA antenna (which they raised earlier) and on to Houston.]108:13:53 Armstrong: Roger. Houston, this is Neil. How do you read?
108:13:57 McCandless: Neil, this is Houston. We're reading you loud and clear. Break, break. Buzz, this is Houston through Tranquility. Over.
108:14:06 Aldrin: Roger, Houston. This is Buzz through Tranquility. How do you read? Over.
108:14:10 McCandless: We're reading you loud and clear, Buzz. Out. (Pause)
108:14:18 Aldrin: And you're getting a signal on the TV? Over.
108:14:24 McCandless: (Making a mis-identification) That's affirmative, Neil. The data that we're receiving looks good and we are receiving Sync pulses and a black signal on TV.
[At the top of Sur-30, they closed the TV circuit breaker so that Houston could make sure that they were getting a good signal. The TV is inside the MESA (Modular Equipment Stowage Assembly) which is folded up against the side of the LM just to the north of the ladder. In addition to the TV, the MESA contains the rock boxes and various tools. Once he crawls backwards out of the hatch, Neil will reach to his left and, by pulling on a lanyard, will release a latch at the top of the MESA, letting it swing down into position and, in the process, point the TV at the bottom of the ladder.]108:14:35 Armstrong: Okay. You'll find that the area around the ladder is in a complete dark shadow, so we're going to have some problem with TV, but I'm sure you'll get a picture from the lighted horizon (garbled).
108:14:53 McCandless: This is Houston. We copy, and right toward the end of your transmission after you mentioned "lighted horizon", you trailed off down into the noise level, Neil. Over.
[Comm Break]108:16:59 McCandless: Columbia, this is Houston. Are you reading Tranquility all right on the relay? Over.
108:17:07 Collins: I believe so. I haven't heard anything from him lately, and it's breaking up. But up until about 3 minutes ago, I was reading them loud and clear.
108:17:15 McCandless: Roger. Sounds like you're getting it all.
108:17:22 Collins: Thank you.
[Comm Break]108:19:22 McCandless: Tranquility Base, this is Houston. We request you open the TV circuit breaker at the present time. We've had it on about 15 minutes now with the MESA closed. Over.
108:19:37 Armstrong: Roger. (Garbled) (Long Pause)
[Now that Houston is getting a good signal from the TV, they want to turn it off so that it doesn't overheat in the well-insulated confines of the MESA. They will turn it on again when Neil is ready to go out. Evidently, Neil and Buzz overlooked that step on Sur-32 and Bruce is reminding them, without calling attention to the mistake.]108:20:22 Armstrong: Houston, do you read (garbled)
108:20:27 McCandless: Say again, Neil.
108:20:33 Armstrong: (Garbled) (Pause)
108:20:43 McCandless: Neil. Neil. This is Houston. I can hear you trying to transmit; however, your transmission is breaking up. Over.
108:20:55 Armstrong: (Garbled)
108:21:01 McCandless: Buzz. Buzz. This is Houston. Do you read? Over.
108:21:08 Aldrin: Roger, Houston. This is Buzz. How do you read? Over.
108:21:11 McCandless: Roger. You're coming through loud and clear, Buzz. It's a beautiful signal.
108:21:19 Aldrin: Neil's got his antenna up now. Let's see if he comes through any better now.
108:21:23 Armstrong: Okay. Houston, this is Neil. How do you read?
108:21:26 McCandless: Neil, this is Houston. Reading you beautifully. (Long Pause)
108:21:41 Armstrong: (Static) My antenna's scratching the roof.
108:21:44 McCandless: We copy (that) your antenna (is) scratching the roof. Roger.
[Aldrin, from the 1969 Technical Debrief - "The initial comm checkout on the audio panel and the various communications checks that we made in the FM mode all seemed to go quite well, until we started switching the PLSS modes. For a while, we ascribed some of the difficulty perhaps to the antenna being stowed. So we unstowed Neil's, and that didn't help immediately. A little later, it seemed to help out, but then we got back into about the same problem, so I stowed his antenna. There didn't seem to be any particular rhyme or reason to when we did appear to have good comm and when we didn't."]108:21:50 Armstrong: Do we have a Go for cabin depress? (Pause; no answer)
[Armstrong, from the 1969 Technical Debrief - "It suffices to say that we never did understand what was required to enable good comm while we were inside the cockpit, relaying through the PLSSs. We had it part of the time, and we didn't part of the time. We tried a lot of various options, and they just weren't universally successful. But we were able to have adequate comm to enable us to continue. I think, once outside, we really didn't have any appreciable comm problems at all. It seemed to work quite well."]
[On the later missions, the quality of PLSS-relayed comm from the cabin was also erratic. Generally, raising the antennas in the cabin didn't help much. With regard to comm during the EVA, Neil's was excellent but Buzz's tended to be broken, most likely because the sensitivity of the VOX circuitry was not set to its maximum value. The control was not set properly prior to the EVA; and, although it might have been brushed by one of the PLSSs, Ken Glover notes that, at 108:08:30, Buzz appears to have reduced the volume setting. None of the later crews experienced a similar problem.]
[In the interest of caution, the Flight Director is making a final check of all systems before giving the Go. Neil and Buzz are starting the paragraph "Final Systems Prep for Egress" on page Sur-32. They have attached their OPS oxygen hoses to the PLSSs and the OPS actuator cables to the RCUs. Training photo S69-32234 shows Buzz's OPS actuator on the left side of his RCU mockup.]108:21:59 Aldrin: They hear everything but that. Houston, this is Tranquility. We're standing by for a Go for cabin depress. Over.
108:22:06 McCandless: Tranquility Base, this is Houston. You are Go for cabin depressurization. Go for cabin depressurization.
108:22:15 Armstrong: Roger. Thank you.
[I, for one, remember getting excited at this point in the proceedings, thinking that they were close to opening the hatch. In reality, they still have to configure the LM ECS (Environmental Control System) for the depress, get their helmets on, get themselves off of LM oxygen, cooling water, and comm, hook themselves up to the PLSSs, and get their gloves on. It will be another half hour before they start the depress.]108:22:18 Aldrin: Okay, Descent Water Valve is Closed.
108:22:21 Armstrong: Okay.
108:22:23 Aldrin: Verify Cabin Fan Number 1 circuit breaker open.
108:22:27 Armstrong: (Garbled)
[Neil is turning off the fan which circulates oxygen through the ECS. He and Buzz will be able to hear the fan stop running but will also note a warning light, again as a test of the warning system.]108:22:30 Aldrin: Suit Fan number 1 breaker. We'll have to pull that one out. (Garbled) (Pause) Now wait a minute.
108:22:54 McCandless: Columbia, this is Houston. Your LM line-of-sight Comm acquisition with the Tranquility Base is 108 plus 29. LOS is plus 42. Over.
108:23:11 Aldrin: Suit Circuit Relief Valve to Auto.
108:23:14 Armstrong: In Auto.
[The LM ECS is controlled with a combination of circuit breakers located on the panel at Buzz's right shoulder and by various valves located on the ECS cabinet located behind Buzz's station. Some of the valves are located on the forward surface and some on the inboard surface. With both of them wearing PLSSs and their freedom of motion restricted, it is Neil who operates most of the ECS valves, reaching across with his right hand.]108:23:15 Aldrin: Suit Gas...
[Armstrong - "It was easier for me to see the controls and to reach them."]
108:23:16 Collins: I'm going over to (garbled) I'll pick you up...
108:23:16 Aldrin: ...Diverter Valve to Egress. Pull.
[With the Suit Gas Diverter Valve in Egress, they are cutting off the flow of oxygen from the ECS to the cabin. The Diverter Valve has a push/pull control.]108:23:18 Collins: ...on Omni C or D.
108:23:21 McCandless: (To Mike) Stand by please.
108:23:22 Aldrin: Verify Master Alarm. Pushbutton Light, Reset. (Pause) ECS Caution Light and Water Separator Caution Light (will come) On.
108:23:42 Armstrong: Takes a while for the water separator. Maybe.
108:23:45 Aldrin: I don't understand. Suit Fan Number 1 circuit breaker, Open. (Long Pause)
[They are waiting for the warning system to sense that the ECS fan and the airflow-driven water separator have stopped operating. This typically takes 4 minutes.]108:24:09 McCandless: Buzz, this is Houston. We'd like you to pull the Suit Fan Delta-P circuit breaker on panel 16. Over.
108:24:28 Aldrin: Roger, I have it.
[Houston is reminding Buzz to turn off a sensor which detects a pressure difference across the fan, another indication of whether or not the fan is running. They had skipped over that step.]108:24:30 Armstrong: That's what the difference... Yeah. (Pause)
108:24:41 Aldrin: Cabin Gas (Return Valve, Egress).
108:24:43 Armstrong: Yep. (Pause) It's in Egress. (Long Pause)
[They are verifying that there can be no flow from the cabin into the ECS.]MP3 Audio Clip (28 min 11 sec; 27Mb) from the Public Affairs loop starting at about 108:25:05. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.
108:25:15 Aldrin: Okay. There it is. ECS Master Alarm, Water Separator.
[With flow in the ECS turned off, the centrifugal water separator also stopped working and they are now seeing a warning light indicating that the separator has spun down. They will now start the tasks on Sur-33.]108:25:20 Armstrong: Okay.
108:25:25 Aldrin: All right; "Both Suit Isolation Valves to Suit Disconnect."
108:25:26 Armstrong: I'll get them. Both. Got it.
[They are shutting off the flow of oxygen from the ECS into the suits. The valves are behind Buzz but fairly low and it is easiest for Neil to reach across with his right hand.]108:25:30 Aldrin: Okay. Disconnect LM (oxygen) hoses (from the suits). (Long Pause)
108:25:46 Armstrong: Okay.
108:25:50 Aldrin: Connect OPS O2 hose to right-hand PGA blue connector and lock.
108:25:54 Armstrong: Let me do that for you. (Pause) Okay. Locked and it's lock-locked.
[Each of the hose connectors has a ring lock and then, built into the ring, a "lock-lock" which prevents the ring from accidentally rotating open.]108:26:06 Aldrin: (Connecting Neil's OPS hose) Raise your arm up. (Long Pause) Locked, lock-locked. Okay. "Retrieve purge valves from (ISA) pocket." (Pause)
[Training photo S69-38499 shows Neil working on Buzz's connections during training.]
[Next, Buzz connects Neil's OPS hose.]
108:26:48 Armstrong: Okay.
[The purge valve is mounted on the right side of the chest and can be opened in the case that the PLSS fails and the astronaut has to use the emergency oxygen supply stored in the OPS. In the event of a PLSS failure, the astronaut would open the purge valve by pulling the so-called Red Apple, which pulled a lock pin out of the purge valve, and then use the OPS actuator mounted on the side of the RCU which would let oxygen flow out of the OPS, through a regulator, into the suit, and then out through the purge valve. The valve has two flow settings: a low flow rate of 4 pounds per hour and a high flow of 8 pounds per hour, the choice depending on the availability of cooling. The OPS contains roughly four pounds of oxygen, giving either a one-hour or thirty-minute supply.]108:26:49 Aldrin: Verify (that the purge valve is) closed; lock pin installed.
108:26:51 Armstrong: Okay.
108:26:52 Aldrin: Install in red (coded connector), PGA red (garbled, undoubtedly "connector"). (Long Pause)
108:27:09 Armstrong: Okay. It's installed, locked and lock-locked.
108:27:14 Aldrin: Did you put it...
108:27:16 Armstrong: Oh, wait a minute. Should be...(Pause) Stand by.
[Neil may be changing the purge valve orientation so that the Red Apple - which Buzz would grab and pull to open his purge valve - is in easy reach. In EVA photo AS11-40-5903 Buzz's Red Apple is at the center of his suit at about navel height.]108:27:21 Aldrin: I'll get the other one.
108:27:26 Armstrong: That's right on your...(over) the middle (of the suit front).
108:27:44 Aldrin: All right. Check my diverter valve's vertical. Both vertical?
108:27:55 Armstrong: That's two vertical.
[With the PGA diverter valve in the vertical position, all of the oxygen flow will enter the suit through vents in the helmet.]108:27:57 Aldrin: Okay. Hold this (possibly Neil's Red Apple and the attached pull-pin). I'll put in your purge valve. (Long Pause) Locked and double locked.
108:28:25 Armstrong: Okay.
108:28:35 Aldrin: Lean forward. (Red Apple and pull-pin?) Locked. (Pause) Position mikes. (Long Pause) Sure wished I'd shaved last night. (Pause) Okay; we need the helmets. Got your mikes where you want them? (Long Pause)
[They each have a pair of mikes as part of the "Snoopy cap" or, more formally, the "Communications Carrier". "Snoopy" is Charlie Brown's beagle in the comic strip "Peanuts" drawn by Charles Schulz. Journal Contributor Ulli Lotzmann had discussions with Ernie Reyes in mid-2000 about Snoopy's association with Apollo. Reyes was Chief of the Pre-Flight Operations Branch at the Manned Spacecraft Center in Houston during Apollo; and Lotzmann reports that Reyes, Wayne Stallard and others drew little cartoons on the daily schedules to make them more interesting. The Reyes Snoopy, who looks a little bit different to the Schultz-Snoopy as can be seen from examples in the Apollo 12 cuff checklists, became popular with the Astronaut Corps. Because the cartoons were never intended for commercial publication, Reyes never asked Schultz for permission to use the character. After the Apollo 1 fire, Snoopy became the symbol of the revitalized NASA safety program.]108:29:42 Armstrong: (Garbled) (Long Pause)
[Getting back to the subject of the "Snoopy cap", in the Schulz comic strip, Snoopy often fantasized that he was a World War I flying ace and, while in that fantasy, wore a leather flying helmet. This and the fact that the Apollo Snoopy caps were dark-brown & white may explain why they were named "Snoopy" caps. Post-EVA photo A11-37-5528 is an excellent picture of a very pleased Neil Armstrong in full Snoopy regalia after the EVA. Journal Contributor Markus Mehring notes that the names "Snoopy" and "Charlie Brown" where also used for the Apollo 10 Command Module and Lunar Module, respectively. The Apollo 17 crew named a large crater in Snoopy's honor.]
[Note that, in the following, they get Buzz into his helmet first, as per checklist.]
108:30:07 Aldrin: Verify PLSS (comm) mode select in AR.
108:30:11 Armstrong: Verified. (Pause)
108:30:19 Collins: I don't know if you guys can read me on VHF, but you sure sound good down there. (Long Pause)
108:30:46 Aldrin: And locked.
108:30:48 Armstrong: Okay. (Pause)
108:30:53 Aldrin: All right. The vent window is clear.
[They have turned on Buzz's PLSS fan to start the flow of oxygen through the suit. A clear vent window indicates that the flow is adequate. In the event of inadequate flow, a "P" would appear in the window, indicating that Buzz should activate his OPS and open his Purge Valve.]108:30:56 Aldrin: And remove LEVA (Lunar Extravehicular Visor Assembly) from the engine cover. Verify EV visor is up and attach to helmet. (Long Pause)
[The LEVA consists of visors to cut down on the solar glare - visors which can be raised and lowered - and layers of fabric which provide mechanical and thermal protection to the clear, bubble helmet. The LEVA is worn over the helmet and is held in place by front and rear straps.]108:31:12 Aldrin: How's the Comm now, Houston? Over.
108:31:16 McCandless: Buzz, this is Houston. The Comm is very good. You are coming in loud and clear, and Mike passes on the word that he is receiving you and following your progress with interest.
108:31:27 Aldrin: Very well, thank you. (Long Pause) Got all the material up in the back? (Long Pause)
[Neil is checking to see that the back flap on Buzz's LEVA is properly covering his neck ring.]108:32:40 Armstrong: Complete.
[Comm Break. They will now get Neil into his helmet and LEVA.]108:33:43 Armstrong: (Garbled) locked?
[Aldrin - (To Neil) "I think we should have brought the boots back and not the LEVAs. It was a last minute decision and they're not as publicly appreciated as the boots are."]
[Journal Contributor Ulli Lotzmann notes that Neil and Buzz brought their EVA gloves back to Earth.]
[Journal Contributor Harald Kucharek notes that page 183 of the Apollo 11 Press Kit contains the following statement under the heading Contamination Control. "The equipment shown in table I as jettisoned equipment will be assembled and bagged to be subsequently left on the lunar surface. The lunar boots, likely the most contaminated items, will be placed in a bag as early as possible (after the EVA) to minimize the spread of lunar particles (in the cabin)."]
108:33:46 Aldrin: Yeah, it's locked and aligned.
[Comm Break. They have finished with Neil's LEVA and Buzz has confirmed that Neil's helmet neckring is properly seated, aligned, and locked. Next, they will get out cue cards that list the final steps of the EVA Prep and, also, show the final circuit breaker configuration.]108:34:47 Aldrin: Now, if you'll pull the RCU down. (Long Pause)
[During the 1991 mission review, we turned to a discussion of the EVA checklists that they had out on the surface.]
[Aldrin - "When we were out on the surface, the only thing we had was whatever you (Neil) had on your wrist. We didn't have stuff for outside the cabin. We didn't take the checklist and we didn't have a lot of extensive things at all for the outside."]
[Armstrong - "I had a very abbreviated checklist of all the major items that we were going to do, in the order that we had planned to do them. Setting up the various experiments and getting the samples..."]
[Jones - "A single page?"]
[Aldrin - "I think, in retrospect, we could have done better in the outside the cabin prompting system."]
[Jones - "On the later missions, they had what was, essentially, a little spiral notebook bent slightly over the wrist so that the pages would stay open. Yours was more primitive than that?"]
[Aldrin - "Oh, much more."]
[Armstrong - "No pages."]
[Aldrin - "It may have even been sewn on, or something. I don't know that I had any thing like that. Although I should have. I think we both should have had a set of outside cues."]
[In reality, they each had a checklist page sewn to the gauntlet of the left glove. Neil's cuff checklist can be seen in NASA photo S69-38889 and in a detail from S69-38898. Journal Contributor Ulli Lotzmann calls attention to the fact that, during training, Neil and Buzz used strap-on checklist cards, as can be seen in NASA photo 69-H-666.]
[The RCU is the Remote Control Unit, a small box worn on the chest which has PLSS and Comm controls, the oxygen gauge and assorted warning flags.]108:35:38 Armstrong: Wonder if we're triggering (the voice-activated comm) all the time.
108:35:42 Aldrin: I don't think so.
108:35:45 Armstrong: Houston, Neil. How do you read?
108:35:48 McCandless: Neil, this is Houston. Read you loud and clear and I read both the comments that said: "I wonder if we're triggering all the time" and "I don't think so." Prior to that it was relatively quiet. Over.
108:36:01 Armstrong: Okay. We're hearing a little bit of background noise, and I just wanted to make sure that we weren't continually keyed.
108:36:07 McCandless: Don't sound like it. (Long Pause)
[Aldrin - "With all this comm problem, and that being so essential, (it is unfortunate) we (had) overlooked dress rehearsals that included that sort of stuff."]108:36:26 Armstrong: Want to put the light back up?
[Armstrong - "You might ask Gene (Cernan) if he remembers doing any of that (suited comm checks during Apollo 10). My guess is that they focused on the things they had to do..."]
[Aldrin - "Yeah. Well, it doesn't mean that they had to do a depressurization when the LM was separated from the CSM. They could have done that in a safer condition but with the same equipment after they joined back up again."]
[Jones - "Didn't Rusty don the backpack on 9?"]
[Aldrin - "Yeah, he did. But I don't think he went through a lot of this VOX communication period."]
[Jones - "He probably stayed hooked up to the LM, but I can check that."]
[The light in question may be one or both of the two utility lamps which had long, gold-colored cords and could hung at various places around the cabin when needed. At the top of Sur-26, they secured the utility lights to the guard cage surrounding the Alignment Optical Telescope (AOT); but they may have moved one or both since then.]108:36:36 McCandless: Neil, this is Houston. Would you verify your RCU vent window's clear? Over.
[Training photo KSC-69PC-319 shows Neil in a LM simulator. One of the lamps is over Neil's head, hanging from the yellow bar (aka PLSS Upper Mounting Station Pin) used as a pulley mount when operating the Lunar Equipment Conveyor (LEC). The other lamp is somwhere on Buzz's side of the spacecraft, below his window.]
108:36:46 Armstrong: That's verified.
108:36:48 McCandless: Roger. Out. (Long Pause)
[Houston gets a modest amount of telemetry from the PLSS, including electrocardiogram readouts, suit pressure, carbon dioxide partial pressure, battery voltage and current, oxygen bottle pressure, temperatures at the inlet to the Liquid Cooled Garment (LCG) and the outlet to the PLSS sublimator, and a temperature difference between the LCG inlet and outlet. Houston does not have a direct indication of the status of the vent window - which shows a "P" warning when the oxygen flow is below about 5 cubic feet per minute - and had to remind Neil to give them a report. As per checklist (Sur-33), at 108:30:53 Buzz reported that his vent window had cleared. See the commentary following 108:45:51 for a further discussion of the LCG and the PLSS sublimator.]108:37:12 Aldrin: That's good.
108:37:14 Armstrong: Okay.
108:37:19 Aldrin: (Garbled) (Long Pause) Okay. We can stow this (probably the Lunar Surface Checklist, as per the last step on Sur-33). (Long Pause)
[Having stowed the Lunar Surface Checklist, they will now go through the procedures on EVA Card No. 1.]108:38:05 Aldrin: Okay. It is stowed. All right, Prep for EVA. (Pause) Both, disconnect the (LM) water (hose).
108:38:19 Armstrong: Okay. Let me get yours. (Long Pause)
108:38:36 Aldrin: Okay. Now we should be able to stow these (LM water) hoses.
[Comm Break; Public Affairs informs the media that the LM cabin temperature is 61F.]108:40:10 McCandless: Columbia, this is Houston. Any joy on the LM that pass? Over.
[Aldrin - "The hoses both came from the same place (behind Buzz), and yours were longer and went across and mine sort of came around to the right."]
[Armstrong - "(To stow the hoses out of the way), I would guess (we put them somewhere) in the ECS area."]
[Bruce is asking if Mike saw the LM.]108:40:19 Aldrin: Okay. They're all stowed. "Connect PLSS water hose to PGA (Pressure Garment Assembly, the suit)." (Pause) Let's see; (garbled). (Long Pause) Okay. That's in and locked.
108:41:04 Armstrong: Okay. (Long Pause)
108:41:36 Aldrin: Houston, Buzz here. Over.
108:41:39 McCandless: Go ahead, Buzz. This is Houston.
108:41:44 Aldrin: Roger. Our Comm just seemed to clear up a good bit. Did CSM just go over the hill (out of direct VHF line-of-sight)?
108:41:52 McCandless: Negative. He's been over the hill, here, for a minute or so. (Pause) Correction...
108:42:00 Aldrin: Okay.
108:42:01 McCandless: ...he should be losing contact with you in about a minute.
108:42:10 Aldrin: Okay.
[Several of the crews noted radio interference during Command Module passes over their landing sites. Because of the small radius of the Moon and the low orbit of the Command Module, the CSM is above the local horizon for only about 12 minutes out of each two hour orbit.]108:42:11 Armstrong: The lock-locks are (garbled) checked. Locks are checked, blue locks are checked, lock-locks, red locks, purge locks; and on this side, the PLSS locks and lock-locks, both sides; water locks (pause) and the Comm. Okay.
[During this pass over the landing site, Mike tried the three locations passed up to him at the indicated times: M.8/8.2 ( 106:44:17 ), P.2/6.3 ( 107:05:31 ), and M.7/8.0 ( 107:10:15 ). The first and last of these are virtually identical to the estimated latitude and longitude for the LM that Charlie gave to Mike at about 104:20:42. That lat/long corresponds to map coordinates M.5/8.0 and, because the sextant field-of view corresponds to a circle on the ground 3.2 km in diameter, the differences between M.5/8.0, M.8/8.2, and M.7/8.0 are inconsequential. Near these locations, Mike drew a small circle in pencil with an arrow pointing to it. There is a very small crater at the center of the circle and this may be the 'tiny crater' Mike described at 104:42:48.]
108:42:34 Aldrin: Okay. (Garbled) the gloves. Locked.
[Comm Break as they don their gloves, checking wrist locks and adjusting palm straps.]108:44:15 McCandless: Columbia, this is Houston. Do you read? Over.
108:44:21 Collins: Columbia reads you loud and clear on Omni C/Charlie.
108:44:25 McCandless: Roger. Columbia, I have LOS and AOS times for you this pass with MSFN. LOS 109 plus 21 plus 12. AOS coming around the corner 110:07:35. Over.
108:44:52 Collins: Thank you. That's fine.
108:44:53 McCandless: Roger. Out. (Long Pause)
108:45:32 Aldrin: Okay.
108:45:33 Armstrong: Okay.
108:45:34 Aldrin: You're all locked. Verify your diverter valve's open. Up position. (Pause) Diverter valve's up.
108:45:49 Armstrong: (PLSS) diverter valve's up.
[As shown in Figure I-23 in the EMU Handbook ( 4 Mb PDF ), the diverter valve is part of the oxygen inflow connector. The valve has two positions. In the Open position, used in the cabin, all the incoming oxygen stream is divided between a duct leading to the helmet vent and a duct leading the vents in the torso. In the Closed position, used outside, all the oxygen goes to the helmet vent.]108:45:51 Aldrin: Into Minimum. PLSS pump on.
[This is a pump which circulates water through a network of thin tubes woven into the Liquid Cooled Garment or LCG. This is a closed-loop water supply which carries excess body heat to the sublimator where the heat is transferred to a supply of feedwater which is subsequently evaporated to provide overall cooling. They won't turn on the sublimator feedwater supply until after the hatch is open because the sublimator needs to be in a vacuum for proper operation. On Apollo 12, after the crew had the hatch open and Pete Conrad was down on the surface, Al Bean accidentally knocked the hatch closed and the very small cabin pressure created by the operation of the sublimator was enough to trigger a warning flag.]108:45:57 Armstrong: PLSS (pump) on. Running.
[Armstrong - "The sublimator was not working but the water temperature was cooler than our skin temperature so, as soon as we had water circulating at its normal temperature we felt the result of it."]
108:46:02 Aldrin: And mine's running, also, and it's cooling already.
108:46:08 Armstrong: Mine, too.
108:46:10 Aldrin: Audible tone.
108:46:12 Armstrong: Verified.
108:46:14 Aldrin: That's what it is. Yeah. (Garbled) Why don't you bend down and let me stow that (antenna). See if we (garbled). (Pause) Okay. (Garbled) Inspect the EMU. Already done that pretty well.
108:46:43 Armstrong: Pretty well and complete. Okay. (Long Pause)
108:47:08 McCandless: Columbia, this is Houston. Over. (Pause)
108:47:16 Collins: Houston, Columbia. Go ahead.
108:47:18 McCandless: Roger. Were you successful in spotting the LM on that pass? Over.
108:47:26 Collins: That's negative. I checked both locations, and no joy.
[See the discussion at 108:42:10. 'Both locations' probably refers to (1) the location P.2/6.3 suggested to him at 107:05:31 and (2) the vicinity of nearly coincident points M.8/8.2 and M.7/8.0 suggested at 106:44:17 and 107:10:15]108:47:30 McCandless: Okay. If you'd like to look again next pass, we have a different set of coordinates based on the onboard P57 solution of the LM. These are Echo decimal three and four decimal eight. I say again Echo 0.3, 4.8, same chart. Over.
[The actual landing site is about Juliett 0.65/ 7.52. Each of the grid squares is a kilometer on a side and Echo 0.3/4.8 is, therefore, about 4.4 kilometers south and 2.6 kilometers west of the actual spot. As can be seen in Figure 5-14 in the Apollo 11 Mission Report, this is Houston's worst estimate. Bruce will give Mike the Auto Optics settings at 110:18:39, and he will examine the location during the pass over the landing site at 110:33:40 and reports the negative result at 110:36:58.]108:48:00 Collins: Roger. I'll look there. And, also, how about putting that in your machine and coming out with some coordinates - latitude and longitude over two, and altitude - for P22, so it can help me as best it can.
[Armstrong - "That was quite a distance away from the point they had been looking. Previously, they had been looking up in the Mike area, which is a substantial distance away."]
108:48:14 McCandless: Roger.
108:48:21 Collins: That P22 is still pointing in the wrong place.
108:48:26 McCandless: Columbia, this is Houston. Latitude plus 0 decimal 523, longitude divided by two, 11 decimal 710. Over.
108:48:48 Collins: Roger. Understand plus 00523 and plus 11710. Thank you.
[Aldrin - "When he read it back that way, he was sort of hinting, 'Hey, dummy, you're not supposed to read it up that way'".]108:48:58 McCandless: Houston. Roger. Out. (Pause) Columbia, this is Houston. We're requesting high-gain antenna pitch 0, yaw 200. That is, pitch 0, yaw 200. Over.
[Comm Break]108:51:43 Aldrin: (Garbled) (Long Pause)
[During the 1991 mission review, I put the following question to Neil and Buzz and was so fascinated by Buzz's lengthy answer that I have included the entire exchange here. My question was "On the way home from dinner last night, my wife and I were talking a little bit about a difference in perception: namely that, from the public's point of view, the stuff that's about to happen, the two of you going outside on the surface, the first footprints, and so on is the exciting stuff; whereas, from the program point of view, the goal of the mission is the landing and return, demonstrating the capabilities of the spacecraft. Do you have any comments about that?"]
[Armstrong - "As I've always said, the highlight for me, personally, was the final descent and landing. That was, after all, our major objective and it was a very difficult and risky, complex part of the flight. And I, personally, not being a geologist and so on, saw no special challenge in the surface work, which was something appropriate to do but, in my mind, never had the importance of the landing itself. (Chuckling) From a pilot's perspective."]
[Aldrin - "I'm a transportation person, primarily. An operator of vehicles who found myself thrust into the situation of suited spacewalks - or EVAs - on Gemini 12 and Apollo 11. And I found that my preparation was most adequate for that. There's no doubt that the single most significant achievement on our flight was our descent to a foreign surface and the ascent to orbit to complete a rendezvous, join up, and come back."]
["Outside-the-spacecraft activities (EVAs), in my estimation, are easier in a gravitational field than they are in free flight conditions with people floating around. And I think our evidence of (the need for) energy management in the learning process for EVAs (during Gemini and into Apollo) speaks to that."]
["My concern about how the public is influenced by the media has, of course, been growing. One doesn't necessarily agree with where that leads us, but you have to learn to live with it. My mis-guess about Apollo (EVAs) was confirmed by another guy who walked on the Moon (an unnamed astronaut but not, obviously, Alan Shepard) and that is that we felt that hitting a golf ball on the Moon was a waste of taxpayers' money and that that was not an appropriate thing to be done on a manned mission. But we have both agreed that we were wrong. That's what the public wants to see. They want people (that is, astronauts) to do those kinds of activities and that promotes a positive support system for the things that we were trying to do. So, obviously, we have to change our thinking about that and get behind that."]
["Clearly the public was interested and fascinated by the moment of putting a foot on another planet, whether (or not) you've been there for hours, working over kind of boring procedures, getting ready to go outside. That doesn't seem to have anything to do with it. Rather facetiously, I've constructed a lunar lander for the future that has two exits and two ladders so that both people can come down at precisely the same time. Now, there are some good reasons why you might want two airlocks on a vehicle; but if, in front of engineers, I start suggesting a lunar landing craft with two ladders so that the two guys go down together, it's liable to be looked at in a facetious way and the sound engineering will be set aside because of the facetious nature with which someone might interpret what I'm trying to say."]
["I think that the invasion of the press and the media into the innards of what we're trying to do in exploration is good, but it also has to be dealt with appropriately. And, on that particular subject: if I had had the role of being the first person to make an utterance, I'm sure that what I would have done, in retrospect, would have been to consult the most competent advisors - on my time - absorbed their advice and have come up with whatever I wanted to do and say, based on that. And that's what Presidents do when they give a State of the Union, and that's what anyone else does. And, yet, somehow, that doesn't appear to be available to us to do, without it being judged as interference from the outside. Okay? And I think that's a sorry situation. Of course, I've given that subject a lot of thought. I think that, for people to press Neil about where and how he came up with a very clever (statement for the occasion)....is no business of theirs. But it indicates a need to have a line drawn somewhere."]
["Again, facetiously, about the order in which people get out, I guess it was confirmed...or, a selection was fairly strongly confirmed...by looking at the emergency positions as being based on where the hinge was on the hatch. Well, in the future, things of this nature are going to be anticipated, I'm sure; and we get a little smarter. But, then there'll be something else that will crop up to trouble us."]
["But, I think, the public perception is where our support's going to come from; and, harnessing that, and maintaining that at its proper edge and inspiring people to new careers and not having them come into a career field and dedicate themselves to an experiment and then have that experiment postponed and postponed and postponed and then it never flies. And the person feels like he's really been let down in life by the system. And that can be very damaging, and I think that's happened in many cases. That there's an over-anticipation. We keep crying that we need more and more engineers and, when people do studies, that doesn't necessarily seem to be the case. If we needed a whole lot more engineers, we'd be paying them a lot more money to get good engineers, it would seem to me. (Chuckling) While I'm on the subject, I'll take a moment or two more and talk about the term "NASA scientist". The public perceives the word 'NASA scientist' as being the guy who builds rockets. Well, these are engineers; they're not scientists. And, because of that perception, we now have a space station that's being dedicated to science and it is really an engineering necessity. And it is not being judged by the Academy of Engineering as to its adequacy and its ability to fulfill what's needed. It's, again, being judged by the Academy of Sciences for its scientific content which really means 'Does it do the kind of experiments that these people want to see happen regardless of whether it fulfills the role of engineering long-term soundness'. Now, all of these things, I think, have to do with public perception and that, I think, is what your question was."]
[Readers interested in the question of how the decision was made as to who went out first should consult Andy Chaikin's excellent book "A Man on the Moon", together with Buzz's "Return to Earth". In the simplest terms, the decision hinged (if my readers will pardon the pun) on the design of the hatch, which swung into the cabin to the right, blocking Buzz's access to the exit until after Neil was out. Despite this engineering reality, Buzz expended some effort prior to the flight in trying to convince Deke Slayton, the former Mercury astronaut who was Director of Flight Crew Operations, and others that he, rather than Neil, be the one to go out first. His efforts were in vain.]
108:52:11 Armstrong: (Garbled) cooling unit circuit (garbled). (Pause)
[It has been about five minutes since the last comm from the LM. At that time, Neil and Buzz had turned on their PLSS water pumps. On later missions, after setting the A & B Pressure Regulators to Egress and verifying the CB panel configurations, the crews pressurized the suits and performed a pressure integrity check. In the following dialog, it seems likely that Neil and Buzz have been experiencing some comm problems. However, by 108:53:00, they are ready to close the cabin repress valve and to open the forward dump valve. Clearly, they have pressurized their suits. The Final EVA Configuration Cards will tell us if they planned to do a pressure integrity check ]108:52:36 Armstrong: Houston, this is Neil. How do you read?
108:52:39 McCandless: Neil, this is Houston. Loud and clear.
108:52:41 Aldrin: (To Neil) Okay. I got you a little bit better now. (Hears Bruce) There we go.
108:52:42 Armstrong: Roger. (You read us) loud and clear.
108:52:47 Aldrin: (To Neil) You're not too loud and clear, but I think it's the same problem. Houston, how do you read Buzz?
108:52:52 McCandless: Buzz, this is Houston. Loud and clear. You're really coming in beautifully. Over.
108:52:58 Aldrin: Very good.
108:53:00 Armstrong: Okay. (Pause) Cabin Repress (valve) closed. (Long Pause)
[By closing this valve and opening a corresponding circuit breaker, they are keeping the ECS from repressurizing the cabin after they open the dump valve in the forward hatch.]MP3 Audio Clip (22 min 20 sec; 21 Mb) from the Public Affairs loop starting at about 108:53:27. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.
108:53:37 Armstrong: Okay. (Pause) Now comes the gymnastics.
108:53:46 Aldrin: What?
108:53:47 Armstrong: Now comes the gymnastics.
108:53:49 Aldrin: Oh, I think it'll be a lot easier (than in training) (Pause)
[With two people in suits and backpacks, it wasn't going to be easy to lean down far enough to reach the dump valve built into the forward hatch. The photo shows the dump valve on LTA-1, displayed at the Cradle of Aviation Museum without a bacterial filter.]108:53:56 Armstrong: Okay. We want to go to (brief pause while he finds the line in the checklist) Dump and go down to 3.5 (psi) and back to Auto.
[Aldrin - "That's probably why Neil said what he did, and maybe I was too optimistic."]
[On some flights, the Commander opened the valve and on some flights it was the LMP. On Apollos 16 and 17, Duke and Cernan, respectively, reached up and back to open the overhead dump valve. We talked a little about the difficulty Gene described in getting into position to work the overhead valve, and Neil said "I believe that. And my guess is that's probably true both pressurized and unpressurized. But pressurized would probably be worse." Buzz added, "It'd be barely possible." In order to open the dump valve in the hatch, one or the other of them will have to bend either his knees or his waist and get low enough to reach the valve. After some puzzlement over the dialog, we concluded that it was Buzz who opened the valve. Part of the problem was that the start of the next line of dialog was originally transcribed as "Okay, I want to go to Dump..." whereas I now believe that "Okay, we want..." is correct.]
[Journal Contributor Ken Glover notes that, at 114:10:28 during the depressurization prior to the equipment jettison, Neil reported that they used the forward dump valve down to 2 psi (pounds per square inch) and then opened the overhead valve as well, undoubtedly to speed things along. Because both Neil and Buzz are right-handed, it was probably Neil, standing on the left side of the cabin, who opened the overhead valve. See, also, the discussion after 113:46:23.]
[Once Buzz has the valve open, he will leave it open until the cabin pressure has dropped to 3.5 psi. At that point, Buzz will close the valve again so that he and Neil can watch their suits respond. The drop in cabin pressure increases the relative suit pressure to above 4.5 psi.]108:54:08 Aldrin: Okay. Going dump. (Pause) And it's down to 4.2, 4.1. (Pause)
[In listening to this line, all three of us concluded that it was Buzz who opened the valve.]108:54:25 Armstrong: That's 3.5. (Pause) Are you in Auto? "Verify cabin pressure at 3.5 and LM Suit Circuit pressure between 3.6 and 4.3."
[Armstrong - "I think so."]
[Aldrin - "How could I have read the numbers, then? Come back up, again, and read them."]
[Armstrong - "I guess you must have."]
[The latter is the pressure in the ECS which, for now, is isolated from both the cabin and the suits.]108:54:44 Aldrin: It is. Suit circuit's at about 4.3.
108:54:48 Armstrong: Okay. "Verify the PGA pressure is above 4.5." Mine is 4.6.
108:54:53 Aldrin: Mine is 4.7.
108:54:54 McCandless: Neil, this is Houston. Will you give us a hack when you start your (Omega) chronometer. Over.
108:55:03 Armstrong: Roger.
108:55:08 Aldrin: Give it to them later.
108:55:12 Armstrong: Okay. Okay, let's go to dump.
108:55:17 Aldrin: Dump.
108:55:18 Armstrong: Go to dump. (Long Pause)
108:55:40 Aldrin: Houston, I'll set my watch at 56. Over.
108:55:50 McCandless: Roger.
[Buzz is wearing his watch on his suit sleeve and, apparently, starts his stopwatch function at 56 minutes after the hour, corresponding to the upcoming Ground Elapsed Time of 108:56.]108:56:00 Aldrin: 3, 2, 1.
108:56:02 Aldrin: Mark.
[Aldrin - "I'm sure that Neil didn't wear his watch out on the surface. I'm sure he put it with the Velcro strap up in the AOT."]108:56:03 Collins: Houston, Columbia is back on the high gain.
[Armstrong - "Someone, perhaps in correspondence, asked me about that. And I could not remember, although it seems quite logical, given the mission timer situation, that we would have left one watch inside."]
[Aldrin - "I wasn't sure what the reason was, but I thought it was okay. It was your watch, if you wanted to leave it inside. I remember that specifically at that time, because I reflected back on it a little later when I shipped my watch to the Smithsonian and it turned up missing. That's when it refreshed in my mind, years ago, that you had left yours inside and mine was the only one out on the surface. It was one of those things...I had a watch on but I don't think I looked at it. Which would probably say that I should have had it set at something so that it was just not a normal time going around, but going from some specific...It was a lousy watch to have on the surface. It just didn't give good numbers as far as a stopwatch type thing. To have gone to all that expense and then to have crews out on the surface with just an ordinary watch, in retrospect, is a mistaken priority somewhere."]
[Jones - "The later crews had cuff checklists set up with timing relative to depressurization. They would start the stop-watch function at depress."]
[Armstrong - "Seems logical."]
[Aldrin - "Well, since we didn't have a checklist that was set up on (elapsed EVA) time, why we didn't get to cement in that kind of a procedure. But that's a very good one."]
108:56:05 McCandless: Roger, Columbia. Loud and clear. And we copied your mark there, Buzz.
108:56:09 Armstrong: Okay. I've got my water window.
108:56:18 Aldrin: Okay.
108:56:19 Armstrong: Water warning. Got yours?
108:56:21 Aldrin: Got mine.
108:56:22 Armstrong: Okay. (Pause)
[Sensors in the PLSSs have noted that, although the cabin pressure is low, the sublimators are not yet working. The sublimator consists of a sandwich of honeycomb plates on which, when exposed to vacuum, the feedwater turns to ice and it is the sublimation of the ice layer that provides cooling. The astronauts will not start the flow of feedwater until they get the hatch open and, by noting the warnings, they are making sure that the sensors are working.]108:56:26 Armstrong: Cabin pressure going towards zero. Verify LM suit circuit 3.6 to 4.3. That's verified. Verify PGA pressure above 4.5. Okay. 4.75 (and) coming down. Ready to open the hatch when we get to zero. (Long Pause)
108:57:06 Aldrin: You want to bring down one of your visors now or leave them up? (Pause) (Garbled)
108:57:19 Armstrong: Okay. (Pause) Inner visor down. (Long Pause)
108:58:18 Armstrong: Four-tenths of a pound in the cabin. (Long Pause)
108:59:06 Armstrong: Down to about 0.2.
[Comm Break]109:01:12 Aldrin: Sure takes a long time to get all the way down, doesn't it?
109:01:14 Armstrong: Yeah.
[For Apollo 11, the forward dump valve is equipped with a bacterial filter which is having a considerable effect on the speed of decompression. The filters will not be flown on subsequent missions. With the filter in place, cabin pressure drops from 5.0 pounds per square inch, absolute (psia) to 0.08 psia in 310 seconds versus 180 seconds without the filter. Use of both the forward and overhead valves without filters would bring the time down to 90 seconds. For most of the Apollo EVAs, one or the other of the valves was used; although, for the equipment jettison they will do after the EVA, 114:10:28 Neil and Buzz will use both valves. Because of the relatively large surface area of the hatch, it cannot be opened at cabin pressures much above 0.1 psia.]109:02:45 Aldrin: Okay, let me see if it will open now.
[Aldrin, from the 1969 Technical Debrief - "We didn't really want to go and open the overhead hatch (means the overhead dump valve). We like to open only one of them, and leave the other one the way it's been."]
109:02:48 Armstrong: Okay. (Long Pause)
109:03:02 Armstrong: Bumping my RCU, there, with your visor. (Long Pause)
[Buzz is on the right side of the cabin, leaning down to open the hatch which is hinged below his position. As it opens, it will swing inward and toward him, blocking off his position at about knee height. They have so little room that Buzz's helmet is scraping against Neil's chest-mounted Remote Control Unit.]109:03:52 Armstrong: Push (garbled) (Long Pause)
109:04:23 Armstrong: Need some light?
109:04:26 Aldrin: It's unlocked, yeah.
[Aldrin - "He's wondering if I need some light, and I'm saying I was sure it was unlocked. It just wasn't coming open."]109:04:27 Armstrong: Unlocked? (Pause) How's it getting up?
[Armstrong - "I recall that we thought we could pull it open against a little bit of pressure. And it turned out it took very little pressure to hold that thing closed to where we couldn't unseat it."]
[The lock lever is a very simple mechanism, with a short latching end and a longer handle pointed toward Buzz's side of the spacecraft. Thomas Schwagmeier has provided a labeled photo detail. The latching decal reads, Latch Operation: 1.Insert handle in end of shaft; 2. To lock - push on handle and rotate CW (clockwise) to stop; 3. To unlock - push on handle and rotate CCW (counter clockwise) to stop. In emergency - if latch is jammed in locked position - To open hatch pull lanyard to remove lock pin, rotate cam plate out of way of latch and open hatch.]
[Aldrin - "I think it went all the way through and there was a lever on the outside, too."]
[On Apollo 12, Al Bean grabbed one of the corners of the hatch and peeled it back enough to let some oxygen out.]
109:04:40 Aldrin: It'll pop open. (Long Pause) Get a steady tone in the background?
109:05:28 Armstrong: I have static. I'm getting static.
109:05:34 Aldrin: I've got a little bit of a steady tone.
109:05:39 Armstrong: I don't guess I hear that. (Long Pause)
109:06:15 McCandless: Neil, this is Houston. What's your status on hatch opening? Over.
109:06:22 Armstrong: Everything is Go here. We're just waiting for the cabin pressure to bleed so...To blow enough pressure to open the hatch. It's about 0.1 (psi) on our gauge now. (Pause)
109:06:48 Aldrin: Sure hate to tug on that thing. Alternative would be to open the top one, too.
[They could open the dump valve in the overhead rendezvous hatch to speed depressurization. Neil and Buzz will use the overhead valve when they do the equipment jettison at 114:10:28. Otherwise, the only other time it was used was on Apollos 16 and 17. Because of his height, Cernan found it easier to reach up for the overhead valve than to reach down for the forward valve.]109:06:59 McCandless: Neil, this is Houston. Over.
[Armstrong - "My recollection is - and it may be imperfect - that there was a filter just on the one valve (meaning the dump valve on the forward hatch)." (True)]
[Aldrin - "I don't think you'd want to put a filter on the top one, 'cause that's liable to come loose and get in the way with the docking and all that stuff."]
[As for Buzz's concern about tugging on the handle, pre-flight tests had indicated that the handle would break before the hatch would deform - at 180 pounds of force versus 240 pounds. At 0.25 psi of cabin pressure, opening the hatch took 78 pounds of force versus 118 pounds at 0.35 psi. Pre-flight tests indicated that it was all but impossible to exert more than about 100 pounds when opening the hatch in an inflated suit.]
109:07:04 Armstrong: Go ahead, Houston.
109:07:05 McCandless: Roger. We're showing a relatively static pressure on your cabin. Do you think you can open the hatch at this pressure of about 0.12 psi?
109:07:18 Armstrong: We're going to try it.
109:07:20 McCandless: Roger. (Long Pause)
109:07:33 Armstrong: The hatch is coming open. (Pause)
[Aldrin, from the 1969 Technical Debrief - "When the hatch was finally opened, it took an initial tug on it, and it appeared to bend. The whole hatch, as it opened on the far side, came toward me. As soon as it broke the seal, it appeared as though I could see some small particles rushing out."]109:07:40 Aldrin: Okay. Hold it from going closed and I'll get the valve to (Auto)...
[Several of the crews noticed that ice crystals formed as the moist cabin air rushed out into the lunar vacuum. On one of the Apollo 17 hatch openings, the outflow even carried out a lost piece of bread.]
109:07:43 Armstrong: Okay.
109:07:45 Aldrin: No. I'd better get up first. (Long Pause)
[With the valve in the Auto position, it can be opened from the outside in the event that the hatch closes and there is a pressure build up.]109:08:11 Aldrin: Okay. The valve's in Auto.
109:08:12 Armstrong: Okay. (Pause)
109:08:20 Aldrin: (Garbled) forward. (Long Pause)
109:08:37 Armstrong: Your window cleared yet? Your water window cleared yet? (Pause)
[That is, the PLSS water flag. Evidently, they have turned on their PLSS feedwater diverter valves and, shortly, will begin to get cooling via the sublimator.]109:08:46 Aldrin: It was, yeah.
109:08:48 Armstrong: Mine hasn't cleared yet. (Pause)
[Aldrin, from the 1969 Technical Debrief - "Once the water window did clear, it seemed that the cooling was noticeable almost immediately."]109:08:55 McCandless: Columbia, this is Houston. Over.
109:09:01 Collins: Columbia. Go ahead.
109:09:03 McCandless: Columbia, this is Houston. We'd like you to cycle the fans in cryo(genic) hydrogen tank number 1. And LOS time this orbit is 111:19:31. (Pause) Correction. Make that for the next orbit. You already have the AOS/LOS for this orbit.
109:09:35 Collins: Roger on the time; and you want to cycle the fan...
109:09:36 Armstrong: Okay; going to open (garbled)
109:09:38 Collins: ...in cryo hydrogen tank 1.
109:09:41 McCandless: Roger. Out. (Long Pause)
[Mike is going to turn on a fan inside one of the CSM's tanks of liquid hydrogen in order to stir the contents and prevent radial stratification due to heat loss from the wall. It was a short circuit in a similar fan in one of the oxygen tanks that caused the Apollo 13 accident.]109:10:39 Aldrin: (To Neil) (have you) turned your water valve on (garbled)?
109:10:41 Armstrong: Yeah.
[Evidently, Neil's feedwater flag has not yet cleared. On all of the missions it took several minutes for the sublimators to start working.]109:12:35 McCandless: Columbia, this is Houston. We show you nearing high-gain antenna scan limits. When you lose lock on us, we request Omni Delta. Omni Delta when you lose lock. Over.
[Comm Break. Near the end of this Comm Break, the Public Affairs commentator notes that Neil and Buzz have been using PLSS oxygen for about 16 1/2 minutes, which corresponds to the time when they started the depressurization at 108:56:02.]
109:12:52 Collins: Roger. Omni Delta. (Long Pause)
109:13:22 Armstrong: Okay. My window's cleared. I'm going to go to...Run my cooling up a little bit.
109:13:26 Aldrin: Okay. My window's clear. (Long Pause)
109:13:40 Armstrong: All RCU windows are clear. (Pause) LM Suit Circuit is 4.2...(Correcting himself) 4.3. And I got ascent pressure light, a PREAMP light, and a ECS light.
[Frank O'Brien tells us that the ECS warning light comes on in any of four circumstances: (1) a glycol pump failure; (2) CO2 partial pressure greater than 7.6 mm of mercury; (3) water separator failure; or (4) suit fan #1 failure. When the cabin is depressurized, the water separators shutdown, which is why the ECS caution light has illuminated.]109:14:00 Aldrin: Yeah; and we've got a water separator light...
[Frank O'Brien writes "The Caution and Warning System could be very touchy. Since unintended alarms were known to occur, it was often easier to simply document circumstances when they occurred, rather than take the time and money to find engineering solutions. The ASC PRESS would normally come on if the pressure in the Ascent Helium tanks or in the propellant lines were below certain thresholds. Likewise, the PREAMP light would go on if the power supply for the RCS was out of tolerance. Clearly, illumination of these two lights were unintended in the context of EVA preparations but were unintended consequences of the Caution and Warning System design" During Apollo, NASA developed what is called Sneak Circuit Analysis ( 4 Mb PDF ) to deal with such situations.]
109:14:01 Armstrong: And they're good.
109:14:02 Aldrin: ...(Garbled). Right.
109:14:05 Aldrin: Okay; and I'll look at your cabin fan 1 circuit breaker. And you look at the glycol secondary. (Pause)
109:14:26 Aldrin: I've got good cooling now.
109:14:28 Armstrong: Me, too. (Pause) Okay. Glycol pump secondary circuit breaker open? If I can see that. (Pause) (You'll) have to lean this way.
109:14:48 Aldrin: Can't go any further. My cabin fan 1 (circuit breaker is) open.
109:14:58 Armstrong: Yeah. That's good.
109:15:00 Aldrin: Want me to check it? (Pause)
109:15:05 Armstrong: It's open. Verified. (Pause) Okay. PGNS radar circuit breaker's open. (Long Pause)
109:15:29 Aldrin: Well, I'm looking head on at it. I'll get it.
109:15:32 Armstrong: Okay. Let me get your antenna.
109:15:33 Aldrin: (Garbled under Neil) my antenna? (Pause)
109:15:43 Armstrong: It's out.
[I asked about the problem of moving around in the cabin with both of them wearing pressurized suits. The accompanying photo by Stacey O'Brien shows her husband, Journal Contributor Frank O'Brien, standing next to a LM simulator on display at the Cradle of Aviation Museum.]
[Armstrong - "My impression was that it was pretty tight. I think that, in our training inside both the LMS ( Lunar Module Simulator) and also that other trainer we had (which Buzz called 'the EVA trainer'), we were usually dressed in street clothes and we had lots of room. And when we first did simulations with suits in there, we found out that the suits took up an awful lot of the space and things were much more cumbersome. It was much more difficult to operate in suits than we had come to expect in shirtsleeves. And, of course, when the suit is pressurized, it's that much worse. Suits filled up a lot of that LM cabin volume."]
[Aldrin, from the 1969 Technical Debrief, referring to an early stage in the EVA Prep - "We put the anti-fog (wipe) on (the inside of the clear bubble helmet) as soon as we got the kit out, instead of waiting until a little bit later. I think that maybe there were two things that brought that about. One was that we weren't really sure it was going to appear later in the checklist, and we wanted to make sure we did that. The other was, in training, we wanted to avoid as many activities as we could with the PLSS on our back, because it was very uncomfortable doing any additional exercise in one g. We did find, however, that it was quite comfortable, even without the shoulder pads, to have the PLSS mounted on your back. The mass of it was not objectionable. It did require moving around methodically and very slowly to avoid banging into things - no getting around it. You just couldn't always tell what the back of the PLSS or the OPS might be in contact with at any particular time."]
[Armstrong, from the 1969 Technical Debrief - "As was reported, we broke one circuit breaker with the PLSS and we depressed two others, one on each side, sometime during the operation with the PLSS on the back. So that's an area that we still need to improve on to be able to have confidence that the integrity of the LM itself won't be jeopardized by the operation with the PLSS on the back."]
[Journal Contributor Ulli Lotzmann notes that Buzz brought the broken circuit breaker back to Earth.]
[I asked if they did any training for the egress with pressurized suits.]
[Aldrin - "I think that, eventually, we did; but not very much."]
[Armstrong, from the 1969 Technical Debrief, talking about depressurization - "This is one area of flight preparation that was never completely performed on the ground. In the (vacuum test) chamber, the PLSSs were left on the engine cover and we never put them on our backs because of their weight, and the possibility of jeopardizing the integrity of the LM. So the comm was operated, and the (hose) connections were made, but the depressurization sequence with the PLSSs on our backs was never completed. The times when we actually operated the PLSS was done always in the chamber and never done with the LM systems operable."]
["So two things were new to us. One was that it took a very long time to depressurize the LM through the bacteria filter with the PLSS adding gases to the cockpit environment and the water boiler (the sublimator) operation or something adding some cabin pressure. The second was that we weren't familiar with how long it would take to start a sublimator in this condition. It seemed to take a very long time to get through this sequence of getting the cabin pressure down to the point where we could open the hatch, getting the water turned on in the PLSS, getting the ice cake to form in the sublimator, and getting the water alarm flag to clear so that we could continue. It seemed like it took us about a half hour to get through this depressurization sequence."]
[If, as can be inferred from the air-to-ground, Neil and Buzz did wait until the hatch was open before they turned the feedwater diverter valve, then the only gases the PLSSs were adding to the cabin came from slight leakage of oxygen from the suits, which was expected. If so, Neil's speculation that the "water boiler" slowed depressurization is incorrect.]
[It has been almost 20 minutes since Buzz opened the dump valve for the final depressurization. For the first Apollo 12 EVA, the same sequence of events took only 8 minutes, primarily because Pete and Al went after the hatch as soon as the cabin pressure was under 0.2 psi. In detail, Pete and Al had the hatch open 3 minutes after starting the final depressurization, where as Neil and Buzz took roughly 11 minutes.]
[Armstrong, from the 1969 Technical Debrief - "(The Depressurization sequence) was one that we had never duplicated on the ground. Well, in retrospect, it all seemed to work okay, it was just that we weren't used to spending all that time standing around waiting."]
|Journal Home Page||Apollo 11 Journal Index||One Small Step|