Apollo 15 Lunar Surface Journal


Preparations for EVA-3

Corrected Transcript and Commentary Copyright © 1996 by Eric M. Jones.
All rights reserved.
Scan credits in the Image Library
Last revised 27 September 2012.


MP3 Audio Clip ( 21 min 05 sec ) by David Shaffer
This clip starts with about 7 minutes of PAO commentary.

[Bob Parker said goodnight to the crew at 153:15:21 and told them that their wake-up call would come about 7 hours later. The wake-up call actually comes at 160:02, about 6 3/4 hours after Parker's goodnight. According to the flight plan, they were supposed to start the rest period at 151:25 and end it at 158:25. They started the rest period 1 hour 50 minutes behind and are now 1 hour 32 minutes behind.]

[The following exchange is not on the audio tape I acquired from NASA Johnson in 1989 but is in both the PAO and Technical Air-to-Ground transcripts.]

160:01:57 Allen: Good morning, Hadley Base. This is Houston calling. (Long Pause) Good morning, Hadley Base. This is Houston calling. Schoen guten Tag. Wie gehts euch?

160:02:45 Scott: Guten Morgen, mein Herr. Ist gut.

160:02:50 Allen: Schoen guten Morgen, Dave. (Pause) And we have a beautiful day planned for the two of you.

160:03:07 Scott: Very good. (Long Pause)

160:03:25 Allen: A beautiful good morning, Jim. (Joking) Has the Sun risen over Hadley Mountain, yet?

160:03:36 Scott: Well, give us about 30 minutes here and we'll take a look.

160:03:40 Allen: I wouldn't be at all surprised and I've got things for you to copy. I'm standing by.

[Long Comm Break]

[Scott - "Do you know the reason we did the German thing?"]

[Jones - "Because it was von Braun's program."]

[Scott - "Sure. A lot of the people involved, especially in Huntsville, with the Rover and all that stuff, were Germans. So, maybe one of the reasons Joe and I batted it back and forth was 'cause it was his program."]

[Scott, from the 1971 Technical Debrief - "It seems to me that the last night's sleep was about the same as the others. We talked over getting up early to make sure we didn't fall (further) behind."]

[Irwin, from the 1971 Technical Debrief - "I guess they were concerned about whether we did not get a good night's sleep that night."]

[Scott, from the 1971 Technical Debrief - "Yes. Didn't you feel like you had?"]

[Irwin, from the 1971 Technical Debrief - "I thought I slept just as good that night as I had the night before."]

[Scott, from the 1971 Technical Debrief - "I would question how they know you got a good night's sleep; except other than asking. The heart rate is a great idea - except, do they ever measure your heart rate while you're sleeping at home?"]

[Irwin, from the 1971 Technical Debrief - "No, but I guess they want to do that."]

[Scott, from the 1971 Technical Debrief - "I think they ought to do that. I don't see how they can possibly correlate it, otherwise."]

[Irwin, from the 1971 Technical Debrief - "Well, I got a good night's sleep that night, it felt like to me. When I got up the next morning, I remember asking how you slept. You said you slept fine. So, I felt like we were both well rested for that day."]

[Details of the Post-sleep activities can be found on Surface 8-8 and 8-9. The following discussion relates to the procedures on 8-9.]

[Irwin, from the 1971 Technical Debrief - "On this last morning, we didn't put water bags or food sticks in the suit, because we knew it was going to be a relatively short EVA."]

[Scott, from the 1971 Technical Debrief - "We didn't want to take the time to fill the water bags and put them in, because that was going to take time away from the EVA. We did lubricate all the wrist rings, connectors, and helmet rings on this one, which was easy. I think that little dab of lubrication material works just fine."]

[Irwin, from the 1971 Technical Debrief - "It was easy and I think it paid off because it was very easy to make the connections."]

[Scott, from the 1971 Technical Debrief - "We never had a problem with the zipper at all. Both zippers worked very good throughout the flight. I don't remember ever having your zipper hang up. I thought the lock box worked fine."]

160:10:43 Irwin: Houston, Hadley Base.

160:10:47 Allen: Good morning, Jim.

160:10:54 Irwin: Morning, Joe. Got one question for you. When we repressed the cabin after yesterday's EVA, my (PLSS) water valve was not completely off, and we lost a little water out of the sublimator during the repress. Then during the recharge, I noticed on the Aux water vent portion that initially there were a lot more bubbles in the sight glass. After the 10 seconds, why, it got down to a point there were just a very few bubbles. But I'm wondering whether there might not be a special procedure involved because we did the repress with the water valve open. Over.

160:11:48 Allen: Jim, we copied all that. We'll think about it and be back with you with an answer in a few minutes. By the way, the passive seismometer people tell me that there must be somebody moving around in the LM. (With mock incredulity) Is that true?

160:12:05 Irwin: Oh, we're moving this morning, Joe.

160:12:09 Allen: Roger. You're shaking that seismometer.

[The Passive Seismic Experiment is designed to probe the interior structure of the Moon and, to do that, big signals from distant impacts or moonquakes are needed. One such signal will be generated once Dave and Jim return to orbit. After rendezvous and after they get themselves and samples and film into the Command Module, they will jettison the LM ascent stage and send it crashing into the luanr surface. The accompanying map shows the planned impact site and the actual site as determined from signal arrival times at the Apollo 12, Apollo 14, and Apollo 15 seismometers.]
160:12:16 Allen: And, Jim, I have updates to read to you when you're comfortably ready.

160:12:23 Irwin: Okay. Stand by. (Long Pause) Okay, Joe. I'm ready for the updates.

160:12:46 Allen: Roger, Jim. (As per Surface 8-9) I'll start with lift-off times. T-43, when you're ready. (Pause)

160:13:00 Irwin: Okay. I'm ready.

160:13:02 Allen: Roger. T-43, 161:49:31; T-44, 163:47:36; T-45, 165:45:40; T-46, 167:43:49; T-47, 169:41:53. Over.

160:13:46 Irwin: Okay. Beginning at lift-off for Rev 43, 161:49:31; 163:47:36; 165:45:40; 167:43:49; 169:41:53. Over.

160:14:05 Allen: Roger. Readback is correct. (Joking) Contact tower when you're ready for departure. And I have LM consumables update when you're ready for those.

160:14:22 Irwin: Go ahead.

160:14:25 Allen: Roger. At GET (Ground Elapsed Time) 160: RCS A, 85.0; B, 85.0; O2 descent 1, 59.9; 2, 56.7; O2 ascent number 1, 99; number 2, 99; H2O descent number 1, 18.3; number 2, 16.5; H2O ascent, 100 percent on both 1 and 2; amp-hours: descent, 803; ascent, 572. And I have a note on your descent water when you're ready.

160:14:26 Irwin: Go ahead.

160:14:28 Allen: Roger. Just wanted you to be aware that the descent water (gauge) may show, over the next few hours, between 1 and 0 pounds. You'll have actual usable water, perhaps as much as twenty-two-and-a-half pounds. It might not be quite that much. It depends upon the measurement errors. However, we're very well aware of your water situation; it's no problem at all. We just don't want you to be alarmed if you come up with a zero reading at any time on that water. And, that's about all we have for the time being. We're standing by for your crew status report. We'd like also the radiation devices this morning. And I think we have a very nice traverse plan laid out for you. We can talk about that as you start to get ready. Over.

160:16:26 Irwin: Okay. We copy.

160:16:31 Allen: And, Dave and Jim, basically the EVA is going to last somewhere between 4 and 5 hours (depending on how quickly they get outside), so it will be a short EVA. I'm told that we checked off the 100-percent science-completion square sometime during EVA-1 or maybe even shortly into EVA-2. From here on out, it's gravy all the way; and we're just going to play it cool, take it easy, and see some interesting geology. It should be a most enjoyable day. Over.

160:17:11 Scott: Okay, Joe. Thank you. We're looking forward to it.

[Comm Break]

[In order to launch on schedule, they need to be back in the LM at about 168 hours. As it turns out, the EVA will start at 163:18:09 and will end 4 hours 50 minutes later at 168:08:09.]

160:18:32 Irwin: (Accidental mike key) Re-do my sensors here. (Long Pause)

160:19:03 Irwin: (Accidental mike key) They probably want us to hit the rille for all that good rille photography.

160:19:19 Allen: Jim, this is Houston. You're keying your mike off and on. You might be sitting on it or stepping on it or pressing on it. (Long Pause)

160:19:32 Irwin: Okay. I have Biomed, Left, right now.

160:19:37 Allen: Roger, Jim. I don't know if you copied. I just wanted you to be aware your mike was being keyed on from time to time, perhaps inadvertently.

160:19:51 Irwin: Yeah; we understand, Joe.

[Long Comm Break]
160:23:16 Allen: Jim, this is Houston. Regarding your PLSS question, everything looks normal to us down here. It seems like there's no problem there at all.

160:23:28 Irwin: Roger. We copy. Thank you, Joe.

[Comm Break]
160:24:52 Irwin: And, Joe, Dave fixed my camera last night, so there shouldn't be any problem with it this morning.

160:25:00 Allen: (Joking) And I bet he fixed it with a piece of tape, didn't he?

[Very Long Comm Break]

[Scott, from the 1971 Technical Debrief - "We worked it over that night and I guess the problem with the camera - we brought it back for the people to look at...I think the problem is definitely dirt in the drive mechanism. I fiddled with it that night and got it going. The next day (during EVA-3), it hung up again. After we got into orbit, we worked on it some more, and you could see that the wheel exposed by the Reseau plate was hanging up. If you put your fingernail in there and triggered it, it would get going. I think with the amount of dirt you have, and the fact that the camera is level with the area in which you work when you roll up (the individual sample) bags, you get dirt in the camera. I think we ought to put some little Beta (cloth) booties over the top of the camera to keep it clean, at least over the joint there where the film mag goes on. They were getting so dirty that, every time we reset our f-stop and lens, I had to brush mine off with my finger. I had to wipe it off, because I couldn't see the settings on the camera, it got so dirty. I'd recommend maybe Velcro tabs and a little piece of Beta right up on top of the camera to keep that mechanism clean."]

[The failure of Jim's camera was ultimately determined to be a mechanical failure of the drive mechanism. Two set screws had begun slipping on the motor shaft. A more detailed discussion can be found at 146:32:41.]

[Irwin, from the 1971 Technical Debrief - "Dust accumulation also gave a problem as far as removing the film mags from the camera. There were several times where it was very difficult to release it."]

[Scott, from the 1971 Technical Debrief - "I think the (16-mm DAC) camera would be better off if we'd protect it a little bit better. We used the lens brushes on the cameras, and they were very good."]

[Irwin, from the 1971 Technical Debrief - "On the TV, also."]

[Scott, from the 1971 Technical Debrief - "On the TV also. That lens brush is really a good brush. It cleaned it off very well. The (large) dust brush to clean off the suits seemed to work pretty good. It got the gross dirt off. It didn't get everything. I guess it also worked quite well on the LRV and the LCRU mirrors. (It) cleaned them off pretty well."]

[Scott, from a 1996 letter - "'Lens brush' and 'dust brush' are specific nomenclature to identify the different brushes."]

160:49:58 Irwin: Houston, this is Jim. I'm sensored now, and I'm going to put the Biomed on Right so you can check on my sensors.

160:50:06 Allen: Roger, Jim. We copy that. Thank you.

[Long Comm Break]
160:53:44 Allen: Jim, this is Houston. We've got good biomed data.

160:53:55 Irwin: Thank you, Joe.

[Very Long Comm Break]
MP3 Audio Clip ( 7 min 15 sec ) by David Shaffer

161:19:33 Irwin: Houston, this is Hadley Base. We're about to be off comm here for a short period.

161:19:41 Allen: Okay, Jim. We copy and we're looking for Biomed, Left, when you do.

[Very Long Comm Break]

[Dave and Jim may have started the LMP suit donning procedures on Surface 8-9. As a part of those procedures, Dave and Jim will clean and lubricate the neckring, wristrings, and the various connectors. The following is a continuation of a discussion about lunar dust that was reproduced just prior to 149:39:19.]

[Scott, from the 1971 Technical Debrief - "I might comment that lunar dust is very soluble in water. It seems to wash off very easily. I would say that if you ever have a connector problem that was really stiff, you could take the water gun (photo by Mick Hyde) and spray it and loosen it up."]

[Irwin, from the 1971 Technical Debrief - "We did not loosen the suit connections for EVA-2, but we did for EVA-3."]

[Scott, from the 1971 Technical Debrief - "It seemed like they were still working pretty well. The connectors got covered with dust - one of mine. One of the primary problems was the LEC (Lunar Equipment Conveyor). On EVA-1, when I passed you the rock box on the LEC, I just got covered with dirt all down the front. The result was pretty dirty connectors. We tried to brush them off and clean them off. We found that the booties which had been placed over the PLSS connectors were pretty good protection from dirt. A recommendation would be to put booties over all the connectors - or some sort of protective device. In the old days, they had a bib to keep them clean - or for double protection, I guess. Something like that would surely prevent problems later on and would save time cleaning the connectors. They sure get dirty, and I am just not sure there is any way to prevent them from getting dirty. If you are going to go out there and do the job, you are going to get dirty. If you try to keep everything clean, you are just not going to be able to do the job on time. I think those little booties are a pretty good idea. They were no problem on the donning and doffing."]

161:36:35 Irwin: Houston, 15. Back on comm. (Pause) Hadley Base checking in.

161:36:42 Allen: Thank you, Jim. We read you.

161:36:49 Irwin: Okay, Joe. Our inventory shows that we do not have any more color Mags available. Can you check your inventory down there?

161:37:01 Allen: Roger. (Long Pause) Hadley Base, this is Houston. We think, Jim, that Mag Tango Tango is on your camera in the ETB now, and Tango Tango is color. Over.

161:37:48 Irwin: Okay. Thank you. (Long Pause) Joe, this is Jim. We confirm. We do have color on my camera.

161:38:53 Allen: Okay, Jimmy. Real fine.

[Very Long Comm Break]
162:00:33 Allen: Hello, Hadley Base. This is Houston calling. Over.

162:00:40 Irwin: Go ahead, Joe.

162:00:45 Allen: Roger, Jim. We're looking for a rough hack on where you might be in your EVA number 3 Prep. We're standing by for a crew status report plus the radiation devices (as per Surface 8-8). And, we're wondering when you might be switching over for Dave's biomed data. Over.

162:01:06 Irwin: Okay. He's getting in his suit now. We could switch over to his biomed right now. Well, stand by, it'll be a few minutes.

162:01:13 Allen: Okay, fine. Thank you, Jim. (Long Pause)

162:01:29 Irwin: Okay. Why don't you check Dave's biomed now. (Long Pause)

162:01:46 Allen: We got it, Jim. Clean as a whistle. Thank you.

162:01:55 Irwin: Okay, Joe.

[Long Comm Break]

[Jim's next transmission indicates that they have completed the CDR suit donning as per Surface 8-10. Normally, they would switch to Biomed-Right at this point.]

162:08:04 Irwin: Houston, this is Hadley Base. Do you want to leave the Biomed on Left? And I'm going S-band voice to voice.

162:08:15 Allen: Roger, Jim.

162:08:22 Irwin: And, are you ready for the battery management called out at 160(:15)?

162:08:30 Allen: Stand by. Okay, Falcon. We're ready.

162:08:38 Irwin: Okay, in work. (Pause) ED batteries both check at 37 (volts).

162:08:52 Allen: Copy.

[Long Comm Break]

[During this comm break, they are probably cleaning up the cabin as per Surface 9-1.]

162:15:33 Irwin: Houston, this is Hadley Base. We'll be starting the EVA-3 prep card in about 3 or 4 minutes.

162:15:43 Allen: Roger, Jim. We copy that, and we want to just remind you again on the bottom of 8-10, the page in your (Surface) checklist there, the Suit Gas Diverter Valve should be at Egress and Cabin Gas Return (Valve) at Egress. Over.

162:16:06 Irwin: Okay. Thank you, Joe.

[Long Comm Break]

[Dave and Jim have probably started the PLSS donning procedures on Surface 9-2.]

162:20:31 Allen: Hadley Base, this is Houston. We're still showing the Cabin Gas Return in Cabin. Could you reverify that it's in Egress, please. (Pause)

162:20:52 Irwin: Cabin Gas Return is presently in Auto. I think we pick it up at Egress a little later on in the procedure. (Pause)

162:21:07 Allen: Jim, Rog. Actually we should have picked that up on page 8-10 in your checklist. So we think it should be in the Egress position now.

162:21:19 Irwin: Okay. I'm going Egress.

[Very Long Comm Break]
MP3 Audio Clip ( 13 min 14 sec ) by David Shaffer

[During the comm break, the Public Affairs commentator tells the press that cabin depressurization is expected at about 163:14. This estimate is remarkably close since depress will actually happen at 163:18.]
162:46:24 Scott: Houston, Hadley Base. We'll be coming to you with a comm check (on Surface 9-3) in about 2 or 3 minutes.

162:46:29 Allen: Roger, Dave. Looking forward to it.

162:46:36 Scott: Okay. (Long Pause)

162:47:14 Allen: Dave and Jim, this is Houston. Be advised we've got an EVA update for you, which you can copy onto the checklist if you want, or we can read it to you as you progress through the EVA, and we can talk about that when you want to. Over.

162:47:34 Scott: Well, where does it fall, Joe, and what does it concern.

162:47:37 Allen: Okay, Dave. It's going to be very simple changes to the checklist. I think just a few words concerning the general picture will be plenty sufficient; and then we'll give you the details as you come to them. I just want to give you an idea of how the traverse is going to look before you actually get started. Over.

162:47:57 Scott: Oh, okay. You mean our cuff checklist?

162:48:01 Allen: Roger. You're going to be able to follow your cuff checklist for EVA-3 almost exactly. Just a few changes.

162:48:11 Scott: Okay. Well, can we proceed on here and you want to give us the changes now? It might be better for us to proceed on out, and you change us as we drive or something.

162:48:22 Allen: Okay. That sounds like the second option is a good one, Dave. Although you might want the big picture before you proceed on out.

162:48:32 Scott: Well, why don't you give us the big picture now, before we get too deep in the comm checks and all. (Pause)

162:48:45 Allen: Okay. Roger, Hadley Base. Taking it from the top, we're going to ask you to stop first at the ALSEP site and spend a few minutes recovering the successfully drilled core tube and, then follow that with the Grand Prix photography. From there, press on towards Station 9, as planned. We're going to skip the Delta stop in between.

[EVA-3, part B map and cuff checklist pages CDR-26 and 27 indicate a brief, supplementary sample stop 0.8 km west of the LM at BQ.1/70.7. The planned location is marked with the Greek symbol D.]
162:49:17 Allen: Station 9 is exactly as we planned it. From Station 9. up to Station 10, exactly as we planned it; and at Station 10, we're going to hit a branch point. We can update you there when you arrive at Station 10. The two options are basically, to head north for the Complex, although we think it's more probable we'll just want to loop back towards the north across Alligator Chain doing good mare sampling, and wind up at Quark West crater, that's the western crater of the Quark triplet, and use that as a Station 14 stop. Over.
[As shown on the Named Features map, the Alligator Chain is a string of craters which, on the EVA-3, Part B map extends from BY.0/69.5 to BU.3/68.5. The Quark Triplet consists of the craters at BT.5/71.5, BT.8/72.3, and BT.3/72.8. Elemental particles of matter such as protons and neutrons are made up of triplets of quarks and the name was contributed by physicist Joe Allen. Because of difficulties Dave and Jim will have extracting and disassembling the deep core, they will return directly to the LM from Station 10.]

[As shown on parts A and B of the EVA-3 map, Station 11 was planned for South Twin Crater at BV.7/64.5, Station 11 at Link Crater in the North Complex at CC.0/67.0, Station 13 at the northwest rim of Pluton at CE.6/68.7, and Station 14 at Ring Crater at BW.2/72.0.]

162:50:07 Scott: Okay. I guess we'll proceed on to Station 10 and take a look at it there. I'd sort of would like to get up to the North Complex if we can.

162:50:15 Allen: Roger, Dave. We copy that, and it may well be we can get up there. We'll just see how it goes.

162:50:26 Scott: Okay. On with the comm check.

162:50:29 Allen: Okay. (Long Pause)

162:51:22 Scott: (Reading from the last lines of Surface 9-3) "Mode, Vox; Vox Sensitivity, Max; VHF A, T/R; B, Receive." (Reading from Surface 9-4) Okay, "CB(16) Comm: SE Audio, open; and collect (sic)"...Have you connected those...

162:51:54 Scott: Okay, "CB(16) Comm: SE Audio, closed; PLSS PTT, Maintain, Right; PLSS mode to A; wheel, counter-clockwise."

162:52:05 Irwin: Okay, I'm A.

162:52:06 Scott: Okay. "PLSS O2 pressure gauge greater than 85 (percent)."

162:52:10 Irwin: Verified; reading 94.

162:52:12 Scott: Okay, you're 5 square (that is, 5 by 5) to me; check with Houston.

162:52:16 Irwin: Houston, how do you read the LMP?

162:52:18 Allen: LMP, you're loud and clear.

162:52:23 Irwin: You're the same.

162:52:25 Scott: "CB(11) Comm: CDR Audio, open and connect to the PLSS comm." (Long Pause) Okay. CDR's to B; PLSS O2 pressure gauge is reading 91 percent, and how do you read me, Jim?

162:53:44 Irwin: Oh, I read you loud and clear.

162:53:45 Scott: Okay, you make a comm check with Houston.

162:53:51 Allen: And, Houst...

162:53:52 Scott: You make a comm check with Houston?

162:53:53 Allen: Houston reads...

162:53:54 Irwin: Houston, how do you read the LMP.

162:53:55 Allen: Jim, both you and Dave are loud and clear.

162:53:59 Irwin: Okay.

162:54:01 Scott: Okay, "PLSS mode: LMP to B and CDR to A." Okay, I'm on A. How do you read?

162:54:09 Irwin: Loud and clear.

162:54:10 Scott: Okay, Houston, how do you read the CDR on A?

162:54:12 Allen: CDR, you're 5 by (5).

162:54:17 Scott: "PLSS mode (both) to AR. Tone on." (Pause) Okay, how do you read me on AR?

162:54:26 Irwin: Read you loud and clear.

162:54:27 Scott: Okay, Houston, how do you read the CDR on AR?

162:54:29 Allen: Dave, you're loud and clear.

162:54:32 Scott: Okay, you're 5 by, and how's the TM (PLSS telemetry)? (Pause) (To Jim) Okay, you make a check with Houston.

162:54:43 Irwin: Joe, how do you read the LMP?

162:54:44 Allen: Okay, Jim, you're 5 by and the TM's good.

162:54:52 Irwin: Okay.

162:54:53 Scott: Okay. "CB(16) ECS: LCG Pump, closed, which it is; cold as required. CB(16) ECS: Cabin Repress, close; verify."

162:55:01 Irwin: Verified.

162:55:02 Scott: "Suit Fan Delta-P, Open."

162:55:03 Irwin: Open.

162:55:04 Scott: "Suit Fan 2, Open."

162:55:05 Irwin: Open.

162:55:06 Scott: Okay, "verify ECS caution, H2O Sep Component lights." About a minute. (Pause) Okay, here they come.

[They have completed the tasks on Surface 9-4 and are about to start 9-5.]

[Scott, from a 1996 letter - "Once we have completed the comm check, the reader/listener can hear all of our EVA prep; whereas, before we reconfigure, all of our EVA prep discussion is internal to the LM only."]

162:55:13 Scott: "Suit Gas Diverter (Valve), Pull Egress; verify."

162:55:15 Irwin: Verified.

162:55:16 Scott: "Cabin Gas Return, Egress; verify?"

162:55:19 Irwin: That's verified.

162:55:20 Scott: "Suit Circuit Relief (Valve), Auto; verify."

162:55:23 Irwin: That's verified.

162:55:24 Scott: "OPS connect: Suit Isolation (Valve) to Suit Disconnect. Disconnect the LM O2 hoses and secure about the PGA."

162:55:34 Irwin: Okay. (Pause)

162:55:39 Scott: I'll come back around here. (Pause) (Garbled) get for...

162:55:47 Irwin: Why don't I take care of you and you take care of me?

162:55:49 Scott: Yeah. I think you ought to.

162:55:51 Irwin: Okay, you want me to put you on Suit Disconnect?

162:55:53 Scott: Not yet. Why don't you come on around? (Long Pause) Okay, you're on Suit Disconnect, yeah. (Long Pause)

162:56:25 Irwin: Secure that about the PGA, Dave. Why don't you put those under one of my belts?

162:56:30 Scott: Yeah. (Pause) I'm sorry.

162:56:34 Irwin: That's okay. (Pause)

162:56:48 Irwin: Okay. (Pause)

162:56:57 Scott: Get it? (Pause) Okay, "OPS O2 hose is closed and locked The purge valve"...Okay, it's closed. Locked low and the pin's in. (Pause) Closed and Locked. Get your PGA diverter valve to vertical. (Pause) Okay, and you can get me. Oop. Wait a minute. (Pause)

162:57:31 Irwin: Okay, we'll go to Suit Disconnect on you. (Long Pause) Here. Here are your straps. (Pause) Okay, we'll connect the OPS. (Pause) It's connected and it's locked. Okay.

162:58:42 Scott: Okay.

162:58:43 Irwin: Purge Valve. Low (Pause) Okay, it's connected and locked. Okay, and your PGA diverter valve should be vertical.

162:58:50 Scott: Right.

162:58:51 Irwin: Okay.

162:58:52 Scott: Okay, last drink. (Long Pause)

[After they both get a drink from the water gun, they will don the helmets and gloves.]
MP3 Audio Clip ( 13 min 51 sec ) by David Shaffer

162:59:47 Irwin: Okay, we should drop that back as far as we possibly can. (Garbled) (Pause)

[They may be getting the water hose out of the way.]
163:00:07 Scott: That's going to come out with the ETB. (Garbled) (Pause) Okay. "Descent Water Valve, Closed."

163:00:26 Irwin: Descent water going closed now.

163:00:29 Scott: Okay, "position the mikes". And "helmet and glove donning. PLSS Fan to On, to the right. And vent flags should clear." Mine clears.

163:00:46 Irwin: It's clear.

163:00:49 Scott: "Don helmets and LEVAs, check the drink bag position." Okay, let me get yours here. (Pause) Is that aligned?

163:01:13 Irwin: Yeah. It's aligned. (Long Pause)

[We can hear the locks close on Jim's helmet. A detail from training photo 71-HC-724 shows Jim's drink valve.]
163:01:59 Scott: There we go. Closed and locked. (Pause) Okay, LEVA's locked. (Pause) Front flap secure. Okay. You're locked. (Long Pause)
[Next, Jim gets Dave into his helmet.]
163:02:53 Irwin: (Helmet lock clicks) Sounded good. Locked.

163:02:55 Scott: How about that? (Long Pause)

163:03:20 Irwin: Okay.

163:03:21 Scott: Okay. "Secure tool harness self-doff straps to LEVAs." Okay, let me get yours. (Pause) There's the right one. (Pause) Left one. Okay. (Long Pause) Okay.

163:04:11 Irwin: Dave, that's pretty cold.

163:04:13 Scott: Yeah. Okay. Let's see if you can get back in your corner. (Pause)

163:04:25 Irwin: Okay.

163:04:27 Scott: Okay. "CB(16) ECS LCG Pump, Open."

163:04:29 Irwin: Open.

163:04:31 Scott: "Disconnect the LM water hose. Connect the PLSS water hose." Okay, in work. (Long Pause)

163:05:06 Irwin: Okay, mine's connected and locked.

163:05:08 Scott: Okay. Mine's connected and locked. Says, "Connect PLSS ...Okay, stow LM hoses." (Long Pause) I'll have to wait until you turn around here. (Long Pause)

163:05:52 Irwin: Getting them back as far as you can?

163:05:53 Scott: Yeah. (Pause)

163:05:57 Irwin: Water gun still secure?

163:05:58 Scott: Yeah. (Pause) Whew! (Pause) Okay; they're there.

163:06:16 Scott: Okay, verify the following...Turn around, and we'll check all that stuff. (Pause) Okay.

163:06:30 Irwin: Okay, Dave. I'll read to you, okay?

163:06:32 Scott: Okay.

163:06:33 Irwin: "Helmet and visor aligned and adjusted."

163:06:36 Scott: Okay, they're aligned and adjusted and locked.

163:06:39 Irwin: "02 connectors, three."

163:06:40 Scott: Okay. Locked. Yeah, and that one's locked and the bootie's on. That one's locked and the bootie's on.

163:06:53 Irwin: Okay. "Purge valve."

163:06:54 Scott: Purge valve's locked, closed.

163:06:59 Irwin: "Water connector."

163:07:01 Scott: Locked.

163:07:02 Irwin: "Comm connector."

163:07:04 Scott: Locked.

163:07:05 Irwin: And "diverter valve, vertical."

163:07:06 Scott: Vertical. (Pause) Okay, "helmet and visor, aligned and adjusted."

163:07:12 Irwin: Okay, it is.

163:07:13 Scott: "02 connectors, three, locked." (Long Pause)

163:07:32 Irwin: They're locked. Let me get the bootie around...(Pause) Got booties on all those connectors.

163:07:50 Scott: Yeah, you're right.

163:07:51 Irwin: Okay, and, Dave...

163:07:52 Scott: "Purge valve, locked."

163:07:57 Irwin: It's locked.

163:07:58 Scott: "Water connector, locked."

163:08:00 Irwin: Locked.

163:08:01 Scott: "Comm connector, locked."

163:08:05 Irwin: Comm connector is locked.

163:08:07 Scott: "PGA diverter valve, vertical." (Pause)

163:08:16 Irwin: Stand by a minute, Dave.

163:08:17 Scott: Okay. (Pause)

163:08:29 Irwin: Okay, you're locked. And it's vertical.

163:08:32 Scott: Okay, "verify EVA CB configuration." And then, okay, put on the gloves. (Long Pause) Here's your other glove over here on your left, Jim.

163:08:52 Irwin: Okay. Thanks, Dave.

163:08:53 Scott: Fell down. (Long Pause)

[It is not clear what fell; but, whatever it was, it didn't slow them down. The glove-donning procedures are on Surface 9-6.]
163:09:10 Irwin: Okay, my circuit breakers are verified.

163:09:14 Scott: And mine are verified.

[Irwin, from the 1971 Technical Debrief - "I do not think we ever hit any circuit breakers during the operation."]

[Scott, from the 1971 Technical Debrief - "Yes, that's right. I do not think we ever did. Every time we checked them, they were configured right."]

163:09:17 Scott: Glove donning time.

163:09:20 Irwin: Final test.

163:09:23 Scott: Yeah.

[Glove donning is probably the trickiest of all the EVA Preps, particularly getting the wristrings on the second glove locked. In listening to this, I thought that Jim might have been saying that this was a "final test" of their glove donning prowess.]

[Scott, from a 1996 letter - "Not really. Jim is probably referring to our sore fingers and the final test on how they will feel and function. Glove donning took some effort, but was not really 'tricky'."]

[Comm Break]

163:10:23 Irwin: And mine are locked.

163:10:26 Scott: (Intent on his own gloves) Stand by. (Long Pause) And mine are locked.

163:10:56 Allen: Dave, this is Houston. How do those gloves feel today?

163:11:04 Scott: (Laughing) Gee, I don't know how to answer that, Joe. Sure be nice when I get through with the drill and I can take off the overgloves.

[This statement indicates that Dave has been wearing a fingerless overglove - like a golf glove - to protect the palm of his EVA glove from excessive dust abrasion. Post-mission pictures of one of Gene Cernan's cover gloves show the great amount of wear than can occur in a relatively short amount of time. Dave is eager to get them off because they add bulk to his hands and restrict movement.]
163:11:13 Allen: Roger. Wondered if you're going to shoot a little pool today with Colorado Fats, there.

163:11:21 Scott: Joe, today's the day for a little pool.

163:11:25 Allen: I was thinking the same thing.

[Joe is having fun in this reference to the Jackie Gleason/Paul Newman film The Hustler. See the discussion following 139:43:46. "Colorado Fats" is, of course, Jim, who had taken up residence in Colorado Springs before joining the Astronaut Corps and who returned there after his retirement from NASA.]
163:11:31 Scott: Okay, let's verify the locks and the gloves.

163:11:35 Irwin: Okay. (Pause) Okay, I verify yours.

163:11:48 Scott: Okay, yours are locked, and locked. Okay. Put the covers over. (Long Pause) Okay, "PLSS Diverter on Min, verify." (Pause) Your PLSS Diverter on MIN, Jim?

163:12:28 Irwin: Verified.

163:12:30 Scott: (Checking his own) Okay, verify. "PLSS Pump, On, to the right."

163:12:33 Irwin: Pump coming on.

163:12:35 Scott: Mine's running and...

163:12:37 Irwin: Same.

163:12:38 Scott: "Press Reg A and B to Egress."

163:12:40 Irwin: A and B are Egress.

163:12:43 Scott: Okay. With the PLSS O2 On, we'll do a pressure integrity check. (If I can) find that little valve down there.

163:12:54 Irwin: And my O2 is coming on.

163:13:00 Scott: And my O2 is on. And "the press flag should clear 3.1 to 3.4. Cuff gauge should come up 3.7 to 4.0." (Pause) And I'm coming up. (Long Pause) Okay, I'm off the peg. (Pause)

163:14:16 Irwin: Okay, I'm reading 3.8.

163:14:20 Scott: Okay. I'm coming. Here we go 3.6, 7, 8. (Pause) Okay, I'm stabilized. My O2 flag is clear. If you can get a hold of that little valve again, let's turn them off and get an integrity check.

163:14:43 Irwin: Okay.

163:14:44 Allen: And, Houston marks one minute, and you have got good pumps.

163:14:47 Scott: Mine's off now.

163:14:51 Irwin: And mine's off.

163:14:53 Scott: Okay, thank you, Joe. Give us a call after your minute. (Long Pause)

163:15:46 Allen: One minute, Mark.

163:15:50 Scott: Okay. I'm reading 3.75.

163:15:54 Irwin: I'm reading 3.7.

163:15:56 Scott: Okay, let me get it. Okay, O2 back on.

163:16:01 Irwin: Coming back on.

163:16:05 Scott: Okay, "verify the O2 flag is clear."

163:16:09 Irwin: Mine's clear.

163:16:10 Scott: Okay, let me turn the card. Can you go forward, Jim?

163:16:14 Irwin: Yeah.

163:16:19 Allen: And, Hadley Base, we're ready for depress. Two magnificent suits.

163:16:27 Scott: Good. (Pause) Oh, bad place to have to change that card. (Pause)

[Dave and Jim are using the large EVA Prep & Post Card. Dave may be having some trouble getting to the card with his suit pressurized. If so, it might have been better to have the page turn come before suit pressurization.]
163:16:44 Scott: Okay. Got a Go for the depress. CB(16) ECS: Cabin Repress to open.

163:16:50 Irwin: Standby. (Pause) Open.

163:17:01 Scott: Okay, "Cabin Repress valve to Close."

163:17:04 Irwin: Cabin Repress going Closed. Now.

163:17:08 Scott: Okay. And then the "forward dump valve Open, then Auto at 3-1/2."

163:17:15 Irwin: Okay, standby. (Pause)

[Jim was facing aft as he changed the ECS controls and now has to turn to get the dump valve on the forward hatch.]
163:17:25 Scott: Okay, I've got my eyeball on the pressure gauge, go ahead.

163:17:28 Irwin: Okay. Going open now.

163:17:32 Scott: Okay. 4.5, 4.0, Mark, 3.5. (Garbled) Auto.

163:17:41 Allen: Houston marks it.

163:17:44 Scott: Okay. "Verify cuff gauge doesn't drop below 4.6. I'm looking at 5.1".

163:17:50 Irwin: I'm looking at 5.5.

163:17:55 Scott: "LM suit (circuit) pressure locked up at 4.5." Okay. Something about (starting) the watch. (Pause) And "overhead (or) forward dump valve to Open."

163:18:09 Irwin: Okay. I'm going Open. It's Open.

[Scott, from the 1971 Technical Debrief - "I don't remember exactly what time it was (that they did the depress), but we were letting Houston keep track of the time. I think it would be good to have some sort of procedure for what time we could expect the various events to be occurring. We did the checklist on Houston time (actually, planned mission-elapsed-time) so we could have something to refer to."]

[As is discussed at 118:35:59 and following, Dave and Jim had turned their mission timer off to conserve power. For both Apollo 16 and 17, the time required to complete each subsection of the procedures was indicated in the checklists and, on Apollo 17, the crew used the Digital Event Timer to gauge their progress ]

[The arrival of oxygen released in this depressurization was recorded 110 meters northwest of the LM by the CCGE (Cold Cathode Gage Experiment). The CCGE was co-located with the SIDE, which is shown in Figure 5-52 in the Apollo 15 Preliminary Science Report. As indicated in the Preliminary Science Report, "The CCGE was turned on at approximately 19:34 GMT on July 31, 1971. On initial activation, the gage indicated full scale; but, after approximately 30 minutes of operation, the output began to drop. The high voltage was then commanded off to allow the instrument to outgas. The gage has not been operated for prolonged periods during the lunar day because of voltage restrictions placed on the high-voltage power supply in the SIDE package. The experiment was operated four more times for periods of approximately 30 min each to observe the effects of the LM depressurizations for the second and third periods of extravehicular activity (EVA) and for the equipment jettison and to observe the effects of the LM lift-off from the lunar surface."]

[CCGE data for the EVA-3 depressurization ( Figure 13-4 in the Apollo 15 Preliminary Science Report ) shows peaks at 'elapsed times' of 1:36, 2:17, and 5:38, corresponding to (1) the initial depressurization to 3.5 psi, (2) the second valve opening to complete depressurization, and (3) hatch opening. Although it is tempting to think that zero time corresponds to the reported time of the first valve opening, it seems unlikely that the flow would take 96 seconds to travel 110 meters in the Apollo 15 case versus 30 seconds to travel 190 meters in the case of the Apollo 14 EVA-2 depress. It seems more likely that zero time represents the start of data collection for this event. For the Apollo 15 EVA-3 depress, the relevant mission elapsed times are 163:17:32 for the first valve opening, 163:18:12 for the second opening, and 163:21:35 for hatch open. Dave and Jim did a good job of reporting what they were doing, and the uncertainties in the relative times seems small. The intervals are 40 seconds and 3 minutes 23 seconds, which compare well with the CCGE intervals of 41 seconds, and 3 minutes 21 seconds.]


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