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Day 2, part 1: Checking the SPS Journal Home Page Day 3, part 1: Flashing Lights

Apollo 15

Day 2, part 2: Entering the Lunar Module

Corrected Transcript and Commentary Copyright © 1998-2023 by W. David Woods and Frank O'Brien. All rights reserved.
Last updated 2023-10-27
Index to events
Start of sextant photo test 032:23:50 GET
UV photography of Earth 032:45:55 GET
LM repressurisation 033:30:10 GET
Electrical glitch reported 033:48:32 GET
Start of TV transmission 033:56:06 GET
Scott reports broken glass on LM tapemeter 034:33:07 GET
OPS checkout 035:10:43 GET
Flyby PAD 036:20:36 GET
Although they have travelled for only one of the three days that it takes to coast to the Moon, they have passed the halfway point in terms of distance.
There has been a change of shift in the Mission Operations Control Room and as part of that, Karl Henize has taken over the CapCom console from Joe Allen. Meanwhile, the crew of Apollo 15 are having their midday meal and preparing for the next activities on the Flight Plan.
Flight Plan page 3-36.
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
This is Apollo Control at 31 hours, 41 minutes. The change of shift news conference will begin momentarily in the MSC auditorium. We'll take the air/ground off the release line now, tape during the conference and replay any conversation after the news conference.
Before a series of photography experiments, they are to check the pressure difference across the forward hatch and if it is reading not greater than 2.7 psi (18.6 kPa), they will place the Tunnel Vent valve to its Vent position. This will dump the bulk of the LM's atmosphere prior to its repressurisation from the CM.
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
031:56:22 Irwin: Houston, this is [Apollo] 15.
031:56:26 Henize: 15, this is Houston. Go ahead.
031:56:30 Irwin: You asked a question on the UV procedures.
031:56:37 Henize: Say again, which procedures. You're coming in very weak. [Long pause.]
031:57:21 Henize: 15, this is Houston. Standing by for questions on UV procedures.
031:57:28 Scott: Okay, Karl. Maybe we can get an answer on board. Stand by. [Long pause.]
031:58:16 Irwin: Houston, it's 15. I think we have an answer. Thank you.
031:58:20 Henize: Roger.
Very long comm break.
Flight Plan page 3-39.
The next hour is dominated by the sextant photo test and, afterwards, UV photography of Earth. Page 3-38 of the Flight Plan is given over to the checklist for these two activities.
For the Sextant Photo Test, the Command Module's DAC (Data Acquisition Camera) will be attached to the sextant eyepiece and will use a magazine of very high speed black and white (6,000 ASA) 16-mm film. The DAC was attached to the sextant in much the same way as any other lens might be attached to a camera; the regular lens would be removed, and the camera would instead use the sextant's optics. A cable is carried in the CM to provide the DAC with power from the spacecraft's 28V DC supply. The spacecraft is maneuvered to the required attitude for the first of two tests. Using Program 52, the sextant is pointed at the required star and the cabin lights are dimmed. Two seconds of film are run through the camera at 24 frames per second, using a high shutter speed, in order to bring a fresh frame into the gate; one which would not have any fogging through inadvertent light leakage in the magazine. Four frames are then exposed for the test, one for 60 seconds, then 20, then 5 and 1 second. Finally, another 2 seconds are run through at 24 frames per second to ensure the test frames are not on the surface of the take-up pack. This procedure is repeated for a second target.
032:03:06 Worden (onboard): Yes. And where's the Hasselblad that's got another - got another adapter on it? Oh, it's just this - son of a bitch right through here.
032:03:42 Irwin (onboard): Where you going to plug that other end in, lineman?
032:03:44 Worden (onboard): Huh?
032:03:45 Scott (onboard): Where you going to plug that other end in? You have a place down there?
032:03:50 Worden (onboard): Oh, yes, yes, yes, yes, yes.
032:03:53 Scott (onboard): Where?
032:03:55 Irwin (onboard): That's such a longer cable, though, ... Put...
032:03:58 Worden (onboard): Yes. Hmm.
032:04:05 Irwin (onboard): The only place that plugs in is over here in the girth bay, isn't it?
032:04:09 Scott (onboard): Yes.
032:04:10 Worden (onboard): Well, how the hell do we put a PCM cable in this thing, then?
032:04:14 Scott (onboard): But your Mag isn't on your - You haven't got a Mag on right now.
032:04:18 Irwin (onboard): Be very...
032:04:19 Worden (onboard): Okay.
032:04:20 Irwin (onboard): ...careful then.
032:04:21 Worden (onboard): I have been, too.
032:04:25 Scott (onboard): Look it over.
032:04:26 Irwin (onboard): Oh, my God.
032:04:31 Scott (onboard): Fooling with your pocket's not ...
032:04:34 Irwin (onboard): Another thing you've got to check in getting this thing on is maybe procedures.
032:04:37 Scott (onboard): That's right. You always find...
032:04:40 Worden (onboard): Yes.
032:04:41 Scott (onboard): ...operations to verify.
032:04:42 Worden (onboard): Okay.
032:04:44 Scott (onboard): Yes. You got to crank it around once.
032:04:54 Scott (onboard): Well, we should now make contact.
032:04:59 Irwin (onboard): Press on.
032:05:02 Worden (onboard): Found ... TV ...
032:05:08 Scott (onboard): Which one?
032:05:18 Worden (onboard): There?
032:05:20 Scott (onboard): ...
032:05:23 Worden (onboard): Okay.
032:05:28 Scott (onboard): Okay. That's all right.
032:05:30 Worden (onboard): Hmm!
032:05:33 Scott (onboard): There you go ....
032:05:37 Worden (onboard): Tool.
032:05:41 Irwin (onboard): Hmm?
032:05:47 Scott (onboard): Here. ... Let's see your MAG. Looks all right. Not going in that sprocket.
032:06:09 Worden (onboard): Yes, it looks like it's tight back here.
032:06:11 Irwin (onboard): ...
032:06:13 Scott (onboard): It wasn't - it wasn't before.
032:06:14 Worden (onboard): No, I guess it - again.
032:06:16 Scott (onboard): Egad.
032:06:21 Irwin (onboard): ... I've never put that thing...
032:06:23 Worden (onboard): God damn it - there - I...
032:06:26 Irwin (onboard): Must be another cable...
032:06:27 Worden (onboard): Connector right here.
032:06:28 Irwin (onboard): There must be another cable.
032:06:29 Scott (onboard): Yes, there is.
032:06:34 Irwin (onboard): You remember that fit check?
032:06:35 Worden (onboard): Oh, shit.
032:06:36 Irwin (onboard): The vehicle with the...
032:06:38 Worden (onboard): Yes.
032:06:39 Irwin (onboard): ...with the camera down there on the sextant?
032:06:40 Worden (onboard): Yes?
032:06:42 Scott (onboard): You remember who took...
032:06:43 Worden (onboard): I didn't - No, I didn't do that.
032:07:01 Worden (onboard): Yes, this is the EL...
032:07:03 Scott (onboard): Jim, don't you want to...
032:07:04 Worden (onboard): ...PCM.
032:07:05 Scott (onboard): ...use the cables we've got?
032:07:08 Irwin (onboard): ...
032:07:16 Irwin (onboard): Will those cables hit - hook together?
032:07:20 Worden (onboard): No.
032:07:21 Irwin (onboard): Fit together.
032:08:27 Scott (onboard): Maybe we better do it without PCM.
032:08:29 Worden (onboard): Yes, it's a shame. That PCM thing. (Sigh) That's...
032:09:04 Worden (onboard): That's really something.
032:09:22 Worden (onboard): Could have sworn that goddamn thing was right - right here.
032:09:25 Scott (onboard): No, there's never been one there. The only place they've ever been...
032:09:27 Worden (onboard): Let me have it.
032:09:28 Irwin (onboard): Yes.
032:09:29 Scott (onboard): ...was down behind the rock boxes, but you won't reach that either.
032:09:30 Worden (onboard): No, you just don't reach that either.
032:09:33 Scott (onboard): There's - there's one behind each rock box.
032:09:35 Worden (onboard): Yes?
032:09:37 Scott (onboard): But that's - that's too long for that cable, too.
032:09:39 Worden (onboard): That's too - Yes, that's right. Too long for the cable.
032:09:50 Irwin (onboard): Too long for that one ....
032:09:58 Scott (onboard): In there?
032:10:00 Worden (onboard): No.
032:10:03 Scott (onboard): Look behind the screen.
032:10:07 Worden (onboard): CDR's food locker! No. We don't have a CDR's food locker, do we?
032:10:37 Worden (onboard): Well, that's one of those little things I just never had - for one reason or another, never had checked out, I guess.
032:10:44 Scott (onboard): I thought you had.
032:10:45 Worden (onboard): I thought I had, too.
032:10:46 Scott (onboard): What?
032:10:47 Worden (onboard): Thought I'd looked at everything.
032:10:48 Scott (onboard): Not the cameras. ... camera up.
032:10:57 Irwin (onboard): Well, maybe we better press on through.
032:10:59 Worden (onboard): Yes, okay. Let's do without it.
032:11:01 Irwin (onboard): Okay. Exposure's supposed to be here on 1/500th.
032:11:13 Irwin (onboard): ... PCM.
032:11:15 Scott (onboard): How do you get PCM out of the DAC?
032:11:17 Worden (onboard): Okay. 1/500ths.
032:11:18 Irwin (onboard): Twenty-four fra - frames per second?
032:11:20 Worden (onboard): Right; 24.
032:11:22 Irwin (onboard): You want to shoot 5 percent of the Mag? You got Mag H on there?
032:11:26 Worden (onboard): Mag H. That's correct.
032:11:29 Irwin (onboard): You want to record the percentage. I guess, right now, it's 100 percent.
032:11:34 Scott (onboard): Can't even see 5 percent on that thing.
032:11:38 Worden (onboard): Yes, it's about 95 percent.
032:11:41 Scott (onboard): You can time it, Al. Take 5 percent of the total, times the 24 frames per second.
032:11:45 Irwin (onboard): Yes, you got it...
032:11:46 Worden (onboard): Okay.
032:11:47 Irwin (onboard): ...for 2 seconds.
032:11:48 Worden (onboard): Okay. Yes.
032:11:49 Irwin (onboard): You got it for 2 seconds.
032:11:50 Worden (onboard): Huh?
032:11:51 Irwin (onboard): It calls for 2 second's worth at 24.
032:11:52 Worden (onboard): Two seconds?
032:11:53 Irwin (onboard): Yes.
032:11:54 Worden (onboard): Oh, okay.
032:11:55 Irwin (onboard): No, the next step is Utility Power, On.
032:11:58 Worden (onboard): Okay...
032:11:59 Irwin (onboard): [Garble].
032:12:00 Worden (onboard): ...Utility Power is On. Okay.
032:12:03 Irwin (onboard): I guess you need that. Roger.
032:12:04 Worden (onboard): You want 2 seconds at 24 frames.
032:12:06 Irwin (onboard): Well, let me read - Yes, that's what it calls for.
032:12:08 Scott (onboard): ... That's not 5 per cent. Where do you get the 5 per cent?
032:12:17 Irwin (onboard): Twenty-four ... is this here. ...
032:12:21 Scott (onboard): Oh, about ... seconds ... We got a bunch of brange - a bunch of changes to make here, Al.
032:12:27 Worden (onboard): Oh, okay.
032:12:28 Irwin (onboard): You're not ready to run.
032:12:29 Worden (onboard): Okay.
032:12:30 Irwin (onboard): What you want next is disable jets A-3, B-3, C-4, and D-4.
032:12:35 Worden (onboard): Okay. That gets the - the dark stuff out of the way. Okay, yes, that's...
032:12:40 Scott (onboard): Okay, here we go, A...
032:12:41 Worden (onboard): ...protective.
032:12:42 Scott (onboard): Read them again.
032:12:43 Irwin (onboard): A-3.
032:12:44 Scott (onboard): Yes.
032:12:45 Irwin (onboard): B-3.
032:12:47 Scott (onboard): A - A-3 and B-3?
032:12:50 Irwin (onboard): Yes, Bravo 3.
032:12:51 Scott (onboard): B-3.
032:12:52 Irwin (onboard): C-4?
032:12:56 Scott (onboard): Bravo or Delta?
032:12:58 Irwin (onboard): No, the last one was Charlie 4.
032:13:01 Scott (onboard): Okay, Alpha 3, Bravo 3, Charlie 4...
032:13:04 Irwin (onboard): And Dog 4.
032:13:06 Scott (onboard): Dog 4. Okay, they're disabled.
032:13:09 Irwin (onboard): Then we call P52.
032:13:11 Scott (onboard): Oh, okay. Okay.
032:13:17 Irwin (onboard): We have to Proceed there until we get the Noun 70 display.
032:13:21 Scott (onboard): Yes.
032:13:22 Irwin (onboard): We want all zeros in there.
032:13:23 Scott (onboard): Want to set all zeros in there? Okay.
032:13:29 Irwin (onboard): And then we have some - a load for Noun 88.
032:13:31 Scott (onboard): Yes, right. Okay.
032:13:38 Irwin (onboard): Okay, Noun 88.
032:13:40 Scott (onboard): Yes. Read them off.
032:13:41 Irwin (onboard): Minus 10820.
032:13:46 Scott (onboard): Go.
032:13:47 Irwin (onboard): Minus 79037.
032:13:51 Scott (onboard): All right.
032:13:52 Irwin (onboard): Minus 60300.
032:13:59 Worden (onboard): Before we blow it, let's make sure that there's no PCM cable that'll really...
032:14:05 Irwin (onboard): Okay, we - we got a few more steps to do here anyway. Verify the...
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
032:14:09 Scott: Houston, 15.
032:14:10 Irwin (onboard): Wait a minute.
032:14:12 Henize: 15, this is Houston. Go ahead.
032:14:19 Scott: Okay. With the sextant photo test here, we have a call for a PCM cable, and the only ones we have on board will not reach the connectors over by the right-hand girth shelf. Do you have any suggestions on how we can get the DAC connected to the PCM.
There ought to be a cable which connects between the camera and the spacecraft to carry data to permit controllers on the ground to see when the camera is operating. This PCM (Pulse Code Modulation, essentially digital coding of information) cable ought to be 2.74 metres (108 inches) in length, but is not long enough to reach from the DAC, mounted on the sextant eyepiece, to one of two receptacles on panels on the spacecraft walls. These small panels, number 227 on the right-hand equipment bay, and 162, below the lower equipment bay, have only a socket for the cable with a screw-down cover, and a switch to apply power to it. It is unclear what the exact length of the power cable onboard is.
The crew have tried all the cables they can find, including the one for the Hasselblad camera.
032:14:38 Henize: That's a good question. Stand by.
032:14:42 Scott: Okay.
Long comm break.
032:14:45 Irwin (onboard): Okay Al, you can verify through the sextant, if you can, that the optics are boresighted on the target.
032:14:53 Scott (onboard): Okay. We want to proceed on this display, right? Okay.
032:15:15 Scott (onboard): Okay, now I'm going down to the station there and see if I can see that...
032:15:58 Scott (onboard): Yes, that one's right.
032:16:06 Worden (onboard): Okay, Jim.
032:16:08 Irwin (onboard): Okay, G&N Power AC on panel 5 comes off.
032:16:12 Scott (onboard): Yes, you want to turn G&N Power off?
032:16:15 Irwin (onboard): It's off.
032:16:16 Scott (onboard): Okay.
032:16:17 Irwin (onboard): And mount the DAC on the sextant.
032:16:18 Worden (onboard): Okay.
032:16:19 Irwin (onboard): Then we're ready to dim interior lights; then you can turn the DAC on, 24 frames per second for 2 seconds.
032:16:25 Worden (onboard): Twenty-four frames per second for 2 seconds, you want? Let's wait until we get an answer from them on the PCM.
032:16:30 Irwin (onboard): Yes.
032:16:31 Scott (onboard): Yes. Here's a cap comes right here. It's ...
032:16:38 Worden (onboard): That came out of the - that's the electrical connector for the suit.
032:16:41 Scott (onboard): Yes.
032:16:42 Worden (onboard): The cover. If you'd just find my spoon, I'd be a lot happier.
032:16:45 Scott (onboard): Yes.
032:16:46 Worden (onboard): Why don't you put that in your pocket and then put on suits when we get the PRDs up.
032:16:49 Scott (onboard): Yes.
032:16:50 Irwin (onboard): Okay, Al. Another thing after this - Then you change the time and, 1/60th of a second, you take one frame at 60 - 60 seconds exposure time, one frame at 20, one frame at 5, and one frame at 1.
032:17:06 Worden (onboard): Okay.
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
This is Apollo Control at 32 hours, 17 minutes. We accumulated 1 minute, 18 seconds in air/ground tape during the news conference. We'll play that back now.
032:17:11 Irwin (onboard): Let's see. You want - Let's see. You want ...?
032:17:16 Worden (onboard): I don't care.
032:17:20 Scott (onboard): ... seconds ... watch.
032:17:24 Worden (onboard): Yes. We want to turn out as many lights as we can.
032:17:26 Irwin (onboard): Yes, let me put the shades up then.
032:17:28 Scott (onboard): Okay.
032:17:30 Worden (onboard): Put all the shades up and turn out all the lights inside.
032:18:18 Scott (onboard): We came all the way out here for some poor guy, we might as well try and do his experiment right.
032:18:27 Worden (onboard): Is this for "Dim Light" Dunkelman?
032:18:29 Scott (onboard): Yes. Bob Mercer.
032:18:31 Worden (onboard): Oh, yes.
032:18:33 Irwin (onboard): Try and do it right.
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
This is Apollo Control. We're black - back live on air/ground now. Apollo 15 is 124,660 nautical miles [230,870 km] from Earth. Velocity; 4,524 feet per second [1,379 m/s]. At 32 hours, 19 minutes; this is Mission Control, Houston."
032:18:57 Irwin (onboard): You sure that other cable won't work on that camera? The one for the EL?
032:19:03 Worden (onboard): No.
032:19:04 Scott (onboard): Let's try it.
032:19:05 Worden (onboard): Try it and see. It's...
032:19:12 Scott (onboard): This here?
032:19:13 Worden (onboard): It's always been my understanding that it wouldn't. It's not long enough anyway, I don't think.
032:19:19 Irwin (onboard): We really can't do a thing.
032:19:32 Irwin (onboard): See if it'll hook to the bottom one.
032:19:54 Irwin (onboard): No, it's too short.
032:19:55 Worden (onboard): Certainly.
032:19:56 Irwin (onboard): Shit, it's not even close.
032:19:58 Worden (onboard): Sure.
032:19:59 Irwin (onboard): ...
032:20:00 Worden (onboard): Sure.
032:20:01 Scott (onboard): You can't - can't fit them together.
032:20:03 Worden (onboard): Goddamn it, there's an outlet down here somewhere.
032:20:07 Scott (onboard): Maybe that'll go behind the - rock box, Al.
032:20:10 Worden (onboard): Huh?
032:20:11 Scott (onboard): Fit - will that fit on the camera though? Will this piece go onto the camera?
032:20:19 Worden (onboard): I think that's the same kind of connection as on the - on the Hasselblad.
032:20:23 Irwin (onboard): Yes.
032:20:24 Scott (onboard): There you go, behind the rock box. Jawohl. Yes.
032:20:29 Worden (onboard): That seems like a...
032:20:34 Scott (onboard): That's a hell of a thing to have to do, but I think there's one in - back there. I remember seeing it during checkout. Right there. There's one way back in there.
032:21:04 Scott (onboard): Well, there used to be one back here.
032:21:06 Irwin (onboard): Yes.
032:21:12 Scott (onboard): Science Instrumentation, 162.
032:21:15 Irwin (onboard): How about that.
032:21:18 Scott (onboard): That's - see? It's not long enough to go there. (Laughter).
032:21:27 Worden (onboard): You're kidding.
032:21:28 Scott (onboard): Uh-uh.
032:21:29 Irwin (onboard): How about just - Isn't there one on the other side, Dave?
032:21:31 Scott (onboard): Yes, but it's - There is, but if it's not long enough to go on this side, it certainly won't go on the other side. Does that look that kind like...
032:21:38 Worden (onboard): That's the G&N.
032:21:39 Irwin (onboard): Yes.
032:21:40 Scott (onboard): Does that look like the right kind of plug, anyway, Al?
032:21:41 Worden (onboard): Yes. Yes, it does.
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
032:21:42 Henize: 15, this is Houston.
032:21:46 Scott: Houston, 15.
032:21:48 Henize: I guess we have to agree with you that that cable doesn't reach all the way over to 227, and the request down here is that you voice-record shutter opening and shutter closing on the S - on the DSE.
032:22:02 Scott: Okay. I'll voice-record shutter opening and shutter closing. We'll do that.
The crew will record cues on the voice track of the DSE recorder in lieu of using the cable. However, Al Worden expresses his opinion on this recorder that the experiment is not going to work very well because of a large number of bright particles visible outside the spacecraft. He is aware that the exposures are long and the film is very sensitive.
032:22:06 Henize: Thank you.
032:22:06 Scott (onboard): What's the number of that panel down there, Al?
032:22:08 Worden (onboard): 162.
032:22:10 Scott: Okay; and be advised, we also tried to get it to panel 162 without success. It was too short for that one, too.
032:22:16 Henize: Roger. We copy.
Very long comm break.
Panel 162 should be nearer to the sextant than 227, yet they cannot reach that either.
032:22:19 Worden (onboard): ... panel 162.
032:22:26 Scott (onboard): Well, we did everything we could.
032:22:30 Worden (onboard): Move the rock box for me, please.
032:22:34 Scott (onboard): Nothing else you can do? You tried.
032:22:39 Worden (onboard): Yes, I never thought about the - juice that thing down here in the LEB.
032:23:15 Worden (onboard): Okay, Jim, let's get on with it here.
032:23:18 Irwin (onboard): Turn down the lights. Your first one'll be for 2 seconds.
032:23:28 Worden (onboard): Okay. Let me make sure I got all the right stuff set up here - 1/24th [sic] and 1/500th.
032:23:37 Scott (onboard): Jim, make sure your tape recorder's going. You record the starts and stops like nobody does.
032:23:41 Worden (onboard): That right? Yes, I will.
032:23:43 Irwin (onboard): Tape recorder's moving.
032:23:45 Worden (onboard): It is moving?
032:23:46 Irwin (onboard): Yes.
032:23:47 Worden (onboard): Okay; you ready?
032:23:49 Irwin (onboard): Yes, I'm ready. Two seconds.
032:23:50 Worden (onboard): Okay. Okay, 2 seconds. Count now, one, 1,000; two, 1,000; Off.
032:23:57 Irwin (onboard): Okay. Change to time and - 1/60th.
032:22:01 Worden (onboard): Okay.
032:24:03 Irwin (onboard): Time and 1/60th.
032:24:07 Worden (onboard): Okay, it's time and 1/60th.
032:24:09 Irwin (onboard): Okay, and the first one'll be 60 seconds.
032:24:12 Worden (onboard): Okay. Have you got the clock running there? You can...
032:24:15 Irwin (onboard): Give me a mark, and I'll tell you when to stop it.
032:24:17 Worden (onboard): Okay, on my mark...
032:24:19 Worden (onboard): Mark.
032:24:49 Worden (onboard): I think you'd be better off if you turned that off, Jim. Just - Can you see the timer without turning that light on? Yes. You going to tell me at 1 minute?
032:25:11 Irwin (onboard): Try it again with the kitchen timer.
032:25:13 Worden (onboard): Huh?
032:25:14 Irwin (onboard): Try it again with the kitchen timer.
032:25:15 Worden (onboard): Oh, okay.
032:25:16 Irwin (onboard): Stand by.
032:25:19 Irwin (onboard): Mark.
032:25:21 Worden (onboard): Okay.
032:25:22 Irwin (onboard): That's on the kitchen timer.
032:25:23 Worden (onboard): Okay; let's take two of that.
032:25:25 Irwin (onboard): Yes.
032:25:26 Worden (onboard): At...
032:25:27 Irwin (onboard): Okay - Why don't you give me a mark, and I'll start the kitchen timer.
032:25:32 Worden (onboard): Okay. Let me make sure I got this set up right.
032:25:36 Scott (onboard): That would be a - Okay.
032:25:48 Worden (onboard): Okay. You ready?
032:25:50 Irwin (onboard): Yes, I'm ready.
032:25:52 Worden (onboard): On my mark...
032:25:55 Worden (onboard): Mark.
032:26:08 Irwin (onboard): When you hear the "ding," why, you can release it.
032:26:11 Worden (onboard): Okay.
032:26:35 Worden (onboard): I must say, if that recorder's working okay, I must say that I don't think this - photography's going to come out very good because there's an awful lot of bright - great number of bright particles right out in front of the spacecraft.
032:26:57 Irwin (onboard): Ding.
032:26:58 Worden (onboard): Okay.
032:26:59 Scott (onboard): Mark.
032:27:00 Worden (onboard): Now what's the next one?
032:27:01 Irwin (onboard): The next one's 20 seconds.
032:27:03 Worden (onboard): Okay. Same - 1/60th?
032:27:08 Irwin (onboard): Yes.
032:27:10 Scott (onboard): We want that one much.
032:27:30 Irwin (onboard): Standing by for your call.
032:27:31 Worden (onboard): Okay. On my mark -
032:27:33 Worden (onboard): Mark.
032:27:50 Irwin (onboard): Stand by.
032:27:53 Irwin (onboard): Mark.
032:27:54 Worden (onboard): Mark. Okay.
032:27:55 Irwin (onboard): ...
032:27:59 Worden (onboard): Okay. What's the next speed there, and time?
032:28:02 Irwin (onboard): Next one is 5 seconds.
032:28:05 Worden (onboard): Okay. On my mark.
032:28:10 Worden (onboard): Mark.
032:28:12 Irwin (onboard): Okay. Stand by.
032:28:16 Irwin (onboard): Mark.
032:28:17 Worden (onboard): Okay.
032:28:18 Irwin (onboard): Okay, next one's - 1 second.
032:28:21 Worden (onboard): Okay. One second?
032:28:25 Irwin (onboard): One second.
032:28:26 Worden (onboard): Okay.
032:28:32 Irwin (onboard): Okay...
032:28:33 Worden (onboard): Hmm!
032:28:36 Scott (onboard): Lucky.
032:28:37 Worden (onboard): That sure does look funny.
032:28:41 Irwin (onboard): Sounds like we got more than one frame.
032:28:43 Worden (onboard): Huh?
032:28:45 Irwin (onboard): Sounded like you got more than one frame.
032:28:46 Worden (onboard): Yes, it did.
032:28:48 Irwin (onboard): Do you show it time and 1/60th?
032:28:57 Worden (onboard): No, I'm at 1 frame per second.
032:29:01 Irwin (onboard): You should have been on time.
032:29:02 Worden (onboard): All right. I'll take one on time for 1 second.
032:29:04 Irwin (onboard): Well, how about - All the others were okay though? Yes.
032:29:07 Worden (onboard): Yes, all the others are okay.
032:29:08 Irwin (onboard): Yes. Yes.
032:29:09 Worden (onboard): That - the last two are going to be - one's going to be maybe a couple of frames at 1 second, or one - or a couple of frames per second - yes, at 1 frame per second.
032:29:18 Irwin (onboard): Well, why don't you just take a 5-second one then?
032:29:20 Worden (onboard): At 1/60th. Huh?
032:29:22 Irwin (onboard): In other words, you want to repeat the 5 second, too?
032:29:25 Worden (onboard): No. No.
032:29:28 Scott (onboard): One frame per second's going to be a lot different from 1 second per frame.
032:29:30 Irwin (onboard): One frame per second is a lot different than 1 second frame.
032:29:33 Worden (onboard): I know it.
032:29:34 Irwin (onboard): Yes. That's what I'm saying. Maybe we ought to repeat the 5-second exposure.
032:29:39 Worden (onboard): No, that should be all right. I did that on time.
032:29:43 Irwin (onboard): Okay.
032:29:48 Worden (onboard): Okay.
032:29:49 Irwin (onboard): Okay, okay, go back to 24 frames per second.
032:29:53 Worden (onboard): Okay. (Sneeze).
032:29:56 Irwin (onboard): And 1/500th.
032:29:58 Worden (onboard): And 1/500th; oo, that's going to be a - Okay.
032:30:06 Irwin (onboard): And then run the DAC for 2 seconds.
032:30:11 Worden (onboard): Okay.
032:30:13 Irwin (onboard): And then lights up, enable jets, and do a Verb 49 to another target.
032:30:22 Scott (onboard): Okay.
032:30:23 Irwin (onboard): Don't know what time it is.
032:30:24 Scott (onboard): I got them.
032:30:27 Irwin (onboard): Did you get the jets enabled yet, Dave?
032:30:29 Scott (onboard): Coming up.
032:30:32 Irwin (onboard): Okay, Verb 49.
032:30:37 Scott (onboard): Let me make sure I get the right jets, A-3, C-4, B-3, and D-4.
032:30:43 Irwin (onboard): Right.
032:30:49 Scott (onboard): Okay.
032:30:50 Irwin (onboard): Give me a Verb 49.
032:30:59 Scott (onboard): Okay, 239, 169, 330.
032:31:16 Irwin (onboard): Okay, 239, 169, and 330. That's wrong.
032:31:23 Scott (onboard): Really?
032:31:26 Worden (onboard): Is that for the sextant or the UV?
032:31:30 Scott (onboard): We have to do another with the...
032:31:42 Worden (onboard): Gee. Well, that's fair enough.
032:31:46 Irwin (onboard): G0 maneuver.
032:31:48 Scott (onboard): Golly, that's a...
032:31:54 Irwin (onboard): And, Al, when we get there, we'll repeat - repeat step 3, yes.
032:31:59 Worden (onboard): What? With the sextant and stuff?
032:32:00 Irwin (onboard): Yes.
032:32:01 Worden (onboard): Oh, I thought we were done with it.
032:32:02 Irwin (onboard): No, no, I'm sorry. We got a whole bunch more. We've got...
032:32:05 Worden (onboard): Oh.
032:32:06 Irwin (onboard): ...to do the same thing on another target.
032:32:07 Worden (onboard): Oh, okay, okay.
032:32:09 Irwin (onboard): Now that you got it all put away.
032:32:11 Worden (onboard): Sorry about that. Speak up there, James. Okay, we got to maneuver?
032:32:19 Irwin (onboard): Yes, we're maneuvering now. Oh, boy.
032:32:33 Irwin (onboard): I didn't tell you to remove the stuff, Al.
032:32:36 Worden (onboard): Huh?
032:32:37 Irwin (onboard): I didn't tell you to remove it. Stop.
032:32:39 Worden (onboard): Tough. Why, we're doing the UV next, James.
032:32:45 Scott (onboard): Time wise?
032:32:46 Irwin (onboard): We're a little behind. We're at 25.
032:33:03 Scott (onboard): UV. By golly. You got to hustle, man. I'll be getting some of that stuff out for you.
032:33:44 Scott (onboard): They want you to take all the Mags over on this thing.
032:33:46 Irwin (onboard): Yes.
032:34:11 Worden (onboard): Want to get all your Mags out and stuff like that to take over, huh?
032:34:15 Scott (onboard): Yes, since you're down there - why don't you?
032:34:20 Irwin (onboard): Get the ones in...
032:34:21 Scott (onboard): R-13. They're almost all in R-13, Jim.
032:34:24 Worden (onboard): Okay. That's all over by Jim there.
032:34:26 Irwin (onboard): Yes.
032:34:28 Worden (onboard): I think I can help.
032:34:29 Scott (onboard): A-8 - There are three Mags in A-8 you can get out, Al. You can get those; S, T, and U.
032:34:35 Worden (onboard): They're in A-8, huh?
032:34:36 Scott (onboard): Yes.
032:34:37 Worden (onboard): Okay. Yes, that's right. Those are those - Hasselblad things, since they're in there.
032:34:45 Irwin (onboard): You want me to take these out of R-13 now, Dave?
032:34:48 Scott (onboard): Yes. Let's just get them all ready.
032:34:52 Irwin (onboard): Tie them down there on the couch some way?
032:34:57 Worden (onboard): Let's see. How about O, P, and Q?
032:35:00 Scott (onboard): No. Well, all ours are double letters, really, Al.
032:35:04 Worden (onboard): Yes.
032:35:05 Scott (onboard): So anything that's a single letter is yours. So what I'm really looking for is SS, TT, and UU.
032:35:18 Worden (onboard): Hmm.
032:35:45 Scott (onboard): Yes, and then you got to have the UV done, the TV out, and be over there for a TV pass in an hour.
032:35:51 Irwin (onboard): That's ... Okay.
032:36:00 Scott (onboard): We need the jettison bag out of A-2, Al. If you're in that vicinity.
032:36:09 Worden (onboard): Okay.
032:36:26 Worden (onboard): Very strange. I don't see any SS, TT...
032:36:30 Irwin (onboard): Well, if it just says "LM S, T, and U," that's good.
032:36:34 Worden (onboard): Oh, hey, in here. Yes, I guess this is it here. They didn't mark them double. I bet you this is it.
032:36:43 Irwin (onboard): Sorry about that.
032:36:49 Worden (onboard): Yes, LM S, T, and U.
032:36:50 Scott (onboard): Yes. Can you get us the jettison bag out of A-2?
032:36:53 Worden (onboard): Yes.
032:37:17 Worden (onboard): That your UCTA down there, Jim? Leaking all over.
032:37:21 Scott (onboard): Is it really?
032:37:23 Irwin (onboard): Where? I don't see it.
032:37:25 Worden (onboard): Well, I bumped it, and it's just - coming all over me. Okay. Now what do you want out of A-2?
032:37:36 Irwin (onboard): Want a jettison bag.
032:37:39 Worden (onboard): Okay.
032:37:49 Scott (onboard): Thank you.
032:38:09 Irwin (onboard): Okay. Now for the [garble].
032:38:15 Scott (onboard): Let's see. You want 13, there.
032:38:21 Worden (onboard): Okay. Are we in attitude yet?
032:38:23 Irwin (onboard): No, not yet, Al.
032:38:25 Scott (onboard): No, we're not there, Al. We've got a ways to go.
032:38:27 Worden (onboard): Okay.
032:38:33 Irwin (onboard): [Garble] I think [garble].
032:38:44 Scott (onboard): Fine. That's got it. Okay, we got it. Going to be a [garble] got on your hands.
032:38:52 Irwin (onboard): We're not there yet. We need utility straps and retainer straps.
032:38:57 Scott (onboard): I'll be getting those.
032:38:58 Irwin (onboard): Okay.
032:38:59 Worden (onboard): From where?
032:39:01 Irwin (onboard): Over from R-5.
032:39:03 Worden (onboard): Huh?
032:39:04 Scott (onboard): You get those [garble]?
032:39:06 Worden (onboard): R-5?
032:39:07 Irwin (onboard): No, we don't need...
032:39:08 Scott (onboard): Forget it, Al.
032:39:09 Worden (onboard): Oh, okay. Yes.
032:39:10 Scott (onboard): Peanuts. Let's really get the big stuff.
032:39:12 Worden (onboard): Yes. Okay. You got the film? Okay.
032:39:22 Scott (onboard): And - Got a ways to go. We want to get the LM Data Kit, in R-3. Okay, Ac...
032:39:34 Worden (onboard): Yes, that's right here.
032:39:35 Scott (onboard): ...Activation Checklist in R-3. Because - R-3's connected with...
032:39:54 Worden (onboard): The LM Data Card Kit?
032:39:57 Scott (onboard): Well, the whole thing. The LM Data Kit should be in there.
032:40:02 Worden (onboard): Oh, that's it, probably, stored back there.
032:40:14 Worden (onboard): Is that it?
032:40:15 Scott (onboard): Yes. Should be Activation Checklist.
032:40:21 Irwin (onboard): You want this all over there, Dave?
032:40:23 Scott (onboard): Yes.
032:40:28 Irwin (onboard): Activation Checklist.
032:40:30 Scott (onboard): Why don't we just take the Activation?
032:40:32 Irwin (onboard): Yes, take the other thing when I'm not looking.
032:40:34 Scott (onboard): Yes.
032:40:46 Irwin (onboard): Just a second.
032:40:53 Worden (onboard): What say? Put it back up? Yes.
032:41:12 Scott (onboard): ...
032:41:15 Irwin (onboard): Let's see how close we are. Let's see ....
032:41:24 Worden (onboard): Yes, I can get it out for you, if you want. Here it is.
032:41:25 Irwin (onboard): ...? We got another 30 degrees to go.
032:41:30 Worden (onboard): All right.
032:42:12 Irwin (onboard): ...
032:42:15 Worden (onboard): Jim, you're absolutely unreadable. I can't make out a word you're saying, usually.
032:42:20 Irwin (onboard): Okay. I got it, Al.
032:42:21 Worden (onboard): There you go. I can hear you. Got the cables?
032:42:29 Irwin (onboard): Yes. I got them.
032:42:30 Worden (onboard): Okay. You want the bracket?
032:42:35 Irwin (onboard): No.
032:42:36 Worden (onboard): This is going to be just hand held.
032:42:37 Irwin (onboard): Taking it over to the LM.
032:42:39 Worden (onboard): Okay.
032:42:42 Irwin (onboard): Keep watching the monitor.
032:42:44 Worden (onboard): Yes. Okay.
032:42:47 Scott (onboard): Hey! How did you ever get L-2 closed, Al?
032:42:51 Worden (onboard): L-2 closed. I didn't.
032:42:59 Scott (onboard): Somehow...
032:43:04 Worden (onboard): I didn't get it closed. I couldn't close it on all those cables. Could you?
032:43:10 Scott (onboard): No. Not unless I rewind the cables.
032:43:12 Irwin (onboard): Here.
032:43:17 Scott (onboard): Too much in here.
032:43:18 Worden (onboard): Yes, there is.
032:43:44 Worden (onboard): Here.
032:44:03 Irwin (onboard): Hmm. I don't understand why I can't get A-1 closed.
032:44:17 Scott (onboard): Huh?
032:44:21 Irwin (onboard): It's got too much in it with the strut that's in the way there. Dave, can you reach down through there and rotate that strut a little bit so that it gets - so that it's...
032:44:32 Scott (onboard): Yes.
032:44:33 Irwin (onboard): ...out of the way of the lid of A-1?
032:44:38 Scott (onboard): No, I can't. I don't know which way to rotate the darn thing here. It's got to rotate - that's right - it's got to rotate towards you.
032:44:44 Irwin (onboard): Why don't you ... get that thing?
032:44:46 Scott (onboard): Mmm.
032:44:47 Irwin (onboard): Get it ... I guess. Better than ...
032:44:51 Scott (onboard): No, no, it won't go that way. It won't make any difference.
032:44:54 Irwin (onboard): ... Get it - get it all the way up ...
032:45:06 Scott (onboard): Yes.
032:45:16 Irwin (onboard): ...?
032:45:17 Scott (onboard): No. It doesn't bend that way.
032:45:27 Irwin (onboard): I don't know what there is about that strut there that - that changed.
032:45:39 Irwin (onboard): Well, something's different there.
032:45:41 Scott (onboard): There sure is.
032:45:43 Worden (onboard): The ... attitude. Why don't you do that...
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
032:45:47 Henize: 15, Houston. We'd like to have Omni Delta, please. [Pause.]
032:45:55 Irwin: Roger, Omni Delta.
Very long comm break.
With the HGA (High Gain Antenna) stowed behind the Service Module, communication is through one of the four omni-directional antennas mounted around the Command Module. Mission Control have limited control over which antenna is currently in use. They can switch between antenna D and another. In this case, it is unclear why they have asked the crew to switch for them. Perhaps low signal strength means they are not able to get the switching signal through.
Once the sextant photo test is complete, the crew will take a sequence of photographs of Earth. The procedure is similar to that employed at 010:10:07, including the change to the second pair of photographs taken through filter 2. To summarise, the UV transmitting window, number 5, is brought to face Earth. Magazine N, loaded with UV sensitive film, is mounted on the Hasselblad along with a UV transmitting lens. Two photographs are taken through each of four filters.
Composite of AS15-99-13425 to 13432, 8 UV photos of Earth.
The first four images appear grossly overexposed with cloud detail only appearing in the fourth. Multiple reflections, presumably from the quartz panes, are visible. The pair taken through filter 3 are rather dark while the last two, taken through filter 4, are good, clear images of a half-Earth.
AS15-99-13425 - Ultraviolet image of Earth, taken through filter 1 - Image from National Archives
AS15-99-13426 - Ultraviolet image of Earth, taken through filter 1 - Image from National Archives
AS15-99-13427 - Ultraviolet image of Earth, taken through filter 2, 20 second exposure - Image from National Archives
AS15-99-13428 - Ultraviolet image of Earth, taken through filter 2, 2 second exposure - Image from National Archives
AS15-99-13429 - Ultraviolet image of Earth, taken through filter 3 - Image from National Archives
AS15-99-13430 - Ultraviolet image of Earth, taken through filter 3 - Image from National Archives
AS15-99-13431 - Ultraviolet image of Earth, taken through filter 4 - Image from National Archives
AS15-99-13432 - Ultraviolet image of Earth, taken through filter 4 - Image from National Archives
Afterwards, magazine M is used on the camera to take a photograph using 64 ASA Ektachrome film.
AS15-91-12347 - Visible light image of Earth to match ultraviolet sequence - Image by NASA/Johnson Space Center.
032:45:55 Scott (onboard): Okay. I want to get my su - want to get my suit back out of the way. You got to - you got to rotate that strut.
032:46:03 Irwin (onboard): ...
032:46:09 Worden (onboard): What are you doing?
032:46:l0 Irwin (onboard): ... through there.
032:46:12 Scott (onboard): Yes. Get my suit back out of the way here.
032:46:23 Scott (onboard): Okay.
032:46:30 Irwin (onboard): Okay, if we're at attitude, Dave, you want to disable those jets?
032:46:34 Scott (onboard): ...
032:46:35 Irwin (onboard): A - Able 3, Baker 3, Charlie 4, Dog 4.
032:46:40 Scott (onboard): Okay. They're disabled.
032:46:41 Irwin (onboard): Okay. Call P52.
032:46:44 Worden (onboard): Okay. Okay.
032:46:51 Irwin (onboard): And we want a - all zeros and Noun 70.
032:46:53 Worden (onboard): Yes.
032:47:11 Irwin (onboard): And the Noun 88 - we want the same values.
032:47:14 Worden (onboard): Oh, we do?
032:47:15 Irwin (onboard): Yes.
032:47:16 Worden (onboard): Oh, yes. Yes, that's right; 108. Okay. Same values, eh?
032:47:22 Irwin (onboard): Yes.
032:47:23 Worden (onboard): Okay.
032:47:24 Irwin (onboard): It says verify that, through the sextant, that the optics are boresighted on your target. Get G&N Power on for you.
032:47:36 Worden (onboard): Okay, we can go to - Let me just make sure I got the same target.
032:47:59 Worden (onboard): Yes. That's the same one. All right. Up.
032:48:02 Irwin (onboard): G&N Power going off. Mount the DAC on the sextant.
032:48:08 Worden (onboard): Yes.
032:48:09 Irwin (onboard): Okay, dim interior lights, and - You on 24 frames per second?
032:48:16 Worden (onboard): Okay. I am now.
032:48:18 Irwin (onboard): Okay, you want to do...
032:48:19 Worden (onboard): And - and 1/500th?
032:48:23 Irwin (onboard): Uh-huh. Yes, it'll be 1/500th.
032:48:25 Worden (onboard): Okay. You want it 2 seconds?
032:48:26 Irwin (onboard): Two seconds, yes.
032:48:29 Worden (onboard): Okay.
032:48:30 Irwin (onboard): Okay. Change the time to 1/60th.
032:48:32 Worden (onboard): Okay.
032:48:36 Irwin (onboard): You there?
032:48:37 Worden (onboard): Yes.
032:48:38 Irwin (onboard): Okay. At 60 seconds, give me a mark and I'll give you a time.
032:48:40 Worden (onboard): 1/60th.
032:48:50 Worden (onboard): Okay. You in what - now what do you want it now?
032:48:53 Irwin (onboard): Sixty seconds.
032:48:55 Worden (onboard): First one 60 seconds, huh?
032:48:56 Irwin (onboard): Yes.
032:48:57 Worden (onboard): Okay.
032:49:03 Worden (onboard): Mark.
032:49:05 Irwin (onboard): Okay.
032:49:43 Worden (onboard): You going to give me a mark?
032:49:44 Irwin (onboard): Mmm-hmm,
032:49:45 Worden (onboard): Okay.
032:49:46 Irwin (onboard): About 20 seconds.
032:49:58 Irwin (onboard): Stand by.
032:49:59 Worden (onboard): Okay.
032:50:03 Irwin (onboard): Mark.
032:50:05 Worden (onboard): Okay. I want to do that one again. Ready?
032:50:10 Worden (onboard): Mark.
032:50:15 Irwin (onboard): Why you doing it again?
032:50:17 Worden (onboard): Hmm?
032:50:18 Irwin (onboard): Why do you want to do it again?
032:50:19 Worden (onboard): Oh, I was a little bit leery of that last one. I didn't like the way that shutter sounded.
032:51:05 Irwin (onboard): Stand by.
032:51:07 Worden (onboard): Okay.
032:51:11 Irwin (onboard): Mark.
032:51:12 Worden (onboard): Okay. Okay. Next?
032:51:21 Irwin (onboard): The next one is 20 seconds.
032:51:23 Worden (onboard): All right. You ready?
032:51:25 Irwin (onboard): Definitely.
032:51:26 Worden (onboard): Mark.
032:51:42 Irwin (onboard): Stand by.
032:51:43 Worden (onboard): Okay.
032:51:46 Irwin (onboard): Mark.
032:51:47 Worden (onboard): Okay.
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
This is Apollo Control at 32 hours, 51 minutes. It appears that the crew is running behind the Flight Plan [by] approximately 15 minutes at the present time. Flight Director reports that they may be able to make this up prior to the scheduled TV time at 33 hours, 45 minutes [Ground] Elapsed Time. That's 06:19 Central Daylight Time. However, we're unable to determine that at present, and the possibility that does exist that the television transmission will begin late. Apollo 15 now 126,083 nautical miles [233,505 km] from Earth. Velocity; 4,480 feet per second [1,366 m/s]. This is Mission Control, Houston.
032:51:48 Irwin (onboard): Okay, tell me when you're ready. The next one's 5 seconds.
032:51:51 Worden (onboard): Okay. I'm ready.
032:51:53 Irwin (onboard): Yes.
032:51:54 Worden (onboard): Mark.
032:51:55 Irwin (onboard): Okay. Stand by.
032:51:59 Irwin (onboard): Mark.
032:52:00 Worden (onboard): Okay.
032:52:01 Irwin (onboard): Your next one's 1 second.
032:52:02 Worden (onboard): Okay. Okay.
032:52:08 Irwin (onboard): Okay. Then you change to 24 frames per second.
032:52:11 Worden (onboard): Okay.
032:52:12 Irwin (onboard): And 1/500th of a second.
032:52:16 Worden (onboard): Okay.
032:52:17 Irwin (onboard): Then run the DAC for 2 Seconds.
032:52:20 Worden (onboard): Okay. Done.
032:52:22 Irwin (onboard): Okay. Enable jets.
032:52:25 Scott (onboard): Okay. Coming on; A-3, Charlie 4, Bravo 3, and Delta 4.
032:52:32 Irwin (onboard): Okay. Record the Mag - percentage. Al, did we use 5 percent?
032:52:38 Worden (onboard): Yes, we didn't use any more than that.
032:52:40 Scott (onboard): Select attitude, Jim.
032:52:41 Irwin (onboard): Okay. Verb 49 maneuver to the UV photos .... load them.
032:52:51 Scott (onboard): Okay. Go ahead.
032:52:54 Irwin (onboard): Okay. 150, 052, and 033.
032:53:06 Scott (onboard): 150, 052, and 033.
032:53:12 Irwin (onboard): We maneuvering?
032:53:16 Scott (onboard): What did you get on percentage on the Mags, Al?
032:53:38 Irwin (onboard): Al, percentage on the Mags.
032:53:40 Worden (onboard): Well. It looks to me like it's about - we started out at about 95 percent and we're down to about 90 percent.
032:53:49 Irwin (onboard): Okay.
032:53:59 Scott (onboard): ... take this ...
032:54:09 Worden (onboard): Okay. I'm going to put some of those cameras away here. We don't need the pictures any more here, right?
032:54:13 Irwin (onboard): No.
032:54:14 Worden (onboard): Okay, Dave. Dave, you want to - stash that just for now, and -
032:54:19 Scott (onboard): Yes.
032:54:21 Irwin (onboard): Still be one more left.
032:54:23 Scott (onboard): Oh, it'll be a long time.
032:54:24 Worden (onboard): Yes.
Flight Plan page 3-40.
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
033:05:25 Henize: 15, this is Houston. We're anxious to know down here if you've checked the LM/CM Delta-P. [Pause.]
This query refers back to a comment in the Flight Plan at 032:00:00. This instructed the crew to increase the pressure difference between the two craft, if it was less 2.7 psi (18.6 kPa), by using the Tunnel Vent Valve. As CapCom Karl Henize is about to explain, this is to allow the atmosphere in the LM to be replaced as, in an hour's time, they will be opening up the tunnel to enter the lander.
033:05:36 Scott: Not yet, Karl. We will though.
Long comm break.
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
033:13:28 Scott: Okay, Houston, 15.
033:13:30 Henize: 15, this is Houston.
033:13:34 Scott: Okay. The LM/CM Delta-P is now plus .8 [psi, 5.5 kPa], and I guess - there's no need to do the Tunnel Vent Valve, is there, at this stage? Looks to us like we can go ahead and bring the pressure back up - equalize the Delta-P before we get into the tunnel.
033:13:54 Henize: Stand by. [Long pause.]
033:14:26 Henize: 15, this is Houston. We would like to go to Vent on the Tunnel Vent Valve until the Delta-P is - is greater than 2.7.
033:14:39 Scott: Okay. We'll do that. [Long pause.]
033:15:32 Henize: Dave, we'd like for you to tell us when the Delta-P gets to 2.7 [psi], and stop there. The basic problem here is, we want to dump the residual atmosphere out of the LM in order to put in good fresh oxygen before we have you climb in. We're sort of up against the time line now...
At launch, the LM is filled with ambient air at sea level pressure. This is vented away via the open overhead Pressure Equalization Valve (also referred to as a 'depress valve') as the LM ascends through the atmosphere. After the CSM docks with the LM, the LM cabin is pressurized to about 34 kPa (5 psi) using the CM's air, again through the open depress valve. No replenishing is done after this, and the LM's atmosphere is allowed to leak away. Valuable information about leak rates are obtained in this way, which is essential for calculating LM's oxygen usage later in the flight. However, this atmosphere may have a significant amount of nitrogen in it as the CM was still flushing out the nitrogen/oxygen mix it had from the moment of launch. Nitrogen is undesirable in the Apollo cabin because it can build up in the suit circuit, not being metabolised by the body. Therefore, to flush out any remaining nitrogen in the LM's atmosphere, the air it gained earlier in the mission is dumped and replenished with the purer air now in the CM cabin.
033:15:49 Scott: Okay. That's what we...
033:15:53 Henize: Righto.
033:15:54 Scott: Okay. That - that's what we figured, Karl, [garble].
033:15:56 Henize: Good; okay. Don't - don't go below 2.7 Delta-P there.
033:16:02 Scott: Rog.
Comm break.
033:17:38 Scott: Okay, Houston. We're at 2.7 on the Delta-P on tunnel vent.
033:17:42 Henize: 15, this is Houston. Say again.
033:17:47 Scott: Roger. We're at 2.7 on the Delta-P on the tunnel vent. [Pause.]
033:18:01 Henize: 15, this is Houston. The number that we need now [for the LM/CM Delta-P], since the [CM] cabin [pressure] went up, is; we need a Delta-P of 3.1 [psi]. We have to vent the tunnel.
The absolute pressure of the cabin is a little higher than normal. They don't, at present, have a measurement of the absolute LM cabin pressure so they rely on reading differences in pressure across the tunnel hatch. To bring the LM cabin pressure down to the required value, they must take account of the CM cabin pressure.
033:18:12 Scott: Okay, Delta-P at 3.1. [Garble]. [Pause.]
033:18:21 Henize: 15, we'd like Omni Bravo.
Note that Houston are asking them to switch between antennas that are 180° apart on the skin of the spacecraft. They have been using Omni Delta for the last half hour and Mission Control have not been able to switch it. When the crew switch to omni B, Mission Control ought to be able to switch between it and D.
033:18:25 Scott: Yeah, Rog. Omni Bravo. And what was your last, after you said you wanted 3.1 on the LM tunnel vent?
033:18:31 Henize: Stand by on that one. [Long pause.]
033:19:05 Henize: 15, this is Houston. To keep our records straight here, we're anxious for you to bring the tunnel down until we have a Delta-P of 3.1. [Pause.]
033:19:19 Scott: Rog, Houston. That's in work, and we're up to 2.9 [psi].
Comm break.
033:20:27 Henize: 15, this is Houston. There's a couple of read-outs we'd like to get, when you have time. First of all, we'd like to get the PRD read-outs for all three of you. And we'd also like to have the magazine numbers used for the sextant photography and for the UV photography.
033:20:46 Scott: Okay. Those are as - magazines are as per Flight Plan, and we'll get you the PRD's when we can get down into our suits. We'll get them before the day is out.
As happened soon after the crew's awakening today, the read-outs from the PRDs (Passive Radiation Dosimeter) are low on the crew's priorities.
033:20:54 Henize: Okay, Dave. And, incidentally, can you give us any sort of report on that number 5 window? [Pause.]
One of the last items on the checklist for the UV photography was to comment on the condition of window 5, the right-hand window which is made from quartz panes to transmit UV light.
033:21:05 Scott: [The window] looks clear.
033:21:08 Henize: We copy. Thank you. [Long pause.]
033:21:22 Scott: Okay, Houston. The Delta-P is hanging right in at about: 2.9 to 3.0. I'd suggest we pressed on, huh? [Long pause.]
Venting of the LM is slower than Dave would like and seems to be settling at a figure just below what Mission Control requested.
033:21:42 Henize: Stand by on that, Dave.
Comm break.
033:23:07 Henize: 15, This Houston. Time is not too critical. We'd like to let it vent a little longer. Try to get 3.1 [psi on the gauge]. If we don't reach it in about 5 minutes, we'll probably go ahead.
033:23:19 Scott: Okay; understand.
Long comm break.
Pressure drop during a vent is relatively fast at first but it slows as the pressure, which is driving the gas out through the valve, also drops. This effect was noted during depressurisation of the LM before the moonwalks on the lunar surface. The inward-opening door of the LM could not be opened against more than about 0.7 kPa (0.1 psi) of pressure and crews got impatient waiting for the final few wisps of air to escape through the dump valve.
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
033:29:29 Scott: Okay, Houston; 15. We're reading 3.1 [psi] now. [Pause.]
033:30:10 Henize: 15, Houston. That's excellent. I guess we can go ahead with pressure - pressurizing the LM.
033:30:18 Scott: Okay.
Very long comm break.
The crew is on page 3-40 of the Flight Plan. From there, they are instructed to follow page 2-1 on the CSM Systems Checklist. This deals with the steps required to prepare the LM to be entered by pressurising it, removing the forward hatch, docking probe and drogue, and reading off the tunnel index angle. This angle indicates by how much the CSM is rotationally aligned with respect to the LM in the current docked configuration.
The Docking Tunnel Index marks are painted on the inside of the tunnel connecting the CSM and LM. Measured in degrees, they have complementary scales on the CM and the LM. When perfectly aligned, the indexes are lined up, with a zero degree difference. Aside from a simple indication of how accurate the docking was performed, this angle is used as part of the initial calculations necessary to perform a coarse alignment of the LM's inertial platform.
This coarse alignment is performed using a surprisingly low-tech procedure: To simplify the arithmetic to come, the spacecraft is oriented at right angles to the present platform alignment. Thus the crew will only have to deal with multiples of 90°. The IMU gimbal angles are then recorded from the CM's computer display. Next, the angular difference, 90°, between the orientation of the CM's and LM's IMU is added in. Finally, the angular difference along the X-axis, as indicated by the Docking Tunnel Index Angle is added in. The resulting set of angles is a good first order approximation to how the LM's platform should be oriented. These angles are entered into the LM's computer, and the platform is then torqued to that orientation. Following this "coarse alignment," it becomes easier to perform a "fine alignment", a standard P52 IMU realignment, as the appropriate stars will already be in the sextant's field of view.
The LM is pressurised from the oxygen in the CM. The CM pressure is brought up prior to this and when filling of the LM has brought it down to a predetermined figure, it is repressurised before recommencing LM pressurisation. Once the two spacecraft are at the same pressure, the hatch and docking equipment can be removed.
Irwin, from 1971 Technical debrief: "Removing the tunnel hatch and the probe and the drogue was an order of magnitude easier than it's ever been in practise. It went exactly as we'd seen on the mockup over here. I thought it was a very easy operation. We put the hatch underneath the left-hand couch. We put the probe in the center couch, and lashed it down. We put the drogue underneath the left-hand couch and tied it down so that we had good clear access to the tunnel area. I thought the whole operation was very easy. No problem."
The crew are also to prepare an assemblage of items which will be transferred to the LM and a list of these is given in the LM Activation Checklist. The list goes over a second page. Among these items are 13 magazines for the Hasselblad cameras that Dave and Jim will use on the Moon, and 10 magazines of 16-mm movie film for the LDAC (Lunar Data Acquisition Camera). Use of the LDAC would be largely unsuccessful during the lunar EVAs.
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
This is Apollo Control at 33 hours, 33 minutes. The Apollo 15 crew has picked up some time in the Flight Plan. We're unable to determine at the moment whether the TV will be precisely on schedule. However, Flight Director Milt Windler says that it could be, and if there is a delay he believes it will be less than 10 minutes - less than a 10-minute delay. Apollo 15 now 127,861 nautical miles [236,798 km] from Earth, traveling at a velocity of 4,427 feet per second [1,349 m/s].
The spacecraft is now maneuvered to the preferred attitude for the transfer to the Lunar Module. Angles are also given in the Flight Plan for pointing the HGA.
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
033:41:26 Henize: 15, this is Houston. Can you tell us how the pressurization is going?
033:41:32 Scott: Oh, we're all squared away, and the probe's coming out. [Pause.]
033:41:41 Henize: Roger. And - if you could give us the high-gain angles [in the Flight Plan] there, we'd like to get that going.
033:41:49 Scott: Okay. We'll set 'em up. [Long pause.]
033:42:16 Scott: Okay, Houston. The probe is out, and it worked very smoothly.
033:42:21 Henize: We copy.
Comm break.
The probe sits between the CM and LM hatches. By the operation of a lever, the probe folds to allow it to be removed from either the LM or the CM side.
033:43:05 Worden (onboard): Okay. Here it is. Jettison, Jim.
033:43:12 Irwin (onboard): I've got the drogue here, Al, if you can get the TV between my legs.
033:43:19 Worden (onboard): Okay.
033:43:24 Scott (onboard): I got the probe, Jim. Let's see, you take the jettison bag. I want to put the probe over here by the hatch.
033:43:32 Irwin (onboard): Okay, I've got the Jett bag.
033:43:38 Henize: 15, Houston. We'd like to have Narrow Beam, please. [Pause.]
A narrow beamwidth on the HGA is required for the upcoming TV transmission, as well as telemetry from the spacecraft during LM activation.
033:43:48 Scott (onboard): Tell them Narrow Beam.
033:43:50 Worden: Okay, Karl. You got Narrow.
033:43:52 Henize: Thank you.
Comm break.
033:43:58 Irwin (onboard): We go over there yet?
033:44:01 Worden (onboard): Just a second.
033:44:03 Scott (onboard): Not yet, Jim. We're not going anywhere yet. There. Okay, now -
033:44:11 Worden (onboard): Got them lashed down?
033:44:12 Scott (onboard): Yes, lashed down.
033:44:13 Worden (onboard): Okay.
033:44:14 Scott (onboard): Now we need the drogue.
033:44:15 Worden (onboard): Yes.
033:44:16 Scott (onboard): It seems to me that - the best thing - Give Jim back that TV. I think we can probably put his drogue also under the couch.
033:44:28 Worden (onboard): Under Jim's couch?
033:44:29 Scott (onboard): Well, that's too crowded, but I think under - under here.
033:44:41 Scott (onboard): Let's see how we might make out. Okay, watch your suit.
033:44:48 Worden (onboard): Yes.
033:44:50 Scott (onboard): Change ribbons.
033:44:52 Irwin (onboard): One moment here.
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
033:46:22 Henize: 15, this is Houston. Whenever you have a chance up there, we're interested in seeing some TV.
Television coverage of the ingress to the LM is due to be transmitted from 33:45 to 34:30.
033:46:30 Scott: Rog, Houston. We thought we'd get the tunnel cleared out because, with all that extra gear in the Command Module, it's sort of tough to find a place to stow everything. And the TV is - right now, sort of in the way. So we'll try and get to you as soon as we can.
All the 'extra gear' is the items they will take over to the LM once they get it opened up.
033:46:44 Henize: Okay. [Pause.]
033:46:52 Scott: It's a new world in this Command Module, with all these extra box - boxes and everything.
Comm break.
Apollo 15 has just experienced a glitch in its electricity supply. There is a disturbance in the communications at 033:47:26.
033:48:32 Scott: Houston, this is 15.
033:48:37 Henize: 15, this is Houston. Go ahead.
033:48:42 Scott: Roger. We had an AC Bus 2 light and a Main Bus B Undervolt. Voltage looks good, and AC Bus 2 looks good. Reading 28.5 volts on Main Bus B and AC Bus 2 looks good. [At] about that time, we had a loss of S-band. I don't know whether it was coincidental or not.
Journal reader, George Giusti noticed the similarity between Dave's read-out to Mission Control, and the comm from Apollo 13 immediately after it was rocked by an explosion in one of its oxygen tanks. He wondered if the Caution and Warning light caused the Apollo 15 crew any moments of "deja vu".
Scott, from 1999 correspondence: "The Main Bus B Undervolt was no big deal at the time - we had seen so many of those during sims due to so many causes, that, at least for me, the thought of another A-13 situation did not even occur - there are just too many other loops to go thru to begin isolating the cause. Besides, the probability of the same fault occurring on two missions is really remote, especially when the first one was so well exercised - it's usually the new things that will get you; so its best to look for new trails rather than going back over plowed ground."
033:49:05 Henize: We copy. [Long pause.]
033:49:42 Henize: 15, this is Houston. We saw some of those problems here on the ground, too. And we would like to get back on the High Gain [Antenna], if you would reacquire.
The glitch has caused the High Gain Antenna to cease pointing at Earth and must be aimed correctly again.
033:49:56 Scott: Okay. [Long pause.]
033:50:04 Worden (onboard): Yes. Did you...?
033:50:36 Scott (onboard): You like Auto? Or Reacq.
033:50:42 Worden (onboard): Auto's fine for what we're doing.
033:50:46 Scott: Okay, Houston. You should have the [signal from the] High Gain [Antenna, HGA] now.
033:50:54 Henize: Roger, 15. Give us Narrow Beam, please.
033:50:56 Scott: Narrow.
033:51:12 Scott (onboard): Anything over there, Jim?
033:51:25 Scott: Okay, Houston, the LMP is in the LM.
033:51:28 Henize: Houston copies.
033:51:33 Scott: And how's your High Gain?
Dave Scott is actually asking "How is your received signal from our High Gain Antenna?
033:51:36 Henize: High Gain is perfect.
033:51:39 Scott: Okay. [Long pause.]
033:52:27 Henize: 15, this is Houston. Could you give us a description of any actions you took when you had that electrical glitch? [Long pause.]
033:52:52 Worden: Karl, Jim just reset both [electrical buses] and they - everything seems to be okay now. He checked the voltages, and they were fine.
033:52:59 Henize: Thank you.
Long comm break.
Dave and Jim have moved into the LM. Al has configured the TV system and is transmitting a signal. He floats through the tunnel with the camera to join them. The first image we see is of Jim working at his station to the right of the LM.
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
We're getting a black and white picture now. It should be coming up color soon.
033:56:06 Worden: Houston, 15.
033:56:08 Henize: 15, this is Houston.
033:56:12 Worden: Hey, Karl, [are] you getting anything in on the TV?
033:56:15 Henize: Negative, we have no signal yet. [Voice in background: "It's coming, it's coming."] Pardon me; something is just now coming down.
033:56:23 Worden: Okay, fine. I'm over in the LM with them, and they're just going through the checklist.
033:56:29 Henize: Very good.
Comm break.
For a while, we can see Jim checking the positions of the circuit breakers against a diagram in the checklist. Al them moves the camera to the instrument panel and Dave comes into shot.
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
033:58:39 Henize: 15, this is Houston. We're getting a reasonably good TV signal from you. And, we have about four procedure changes connected with the ASA [Abort Sensor Assembly] heater circuit breaker coming up at about 34:30 in your time line, and we'd like your choice as to whether I read it up to you as a block, or whether you want us to read it to you step by step when the time comes. [Long pause.]
The ASA is a set of accelerometers and gyros in the LM which provide inertial information for that spacecraft's alternate guidance electronics.
033:59:26 Worden: Houston, 15. Hey, Karl, how about waiting until Jim and Dave get on comm, and then read up the procedure.
033:59:35 Henize: Roger.
033:59:38 Worden: If that's satisfactory, let's do it that way.
Long comm break.
The camera is giving a good shot of the instrument panel. The Sun is coming in on Dave's side and small particles can be seen floating in the middle of the cabin. After a while, Al aims the camera to the left of the panel where Dave is inspecting one of spacecraft's displays, the tapemeter. Bright sunlight illuminating objects in the camera's field of view causes the automatic exposure to darken the image. When the camera's exposure rises again, we can see quite a few particles floating around Dave.]
Al then takes the camera towards the instrument panel and the tapemeter. As he does so, many particles become visible.
Flight Plan page 3-41.
This is Apollo Control at 34 hours, 1 minute. Dave Scott and Jim Irwin are going through a LM checklist to ensure that all the switch settings in the LM are the same as they were prelaunch; that they have not somehow changed position since launch.
The LM Activation Checklist is being followed by the crew. The initial status of the LM circuit breakers is checked by reference to page 1-3 and page 1-4 which show nine diagrammatic lines which illustrate each breaker in its position with respect to the others. If the breaker is white in the diagram, it should be open; black, and it should be closed. Pilots will be familiar with the white ring found on aircraft circuit breakers which appears when the button is pulled out and the breaker is opened.
This begins the first of two LM inspection and housekeeping tasks that Dave and Jim will perform on the way to the Moon. The second will be relatively brief as it is primarily to allow flight controllers to gather data on the health of the lander's batteries. During this first visit, film and equipment are transferred to the LM from the CSM's stowage cabinets and initial checks of various LM systems are performed. A check is made to see that all the circuit breakers and switches haven't changed since launch. Next, two major housekeeping tasks are performed: Unstowing equipment and setting up cameras. After that, only a few systems are truly exercised. The LM batteries are brought online, and the electrical system is checked. All the various communications modes are checked, the Environmental Control System is activated and the Oxygen Purge Systems are checked out.
Several important systems are not tested. The guidance system is not powered up and neither are the RCS, Descent and Ascent Propulsion Systems powered up or pressurized in order to minimize the stresses on these systems. The useful lifetime of the propulsion components are limited once they are pressurized. For example, once the supercritical helium system for the Descent Propulsion System is opened up through a series of explosively actuated valves, heat starts to leak into the system, raising the pressure of the entire system. Once the helium pressure rises above a certain point, the excess pressure is released through a "burst disk". Once broken open, all the helium in the system is vented out into space and descent engine capability is lost. The movie, Apollo 13, portrays the moment when the LM Aquarius' burst disk blew for just this reason, providing a small moment of drama in the film during the journey home, though fully expected in the real flight.
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
034:04:08 Henize: 15, this is Houston.
034:04:14 Worden: Go ahead, Houston; 15.
034:04:17 Henize: 15, when you had the S-band loss back there a few minutes ago, we think the problem was basically on the ground. And, when you lost uplink, it's - it's likely that your High Gain Antenna slewed against the limits; and we wonder if there was any circuit breaker resetting required to get you back up?
There has been a suspicion that the loss of S-band comm at about the same time as the electrical glitch meant the two were related. Mission Control are not so sure now and think that the HGA reached the limits of its articulation when a problem on Earth interrupted the signal to the spacecraft and caused the antenna to lose lock.
034:04:39 Worden: Okay, Karl, stand by one, and I'll find out. [Long pause.]
034:04:54 Worden: Negative, Houston. No circuit breakers are reset.
034:04:57 Henize: Very good. [Pause.] And, Al, we're getting a real good picture down here.
034:05:07 Worden: Okay, Karl.
Long comm break.
The conversations since the start of the TV have been between CapCom Karl Henize and Command Module Pilot Al Worden. Major Worden reporting that Dave Scott and Jim Irwin are not on the air/ground communications while they are completing the checklist.
The TV picture clearly shows Dave going through each switch and control as he works his way across the panel. Al goes to the right where Jim is checking the switches on panel 14 which deals with the LM's power systems. Between the two crewmen, we see one of the two backpacks or PLSS (Portable Life Support System) they will wear on the Moon. Further round to the right, behind Jim's station, we see the controls for the ECS.
You can get brief glimpses of Dave Scott from time to time on the left. His head coming into view now. Checking part of the Environmental Control System now.
It is actually Jim who is checking the ECS.
034:09:20 Henize: 15, the TV picture is beautiful, and we're going to give that cameraman an honorary union card. [Long pause.]
034:09:38 Worden: That cameraman's got too many hands busy to answer you right now, Karl.
Comm break.
Jim removes a movie camera from its stowage position and mounts it on a bracket in his window.
We're getting a look at Jim Irwin now.
034:11:28 Worden: Houston, 15.
034:11:31 Henize: 15, this is Houston.
034:11:34 Worden: Okay, give us a time hack, would you Karl, please? GET. [Pause.]
034:11:42 Henize: Roger. We're counting up to 34 hours, 11 minutes and 50 seconds. 4, 3, 2, 1...
034:11:50 Henize: Mark. [Long pause.]
Neither the LM Activation Checklist nor the Flight Plan explain why Al is requesting a time check from Mission Control at this moment but it is probable that he simply wishes to ensure his mission timer is correct before using it to help Dave set the clock in the LM.
034:12:11 Worden: Houston, 15.
034:12:13 Henize: 15, go ahead.
034:12:16 Worden: Rog. If you're ready, Dave and Jim are ready to activate the comm now.
034:12:21 Henize: Roger. Did you get that time hack okay.
034:12:25 Worden: Yes, sir, sure did. Thank you.
Long comm break.
Al is giving us an excellent view of the LM instrument panel. Above it can be seen te AOT (Alignment Optical Telescope) with the yellow bars around it. This is the equivalent of the CM's optics. Both Jim and Dave are sometimes visible in the shot. Behind Dave's head is his window, lit by the Sun. When the camera's exposure drops, we can clearly see the lines inscribed on the window that Dave will use as a guidance aid when landing on the Moon. This is the LPD (Landing Point Designator). With the camera now being held by Dave while Al returns to the Command Module, the shot returns to Jim and we catch a glimpse of the keyboard for the AGS (Abort Guidance System), a small computer that provides redundancy.
That picture's coming from 129,473 nautical miles [239,784 km] in space.
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
034:16:13 Worden: Houston, 15.
034:16:17 Henize: 15, go ahead.
034:16:21 Worden: Roger, Karl. You guys ready to start a comm check now? [Long pause.]
034:16:34 Henize: Roger. We're ready down here for a comm check.
034:16:38 Worden: Okay, coming your way.
Long comm break.
Two independent sets of VHF systems are tested. Both are used exclusively for communications between the LM and CSM. An additional function of the VHF system is that it supplied range and range-rate data to the CSM, which is used as a back-up to the LM's rendezvous radar. S-band communications with Earth via MSFN (Manned Space Flight Network) are also tested.
Dave turns the camera's view to look up the tunnel to the Command Module where we see Al prone across the cabin at the far end. Al then dives back into the LM towards us and takes the camera.
That looked like Al Worden coming through the tunnel there.
We see Dave at the circuit breaker panel at the left of the LM cabin with the overhead window at the top of the frame. Al then moves in to give a close-up of Panel 1, Dave's main instrument panel, where he stops momentarily on the tapemeter.
Frame from TV transmission showing shattered glass pane on tapemeter.
This frame is from the television pictures during the instant when we can clearly see that the glass face of the meter is broken. Just to the left is a small swatch of velcro the crew use to carry their cue cards. The camera moves to Dave's station looking over to Jim as Dave is holding it once again While Al return to the CM to begin a communications check.
Now that there are essentially two separate entities in communication with each other, as far as radio is concerned, the crew begin using the callsigns for each vehicle; 'Endeavour' for the Command and Service Module, 'Falcon' for the Lunar Module.
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
034:22:37 Crewmember: [Garble]. [Long pause.]
034:23:16 Worden: Falcon, this is Endeavour reading you 5 square in Duplex B. [Pause.]
034:23:24 Henize: Endeavour, this is Houston. I got your message loud and clear.
Comm break.
"5 square" means 5 by 5 or, as Karl Henize put it "loud and clear.
034:24:45 Worden: Houston, Endeavour.
034:24:49 Henize: Endeavour, this is Houston. Go ahead.
034:24:52 Worden: Rog, Karl. Jim's been calling you on S-band.
034:24:58 Henize: Sorry about that. They're just telling me here that we do have some problems, and we need to stand by for a few more minutes.
034:25:07 Worden: Okay; understand. Stand by for a few minutes before we try again.
Comm break.
[The] problem is with the tracking station at Goldstone. It's expected to be cleared up very shortly.
While Goldstone work to sort their problem, we see Jim working at panel 12 to his right, the comms panel.
Goldstone's ready now.
034:26:30 Henize: 15, this is Houston, and we're all set up for the voice check. [Long pause.]
The camera pans from Jim to Dave, implying that Al is being cameraman again, filming from above the ascent engine cover. For a few seconds, the TV disappears. When it returns, Dave is in shot.
034:27:17 Henize: 15, Houston is now configured to go along with you on the voice check. [Long pause.]
034:27:37 Worden: Houston - Houston, this is Endeavour. It - apparently Falcon is reading you five square, but you're not reading him.
034:27:44 Henize: That's correct, I've had no messages from Falcon.
034:27:49 Worden: Okay, he has been calling you, Karl. [Long pause.]
On the TV, we can see Dave trying to speak to Mission Control but we cannot hear him.
034:28:18 Worden: Houston, 15.
034:28:21 Henize: 15, this is Houston.
034:28:24 Worden: Okay, Karl. What are you receiving? Are you getting any low bit rate [data] from the - from the LM - from the Falcon?
034:28:31 Henize: That's affirmative.
034:28:34 Worden: You are? Okay. [Pause.]
Since the data link is working, the crew know the S-band system is up and running and only the voice requires patching through.
034:28:44 Worden: Houston, this is Endeavour. Be advised Falcon's going high bit rate, we'll give you another call.
Telemetry data is relayed to Earth over the S-band system in a PCM (Pulse Code Modulation) format. Two data rates are available; 9,600 bits/second and 56,000 bits per second. Although contemporary readers will see these speeds as being perfectly ordinary modem speeds, it is important to remember that this hardware was designed in the mid-1960s; almost 30 years before commercial modems became widely available.
034:28:50 Henize: Roger. [Long pause.]
034:29:19 Henize: Falcon, this is Houston. How do you read? [Pause.]
034:29:31 Worden: Houston, this is Endeavour again. Apparently Falcon's still reading you, but you're not reading him. How do you pick him up with high bit rate? [Pause.]
034:29:50 Henize: Endeavour, Houston is getting the high bit rate data okay, and we'd like to have you hold this present configuration while we think a bit.
034:30:00 Worden: Okay, Karl.
Comm break.
The camera returns to the instrument panel and particularly, the DSKY (Display and Keyboard).
In the LM, a switch has been thrown which puts the crew's voice circuit onto the S-band.
034:31:40 Irwin: Aren't those pretty?
034:31:41 Scott: Say again.
034:31:42 Irwin: Aren't those pretty little things?
As Dave and Jim set up the S-band comm system in the LM for a voice check, they have switched it to Voice (or Vox) mode, as shown on page 1-15 of the LM Activation Checklist. The transmitter is controlled by a voice-operated switch and every time they speak, they can be heard in Houston. This time, it is fully intended, but on occasion, Apollo crews have forgotten Voice mode was on, or had accidentally been selected, requiring a gentle prod from the CapCom to prevent further embarrassment.
034:31:44 Scott: Oh boy. Navy blue, yet. Colorful. Too bad they don't work very well.
034:31:59 Scott: [Garble] had them watch you configure the camera.
034:32:02 Irwin: You do?
034:32:03 Scott: Yeah. That might be embarrassing.
034:32:06 Irwin: Really?
034:32:07 Scott: Because you might not get it con - Should be back over on the right-hand side. Oh my! You had it last, Al, when you were cleaning up the - screens. I put it in that compartment there, Al, just above the emergency medical kit - compartment above the emergency medicikinal [sic] kit.
034:32:31 Henize: 15, this is Houston. We're reading you on Vox.
034:32:36 Irwin: [Ha, ha] Hot on Vox. ...
034:32:39 Scott: Okay. Down Voice Back-up...
034:32:40 Irwin: Oh, yeah, yeah, yeah, they would - hot mike.
034:32:42 Scott: Good, I'm glad you're reading us, Fi - Houston, finally. [Pause.] Are we coming through loud and clear now, Karl?
034:32:56 Henize: Roger, Falcon. You're coming through loud and clear.
034:33:01 Irwin: Okay. I guess while we're in this position, we ought to go back to low [bit rate].
034:33:04 Scott: We've got...
034:33:06 Irwin: We ought to go back to low bit rate.
Apollo 15 is the first mission on which the LM is being entered on the day after TLI. Previous missions have had the crews perform these tasks the day before entering lunar orbit. The foresight in checking the LM early for any problems is confirmed when Dave and Jim find the glass cover to the Range/Range-Rate tapemeter broken with small pieces of glass scattered throughout the LM cabin.
034:33:07 Scott: Yeah. One little problem we ought to discuss with you before we go on. It seems that somewhere along the way, the outer pane of glass on the tapemeter has been shattered. I don't know whether you can get a picture of it on the TV or not; we'll get Al to try and zero in. [Dave points to the offending display.] But about 70 per cent of the glass is gone. The inner pane of glass seems to be okay. There's no apparent damage to the tapemeter itself. It's sitting on 520 and 482. But, I don't know whether you can see it or not, but I'll trace the area which is missing with my finger here. And it looks like the pieces we found - I found one piece that's almost an inch in size, and there's some small ones around. We'll try to pick it up with the tape, and then get the vacuum cleaner later on - to get it all up. So far that's the only obvious discrepancy we've found.
034:34:10 Henize: Roger. Dave, we're reading you loud and clear.
This breakage raises some concerns. Floating shards of glass could be inhaled by the crew or interfere with the suits and associated hoses. The tapemeter displays crucial range and range-rate information during the landing and rendezvous and Mission Control must determine whether the loss of the glass impairs its operation. Two out-of-focus photographs are taken of the instrument panel, including the tapemeter.
AS15-91-12348 - Out-of-focus image of the LM instrument panel - Image by NASA/Johnson Space Center.
AS15-91-12349 - Out-of-focus image of the LM instrument panel - Image by NASA/Johnson Space Center.
Several of the critical instruments in the LM were implemented as tapemeters, an instrument which displays its values through a moving length of tape rather than a needle, gauge or digital display. A tape, with values such as altitude pre-printed on it, was stored on spools not unlike a video cassette tape cartridge. The tape moved forwards and backwards under control of the LM's computer, and was read using an indexing bar on the face of the instrument. Tapemeter instruments were popular in a number of high performance aircraft at the time, most notably the astronauts' favorite, the F-106. Further validating the utility of tapemeters, the Space Shuttle would incorporate several in the early versions of its cockpit.
Scott, from 1971 Technical debrief: "Having the LM housekeeping moved up a day, or the day after TLI, gave them a chance to do all the testing on the tapemeter. That gave me a warm feeling to know that they had checked the thing out and it would work with a broken outer pane of glass."
Scott, from 1971 Technical debrief: "I think it is a good idea to go take a look at the LM early and analyze your problems and get a good handle on them before you get too far down the road. If they want to take another look at the batteries, the second housekeeping day is no problem. It is nice to go back and take another look around anyway. We got another chance to clean up some more glass. We did find a number of pieces on the second day."
034:34:12 Scott: [Garble] you want to go back? [Pause.] Okay; back to low bit rate. Let's try that.
034:34:19 Irwin: Yeah. [The] camera's configured, Dave.
034:34:21 Scott: Okay.
034:34:23 Irwin: Except for the Mag. [Pause.]
034:34:34 Scott: Okay; we're on low bit rate. [Pause.]
034:34:42 Irwin: Houston, how do you read Falcon on low bit rate?
034:34:46 Henize: Falcon, Houston is reading you loud and clear on low bit rate.
These are the checks in step 3 on page 1-15.
034:34:51 Irwin: Roger. We read you the same.
034:34:53 Scott: Okay; let's go back Biomed, Right and High bit rate.
This is step 4 on page 1-16.
034:34:57 Irwin: Okay. High and Right. [Pause.] Houston, This is Falcon on high bit rate, with Biomed, Right. How do you read?
034:35:09 Henize: Roger, Falcon. We're writing - we're reading you loud and clear.
034:35:14 Irwin: We're reading you the same. [Long pause.]
034:35:34 Irwin: Houston, this is Falcon again. Biomed, Right and Low bit rate.
034:35:39 Henize: Roger, Falcon. We're reading you loud and clear on Biomed, Right, and low bit rate.
Comm break.
The TV from the LM is continuing but a disturbance in the picture upsets the colour system on Earth, making the colours wrong. The camera settles on Dave's hand where he is holding a checklist and a roll of grey tape with pieces of glass stuck to the end of it.
034:37:17 Henize: Endeavour, we're not reading Falcon at the present time, and we've had loss of signal.
034:37:27 Worden: Houston, Endeavour. Roger; understand. And I wonder if you just got that last piece on the TV there. It was a piece of gray tape with some glass on it that came out of the tapemeter.
034:37:38 Henize: We're getting a very good picture of it, thank you.
034:37:41 Worden: Rog.
034:37:46 Irwin: Houston, this is Falcon. How do you read?
034:37:48 Henize: Falcon, this is Houston. Reading you loud and clear. How us? [Pause.]
034:37:57 Irwin: Houston, we caught the first part of your transmission, and then you were cut out.
034:38:02 Henize: Roger. Falcon, this is Houston. How do you read us?
034:38:07 Irwin: Read you loud and clear. [Long pause.]
034:38:23 Irwin: Okay, Houston. We're in PCM High. How do you read?
034:38:30 Henize: Roger. Houston is reading you loud and clear. And did I understand PCM High?
Where the crew and ground use the term "PCM", the checklist uses "TLM" though they both mean the same thing as the telemetry uses Pulse Code Modulation, an early term for what we now just call "digital".
034:38:37 Irwin: That's affirm. [Long pause.]
034:38:51 Irwin: Houston, this is Falcon. Standing by for a voice and range check. [Long pause.]
034:39:08 Henize: Roger, Falcon. We're ready for step 8. [Pause.]
034:39:16 Irwin: Houston, we're configured for step 8.
034:39:23 Henize: Roger, Falcon. We're reading you loud and clear. How us?
034:39:28 Irwin: Loud and clear. [Long pause.]
The picture is Dave Scott, the voice is Jim Irwin.
034:39:41 Irwin: ED Voltage reading 37 on both.
034:39:46 Henize: Roger, Falcon. We copy that.
Comm break.
Jim is relaying the voltage on two batteries that provide power for the explosive devices in the LM. There are quite a few of these on the LM, used for separating the stages, actuating helium valves and deploying the landing gear.
034:41:07 Henize: Falcon, this is Houston.
034:41:12 Irwin: Go ahead Houston, Falcon.
034:41:14 Henize: Roger. We'd like to tell you that the initial problem with and - with the S-band was a ground problem, and it looks as though all of the comm checks are Go. And, we would like to ask if our VHF uplink was okay. [Pause.]
034:41:36 Scott: Okay, VHF A and B both checked out, with Endeavour, loud and clear. And since we don't have anything other than the sequence camera to check out here, we're going to check that out and then powerdown and take care of the rest of the housekeeping without the power. [Pause.]
The checkout of the sequence camera, or the LDAC (Lunar Data Acquisition Camera), a battery powered version of a similar camera stowed in the CM, is step 10, the final step on page 1-16.
034:42:02 Henize: Roger, Falcon. [Long pause.]
034:42:47 Henize: Falcon, this is Houston.
034:42:51 Scott: Go ahead, Houston.
034:42:54 Henize: Be advised that we have - had an excellent TV show here, and that you can secure it, as you like. And I'd like to remind you that we have a - an update to the LM Contingency Checklist that we need to make before you leave - leave the LM.
034:43:16 Scott: Okay, we'll take that over in the Command Module, Karl. We'll go ahead and power the LM down now and clean up the housekeeping, and see you on the other side. [Pause.]
034:43:30 Henize: Falcon, stand by. We're interested in the OPS checkout.
Page 1-17 of the LM Activation Checklist has a single step which is to read and record the source pressures on the OPS (Oxygen Purge System). The OPS attaches to the top of the PLSS (Portable Life Support System), the backpack worn by a crewman on the surface. The OPS is intended as an emergency supply of oxygen for up to an hour during Dave and Jim's forays onto the lunar surface, in case an excessive leak develops in a suit or if there is a failure in the PLSS. It consists of two high-pressure, non-rechargeable, spherical tanks which are fed into the suit through a regulator at one of two rates, 50 per cent or 100 per cent flow. Although the PLSSs are discarded on the Moon, the two OPS will be retained in case the LM crew have to transfer to the CM by embarking on a spacewalk. During the trans-Earth coast, one will be used by Al Worden when he goes out to the SIM bay to retrieve the films from the Panoramic and Mapping cameras. Then, on the journey home, the CM cabin will be topped up by emptying both units.
A gauge on the OPS gives a reading of the pressure in the tanks, This is called the "source pressure" in the checklist.
034:43:36 Scott: Rog. We can give you that from the Command Module.
034:43:42 Henize: Roger.
034:43:46 Scott: We'll do all the housekeeping. We'll just give you the report from Endeavour. [Pause.]
034:43:59 Henize: Falcon, that all sounds good, and only one other mat - matter, and that's the docking index angle as you go back through.
034:44:08 Scott: Rog. We checked that. It was plus .1.
034:44:14 Henize: We copy. [Long pause.]
034:44:38 Scott: Hey, Houston, correction. That's a minus .1.
034:44:43 Henize: Correction received.
034:44:47 Scott: It's so close to zero it's hard to tell.
Comm break.
When Al docked the CSM, there was some swinging of the spacecraft in pitch and yaw after initial capture and soft-dock. However, Al's alignment in roll has essentially been spot on.
Al takes the camera back up the tunnel, looking down towards the ascent engine cover.
034:46:02 Worden: Houston, Endeavour.
034:46:05 Henize: Endeavour, this is Houston.
034:46:08 Worden: Okay, Karl. I'll go ahead and secure the TV now.
034:46:12 Henize: Very good.
Very long comm break.
TV coverage ends.
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
This is Apollo Control at 34 hours, 49 minutes. That television transmission duration was 49 minutes, 6 seconds. The broken glass on the tapemeter will not be a constraint to the mission. The tapemeter is the instrument on the Lunar Module that shows altitude and altitude-rate during the landing sequence; and range and range-rate during the rendezvous sequence.
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
This is Apollo Control at 34 hours, 54 minutes. TELMU, the flight controller who monitors the Lunar Module Electrical Power System, got a good look at Falcon's batteries on telemetry while the Lunar Module was powered up. Reports that the battery condition is excellent.
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
Flight Plan page 3-42.
This is Apollo Control at 35 hours, 3 minutes. Apollo 15 now 131,660 nautical miles [243,834 km] from Earth. Velocity; 4,314 feet per second [1,315 m/s].
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
035:10:36 Worden: Houston, 15.
035:10:40 Henize: 15, this is Houston.
035:10:43 Worden: Okay, Karl. I've got the OPS checkout numbers for you if you want them.
035:10:47 Henize: Very good. Go ahead.
035:10:50 Worden: Okay. Commander's OPS had a source pressure of 5,800 [psi, 40,000 kPa], 5,800, And a regulated pressure of 3.8 [psi, 26.2 kPa]. And the LMP's source pressure was 5,800, and regulator pressure was 3.85 [psi, 26.5 kPa].
035:11:13 Henize: Roger. Houston copies.
035:11:17 Worden: Rog. [Long pause.]
That was Al Worden giving that report.
035:11:34 Henize: And, 15, when Jim has a couple of minutes, we'd like to ask a few questions about the High Gain Antenna.
035:11:45 Worden: Okay; he's off the headset right now, Karl. I'll get him as soon as I can.
035:11:50 Henize: Okay.
Very long comm break.
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
This is Apollo Control at 35 hours, 35 minutes. Apollo 15 is 132,936 nautical miles [246,197 km] from Earth, traveling at a velocity of 4,278 feet per second [1,304 m/s]. We'll continue to stay up live, monitoring for any air/ground conversation.
Flight Plan page 3-043.
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
036:16:33 Henize: 15, this is Houston.
036:16:39 Worden: Hi, Karl. Hey, listen; we're start - going to start up PTC here pretty soon. Do you want to update which RCS jets you want me to use? [Pause.]
Al's query is based on the note for Mission Control listed on the left-hand column of the Flight Plan.
The PTC (Passive Thermal Control) was stopped at around 026:55:00. It is desirable to restart it before too long to keep temperatures in the Service Module's systems under control and to protect the Command Module's heatshield. See commentary at 005:29:22, 010:40:06, 011:44:58 and at 013:03:55 for discussion of the PTC maneuver.
036:16:59 Henize: Stand by on that, Al.
036:17:09 Worden: Okay. I'll go ahead and do the Verb 49 maneuver and start damping rates.
Verb 49 commands the spacecraft to maneuver to an attitude defined by the crew. In this case, Al is requesting the initial attitude for the PTC, and he will then wait for rotation rates to settle.
036:17:14 Henize: Negative, Al. We want to stand by in this attitude.
036:17:20 Worden: Oh, okay.
036:17:24 Henize: We - we are thinking real hard down here about your AC glitch and its possible connection to the loss of comm. [Pause.]
036:17:38 Worden: Okay. [Long pause.]
Mission Control believed that the loss of the S-band link at about 033:48:00 was due to a problem at the ground receiving station. However, the crew's report of a glitch in the spacecraft's power buses is causing them to rethink their theories.
036:17:50 Henize: Whenever Jim is available, we'd be pleased to ask a couple of questions.
036:17:58 Worden: Roger, Karl. You have to stand by on that. He's finishing up over in the LM right now.
036:18:04 Henize: Okay. [Long pause.]
036:18:32 Henize: Al, if you are looking for a job, I could read you up a flyby PAD.
036:18:42 Worden: Okay, Karl. [I'll] be a moment.
Comm break.
036:20:32 Worden: Okay, Houston; this is 15. Go ahead with the PAD, Karl.
036:20:36 Henize: Roger. Purpose is flyby, SPS/G&N; 66655; plus 1.24, minus 0.11; 073:30:56.80; plus 0257.2, plus 0230.9, minus 0314.9; 331, 109, 079; NA [meaning not applicable], plus 0020.8; 0467.6, 1:11, 0463.0; sextant star is 02, 148.5, 26.4; boresight star is NA; latitude, plus 13.32, minus 174.04; 1098.7, 36170; 170:59:57. GDC Align stars, Vega and Deneb; 209; 009; 349. No ullage. Comments. The burn is SPS docked. Number 2, use onboard preferred REFSMMAT, because of yaw gimbal angle. Number 3, LM weight is 36220. And that's all. [Long pause.]
Page 2-15 of the Flight Plan carries a table listing a schedule of block data read-ups, or PADs which are to be given to the crew throughout the mission. These PADs give the necessary information to allow the spacecraft to return to Earth in an emergency. The table lists what the purpose of each PAD is, when it is due to be read up, approximately when it would be used, and what type of PAD it is. A complete PAD for use in Program 30 was read up at 001:30:00 GET and the following PADs gave the data to be used in Program 37 where they are factored in with already available data if an abort curtails the mission. These P37 PADs are designed to return the spacecraft to Earth immediately, without continuing around the Moon, and are effective until 60 hours GET.
CapCom Karl Henize has just read up the eighth PAD in this table, the LOI minus 5, or flyby PAD, and it is a complete P30 PAD.
An interpretation of the PAD follows. The next five parameters all relate to re-entry, during which an important milestone is "Entry Interface," defined as being 400,000 feet (121.92 km) altitude. In this context, however, a more important milestone is when atmospheric drag on the spacecraft imparts a deceleration of 0.05g. With the SPS propellant tanks nearly full, there is no need for an ullage burn to settle their contents. The burn is made with the LM docked as its consumables would be useful to have in an emergency. The attitude reference is the preferred REFSMMAT so as to avoid the possibility of reaching gimbal lock. The mass of the LM is 36,220 pounds (16,429 kg), a figure which is required to allow the attitude control system to calculate the moment of inertia of the stack, and thence the required RCS thrusting durations.
036:23:34 Worden: Roger; understand. Purpose is flyby, that's SPS/G&N; and PAD's as follows: 66655; plus 1.24, minus 0.11; 073:30:56.80; plus 0257.2, plus 0230.9, minus 0314.9; 331, 109, 079; and the next is NA; and I missed a couple in there. Picking up at sextant star would be 02, 148.5, 26.4; boresight star is NA; latitude is plus 13.32, longitude, minus 174.04; 1098.7, 36170; 170:59:57. Vega and Deneb are set stars; with angles of 209; 009; and 349. No ullage. And the SPS docked burn, use a preferred REFSMMAT because of the yaw gimbal angle, and the LM weight is 33260.
036:24:51 Henize: The LM weight is 36220. [Pause.]
036:25:04 Worden: Okay, Karl. Understand; 36220.
036:25:06 Henize: That's correct. And down in Noun 44, HP is plus 0020.8, Delta-VT, 0467.6, burn time, 1:11, Delta-VC, 0463.0. [Pause.]
036:25:49 Worden: Roger, Karl; understand. HA is NA, HP is plus 0020.8; Delta-VT is 0467.6, with a burn time of 1:11. Delta-VC, 0463.0.
036:26:08 Henize: Roger. That's all correct.
036:26:13 Worden: Okay.
Long comm break.
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
036:29:50 Irwin: Houston, this is - Endeavour. [Long pause.]
036:30:12 Irwin: Houston, this is Apollo 15. Over.
036:30:16 Henize: 15, this is Houston. [Pause.] This is Houston; go ahead.
036:30:27 Irwin: Yes, Karl, this is Jim, I'm back in and on comm. As far as that AC and main bus undervolt [are concerned], I have not much more to add than what I said before. Do you have any other questions?
036:30:44 Henize: Roger. Stand by just about 30 seconds, and we'll come up with a couple.
036:30:51 Irwin: Okay. [Long pause.]
036:31:32 Henize: 15, this is Houston.
036:31:38 Irwin: Go ahead, Karl.
036:31:41 Henize: Jim, we've been doing a lot of thinking about that AC glitch down here, and - the coincidence of time - makes us guess that there was a connection with that power loss, but we don't see how. We'd like to start off with a couple of questions. The first one is, when you - reacquired on the High Gain Antenna, did you possibly notice that the High Gain angles were different from what you'd set on the knobs?
036:32:13 Irwin: Yes; as a matter of fact, they were.
036:32:16 Henize: Okay.
036:32:20 Irwin: I - I did nothing up here to reacquire on the - the High Gain [Antenna]. It came back automatically.
036:32:27 Henize: Okay; that's interesting information. Were there any talkbacks noted - changing state at the time of the glitch?
Talkbacks are indicator windows which, by putting a gray flag in front of a striped, or barber pole background, annunciate the status of various systems aboard the spacecraft.
036:32:37 Irwin: No change that I noticed.
036:32:41 Henize: Okay. Was anyone in the tunnel at the time of the glitch? [Pause.]
036:32:50 Irwin: Say again about the tunnel, Karl.
036:32:52 Henize: Was anyone in the tunnel at the time of the glitch? [Pause.]
036:33:04 Irwin: Stand by.
Comm break.
The crew may be trying to work out Mission Control's thinking when they asked this question.
036:34:12 Irwin: Okay, Karl. Al was in the tunnel, but there were no electrical connections being made at the time.
036:34:20 Henize: Roger. I - I guess a follow up question then - and you've probably answered it - is, was there any unusual activity associated with the tunnel umbilicals?
036:34:37 Irwin: Don't think so - we don't think so, Karl, not at that time.
036:34:41 Henize: Okay. And another question on this line is, what was and what is the position of the LM power 1 Main B and 2 Main B circuit breakers on panel 5?
Panel 5 is a panel of mostly circuit breakers adjacent to the right of the Main Display Console.
036:34:54 Irwin: Stand by. [Pause.]
036:35:04 Irwin: They're both in [that is, they are Closed].
036:35:08 Henize: Roger. [Pause.]
036:35:18 Henize: Okay. If you have some minutes to spare up there, we'd like to go through a cockpit check for open circuit breakers connected with Main [bus] B and AC [bus] 2, on the theory that whatever happened might have blown a circuit breaker that wasn't obvious to you.
036:35:37 Irwin: Okay. I'll - I'll do that now.
036:35:40 Henize: We suggest - that - well, you know, this - figures 3-1 and 3-2 are a good guide to that for the normally open circuit breakers.
036:35:53 Irwin: I'll check all circuit breakers. [Long pause.]
036:36:22 Henize: Jim, I've got the diagrams down here, if there's anything I can do to help you.
036:36:30 Irwin: Okay; we'll look around.
Comm break.
The button type circuit breakers are closed by pushing the button in. If the button is pulled out, or if the breaker should 'blow', this is highlighted by a white ring around the button being exposed.
036:38:23 Irwin: Karl, this is Jim.
036:38:26 Henize: Go ahead.
036:38:30 Irwin: Roger. On [panel] 226, under Lighting, Numerics/Integral, LEB [Lower Equipment Bay] AC 2 has been popped, or I believe it's popped, I would think it'd normally be closed now. [Long pause.]
Diagram showing layout of panel 226 on the right-hand side of the spacecraft.
Panel 226 has five rows of seven or eight breakers per row. It is sited on the spacecraft wall, well to the right of the Main Display Console.
036:39:06 Henize: Roger, Jim. We confirm that that is normally closed. [Pause.]
036:39:13 Irwin: Okay; it looks like it might be the problem.
Very long comm break.
Scott, from 1971 Technical debrief: "I think the only consequence of that was [that] it sort of changed your pattern of operation down in the LEB because you didn't have the timer down there."
Worden, from 1971 Technical debrief: "We didn't have the mission timer down there, and the other thing that I missed in the LEB, which I found, I stubbed my toe on a few times, was that all of the program lights in the DSKY [Display and Keyboard, the computer's keypad] were out. The only thing we had was caution and warning panel down there. That was operational, but all of the status lights on the DSKY were out. They went with that circuit breaker. The backlighting in the EMS [Entry Monitor System] scroll was out. That was also off that circuit breaker."
From the 1971 Mission Report: "Postflight testing [showed that a] short circuit was in the mission timer. ... Teardown analysis revealed a shorted input filter capacitor. The capacitor is rated for 200-volt d-c applications and is being used in an a-c application at voltages up to 115 volts. Since the dielectric in the ceramic capacitor is a piezoelectric material (barium titanate), the 400-cycle [per second] a-c voltage actually causes the materials in the capacitor to mechanically vibrate at that frequency. Over a period of time, the unit could break down because of mechanical fatigue. This may have been the cause of failure of this capacitor."
The popped circuit breaker will not be reset throughout the mission. The circuit it was protecting supplied integral lighting to the EMS (Entry Monitor System) scroll, some lights in the DSKY (Display and Keyboard) and various other backlighting as well as the now defunct mission timer. The loss of these facilities is not serious but will have subtle repercussions on spacecraft operations in lunar orbit when Al will try to work around the lack of a timer in the LEB by using one of the programs in the computer to make the LEB DSKY into a timer. This then impairs the updating of the spacecraft's state vector over a period of time.
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
036:49:48 Henize: 15, This is Houston. [Pause.]
036:49:56 Irwin: Go ahead, Karl.
036:49:57 Henize: When you're through checking the circuit breakers, we have a little procedure we'd like to go through here as a - as a further check.
036:50:08 Irwin: Okay. Did you want me to continue checking? I figured after I - Stand by.
036:50:13 Scott (onboard): Yes. I thought you checked them all, Jim. Sure. Check them all. Sure.
036:50:17 Henize: Roger, Jim. We - we'd like to have a - a complete check there, and don't - don't reset that circuit breaker, incidentally.
036:50:25 Irwin: I understand.
Comm break.
036:50:26 Scott (onboard): Not yet.
036:50:32 Irwin (onboard): ... do this?
036:50:33 Scott (onboard): Okay. TV.
036:50:38 Irwin (onboard): ...
036:51:09 Irwin (onboard): ... That's over ...
036:51:12 Scott (onboard): Yes, when I read it out to you. Not before.
036:51:17 Irwin (onboard): ...
036:51:54 Scott (onboard): Oh, yes.
036:51:58 Irwin: Okay, Karl. I've checked all circuit breakers, and that's the only one that seems to be out of [the proper] configuration.
036:52:04 Henize: Okay; very good. What we're going to do, Jim, is to drop the uplink and see what happens. And just to clarify the communications glitch that we had, the ground station lost the power amplifier, and we lost uplink to you. There was apparently no loss of downlink. So what we want to do now is to - is to drop the uplink and see if it creates the same glitches that - as you got on the AC bus that time. In view of your circuit breaker being out, we don't think there's a connection, but we'd just like to have this final confirmation. And...
Mission Control are hoping that by re-enacting the failure from their end, they can reproduce the same consequences.
036:52:43 Irwin: Okay; we're standing by.
036:52:44 Henize: ...to start the procedure here, we'd like to just double check that you - that the dials for the High Gain Antenna are setting at Pitch, minus 30; Yaw, 276.
036:52:58 Irwin: Yes, that's correct.
036:53:00 Henize: Roger. And verify that we have...
036:53:02 Irwin: Yaw - yaw is really...
036:53:07 Henize: Go ahead.
036:53:08 Irwin: Yes, we're in Track, Auto.
036:53:10 Henize: We - we'd like to have Auto and Narrow [beam width].
036:53:12 Irwin: Yaw is... [Pause.]
036:53:14 Scott (onboard): Just let it go for a while. It's black and it's black and it's black.
036:53:23 Irwin: Pitch is minus 30, Yaw is 270, and Track is Auto. [Long pause.]
036:53:41 Scott (onboard): ... 280.
036:53:42 Irwin (onboard): You can stop that one someplace.
036:53:44 Scott (onboard): Okay.
036:53:44 Henize: Roger, Jim. And what we're going to do now is to drop uplink for 20 seconds, and you are to read out and record the High Gain Antenna dials and any changes that occur there. Then we'll bring up the uplink; and, at that time, we want you to require - reacquire High Gain Antenna on - on Auto, Narrow. Okay?
036:54:10 Irwin: Okay. Right now the Yaw indicator [for the HGA] is reading about 280. [Pause.]
036:54:19 Henize: What does your dial say? [Pause.]
036:54:24 Irwin: The dial is 280. The thumbwheel is 270.
036:54:31 Henize: That's okay. And are you ready for us to drop the uplink? [Pause.]
036:54:39 Irwin: [Faint] Yes, go ahead. [Pause.] Yes, go ahead.
036:54:46 Henize: Okay. We'll be dropping - dropping the uplink for 20 seconds. Here we go.
Comm break.
036:56:07 Henize: 15, this is Houston. How do you read?
036:56:13 Scott: This is 15. I read you loud and clear.
036:56:16 Henize: Roger. Did you observe anything special up there?
036:56:22 Scott: Well, nothing other than the - the Pitch went to zero, and the Yaw decreased just very slightly. And, of course, when you reacquired, it went back to Pitch went back to 30. [Pause.]
036:56:39 Henize: We copy.
Comm break.
036:56:35 Irwin (onboard): That's right ....
036:56:36 Worden (onboard): Take this here ....
036:56:39 Scott (onboard): Get it off?
036:56:41 Worden (onboard): Yes, I ... turn this PRD in.
036:56:49 Scott (onboard): Get the PRD out of there while you're at it.
036:56:51 Worden (onboard): Out of - where is it?
036:56:53 Scott (onboard): It's in the pocket with yours, ... It's in your cuff - by your - top of your right hand. Ah, I got it.
036:57:01 Worden (onboard): Oh, okay ....
036:57:07 Scott (onboard): Is this PAD you copied down, Al, is that - the next midcourse, huh?
036:57:10 Worden (onboard): No. That's a flyby PAD.
036:58:04 Henize: 15, this is Houston. That's enough troubleshooting, and we're ready to go to PTC now. And we'd like to have you use the A and D quads for damping. And use the B and D quads for spin up. And we'd like to confirm that we are using a spin rate of .375 [degrees per second] this time. [Pause.]
036:58:35 Irwin: We copied all that, Karl. A and D for damping, B and D for spin up. And .375 for the rate.
036:58:43 Henize: Roger.
Very long comm break.
Flight Plan page 3-44.
Only two quads are needed for the gentle spin up. Uncoupled single quads can be used to make the tiny corrections required to damp the spacecraft's rates. The crew are going to use the slightly faster spin rate that they resorted to when the first attempt at PTC failed at 013:37:48. The PTC is about an hour late in getting started.
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
This is Apollo Control; 37 hours, 4 minutes. Apollo 15 now 136,611 nautical miles [253,003 km] from Earth. Velocity; 4,173 feet per second [1,272 m/s]. We'll attempt to - to recap and summarize what we've been doing here for the last hour or so and some of these tests we've been running. The Goldstone tracking station lost a power amplifier affecting a transmitter. We had a temporary loss of data. At the same time on the Command Module, an AC bus voltage alarm occurred. We've been running some tests to see whether there was any connection between the mishap at the tracking station and the alarm on the spacecraft. It now appears that these two things were coincidental; that there was no connection. We found an AC lighter [means lighting] circuit circuit breaker that has popped, which would have given the alarm. The crew has checked all the circuit breakers. This circuit breaker going out would have triggered the alarm seen in the Command Module. The circuit breaker affects only some lighting in the Command Module and can be worked around if it presents a problem. We see no major problem at the present time on the spacecraft in connection with this.
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
This is Apollo Control at 37 hours, 9 minutes. The flight controllers who monitor Lunar Module systems have been reporting to Flight Director Milton Windler on the status of these systems as they were observed by telemetry during the LM activation period. They all appear to be in good shape. The batteries look good, the Descent Propulsion System parameters are normal. The LM Reaction Control System parameters all normal. The supercritical helium pressure is good. That's the pressurization [system] for the Descent Propulsion System.
037:10:58 Henize: 15, this is Houston. Your rates look low enough to go into spin-up, if all of your vents have been closed.
037:11:08 Scott: Okay, Karl. I think we got everything closed, and we'll go ahead and spin her up.
037:11:12 Henize: Very good. [Long pause.]
This is Apollo Control. This spin-up will establish the Passive Thermal Control mode for the rest period. Spacecraft will be rotated at a rate...
037:11:37 Henize: 15, could you please confirm that you're on Omni Bravo. [Pause.]
Mission Control will gain the best control of the omni-directional antennas by having the crew switch to antenna B. They will then be able to switch between B and D, as the PTC mode rotates the two opposite-facing antennae towards and away from Earth.
037:11:45 Scott: That's affirm, Karl. We're on Omni Bravo.
037:11:48 Henize: Thank you.
Long comm break.
The desired rotation rate for PTC is 3 tenths of a degree per second.
Actually, it is a bit faster than that at 0.375° per second, as discussed at 036:58:04 above.
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
037:20:07 Henize: 15, this is Houston. We have a read-out down here that A-1 jet is on. Could you confirm that? And if it is on, let's turn it off. [Pause.]
037:20:22 Worden: Roger, Houston; 15. Your read-out is correct and it's now off. Sorry, Karl, I overlooked that one.
037:20:28 Henize: Thank you.
Long comm break.
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
037:23:41 Henize: 15, this is Houston. Your spin-up is looking very good to us, and when you have a couple of minutes to listen, we have a brief status report to send up to you. [Pause.]
037:23:56 Scott: Okay; go ahead, Houston. We're standing by.
037:24:01 Henize: Okay. In regards to your range-rate tapemeter - That is normally sealed in a helium atmosphere at 15 psi [103 kPa], and with that outer glass broken, this seal is broken and the meter is now operating in zero to 5 psi [34 kPa] in an oxygen environment. We don't know that this has any effect on it, but Grumman is doing tests to show whether or not its okay. Concerning the SPS...
037:24:34 Scott: [Garble.]
037:24:36 Henize: Yes, go ahead.
037:24:40 Scott: I was just going to say, it'd be interesting to hear what they find out.
Although there was no visible damage to the instrument itself, it is important to ensure that such a vital instrument will operate properly with an internal environment it was not designed for as the LM cabin will spend extended periods as a vacuum while on the lunar surface. For example, lubricants between the moving parts of the mechanism may outgas and dry up.
Before the breakage, the interior of the instrument was hermetically sealed and pressurised with helium at 101 kPa (14.7 psi). Extreme temperatures and a vacuum in the LM cabin could increase this to 111 kPa (16.1 psi). The post-mission report concluded that the glass must have had a flaw which exceeded that which causes breakage at the stress levels encountered during the early stages of the flight. Subsequent flights had a second pane of glass to reduce the pressure differential across each pane and Velcro applied Teflon covers for similar instruments to retain broken glass particles.
037:24:44 Henize: Roger, we'll let you know. Concerning the SPS, we're still reviewing the LOI [Lunar Orbit Insertion] procedures that we'll use, but it's probable that we'll want to start automatically on bank B and bring on [bank] A five seconds later, using the circuit breaker and then turning it off at 6 minutes and finishing up the burn on bank B. Its probable that the other burns, except for TEI, will be done on bank B only. Any comments on that?
037:25:23 Scott: No, that's just about what we were thinking too, Karl.
The SPS can still be controlled by the computer using bank B, one of the two redundant control systems for the engine. The electrical short in bank A will cause the engine to ignite as soon as it is brought online, so brief burns can be carried out using the single, good control bank. However, the rated thrust of the engine is achieved when both banks are supplying propellant to the engine. By starting and stopping the engine automatically using bank B, the crew can bring bank A into use a few seconds after ignition, and disable it just prior to the automatic cutoff, simply by operating the pilot valve circuit breaker, thereby achieving full thrust for the majority of the burn.
037:25:27 Henize: Okay. In the LM, the batteries and the SHe [Supercritical Helium] look in perfect shape. And concerning the lighting circuit breaker problem: we're still getting in the data in down here, and we'll review the situation with you tomorrow. We see no problem with the High Gain Antenna. And other than your - and other than your crew status report, and your onboard read-outs, that just about wraps up the evening. We'd still like to have your PRD read-outs, and I guess we have a battery charge in progress that will need to be cut off.
Mission Control have been prompting for a read-out from each crewman's PRD (Passive Radiation Dosimeter) since they awoke nearly 12 hours ago.
Between 37:00 and 37:30, the crew are scheduled to take an exercise period. They have, however, got behind their time line and it is unclear whether they had a physical workout.
037:26:16 Scott: Okay, Karl; we'll finish up the rest of the items here and bring you up to date on all the read-outs, and - sorry about the PRDs, but since [garble] the suits [garble] tonight.
037:26:33 Henize: Okay. No problem on that. And I have a - I have the update to LM Contingency Checklist, and if you want to take it this evening, I can give it to you; otherwise, it can be put off until tomorrow. [Long pause.]
037:26:58 Irwin: Okay, stand by. [Long pause.]
037:27:37 Irwin: [Garble] Karl, [garble] copy notes you have [garble, probably the LM] Contingency Checklist.
037:27:49 Henize: 15, this is Houston. I heard you trying to come through but we were noisy just then. Hold off just a minute.
037:27:58 Irwin: Houston, 15.
037:28:01 Henize: Reading you better now; go ahead. [Pause.]
037:28:09 Henize: 15, this is Houston. [Long pause.]
037:28:27 Irwin: Houston, 15.
037:28:31 Henize: 15, this is Houston. I'm reading you loud and clear. [Long pause.]
037:29:00 Henize: 15, this is Houston. How do you read? [Pause.]
037:29:07 Irwin: You're loud and clear.
037:29:09 Henize: Roger. Did I understand that you were ready for the LM Flight Plan - Contingency Checklist update?
037:29:19 Irwin: Yes, I am, Karl. [Pause.]
037:29:27 Henize: Roger. On page 1-1, down under "Power Transfer and RCS Heater Activation."
037:29:45 Irwin: Go ahead.
037:29:49 Henize: At the end of step 2, add the following line: "Circuit breaker 16, Stabilization/Control. ASA, Close." [Long pause.]
037:30:17 Irwin: Okay; I copy that.
037:30:19 Henize: Roger. On page 1-7, under "AGS activation." [Long pause.]
The AGS (pronounced "aggs") is the Abort Guidance System, which is a back-up to the LM's Primary Guidance and Navigation System (PGNS or "pings"). It consists of 2 sections. The ASA (Abort Sensor Assembly) makes its own measurements of attitude and acceleration using separate gyros and accelerometers, feeding this information to a computer (AEA or Abort Electronics Assembly) which has the simple brief to get the crew back into safe lunar orbit if the primary system should fail.
037:30:51 Henize: Okay?
037:30:52 Irwin: I was standing by.
037:30:55 Henize: Add before step 1: "Verify ASA circuit breaker - has been Closed for 10 minutes. [Long pause.]
037:31:20 Irwin: Roger. Understand before step 1, "Verify ASA circuit breaker's been Closed for 10 minutes."
037:31:26 Henize: Roger. The next one is page 2-5. [Pause.]
037:31:38 Henize: And on that circuit breaker configuration, in the second row down, put a black dot under the ASA circuit breaker. [Pause.]
Both spacecraft use button type circuit breakers familiar to pilots, which are closed when the button is in but which reveal a white ring when it is out and open. Diagrams in the LM Activation Checklist use white or black circles to indicate which breakers should be closed or open in the required initial configuration and the pattern of circles allow a quick visual guide that the row of breakers in front of him are properly set.
037:31:57 Irwin: Okay; I understand.
037:31:58 Henize: And on page 2-13. Under "AGS activation and Self Test" add before step 1: "Verify ASA circuit breaker - has been Closed for 10 minutes." [Pause.]
037:32:30 Irwin: Okay; I copied all of that.
037:32:32 Henize: Very good. That's all of the update.
037:32:37 Irwin: Okay; thank you, Karl.
Very long comm break.
Flight Plan page 3-45.
At 38 hours, the crew are scheduled to begin their evening meal so Mission Control are leaving them alone for over an hour. The few tasks in the Flight Plan include Al donning his biomedical harness and Dave taking his off. It is Al's turn to be monitored overnight. They will also change one of their LiOH canisters, taking number 3 out of the A receptacle, stowing it in compartment B5, and replacing it with canister 5.
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
This is Apollo Control at 38 hours, 1 minute. Apollo 15 now 138,871 nautical miles [257,189 km] from Earth. Velocity; 4,110 feet per second [1,253 m/s]. Guidance, Navigation and Control Officer says it looks like a good PTC has been set up by Apollo 15. All indications point to that fact. However he wants to watch it a little while longer to make sure that we're in the proper rotation. Took three attempts last night to - to get the desired rotation. However, historically, we've had problems the first night in setting up Passive Thermal Control mode.
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
This is Apollo Control at 38 hours, 27 minutes. Apollo 15 is 139,914 nautical miles [259,120 km] from Earth. Velocity; 4,082 feet per second [1,244 m/s]. Apollo 15 will reach the halfway point, in time, to lunar orbit at 39 hours, 17 minutes, 21.7 seconds. At that time, distance from Earth will be 141,860 nautical miles [262,724 km] and it will be 86,864 nautical miles [160,872 km] from the Moon.
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
038:37:15 Henize: 15, this is Houston. How are you enjoying dinner?
038:37:23 Scott: It's just fine, Karl.
038:37:26 Henize: Great, glad to hear it. Hey, we'd like to ask a question about that glass breakage in the LM. Did it shatter into little bits or just a few big hunks? How well do you think you got it cleaned up? [Pause.]
038:37:42 Scott: Oh, I think we probably got about - maybe 50, 60 percent of what was broken, and it was broken into - some pieces on the order of three-quarters to an inch and other little millimeter type pieces.
038:37:58 Henize: Okay. I guess that gives us a picture of the situation. We're somewhat concerned about that having drifted into equipment or - yeah, into equipment. [Pause.]
038:38:06 Scott: Okay. Well we looked around and picked up what we could with [sticky] tape, and we took the vacuum cleaner over and ran it for quite a while to try and pull up what we could.
038:38:15 Henize: Very good. [Pause.]
038:38:25 Scott: We don't have any idea why it broke. It didn't look like there was anything in the ISA [Interim Stowage Assembly] which could have done that to the - just the face of that meter. The ISA had mostly soft equipment. It was pretty well padded.
The Interim Stowage Assembly is a stowage bag that is spread across the forward instrument panels in the LM, including the Range/Range-Rate tapemeter.
038:38:37 Henize: Okay.
Very long comm break.
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
This is Apollo Control at 38 hours, 47 minutes. GNC [Guidance, Navigation and Control officer] says the Passive Thermal Control has been established satisfactorily on the first try tonight. So, we'll not need another attempt to do that. Apollo 15 is 140,707 nautical miles [260,589 km] from Earth. Velocity; 4,060 feet per second [1,237 m/s]. Crew should be going through the presleep checklist very shortly now. Rest period scheduled to start at 39 hours. We'll continue to stand by live for the final air/ground transmissions of the day.
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
038:53:51 Henize: 15, this is Houston. We're ready to terminate the charge on Bat A now.
038:53:59 Scott: Roger. Terminate charge on Bat A.
Battery B was charged yesterday, and is scheduled to be recharged tomorrow.
038:54:02 Henize: And incidentally, we see a - an off-nominal drain on Bat A, and we'd like to verify that the Pitch 1 and the Yaw 1 circuit breakers on panel 8 are Open. If not, we'd like to Open them. [Pause.]
Panel 8 is adjacent to the left side of the Main Display Console. These two breakers, on the fourth from top row, route power to the gimbal motors that aim the SPS engine.
038:54:19 Scott: Okay. Standby. [Pause.] Circuit breakers are verified Open.
038:54:30 Henize: Thank you. And, let's leave them Open.
038:54:35 Scott: Rog.
Comm break.
038:56:15 Henize: 15, this is - 15, this is Houston. I want to correct a false impression I gave you. We don't see any off-nominal drain on battery A.
038:56:27 Scott: Oh, that's good. Thank you.
Very long comm break.
The final act of the day is the presleep checklist which is on page 1-26 of the CSM Systems Checklist. As part of this task, the crew will give a status report on their condition, and a read-out of the onboard gauges. They will also stir the cryogenic hydrogen storage tanks, chlorinate their water supply and dump the contents of the E(erasable)-memory to Mission Control before configuring the communications system for the night.
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
This is Apollo Control at 39 hours, 15 minutes. Flight Director Glynn Lunney and his team of flight controllers are now preparing to take over in the Mission Control Room, relieving...
039:16:03 Scott: Okay; Houston, 15.
039:16:10 Henize: 15, this is Houston. Go ahead. [Pause.]
039:16:17 Scott: Okay. We have our presleep checklist when you're ready to copy. [Long pause.]
039:16:34 Henize: Roger, 15. Go ahead.
039:16:40 Scott: Okay. Crew status report, everybody's in good shape. No medication today. The onboard read-outs: Bat C, 37 [volts]; Pyro Bat A, 37.2; B, 37.2; RCS A, 90 [per cent propellant remaining]; B, 89; C, 91; and D, 89. The [H2 cryo] fans are being cycled now. The water has been chlorinated. All the valves are closed. We're getting ready to pump up the cabin. And we'll give you an E-memory dump whenever you are ready. [Pause.]
One of the steps in the presleep checklist is to open the direct O2 valve and raise the cabin pressure to 39.3 kPa (5.7 psi), if it is not already there.
039:17:22 Henize: Roger, Dave. [Pause.]
039:17:28 Scott: And one more thing, we've - I've got the PRDs for you.
Finally, at the end of the day, Mission Control gets its dosimeter readings!
Woods, from 1998 correspondence with Scott: "Judging from the transcript, I have the impression the three of you had little time for the radiation dosimeters during the translunar coast. Despite the Flight Plan calling for readouts to be given to Houston as part of the postsleep checklist on the morning of the second day, they are deferred until the evening of that day and Joe Allen has to specifically request them on the morning of the third day. Did you have an 'attitude' towards them?"
Scott, from 1998 correspondence: "Not really, but as I recall, they did take a fair amount of time to read since they were not in a convenient location, and the values changed very little - maybe we thought other activities and items were of higher priority at the time. However, we were clearly aware of the significance of radiation, especially during this particular period of high solar activity, i.e., during the A15 mission. You have probably read The Throne of Saturn, by Alen Drury? As I recall, radiation was the major contributor to suspense in this story."
According to information from the Greenwich Photoheliographic programme on sunspot area, the entire sequence of Apollo flights from Apollo 7 to 17 coincided just about perfectly with the high plateau of solar activity at that time.
039:17:32 Henize: Great. Go ahead.
039:17:37 Scott: Okay. CDR is 23020, the CMP is 5008, and the LMP is 8008. [Pause.]
039:17:55 Henize: Thank you, Dave. And incidentally, if you'd like to get rid of that biomed harness, you can change off now, you know.
039:18:08 Scott: Oh, that should work, right now.
Long comm break.
This is Apollo Control. We're estimating the change of shift news conference for 12:15 am Central Daylight Time in the briefing room at the news center. Apollo 15 now 141,903 nautical miles [262,804 km] from Earth. Velocity; 4,028 feet per second [1,228 m/s].
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
039:23:41 Henize: 15, this is Houston. We're ready for the E-memory dump.
039:23:47 Scott: Roger. And here it comes. [Pause.]
039:23:54 Henize: And, Dave, a - we - our telemetry says that the optics power is still on, and I'd like to remind you to turn it off.
Turning off the power to the optics system is part of the presleep checklist.
039:24:04 Scott: Yeah, but we just got that off.
039:24:09 Henize: Sorry about that. [Pause.]
039:24:19 Scott: Well, Karl, does your telemetry tell you it's on or off now?
039:24:25 Henize: They were just telling me that - hey, it was off about the time that I called you.
039:24:31 Scott: Oh, okay.
Very long comm break.
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
This is Apollo Control at 39 hours, 38 minutes. We've completed the shift handover here in Mission Control. At the moment Flight Director Glynn Lunney is reviewing the status of the mission with each of his flight controllers. Our capsule communicator on this shift will be astronaut Robert Parker. A change of shift press briefing is scheduled to begin shortly in the MSC news center auditorium. Although we haven't said goodnight to the crew yet, we don't expect a great deal of conversation with them. Should we receive any communications between - with the crew during the briefing, we'll tape record that. At the present time, Apollo 15 is travelling at a speed of 4,015 feet per second [1,224 m/s]. The spacecraft, 142,377 nautical miles [263,682 km] from Earth.
[Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
039:57:11 Parker: Endeavour, Houston. Over. [Long pause.]
039:57:24 Scott: Houston, Endeavour. Go ahead.
039:57:26 Parker: Roger. Guys, before you go to sleep, I'd like to have the mode - S-band Normal Mode - switch Voice to Off, please.
039:57:36 Scott: S-band Normal Mode Voice - switch Voice to Off. Is that it?
039:57:41 Parker: Roger. And, unless you guys have something else, we're going to let you go to sleep now.
039:57:47 Scott: Okay, Bobby. Thank you.
039:57:50 Parker: See you sometime.
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