Launch and Reaching Earth Orbit	Journal Home Page	Transposition, Docking and Extraction

Apollo 15

Earth Orbit and Translunar Injection

Corrected Transcript and Commentary Copyright © 1998 by W. David Woods and Frank O'Brien. All rights reserved.

000:16:56 Worden (onboard): The first Line Heater's on.

000:16:58 Scott (onboard): Okay. Have you got the torquing angle?

000:17:02 Worden (onboard): Mm-hum. Okay, we could do the SM RCS monitoring check and the CM...

Public Affairs Officer - "We've had loss of signal through Bermuda. About a minute out of Canary Islands. To recap a moment, the measured orbital... here is a call now to the crew."

000:17:06 Fullerton: Apollo 15, Houston through Canaries. Over.

000:17:10 Scott: Go ahead, Houston, 15.

000:17:12 Fullerton: Roger. You're loud and clear.

000:17:16 Scott: Okay. The S-IVB tank pressures are - about 41 [psi] on the oxidizer and about 21 [psi] on the fuel.

000:17:21 Fullerton: Roger; 41 and 21.

[Long Comm Break.]

000:18:05 Scott (onboard): Oh...

Public Affairs Officer - "Apollo 15 [is] in a 92.5 by 91.5 nautical mile [171.3 by 169.5 km] Earth orbit. 1 [nautical] mile [1.85 km] out of perfectly circular. Communication [will be] through the Canary Island tracking station for about 4 minutes and 11 seconds total pass time."

[The parking orbit around Earth does not permit continuous communication with Mission Control. Indeed, the orbit is so low that when the spacecraft does come within range of a station, it is only above the horizon for a short period of time, even if it passes directly overhead. If it passes to one side or the other, the period of contact is further constrained; for this pass over the Canary Islands tracking station, communication lasts only 4 minutes and 11 seconds.]

[The Insertion and Systems checklist is split into 30 main sections covering 8 pages. The crew's workload is very high as there is a limited amount of time available to ensure the spacecraft and booster are fit to continue on to the Moon. Section 1, now completed, deals with shutting down the S-IVB control systems until they are needed again for the boost to the Moon, and checking that the booster's fuel and oxidizer pressures are within limits. The checklist includes a note, that after section 1, the other sections are not sequential; i.e. one section does not depend on others having been completed. However, Dave's comm later will suggest they are following the checklist items in the order they appear.]

[Scott, from 1998 correspondence - "These are set up in an optimum sequence before flight, and very seldom deviated. The checklist is normally followed precisely, to ensure there are no surprises."]

000:21:34 Scott: Okay. Carnarvon at 52.

[Very long comm break.]

000:22:12 Worden (onboard): Yes.

Public Affairs Officer - "Flight Dynamics Officer reports that the data coming from the Canary Islands tracking station confirms the initial measurements of the Earth parking orbit, and we are expecting to acquire Apollo 15 again over the Carnarvon, Australia, tracking station at 52 minutes Ground Elapsed Time, about 30 minutes from now. And at 22 minutes, 13 seconds Ground Elapsed Time; this is Apollo Control."

000:22:13 Irwin (onboard): With that indicator out, I can't confirm an H₂ purge on fuel cell 2.

000:22:19 Scott (onboard): Really?

000:22:20 Worden (onboard): Can't you get the - get the H₂ -

000:22:26 Scott (onboard): Caution and warning tone?

000:22:27 Worden (onboard): No, we don't get it.

000:22:29 Worden (onboard): Hmm.

000:22:30 Scott (onboard): Hmm. Better discuss that with them next time we...

000:22:32 Irwin (onboard): Yes.

000:22:34 Scott (onboard): ...go by.

000:22:53 Scott (onboard): Well, shall we gently step along?

000:22:55 Worden (onboard): Yes.

000:22:56 Worden (onboard): Yes. Do you want R-12 out now, Jim? Anything Flight-Data-File-wise that you need now?

000:23:04 Irwin (onboard): I don't need anything, Al.

000:23:06 Worden (onboard): Okay. I'm just going to stick these cards here in the compartment then, and...

000:23:18 Irwin (onboard): Okay, Dave. Do you want to swing over and get the SM RCS monitoring check? Or do you want me to get that?

000:23:23 Scott (onboard): Oh, I can get it.

000:23:24 Irwin (onboard): Here. I can just read it to you.

000:23:27 Scott (onboard): Shoot.

000:23:28 Irwin (onboard): SM RCS Propellant talkback, eight, gray.

000:23:30 Scott (onboard): Eight, gray.

000:23:31 Irwin (onboard): RCS Helium1 and 2...

000:23:32 Scott (onboard): Whoops, stand by; we got one - one barber pole right down - we got B Propellant - barber pole. That was probably a mistake. We open it, and it's gray.

000:23:46 Irwin (onboard): You want to make a note?

000:23:48 Scott (onboard): Yes.

000:23:49 Irwin (onboard): B Propellant...

000:23:50 Scott (onboard): B Secondary Propellant - B Sec Propellant was barber pole, and it reset to gray.

000:23:58 Irwin (onboard): Okay. Okay. SM RCS Indicator, Helium Tank Temp.

000:24:05 Scott (onboard): Okay. Helium Tank Temp.

000:24:06 Irwin (onboard): RCS Indicator selector to A through D. Give me Package Temp, Helium Pressure - all four.

000:24:15 Scott (onboard): Okay. Let me get calibrated here. You want - That's in temperatures only, huh?

000:24:21 Irwin (onboard): No, I want Temp, Pressure, ... Pressure, and Helium Tank Temp.

000:24:26 Scott (onboard): Okay. 140, 4000, 200, 71.

000:24:32 Irwin (onboard): Good.

000:24:34 Scott (onboard): 150, 4000, 195, 70.

000:24:39 Irwin (onboard): Good.

000:24:41 Scott (onboard): 140, 4200, 195, 74.

000:24:46 Irwin (onboard): Good. D.

000:24:48 Scott (onboard): D is 150, 4000, 190, and 72.

000:24:55 Irwin (onboard): Okay, your Manifold Pressure's too low.

000:24:59 Scott (onboard): Say again?

000:25:00 Irwin (onboard): The Manifold Pressure on D is a little low, about 2.

000:25:03 Scott (onboard): Oh.

000:25:04 Irwin (onboard): Its lower - lower limit is, accord - 192.

000:25:08 Scott (onboard): Oh, okay, I'll give you one - Well, shoot, ...

000:25:10 Irwin (onboard): You can't read it. Okay. CM RCS monitoring check.

000:25:12 Scott (onboard): Okay.

000:25:13 Irwin (onboard): CM RCS Propellant talkback, two, gray.

000:25:15 Scott (onboard): Two, gray.

000:25:16 Irwin (onboard): RCS Indicator, switch to CM 1 and 2.

000:25:20 Scott (onboard): Okay. CM 1 - I'm waiting - Okay, you want...

000:25:23 Irwin (onboard): Helium Temp, Pressure and Manifold Pressure.

000:25:26 Scott (onboard): Okay. Helium Temp's about 70...

000:25:31 Irwin (onboard): Good.

000:25:32 Scott (onboard): - - 4000, and 95.

000:25:37 Irwin (onboard): Okay, Helium should be 4100 to 4200.

000:25:39 Scott (onboard): Okay, it's right on 4000.

000:25:41 Irwin (onboard): Okay. Okay. For 2?

000:25:45 Scott (onboard): Two; I'm looking at 70, 4000, and about 90.

000:25:52 Irwin (onboard): Okay. Okay. I'm going to do a caution and warning operational check here.

000:25:59 Scott (onboard): Okay.

000:26:06 Irwin (onboard): We're going to get a Master Alarm here.

000:26:16 Scott (onboard): Okay, let me check.

000:26:18 Irwin (onboard): Okay, you're down in the LEB, Al?

000:26:20 Worden (onboard): Yes.

000:26:21 Scott (onboard): Get those...

000:26:22 Irwin (onboard): Okay, can you get the strut unlocked while you're getting those?

000:26:23 Scott (onboard): I'm getting them right - I'm getting them right now.

000:26:25 Irwin (onboard): Okay.

000:26:40 Worden (onboard): That was a fantastic ride! (Laughter)

000:26:45 Worden (onboard): I'm just now beginning to understand what went on.

000:26:47 Irwin (onboard): Yes, boy.

000:26:49 Worden (onboard): That S-IC really does shake!

000:26:52 Scott (onboard): Yes.

000:26:54 Irwin (onboard): Are you still working on that, Al?

000:26:56 Worden (onboard): Got the lanyard low - stowed.

000:26:58 Irwin (onboard): Okay. Drinking Water Supply valve, On.

000:27:00 Worden (onboard): Okay. See if I can get to it here.

000:27:04 Scott (onboard): Quit having a good time and go to work (laughter).

000:27:13 Worden (onboard): Okay, it's On.

000:27:15 Irwin (onboard): Okay. CB: COAS/Tunnel Lighting, Main B, closed.

000:27:18 Worden (onboard): Get your big foot out of the way.

000:27:21 Scott (onboard): Push me down.

000:27:22 Worden (onboard): I did. Okay. It's closed.

000:27:24 Irwin (onboard): Okay. Unstow helmet bags, accessory bags, and tool E.

000:27:27 Worden (onboard): Okay. David, the helmet bags - Let's see, they're behind you, aren't they?

000:27:31 Scott (onboard): Yes, they're - I got to get those stupid things.

000:27:33 Irwin (onboard): They're in U-4 - or U-1. Tool E is in L-2.

000:27:38 Scott (onboard): Yes. I'll get it. I don't know what this little thing is here, ...

000:27:47 Irwin (onboard): Okay, I'm going to switch around and get that window cover.

000:27:51 Scott (onboard): Okay. Let's see, where the heck is tool E? ... Here it is.

000:28:06 Irwin (onboard): (Laughter) I didn't see the - the decal on the light over here.

000:28:10 Worden (onboard): On the light?

000:28:11 Irwin (onboard): Yes. "This vehicle will not be placed in motion until all seat belts are properly fastened. By order of the Chief of Staff, USAF."

000:28:16 Scott (onboard): Oh, you didn't see that? (Laughter)

000:28:17 Irwin (onboard): No.

000:28:29 Irwin (onboard): It would sure be easy to knock some switches here.

000:28:31 Worden (onboard): Yes. It sure would be. Okay , that's a thing we got to watch pretty close, huh?

000:28:35 Scott (onboard): Yes.

000:28:36 Irwin (onboard): I - I might get you to get that window shade, Al, if - if you have a chance.

000:28:42 Worden (onboard): Oh, it's in the...

000:28:43 Irwin (onboard): I know where it is - it's just hard for me to get over to one of them - ... below it...

000:28:46 Worden (onboard): I'll get it. Yes.

000:28:47 Scott (onboard): Is it in with the other window shade?

000:28:48 Irwin (onboard): Yes.

000:28:49 Worden (onboard): Yes.

000:28:50 Scott (onboard): I can get it, it's right in here.

000:28:51 Irwin (onboard): We want to put that in here so we don't get sunburned.

000:28:52 Scott (onboard): Good boy.

000:28:56 Irwin (onboard): Give us the Lexan.

000:28:57 Worden/Scott (onboard): Yes.

000:28:58 Scott (onboard): ... Okay, there's tool E.

000:29:02 Worden (onboard): Now, let's see. You want to do that Emergency Cabin Pressure thing?

000:29:08 Irwin (onboard): Yes, let me - I've got a - I'm confirming normal suit and cabin pressure.

000:29:12 Worden (onboard): Okay.

000:29:13 Scott (onboard): Here's your Lexan, Jim.

000:29:15 Irwin (onboard): Okay.

000:29:16 Scott (onboard): Got it?

000:29:17 Worden (onboard): Be very careful of that Lexan, because I - I'm going to need to take some pictures through it.

000:29:21 Irwin (onboard): Yes, okay.

000:29:25 Scott (onboard): Make sure you get everything tied down when you get through using it, because we got one more little g-level thing to go through here.

000:29:32 Worden (onboard): Yes, right.

000:29:46 Scott (onboard): Okay. Helmets and access - helmet bags and accessory bags.

000:29:50 Worden (onboard): Right here.

000:29:55 Irwin (onboard): Okay. The Lexan shade is on.

000:29:57 Worden (onboard): And grab the TSBs while you're there, too. Dave.

000:30:01 Scott (onboard): Okay.

000:30:02 Worden (onboard): Okay, Jim. I guess we could do the - -

000:30:06 Scott (onboard): Where are the TSBs, Al? They're not up here. They're down in one of those other things.

000:30:22 Worden (onboard): Must be in U-1.

000:30:23 Scott (onboard): Really?

000:30:24 Worden (onboard): Yes.

000:30:27 Scott (onboard): In U-1 - I was looking in U-27

000:30:30 Worden (onboard): Oh, okay.

000:30:32 Irwin (onboard): Let's see. The O₂ flow is high.

000:30:34 Worden (onboard): What's the cabin pressure - -

000:30:35 Irwin (onboard): Oh, it - it Just dropped down.

000:30:36 Scott (onboard): Yes. Okay.

000:30:37 Worden (onboard): What's - what's the cabin pressure? We still got the waste stowage vent - -

000:30:38 Irwin (onboard): Yes. It's ...

000:30:39 Scott (onboard): It's 6.

000:30:40 Irwin (onboard): Well, it was Just high for a little bit.

000:30:41 Worden (onboard): Yes.

000:30:42 Irwin (onboard): Okay. Cabin Pressure - Emergency Cabin Pressure valve to Both, Al.

000:30:48 Worden (onboard): Okay. Emergency Cabin Pressure going to Both.

000:30:50 Irwin (onboard): And Suit Circuit Return Value, Open, Dave.

000:30:55 Scott (onboard): Yes, sir. It's open.

000:31:00 Irwin (onboard): Okay. We can - I got the window cover on. We can remove helmet and gloves and stow in PGA bag.

000:31:05 Scott (onboard): Don't we - don't we do a check first?

000:31:08 Irwin (onboard): No, we don't. That Main Reg[ulator] check's on the next page.

000:31:11 Scott (onboard): Well...

000:31:12 Irwin (onboard): As long as you're in position though, Al, let's do it.

000:31:13 Worden (onboard): Yes.

000:31:14 Scott (onboard): Let's do it.

000:31:15 Irwin (onboard): Okay. Main Reg B valve, closed.

000:31:17 Worden (onboard): Main Reg B, closed.

000:31:18 Irwin (onboard): Emergency Cabin Pressure, select to 1.

000:31:20 Worden (onboard): 1.

000:31:21 Irwin (onboard): Push To Test pushbutton, push for O₂ Flow increase.

000:31:23 Worden (onboard): Okay.

000:31:30 Worden (onboard): Don't see anything.

000:31:31 Irwin (onboard): There it goes...

000:31:32 Scott (onboard): Okay. There it goes.

000:31:33 Worden (onboard): Okay.

000:31:34 Irwin (onboard): Okay. Main Reg B valve, Open.

000:31:35 Worden (onboard): Open.

000:31:36 Irwin (onboard): Main Reg A valve, closed.

000:31:37 Worden (onboard): Closed.

000:31:38 Irwin (onboard): Emergency Cabin Pressure, select to 2.

000:31:40 Worden (onboard): To 2.

000:31:41 Irwin (onboard): Push To Test pushbutton, push for O₂ Flow increase.

000:31:44 Worden (onboard): Okay. Pushing. I got it.

000:31:47 Irwin (onboard): Okay, Main Reg A valve, Open.

000:31:49 Worden (onboard): Open.

000:31:50 Irwin (onboard): Emergency Cabin Pressure, select to Both.

000:31:52 Worden (onboard): Both.

000:31:53 Irwin (onboard): Okay. That's complete.

000:31:55 Scott (onboard): Okay.

000:31:56 Irwin (onboard): So, we - you want to take off helmets and gloves now?

000:31:58 Scott (onboard): Yes.

000:31:59 Worden (onboard): ..., yes.

000:32:01 Scott (onboard): Cabin pressure look good?

000:32:02 Irwin (onboard): Yes.

000:32:03 Scott (onboard): Okay. Let's get into our little home. Shall we do it?

000:32:23 Worden (onboard): The accessory bags inside here, Dave?

000:32:25 Scott (onboard): Yes.

000:32:26 Worden (onboard): Let's see, you're C.

000:32:27 Scott (onboard): Okay, thank you.

000:32:28 Worden (onboard): And let's see what kind of label you got on yours today. Jim, you got an R - for you today.

000:32:36 Irwin (onboard): R, okay.

000:32:40 Scott (onboard): R, C, and L. Guess we can keep track of that.

000:32:52 Irwin (onboard): It's so pretty out here, Dave, I'd almost settle for an Earth-orbit mission.

000:32:56 Scott (onboard): Don't you say that.

000:32:57 Worden (onboard): (Laughter)

000:33:00 Scott (onboard): Well, you'll get one, maybe someday. Who knows?

000:33:18 Worden (onboard): Boy. Sure doesn't take much to scratch these helmets.

000:33:23 Scott (onboard): No. Sure doesn't.

000:33:30 Worden (onboard): Oh, it's quiet.

000:33:32 Irwin (onboard): Sure is.

000:33:34 Worden (onboard): Let's see, what have we got going, Just the suit fans?

000:34:09 Irwin (onboard): It's so quiet, it's kind of eerie...

000:34:11 Worden (onboard): Yes.

000:34:12 Irwin (onboard): Almost like a space flight.

000:34:18 Worden (onboard): (Singing)

000:34:19 Scott (onboard): Okay. We got to snap these things ...

000:34:24 Worden (onboard): Yes. We're supposed to try to keep them up there where we can get them ...

000:34:29 Scott (onboard): You give me a hand here, will you?

000:34:30 Worden (onboard): Yes, we'll give you one.

000:34:32 Irwin (onboard): ... onboard ...

000:34:40 Scott (onboard): ... convenient place ...

000:34:45 Worden (onboard): Yes.

000:34:47 Irwin (onboard): ...

000:34:53 Worden (onboard): ...

000:35:08 Irwin (onboard): You want to ... them all?

000:35:10 Scott (onboard): I guess - -

000:35:11 Worden (onboard): ... all ... put them up.

000:35:20 Worden (onboard): I'll never do this again.

000:35:28 Scott (onboard): I'll bet you would (laughter).

000:35:30 Worden (onboard): Oh, what a joy! (Laughter) Oh, what a joy!

000:35:34 Scott (onboard): You don't ... to mind it.

000:35:35 Worden (onboard): What a joy! Too much ...

000:35:40 Scott (onboard): Let's see. If you're going to do that, hand me the checklist - -

000:35:42 Worden (onboard): Okay. What do we - what do we need, Dave? Why don't you read it out to me now? ...

000:35:47 Scott (onboard): DAC.

000:35:48 Worden (onboard): Got magazine Able.

000:35:50 Scott (onboard): Able. Okay.

000:35:51 Worden (onboard): Okay, which lens?

000:35:52 Scott (onboard): Power cable, 18-millimeter lens.

000:35:54 Worden (onboard): 18-millimeter lens. Okay, 18 lens.

000:36:09 Scott (onboard): Right-angle mirror.

000:36:10 Worden (onboard): Right-angle mirror.

000:36:12 Scott (onboard): Assemble and mount in the left-hand window ...

000:36:16 Worden (onboard): Left hand ... Okay, ... need to get out of here ...

000:36:29 Scott (onboard): Here's the mirror.

000:36:31 Worden (onboard): ... the power cable.

000:36:39 Irwin (onboard): Okay, Dave, When you get a chance, you want to monitor Secondary Accumulator Quantity.

000:36:45 Worden (onboard): Now - do you want to get the Hasselblad out?

000:36:49 Scott (onboard): Oh, yes. Yes, we want...

000:36:51 Worden (onboard): It's got a mag.

000:36:53 Scott (onboard): Well, better cross it out ....

000:36:55 Worden (onboard): Mag M. Oh, it is crossed out?

000:37:00 Scott (onboard): ... EL. Oh, okay. Spotmeter. Stow in the LMP TSB. I guess you better get the TSBs out ...

000:37:08 Worden (onboard): Yes.

000:37:10 Scott (onboard): And the TSBs are up behind Jim.

000:37:12 Worden (onboard): Yes. Yes. They're behind you, Jim.

000:37:15 Irwin (onboard): What, the TSBs?

000:37:16 Worden (onboard): Yes.

000:37:17 Irwin (onboard): Up over here?

000:37:22 Worden (onboard): Guess that's all we need out of here for now ...

000:38:04 Irwin (onboard): Boy, you really get a Coriolis effect by looking at that ... in here.

000:38:08 Scott (onboard): Yes; that's why I say, just go slow, because it will all go away here in a few hours. Won't even notice it...

000:38:14 Irwin (onboard): ... always felt we'd parted some company, didn't you?

000:38:17 Worden (onboard): Yes.

000:38:18 Scott (onboard): No, but it's nice to just go slow.

000:38:20 Worden (onboard): Yes. Oh, yes, it's...

000:38:21 Irwin (onboard): Are you ready for some TSBs?

000:38:23 Worden (onboard): Yes, you need yours most of all.

000:38:25 Irwin (onboard): I - I need mine?

000:38:26 Worden (onboard): Yes, because you need to put these two cameras in it.

000:38:29 Irwin (onboard): Okay.

000:38:43 Irwin (onboard): Okay. You want to hand me the camera, Al?

000:38:46 Worden (onboard): Okay, Jim, that's the - Yes, here you go.

000:38:49 Irwin (onboard): Is that for my UV work?

000:38:51 Worden (onboard): Your EL with magazine M in it.

000:38:54 Irwin (onboard): For the UV?

000:38:55 Worden (onboard): Yes. Okay. And here's your spotmeter.

000:39:00 Irwin (onboard): Spotmeter go in here, too?

000:39:02 Worden (onboard): Yes. Got it? Okay. I'll get the TV camera out.

000:39:36 Irwin (onboard): Okay, I'm going to do the - Dave, are you ready for that leak...

000:39:39 Scott (onboard): Yes.

000:39:40 Irwin (onboard): - - that secondary Rad leak check?

000:39:41 Scott (onboard): Yes, sir.

000:39:42 Irwin (onboard): Okay. If you'll - put the Secondary Glycol To Rad valve, Normal, for 30 seconds.

000:39:48 Scott (onboard): Have, you got tool E?

000:39:50 Worden (onboard): Yes. Yes, it's right up in front of you there, Dave.

000:39:53 Scott (onboard): Oh, thank you. Jimmy? Can you reach here?

000:39:57 Irwin (onboard): No. And it's starting to get dark.

000:40:02 Scott (onboard): Really? I've got to get going on the P52.

000:40:05 Worden (onboard): Yes.

000:40:08 Scott (onboard): Okay. I can't get that, Jim, until A1 closes the door there.

000:40:11 Worden (onboard): Yes; okay.

000:40:13 Irwin (onboard): I'll do this ECS Postinsertion Configuration.

000:40:16 Scott (onboard): Okay.

000:40:17 Irwin (onboard): Okay. Glycol Reservoir Bypass valve to Open.

000:40:20 Scott (onboard): Okay, Open.

000:40:21 Irwin (onboard): Glycol Reservoir Out valve, Close.

000:40:23 Scott (onboard): Closed.

000:40:24 Irwin (onboard): Glycol Reservoir IN valve, Closed.

000:40:25 Scott (onboard): Closed.

000:40:26 Irwin (onboard): And the Prim quantity, let me check it - 25 to 50 at - It's good.

000:40:34 Scott (onboard): Okay.

000:40:35 Irwin (onboard): Al, let's - Can you reach the Prim Accumulator Fill valve?

000:40:38 Worden (onboard): Yes.

000:40:39 Irwin (onboard): Okay, put it On.

000:40:47 Worden (onboard): Here, Jim, can you reach the cable? ...

000:40:51 Irwin (onboard): Yes. I've got it now.

000:40:52 Worden (onboard): Okay.

000:40:57 Irwin (onboard): You working on that one, Dave?

000:40:59 Scott (onboard): Sure am.

000:41:02 Worden (onboard): Can you get to it there, Dave?

000:41:06 Scott (onboard): Haven't yet; No. Can you get to it?

000:41:12 Worden (onboard): Well, what do you need? Primary Accum?

000:41:15 Scott (onboard): Yes.

000:41:16 Worden (onboard): Yes, sure. Which way do you want it?

000:41:22 Scott (onboard): Well, it was the Primary Accumulator Fill valve -

000:41:25 Worden (onboard): Primary Accumulator Fill; okay.

000:41:26 Scott (onboard): ...

000:41:28 Irwin (onboard): Put it On. I'll tel. when to - put it back - -

000:41:34 Worden (onboard): Turn it On?

000:41:35 Irwin (onboard): Okay...

000:41:36 Worden (onboard): It's On.

000:41:37 Irwin (onboard): ...you can turn it back Off.

000:41:38 Worden (onboard): Okay, it's Off. Is that all?

000:41:40 Scott (onboard): Yes. Why don't you get the secondary while you're there? Jim, do you have that?

000:41:43 Irwin (onboard): Yes. Secondary Glycol To Rad valve, Normal, Al, if you're in that position. Let me know when you - when you get it in Normal.

000:41:50 Worden (onboard): Yes, I can't quite reach that.

000:41:51 Scott (onboard): Okay.

000:41:54 Worden (onboard): Can you get it there, or...

000:41:55 Scott (onboard): Yes.

000:41:56 Worden (onboard): If you'll wait a minute, I'll be able to get it.

000:41:57 Scott (onboard): I can get it. Thank you.

000:41:58 Worden (onboard): Okay.

000:42:00 Irwin (onboard): Let me know when you get it to Normal.

000:42:04 Scott (onboard): Okay, going Normal now, Jim.

000:42:06 Irwin (onboard): Okay.

000:42:07 Scott (onboard): It's in Normal.

000:42:15 Worden (onboard): Okay, Jim. Here are the lines to the TV.

000:42:20 Irwin (onboard): Wish I had a place to set that thing.

000:42:22 Worden (onboard): Yes ...

000:42:23 Irwin (onboard): Okay ... the monitor.

000:42:26 Scott (onboard): Okay. How long you want this thing in Normal?

000:42:28 Irwin (onboard): Oh, I'll give you a hack here.

000:42:29 Scott (onboard): Oh.

000:42:36 Irwin (onboard): Okay -

000:42:37 Irwin (onboard): Mark. It's - Secondary, looks okay.

000:42:40 Scott (onboard): Okay, I'm back to Bypass.

000:42:41 Irwin (onboard): Okay.

000:42:42 Scott (onboard): Is that right?

000:42:43 Irwin (onboard): Right. Bypass.

000:42:46 Worden (onboard): Dave, can I hand You the monitor over there?

000:42:48 Scott (onboard): What - Oh, yes...

000:42:50 Worden (onboard): For the TV.

000:42:52 Irwin (onboard): Let me - Let's see, I got ECS Rad Flow Control to Power; Prim Glycol To Rad valve, Normal.

000:42:58 Scott (onboard): Glycol To Rad valve, Normal ... ?

000:43:05 Worden (onboard): I got that. ECS Rad Flow Control , Power.

000:43:08 Scott (onboard): Oh. Okay, it's Normal.

000:43:10 Irwin (onboard): Okay. You've got Prim Glycol To Rad valve, Normal...

000:43:13 Scott (onboard): Okay.

000:43:14 Irwin (onboard): - - Rad Heater going to Prim 1.

000:43:15 Scott (onboard): Okay.

000:43:17 Irwin (onboard): ECS Rad talkback is gray. Glycol Evap Temp In, going Auto.

000:43:26 Worden (onboard): Okay, who can give me a checklist so I can do these optics?

000:43:28 Scott (onboard): Here you go.

000:43:29 Worden (onboard): Okay, I - -

000:43:30 Irwin (onboard): Potable Water Heater to Main A. Okay. ECS Postinsertion Configuration complete.

000:43:36 Scott (onboard): Okay.

000:43:37 Worden (onboard): ...

000:43:38 Irwin (onboard): Give you this monitor, Dave.

000:43:41 Scott (onboard): Okay.

000:44:03 Scott (onboard): What else you got on there, Jim? Oh, the TSBs.

000:44:08 Irwin (onboard): Yes, do you want a TSB?

000:44:09 Scott (onboard): Yes.

000:44:10 Irwin (onboard): I'll get them out. Do you want to put one up on the - -

000:44:14 Scott (onboard): That'll do ...

000:44:15 Irwin (onboard): Down there, Al. You...

000:44:16 Scott (onboard): ... Okay.

000:44:17 Irwin (onboard): Okay. I've got an EPS monitoring check here; secondary glycol loop check, and we've got the cameras out already.

000:44:27 Scott (onboard): Al, you want to check that?

000:44:29 Irwin (onboard): I'm going to go through a secondary glycol loop check here.

000:44:31 Scott (onboard): Okay.

000:44:41 Scott (onboard): Hey, Al?

000:44:42 Worden (onboard): Yes.

000:44:43 Scott (onboard): See that little - see that funny little switch they put on here?

000:44:46 Worden (onboard): Oh, really?

000:44:47 Scott (onboard): It came off.

000:44:48 Worden (onboard): How about ...

000:44:49 Scott (onboard): Well- -

000:44:50 Worden (onboard): I've got a pocket down here.

000:44:51 Scott (onboard): I got a pocket, no sweat, I just don't want to forget it and have it floating around.

000:44:54 Worden (onboard): Yes.

000:44:56 Irwin (onboard): Secondary Glycol Pump...

000:44:57 Worden (onboard): Okay. Optics eyepieces are in, G/N Optics Power going on. Optics Zero, Off, then Zero. Okay.

000:45:22 Worden (onboard): Okay, that's 15 seconds. The Optics Zero, Off - Mode, Manual ... Here we go.

000:45:51 Worden (onboard): Hallelujah!

000:45:54 Scott (onboard): Getting stars?

000:45:55 Worden (onboard): Yes, sir!

000:45:56 Scott (onboard): Oh, okay.

000:45:59 Worden (onboard): Whoops. A good mark there.

000:46:06 Scott (onboard): Okay.

000:46:07 Worden (onboard): Who gave you permission to write ... out here? ...

000:46:21 Worden (onboard): Okay ....

000:46:29 Scott (onboard): Yes. That's true. Oh, dear ....

000:46:35 Worden (onboard): Okay. Okay, old PICAPAR, let's see what you can do.

000:46:47 Worden (onboard): Okay; BB. Antares .... Okay. And ...

000:47:01 Scott (onboard): ...

000:47:10 Irwin (onboard): Boy, at night, you might - might as well be in the simulator (laughter).

000:47:14 Scott (onboard): Yes, except for the physiological change.

000:47:17 Irwin (onboard): Yes. Okay, the EPS monitoring check is complete, Dave.

000:47:25 Scott (onboard): Okay.

000:47:26 Irwin (onboard): Except for the battery relay bus read-out down there in Systems Test meter 5-B.

000:47:33 Worden (onboard): You can pick that up.

000:47:35 Scott (onboard): Yes.

000:47:40 Irwin (onboard): Yes.

000:47:45 Worden (onboard): Okay. It doesn't look too good ... down in there.

000:47:53 Irwin (onboard): EPS monitoring check now.

000:47:56 Scott (onboard): Okay. Did - did you do your fuel cell purge check, or ...

000:47:59 Irwin (onboard): No, I couldn't do the H₂.

000:48:01 Scott (onboard): Oh.

000:48:14 Worden (onboard): Double check ... Forty-one. Okay, Dabih.

000:48:24 Scott (onboard): Forty-one, right.

000:48:45 Worden (onboard): ... Five in ...

000:48:56 Scott (onboard): Forty-one is what?

000:48:57 Worden (onboard): Dabih.

000:48:58 Scott (onboard): Dabih .... okay?

000:49:00 Worden (onboard): Yes. I got it.

000:49:30 Irwin (onboard): Okay, EPS monitoring check's complete.

000:49:11 Worden (onboard): Okay. Let's see how we did. (Cleared throat)

000:49:15 Scott (onboard): Well, pretty good.

000:49:17 Worden (onboard): ... all four ...

000:49:19 Irwin (onboard): About another 3 minutes for AOS,

000:49:23 Scott (onboard): Okay. I'll tell you what I'd like to do here ... the pass.

000:49:27 Worden (onboard): Do?

000:49:28 Scott (onboard): Check out the RCS real quick.

000:49:30 Worden (onboard): Here's the torquing angles, David.

000:49:32 Scott (onboard): Okay ...

000:49:33 Worden (onboard): Go back to zero, and I think I have to get the optics back out. Right? Did you stow the optics, Jim?

000:49:42 Scott (onboard): Okay. Here, do you want to torque at 40? What do we torque at rendezvous?

000:49:46 Worden (onboard): Yes, did - did you stow the optics eyepiece, Jim?

000:49:50 Scott (onboard): Should we torque about 50?

000:49:51 Worden (onboard): Yes.

000:49:52 Scott (onboard): Okay. Good deal.

000:49:53 Worden (onboard): Okay. You got the numbers written down?

000:49:55 Scott (onboard): Yes.

000:50:02 Worden (onboard): Very good, Dave.

000:50:03 Scott (onboard): Okay.

000:50:04 Worden (onboard): Very good ...

000:50:07 Scott (onboard): Okay, Al, and you might - Why don't you come up here and let me show you what the Jets look like when we fire the ...

000:50:14 Worden (onboard): Oh, okay. Yes. Let me - let me check out a quick star here.

000:50:17 Scott (onboard): Well, we got to do - I want to do this before AOS.

000:50:23 Worden (onboard): Okay.

000:50:32 Worden (onboard): Well, let me climb up here...

Public Affairs Officer - "This is Apollo Control, 50 minutes, 34 seconds, Ground Elapsed Time in the mission of Apollo 15. Now approaching the Carnarvon, Australia tracking station. We're [going to have] about a 6½ minute pass over that station. [We are] halfway through the first Earth parking orbit. Next time they pass over Carnarvon or over [the] Australian subcontinent, the crew of Apollo 15 will be preparing for the Translunar Injection maneuver, [in] which the spacecraft and S-IVB stage will break out of Earth parking orbit and begin the 3-day journey to the Moon. Actually the targeting will be toward where the Moon will be three days from now. [We're] still about 30 seconds away from predicted time of acquisition by the antenna at Carnarvon. We've had acquisition of signal. Stand by."

000:50:34 Scott (onboard): Oh, I'm sorry. Okay. It's - it's good.

000:50:38 Worden (onboard): Yes. I ...

000:50:40 Scott (onboard): Yes.

000:50:45 Worden (onboard): Well-

000:50:51 Scott (onboard): Okay. You can probably look out my window.

000:50:54 Worden (onboard): Oh, yes. Very good...

000:50:56 Scott (onboard): I lost my watch.

000:50:57 Worden (onboard): Jim, you got my...

000:50:58 Irwin (onboard): Yes.

000:50:59 Worden (onboard): ...stopwatch?

000:51:00 Irwin (onboard): I'm looking for one.

000:51:05 Worden (onboard): Did you see that?

000:51:06 Irwin (onboard): Yes, I saw a flash.

000:51:07 Scott (onboard): Saw a flash? You did? Couldn't hear it - I didn't hear it. Huh, I'll be darned!

000:51:16 Worden (onboard): Could sure see a flash.

000:51:17 Scott (onboard): Yes. Saw a flash, but I didn't hear it. Gosh, I used to hear them all the time. Huh!

000:51:26 Worden (onboard): You know, it's amazing what ... outside that window ...

000:51:34 Irwin (onboard): Well, yes...

000:51:35 Scott (onboard): That's because you got your ... lights on in here.

000:51:37 Worden (onboard): Yes.

000:51:43 Scott (onboard): Okay, ... here.

000:51:47 Irwin (onboard): Okay, the secondary glycol loop check's complete.

000:51:50 Scott (onboard): Okay.

[Communication is about to be handled through the Carnarvon tracking station in Australia. Apollo 15 still has just over one orbit of the Earth to complete before Translunar Injection (TLI), the 5 minute, 50 second burn of the Saturn's S-IVB stage which takes them out of Earth orbit and on to the Moon.]

000:52:00 Scott: Roger. Houston, 15. You're loud and clear.

000:52:03 Fullerton: You're loud and clear also.

000:52:06 Scott: Okay the insertion [and system] checks are coming along very nicely. We're down through [item] 21 in the checklist. And the cameras are out, and Al's completed his alignment.

[Throughout the mission, one of Al Worden's jobs is to occasionally realign the guidance platform. He has just completed the first of 45 such realignments, a task usually known by the name of the program used, program number 52, or simply "P52".]

[Guidance and navigation are crucial to any journey and even more so in the ballistic dance of getting to the Moon and back. The crew must be able point the spacecraft to precise, well known directions, so that their engines will send them where they want to go. The spacecraft carries a gyroscopically stabilised platform within the IMU (Inertial Measurement Unit) which remains fixed in attitude while the spacecraft rotates around it, connected to it by three orthogonal gimbals. The only way to ensure that the platform is properly aligned is to compare it to a fixed attitude reference - the stars are almost always used. Initially, the CSM (Command/Service Module)'s platform was aligned before launch. Realignment is achieved by using P52 on the CMC (Command Module Computer). With the spacecraft held in a steady attitude the sextant is pointed at a specified star, marked, then to a second star, where another mark is taken. The computer, knowing the attitude of the spacecraft (relative to its own idea of where the stars are), now has new values of where the stars are located. The amount of drift the platform has experienced since the previous realignment is calculated, and displayed as the amount of correction needed to move, or "torque" the gimbals to bring the platform back into accurate alignment. Known as "gyro torquing angles", they are displayed on the DSKY as "Noun 93". These angles are usually very small, and are expressed in thousandths of a degree.]

[Scott, from the 1971 Technical Debrief - "The post-insertion and systems configuration and checks went very smoothly. I don't think we had any problems at all. We took our time. We spent about 10 minutes or so just looking at the scenery after we cleaned everything up with the gimbal motors and all".]

[Worden, from the 1971 Technical Debrief - "The guidance in the CMC was just dead-on, like what we looked at in simulation. I could almost repeat the numbers verbatim, because we had seen them so many times in simulation. It was just absolutely perfect, dead-on. The Z-torquing angle that we got after we got insertion was about half, as I recall, and that's just about what the first P52 showed, right in that ball park. We have the numbers written there somewhere [in their Flight Plan], but the guidance was right-on, super. We had no problems at all with the alignment. In fact, that was generally true with all the alignments. The first alignment went very smoothly. Tracking it in Orb Rate [the rate at which the vehicle was rotating as it orbited the Earth] was no problem. The Z-torquing angle came up about the same as they had called up."]

[Before Al began the platform realignment, the optics dust cover, on the opposite side of the CM from the hatch, was jettisoned to enable the spacecraft's optical instruments to be used. The cover protects the external surfaces of the sextant and scanning telescope during spacecraft preparation and launch. Al is to observe the jettison through the unity power SCT (Scanning Telescope).]

[Scott, from the 1971 Technical Debrief - [to Worden] "Optics cover jettison. Did you see any debris?"]

[Worden, from the 1971 Technical Debrief - "Didn't see any debris. Didn't see anything through the optics when they went. All I heard was a slight thumping noise when the covers came off. That was it, never saw anything in the optics [relating to the jettison]."]

000:52:30 Scott: And I only got one comment [that] Jim's got for you.

000:52:32 Fullerton: Go ahead.

000:52:34 Irwin: Houston - Houston, 15. On the H₂ purge, fuel cell 2, I cannot confirm [the H₂ flow rate] since I had no - no read-out of a flow indication, or a caution and warning associated with that flow.

[Jim Irwin is referring back to section 14 of the checklist which asks that the flow rate during the purge of the fuel cell by hydrogen gas be monitored.]

[The spacecraft's three fuel cells use the chemical reaction of hydrogen and oxygen, stored in cryogenic tanks, to produce the majority of electrical power for the CSM. The by-products from this chemistry are heat and water. The heat is discarded through eight radiators around the upper circumference of the Service Module. The water can be used for drinking or equipment cooling. Impurities in the reactants build up on the electrolyte and a purge is required at regular intervals to remove them and restore full capability. Purges with oxygen are carried out daily, but once every two days suffices for hydrogen purges. Controls on the right-hand side of the Main Display Console are provided for these functions.]

000:52:55 Irwin: And, if you'd like, I could do it any time, and perhaps you could confirm it.

000:53:06 Irwin: Houston, fif...

000:53:07 Fullerton: This is Houston. We're unable to help you on confirming that purge down here, Jim.

000:53:16 Irwin: Okay; understand. [Long pause.]

000:53:36 Worden: Gordo, this is Al. I've got the numbers on the P52 for you.

000:53:39 Fullerton: Okay. Ready to copy.

000:53:41 Worden: Okay. [I] used stars 33 and 41. Noun 05 was plus 000.01 and the torquing angles were minus 00.019, plus 00.021, minus 00.061, and they were torqued out at 50 minutes.

[The Flight Plan requires that after each platform realignment, details of the task's result should be reported to Houston, either by voice or by calling up the angles on the DSKY display from where Houston can read them by telemetry. In this alignment, Al used Option 3 of P52, or the REFSMMAT (Reference to a Stable Member Matrix) option. This extraordinary acronym refers to the simple idea of a reference orientation which can be well defined and used by the crew in their platform alignments. The initial 5½ hours of the mission uses the precise orientation of the launch site at Kennedy Space Center at the time of launch as the reference to which the platform is aligned. As the flight progresses, other REFSMMAT alignments will be brought into play, eight in total, which include one based on the plane of the ecliptic, another based on the alignment of the landing site at the time of lunar landing, and others based on the computed alignment for major engine burns.]

[The realignment of the platform was generally done by sighting on stars, and computer carried a catalogue of the positions of 37 prominent stars distributed across the sky.]

[Scott, from 1998 correspondence - "But the crew had to know how to locate all 37 stars within the celestial sphere - one of the more interesting aspects of training. [We trained in] planetariums and [studied] the night sky while flying cross-country. The sky and its constellations became very familiar. Even though we did have a small diagram in the checklist, it was very important to be able to locate and positively identify each of the 37 stars. If the platform was too far from its desired orientation, the computer would not be able to point to the proper star."]

[The star maps from the G&C checklist are pages 6-8, 6-9 and 6-10.]

[The star reference numbers were given by their octal (base 8) number. The two stars used for Al Worden's first realignment were Antares (number 33) in the constellation Scorpius, and Dabih (number 41) in Capricornus. After the star sightings, the computer found that Al's measured angle between the stars, as given by Noun 05, differed from the angle the computer knows is between them, by only 0.01°. The difference between the intended platform orientation and its actual state was 0.019° in x, 0.021° in y, and 0.061° in z. These values were displayed through the Noun 93 display on the DSKY and were used to bring the platform back into correct alignment at 50 minutes into the flight.]

[The full list of stars, along with their reference numbers is as follows:-

Star Reference List

Number	Star name
00	Planet
01	Alpheratz
02	Diphda
03	Navi
04	Achernar
05	Polaris
06	Acamar
07	Menkar
10	Mirfak
11	Aldebaran
12	Rigel
13	Capella
14	Canopus
15	Sirius
16	Procyon
17	Regor
20	Dnoces
21	Alphard
22	Regulus
23	Denebola
24	Gienah
25	Acrux
26	Spica
27	Alkaid
30	Menkent
31	Arcturus
32	Alphecca
33	Antares
34	Atria
35	Rasalhague
36	Vega
37	Nunki
40	Altair
41	Dabih
42	Peacock
43	Deneb
44	Enif
45	Fomalhaut
46	Sun
47	Earth
50	Moon

Note that four of these are not stars as such but allow the crew member to refer to other celestial objects to the computer.]

000:54:18 Worden: That's affirm.

000:54:20 Fullerton: Thank you.

[Comm break.]

000:55:39 Scott: And, Houston, one other comment. Apparently sometime during launch, the RCS-B secondary propellant isolation valve closed, and we recycled it and got a gray talkback.

000:55:52 Fullerton: Roger, Dave.

[The "gray talkback" referred to by Dave Scott is an example of the indicators which were mounted around some of the instrument panels. Each talkback consisted of a small window with a black and white stripe pattern behind it - the "barber pole" often referred to during the mission. A gray flag could move in front of the barber pole stripes to indicate the status of a particular system. The gray flag would be driven by a control signal from the system in question and it told the crew what was going on in that system, therefore the indicator was called a talkback. Gray was essentially a normal or "doing nothing" indication. A barber pole in the talkback usually meant an abnormal or transient status.]

[This photograph, kindly supplied by Bruce Yarbro, is of the RCS talkbacks in the Apollo 13 Command Module, Odyssey. The two talkbacks to the left are for the Command Module's RCS system, which will not be activated until re-entry. The four talkbacks to the right show half-barber pole in this photo and are the same as those in question.]

[For those who wonder at the term "barber pole", it comes from the red-and-white-striped pole that barbers display outside their establishments to make them identifiable to their clients. It harks back to a time when barbers indulged in dentistry and surgery. The photograph available here is from a barber's shop in Maryhill Road, Glasgow.]

[Irwin, from the 1971 Technical Debrief - "We had one secondary propulsion barber pole."]

[Scott, from the 1971 Technical Debrief - "Yes, that's right."]

[Irwin, from the 1971 Technical Debrief - "Insertion [means RCS-] B, B secondary, right?"]

[Scott, from the 1971 Technical Debrief - "Yes, we sent that and it went great. ...[probably reading from notes] RCS-B secondary isolation valve barber pole, cycle to gray. It didn't come on at insertion. It came on at some other point."]

[Irwin, from the 1971 Technical Debrief - "Yes, we noticed it when we did the check."]

[Scott, from the 1971 Technical Debrief - "I made an SM [Service Module] RCS minimum impulse check, just to make sure that the RCS was working okay. I did that at 01:00 GET, and it worked fine. It was night and we could see the flashes. So I was fairly well convinced it was okay, that there wasn't any problem with it then. I don't remember what event would have triggered those barber poles unless somebody hit a switch, and nobody remembered hitting a switch. We talked about it, how did that thing get barber poled? When we noticed it, Al and I had been down in the LEB getting the helmet bags or something."]

[A recurring problem in the Apollo program was that the RCS propellant isolation valves [essentially, shut-off valves] occasionally closed during periods of heavy vibration or shock, rendering that particular RCS thruster unusable. Because the Service Module and Lunar Module used similar components, the valves in the RCS systems of both spacecraft could be affected by this. Indeed, one of the first post-landing steps for the Lunar Module was to cycle these valves to ensure they were open. Fortunately, this problem usually was regarded as a nuisance, since it was easily remedied. The postflight mission report concluded that variations in the supply voltage combined with the launch vibration was most likely to blame for closing these magnetic latching valves.]

000:57:55 Fullerton: Apollo 15, Houston. About 15 seconds to LOS. Estimating [contact with the] United States at 1:30 [GET].

000:58:06 Scott: Roger. 1:30.

000:58:09 Irwin (onboard): Al, my doggone checklist says Mag M ought to be on here for the UV.

000:58:14 Scott (onboard): Mag N?

000:58:15 Irwin (onboard): Mag M, man.

000:58:16 Worden (onboard): Yes, that's right...

000:58:17 Irwin (onboard): Yes...

000:58:18 Worden (onboard): That - that...

000:58:19 Irwin (onboard): ...

000:58:20 Worden (onboard): ...has the color stuff there, too.

000:58:21 Irwin (onboard): Oh.

000:58:22 Scott (onboard): ...take a picture ...

000:58:23 Irwin (onboard): Yes ... better get two of these...

000:58:26 Worden (onboard): Davy?

000:58:27 Scott (onboard): Yes.

000:58:28 Worden (onboard): You want to put that on there?

000:58:30 Scott (onboard): ...monitor?

000:58:31 Worden (onboard): Yes.

000:58:33 Scott (onboard): Yes. I don't know what we're going to do with this thing. I guess Jim has to hold this during TLI. Or something like that.

000:58:44 Irwin (onboard): Why - why can't I put it on the bracket?

000:58:47 Worden (onboard): You can.

000:58:48 Scott (onboard): ... Okay. Where's the bracket?

000:58:56 Worden (onboard): It's down in - A-1.

000:59:00 Scott (onboard): Okay.

000:59:03 Irwin (onboard): Bracket's in A-1.

000:59:04 Scott (onboard): Okay ... get it.

000:59:20 Worden (onboard): Man, that was some fantastic ride! Gaa!

000:59:26 Scott (onboard): Something you're not likely to forget for a while.

Public Affairs Officer - "And we've had loss of signal through the Carnarvon, Australia tracking station. We're standing by now for the post-launch press conference at press site 39 at Kennedy Space Center. And at 59 hours, 22 minutes [means 59 minutes, 22 seconds] Ground Elapsed Time; this is Apollo Control."

[Flight Plan page 3-002]

[Acquisition of Signal (AOS) will be picked up 31 minutes later by the Goldstone station in California.]

001:28:59 Worden (onboard): (Cleared throat)

Public Affairs Officer - "This is Apollo Control. We join the conversation in progress with Apollo 15 through Goldstone."

001:29:10 Fullerton: Apollo 15, Houston. Over.

001:29:12 Scott: Hello, Houston, 15.

001:29:15 Fullerton: Would you put the - You're loud and clear, Dave. Would you put the IU Uptel to Accept, please?

001:29:20 Scott: IU Uptel, Accept.

[During the hour and a half since launch, tracking stations around the world have been refining the estimates of Apollo 15's position and velocity, collectively known as its state vector. The latest estimates are to be relayed to the guidance systems in the S-IVB's IU (Instrument Unit), and to the CMC (Command Module Computer). Ground controllers cannot update these computers at will, however. Two switches on the Main Display Console can enable either the IU or the CMC to accept data from the ground, or to block it. Section 29 of the Insertion and Systems Checklist calls for Mission Control to send a freshly calculated state vector to the IU once the crew has commanded the IU's computer to accept the data via uplinked telemetry (Uptel in short).]

001:29:38 Scott: Okay; will do. And we're down through 27 on the checklist. The docking probe is out. Looks good. Standing by for a sequence arm and a logic check when you're ready.

[At the apex of the Command Module, a tripod shaped assembly, the docking probe, is extended out as a check of its operation and in preparation for docking operations to come. At the tip of the tripod, an articulated knob with three simple, sprung latches will make the initial contact with the LM's docking assembly, the concave, conical "drogue." The shape of the drogue guides the probe to a central hole where the latches engage to achieve "soft dock." If the probe had not extended, there could be no link-up with the LM and therefore no landing. In this circumstance it is perfectly feasible for the crew to continue to carry out a lunar orbit mission though whether Mission Control would have allowed it is speculation.]

[The crew's request for Mission Control to monitor their arming of the Sequential Events Control System (SECS) arm and logic check is at section 30 in the checklist.]

001:30:03 Scott: Okay. Logic one, on, down. Logic two, on, down.

001:30:18 Fullerton: Logics are good. You're Go for pyro arm.

001:30:21 Scott: Okay; and we had one other little one [an anomaly]. At about an hour [GET], we noticed that the primary and secondary propellant isolation valves on Quad Delta were barber pole. We cycled the switch, and they are now gray. And the RCS checks okay.

[This is a restatement of the RCS valve problem as discussed at 000:55:52.]

[Throughout the mission, large lists of numbers, called PADs, will be read up to the crew which give them the information necessary to carry out a particular maneuver. PAD stands for Pre-Advisory Data. Some of these "block data" are for planned maneuvers such as the TLI (Translunar Injection) or LOI (Lunar Orbit Insertion) burns. Other PADs, such as the "TLI plus 90" and "Lift-off plus 8" mentioned here are the first of 27 abort options which will be read up to the crew at scheduled times throughout the early and middle portions of the mission. Note that the TLI+90 PAD has nothing to do with TLI itself but would occur 90 minutes after a successful TLI burn in the event of an abort. However, mission planners have decided that at no time beyond Earth orbit will the crew be without a get-us-home PAD. Then, any time they might lose communication with Earth, they will have the information to hand to get themselves back manually.]

[To simplify the voice transmission of these huge lists of numbers and reduce the likelihood of errors, each type of PAD was precisely formatted both in Mission Control's and the crew's paperwork - all the crew needed to do was fill in the blanks.]

[Scott, from 1998 correspondence - "Another example of precision planning (a major key to Apollo success)."]

[The abort PADs are the responsibility of RETRO, one of the flight controllers in the front row of the MOCR (Mission Operations Control Room). Chuck Deiterich was one of those who occupied the RETRO console throughout Apollo.]

[Chuck Deiterich, from 2003 correspondence - "There is quite a bit of protocol in the PAD process. Empty PADs were in tablets of no carbon required (NCR) paper. We would make about 6 copies and use a red ballpoint on the top (original) so the CapCom would be sure what was part of the printed form and what was data."]

[Chuck supplied a sample PAD form from the Apollo 8 mission.]

[Deiterich, from 2003 correspondence - "You can see where the capcom checked each item during the crew readback. A printed X on the pad said no data goes here, a printed 0 indicated the computer would always have a zero here (ignition time for example), a heavy box on a square indicated a + or - sign should go here (sometimes a letter like D.) Only the red data was read up, thus saving comm time."]

[Page 2-15 of the Flight Plan includes a schedule of all the "Return to Earth Block Data" PADs. Three basic types of abort PAD are shown; "Complete P30" which defines all the parameters for a return to Earth, "P37" short versions which give data for the computer's P37 Return to Earth program, and the "Abbreviated P30" which assumes some data already has already been given in a full P30 abort PAD. The intention of these PADs is to ensure that at all stages of the flight, the crew have the information to hand with which they can get themselves on a homeward trajectory, in the event that they permanently lose communication with Earth.]

001:30:54 Fullerton: Okay.

001:30:56 Scott: Getting a little UV here.

[Even at this early stage of the mission, and despite the huge workload, the crew have begun to fulfil their science objectives by taking a sequence of photographs of the Earth using ultra-violet (UV) sensitive film, on magazine N. From the point of view of the couches, looking towards the apex of the CM, the extreme right-hand window, no. 5, has quartz panes fitted for high UV transmission rather than the coated tempered glass used in the other windows. A Hasselblad camera, fitted with a 105-mm f/4.3 Zeiss Sonnar UV transmitting lens, is used with four filters, each with a different spectral response, one being in the visual range. The CSM launch checklist, at page 2-19, describes the procedure for this particular sequence of photographs. Two images are taken at 1/60th of a second exposure with filter 1. With the camera's shutter set to B (time exposure), two more are taken through filter 2 with 20 second exposures. Filter 3's pair of exposures are at 1/250th while filter 4's are at 1/500th of a second. The eight photographs are AS15-99-13402 to 13409. AS15-99-13408 is an example of one of the exposures through filter 4. Although the checklist called for an additional photograph to be taken through the same window/lens combination on conventional colour daylight film, the crew have decided that, because of the pressure of time, they would delete this item.]

[Irwin, from the 1971 Technical Debrief - "I don't know that we had a color mag[azine] out at that time. I think we just had a UV mag out."]

[Worden, from the 1971 Technical Debrief - "I recall now, we did discuss that in-flight. I think we decided that the color mag would be nice if we could get the same area that we had taken the UV pictures of. But we couldn't do that because of the time. It wasn't valuable taking a color [picture] of some spot other than where we had taken the UV."]

[By the time their orbit brings them back over the spot where they took the UV pictures, they will be occupied with preparations for TLI. After the UV sequence is finished, the camera is configured with the 80-mm lens and colour film in preparation for photography of the T, D & E (Transposition, Docking and Extraction) maneuver after TLI.]

[When all three crewmen are occupying the Command Module, it is usually Jim Irwin who takes the task of being the secretary and writing down the data read up from Earth.]

001:31:14 Irwin: Okay.

001:31:16 Fullerton: TLI plus 90, SPS/G&N; Noun 47 is 66938; minus 0.52, plus 1.90; GET for ignition is 004:19:56.99; Noun 81, minus 0425.4, plus 0000.1, plus 4921.7; attitude, 180, 166, 002; HA is N/A [not applicable], HP, plus 0021.0; 4940.1, 6:34, 4920.8. Sextant star is 40, 079.5, 35.9; boresight star, N/A; Noun 61, plus 16.04, minus 030.00; 1099.0, 34492; GET for 05g, 017:43:58; GDC align stars are Deneb and Vega; 112, 128, 356; no ullage. Go ahead.

[As Fullerton read the PAD, a complete P30 type, the Lunar Module Pilot, Jim Irwin, copied the values to the appropriate form in the checklist. An example of the form is on page 5-11 of the CSM Launch Checklist.]

[Interpretation of this particular PAD is as follows:

Purpose: In the event of a serious problem soon after a good Translunar Injection, this PAD has the details of a burn which would return them quickly to the Earth. It has an ignition time of 90 minutes after TLI. In the event of such an emergency, the SPS (Service Propulsion System) engine would be used to slow the spacecraft to below Earth escape velocity, resulting in a high altitude ballistic arc that would take them directly to splashdown without any further orbits. Full procedures for the TLI plus 90 abort are given on page 4-13 of the CSM Launch Checklist.

System: The burn would be under the control of the Guidance and Navigation System. Burns can also be controlled by the SCS (Stabilization Control System).

CSM weight (Noun 47): Calculated to be 66,938 pounds (30,363 kilograms).

Note that here, and in all the NASA documentation of the time, the term "weight" is freely used in the context where, strictly speaking, "mass" ought to be used. Weight is defined as the force applied by a mass in a gravity field. In free fall, mass remains the same while weight becomes essentially zero.

Pitch and yaw trim (Noun 48): -0.52° and +1.90°.

The SPS engine bell is gimbal mounted to allow its thrust vector to be aligned with the spacecraft's computed centre of gravity. Two thumb wheels on the left of the Main Display Console allow adjustment of these pitch and yaw trim angles.

Time of ignition, T_ig (Noun 33): 4 hours, 19 minutes and 56.99 seconds, Ground Elapsed Time.

Change in velocity (Noun 81), fps (m/s): x, -425.4 (-129.7); y, +0.1 (+0.03); z, +4,921.7 (+1,500.1). This is the change in velocity as defined along three orthogonal axes with respect to the local vertical/local horizontal.

The three velocity components in a PAD are always expressed with respect to the local vertical/local horizontal. Imagine a coordinate system based on a line from the spacecraft to the centre of the Earth or Moon. (Which you use depends on the sphere of influence you are in, i.e. which gravitational field is stronger.) This line is the Z-axis and is vertical at the point where it intersects the surface. The X-axis is perpendicular to this in whatever direction the spacecraft's orbit is taking it. It is therefore parallel to the local horizontal. The Y-axis is perpendicular to the orbital plane. This arrangement holds even for a very extended elliptical orbit like the one Apollo 15 will take to the Moon, where the spacecraft is clearly not travelling parallel to the local horizontal.

In the above burn, we can see that the largest component of velocity change is in the plus-Z direction which is towards the Earth, countering the spacecraft's velocity away from the planet.

Spacecraft attitude at T_ig: Roll, 180°; Pitch, 166°; Yaw, 2°.

Although the velocity change is expressed with respect to the local horizontal, spacecraft attitude is expressed with respect to the current alignment of the guidance platform. That alignment is currently set to the launch pad REFSMMAT.

H_A and H_P (Noun 44): These are the heights of the resulting orbit's apogee and perigee, respectively. Since the computer cannot display an altitude higher than 9999.9 nautical miles, and the maximum height of the CSM during a TLI+90 abort will be much higher than that, H_A is not applicable. The perigee of the "orbit" is targeted at 21.0 nautical miles (38.9 km). A perigee so low will intercept the Earth's atmosphere and cause the spacecraft to re-enter.

Delta-V_t: 4,940.1 fps (1,505.7 m/s). This is the total velocity change that would be experienced by the spacecraft. It is a vector sum of the three components given earlier.

Burn duration or burn time: 6 minutes, 34 seconds.

Delta-V_c: 4,920.8 fps (1,499.9 m/s). This figure would be entered into the EMS (Entry Monitor System) Delta-V display.

SPS engine burns are normally controlled by the G&N system. If it is a long burn, that is, greater then six seconds, the control is closed loop. The system monitors the achieved Delta-V and shuts down the engine at the appropriate time. In doing this, it takes account of the engine tail-off impulse. It knows how the thrust expected from this tail-off and can calculate the resulting tail-off Delta-V based on this and the spacecraft mass.

If the G&N system were to fail during a burn, the EMS would provide a backup means of shutting down the engine at the right time. This equipment carries a separate accelerometer which measures Delta-V along the longitudinal axis of the spacecraft. Prior to the burn, the crew enter the expected Delta-V into a display on the EMS. As the burn progresses, the figure showing the remaining Delta-V drops towards zero, at which time the EMS itself shuts down the SPS if the G&N system has not already done so. However, the EMS has no knowledge of the tail-off thrust. The flight controllers take this into account and give the crew a low Delta-V figure for entering into the EMS so that if it is called upon to shut down the engine it will do so early enough for the tail-off thrust to effect the correct total Delta-V.

To a very minor extent, account is taken of the fact that the thrust axis is slightly offset from the longitudinal axis (because of the engine's trim), reducing the Delta-V_c figure slightly further.

Sextant star: Star number 40, Altair (in the constellation of Aquila) should be visible through the sextant when its shaft and trunnion are set to the values 79.5° and 35.9° respectively.

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. Another important point is when atmospheric drag on the spacecraft imparts a deceleration of 0.05 Gs.

Expected splashdown point (Noun 61): 16.04° north, 30.00° west; in the mid-Atlantic.

Range to go: To set up their EMS (Entry Monitor System) before re-entry, the crew need to know the expected distance the CM would travel after entry interface: 1,099.0 nautical miles (2,035.3 km).

Expected velocity at entry interface: 34,492 fps (10,513 m/s).

GET of entry interface: Expected at 17 hours, 43 minutes and 58 seconds GET.

GDC align stars: Stars 43, Deneb (in Cygnus) and 36, Vega (in Lyra) are to be used to align the gyro assemblies if it is not possible to use the guidance platform for this purpose. The align angles are 112°, 128°, 356°.

The spacecraft has two independent systems for determining attitude and change in attitude. The primary system is the IMU and its freely stable platform. A secondary system, usually tied to the SCS, comprises a set of gyros attached to the spacecraft structure. Unlike the IMU, which measures absolute attitude, these gyro assemblies measure the rate of attitude change. If need be, absolute attitude can be derived from these but this measurement is imprecise so at regular times, the crew presses the GDC Align button to make the GDCs (Gyro Display Couplers) knowledge of attitude match the IMU. In case the IMU is not working, the crew have a backup method of aligning the GDCs by sighting two stars through the scanning telescope in a particular way. They know what the spacecraft's attitude should be when this is achieved and can dial this into the GDCs, properly aligning them.

The final note in the PAD concerned the ullage burn. Since the SPS propellant tanks are full, there is no need to perform a small RCS burn, known as the ullage burn, to settle their contents.]

[As CapCom Gordon Fullerton was reading up the PAD, the communication route was transferred to a ship in the Atlantic, USNS Vanguard. The changeover has caused Jim to miss some of the information. Journal Contributor Brian Lawrence adds, "I'm guessing that USNS means US Navy Ship? I DO know that it means that it's a ship crewed by civilians - where USS is a Navy-crewed vessel."]

001:34:29 Fullerton: Apollo 15, Houston. Over. [No answer.]

001:34:46 Fullerton: Apollo 15, Houston. We're not reading you. Over.

001:34:50 Scott: Okay, Houston; there is a breakup - breakup in the VHF, and Jim lost some of the first part of the transmission. Could you go through it again?

001:34:58 Fullerton: Okay, just what do you need?

001:35:00 Irwin: We have Noun 47 through roll, pitch and yaw.

001:35:04 Fullerton: Okay, Jim. Noun 47 is 66938; minus 0.52, plus 1.90; Noun 33, 004:19:56.99; Noun 81, minus 0425.4, plus 0000.1, minus 4921.7 - correction on Delta-Vz is a plus 4921.7; roll, pitch, and yaw are 180, 166, 002. Go ahead.

001:36:10 Irwin: Okay; readback: TLI plus 90, SPS/G&N; 66938; minus 0.52, plus 1.90; 004:19:56.99; minus 0425.4, plus 0000.1, plus 4921.7; 180, 166, 002; N/A, plus 0021.0; 4940.1, 6:34, 4920.8; 40, 079.5, 35.9; N/A, plus 16.04, minus 030.00; 1099.0, 34492; 017:43:58, Deneb and Vega; 112, 128, 356, and no ullage.

001:37:13 Fullerton: Okay, Jim, your readback's correct. Lift-off plus 8 PAD is 008:00, 6076, minus 175, 027:06. Go ahead.

001:37:38 Irwin: Roger. 008:00, 6076, minus 175, and 027:06.

[The Lift-off + 8 PAD carries data for P37, a program in the computer to perform a return to Earth. The program requires 4 values, the desired time for ignition of the engine, the desired change in velocity (or Delta-V) and the longitude and GET for splashdown. The other data required for the burn (attitude angles, etc.), have already been read up as part of the "TLI plus 90" PAD. The CSM G&C Checklist provides spaces for the P37 data on pages 4-23 and 4-24.]

001:38:03 Irwin: All right. Go ahead. I'm ready for the TLI PAD.

001:38:07 Fullerton: Okay. Time base 6 predict 2:40:23; attitude for TLI, 180, 045, 001; burn time 5:55; 10401.1, 35599; SEP attitude, 359, 077, 320; extraction attitude, 301, 257, 040. R2 align, 045.0, 038.0; ORDEAL start, 56:45; Yaw 001; ejection time 4:16:00. Go ahead.

[The data read up by Fullerton is structurally different to other PADs as the maneuver is controlled by the IU on the launch vehicle, and not the computer in the CM. A form for filling in the numbers is available on page 2-21 of the launch checklist.]

[The timings for events relating to the launch vehicle are defined relative to a number of time bases, each of which start with a particular event. This allows controllers to move complete sequences of events relative to the overall mission time. The restart sequence for the S-IVB's single J-2 engine is tied to time base 6. When TB-6 begins, all subsequent events to restart the engine such as tank repressurisation, engine chilldown, ullage, etc., follow on, leading to the engine start command 9 minutes, 30 seconds later, and ignition 8 seconds after that.]

[The crew also have tasks to perform in the minutes leading up to the TLI burn and they use their event timer to help them. Around 002:40:23, TB-6 begins and this is shown by both the 'Uplink Activity' and 'S-II Sep' lamps coming on. The former is illuminated for ten seconds, the latter for 38 seconds. At 9 minutes to ignition, the point at which the 'S-II Sep' lamp is extinguished, Dave will start the event timer counting up, having previously set it to 51:00. This will give a visual count-up to and beyond ignition to aid the crew in sequencing their final tasks before and during TLI. Items in the checklist are therefore shown with times from 51:00, through (1:)00:00 and upwards.]

[The PAD is interpreted as follows.

TB-6 predict light: This comes on at 002:40:23, which implies that TB-6 begins at 002:40:31 and that T_ig (time of ignition) will be at 002:50:01.

Attitude for TLI: 180°, 45°, 001° in roll, pitch and yaw respectively. This attitude is with respect to the local vertical/local horizontal.

Duration of burn: 5 minutes, 55 seconds.

Delta-V_c': 10,401.1 fps (3,170.3 m/s) will be entered into the EMS to allow the crew to monitor the remaining velocity to be added.

V_I: Indicated velocity at engine cut-off is 35,599 fps (10,850.6 m/s).

Separation attitude: The correct attitude for separation of the CSM from the launch vehicle is 359°, 77°, 320° in roll, pitch and yaw respectively with respect to the local vertical/local horizontal. Among the criteria for adopting this attitude is solar illumination of the LM to assist the docking procedure.

Extraction attitude: The correct attitude for extraction of the LM from the S-IVB is 301°, 257°, 40° in roll, pitch and yaw respectively.

R2 align: 045.0.

R2 ignition: 038.0.

ORDEAL Start: Relative to the count-up on the event timer, the ordeal should be started at 56:45.

The ORDEAL (Orbital Rate Display - Earth And Lunar) drives the FDAI (Flight Director Attitude Indicator, or "8-ball") to make it display the spacecraft's attitude relative to the ground below.

If a spacecraft is in orbit with a fixed attitude relative to the celestial sphere (i.e. the spacecraft keeps pointing to the same stars no matter where it is in its orbit), then its attitude relative to the body it's orbiting (Earth, Moon or whatever) is constantly changing. For example, at one point in its orbit, the front of a spacecraft can be pointing directly at the planet below. Half an orbit later, it will be pointing directly away. This is known as "stellar inertial."]

[Conversely, if the spacecraft is to be flown in 'orb-rate,' keeping the same face towards the surface (to point cameras for example), it must rotate around one of its axes at a rate which matches the orbital period. Normally, the FDAI displays the spacecraft's attitude relative to the celestial sphere (i.e. it normally shows the inertial attitude) but the function of the ORDEAL is to provide the correct drive signal to rotate the FDAI at a rate which also matches the orbital period. With the ORDEAL, the FDAI will display attitudes relative to the surface below.

During Apollo 15's TLI, the crew are going to use the ORDEAL to drive the FDAI at a rate which matches the pitch rate of the S-IVB during its powered flight. This way, the crew can monitor the progress of the TLI as far as the vehicle's attitude is concerned, and they can take over manual attitude control if required during the burn. They must start the ORDEAL working at a precise time if the FDAI is to show zero attitude errors, otherwise the spacecraft's further motion around the Earth will cause it to be offset one way or the other.

Yaw: 001

LM extraction: The LM will be extracted from the top of the S-IVB stage by the docked CSM at 4 hours, 16 minutes GET.]

001:40:15 Fullerton: Okay. A little static on two readbacks. [Could you] read back Yaw for extraction and R2 align, please?

001:40:24 Irwin: Roger. 040 and 045.0.

001:40:29 Fullerton: Okay. Readback's correct, Jim. [Long pause.]

[Within their high-tech environment, it may seem somewhat strange for the crew to be given large quantities of mostly numerical information in such a low-tech fashion. At first glance it may appear easier to simply have the data uplinked to them and stored in the computer. However, the computer was not designed as a repository of data in the sense that we have come to think of computers thirty years after Apollo. It functions more like a real-time controller, albeit a very sophisticated one, and not completely unlike the embedded controller chips found in a VCR or microwave oven. The abort PADs are, in essence, a 'checklist' of items that the crew have to sequence through (Program 30 can be quite long), and although there are minimum keystroke ("minkey") options, there was never a 'scripting capability' that would automatically execute a program using stored responses. Additionally, there are verbal comments included in the PADs which cannot be entered into the computer.]

[In light of later, post-Apollo computer systems, it was an incredible feat to get the programming into the CM computer's 32Kwords of storage; most of this being hardwired into rope core memory. There was only 2Kwords (4K bytes) of erasable storage in the machine, and this was used to the maximum. During the Apollo 11 landings, using the very similar LM computer, the resource that the 1201/1202 alarms were complaining about was the lack of erasable memory.]

[The crucial importance of the data requires that the crew write it down and have 'hard-copy' available to them in case of the very systems failure that might invoke such an abort. Say, for instance, that the guidance computer fails. Having the abort PADs stored electronically would make them inaccessible. Or, say an oxygen tank blows on the way to the Moon, and you have to power down the entire Command Module, computer and all à la Apollo 13. It's tough to beat having a piece of paper with all the vital information for getting home written on it.]

[It's important to realize that although the computer is a critical part of the spacecraft, it isn't an absolute requirement for its operation. Early in the development of the computer, there were even serious doubts that it would remain functional for the entire mission! As a result, Apollo was designed to be flown without an operational computer. All the tasks that it normally manages could be done manually. (Making attitude adjustments, firing the engine, etc.) An essential design philosophy: Always try to have survivable options even when a critical piece of equipment fails.]

[Scott, from 1998 correspondence - "The design philosophy was even more precise than 'survivable' options - survivable' being exactly what? The back-up system was usually of a completely different design, never two - prime and backup - of the same 'kind.' This was one of the major factors in 'What Made Apollo a Success?' Operating, maintaining, and learning two completely different systems for one purpose was far more difficult and costly than having two identical systems for redundancy - but the concept proved its worth, time and again."]

001:41:07 Scott: Go ahead.

001:41:08 Fullerton: We're wondering if you happened to just notice them [as] barber pole at one hour [GET], or did you notice them close at one hour? Over.

[Although the RCS isolation valve problem was a previously known occurrence, Mission Control would like to understand it better, in case they are facing a new problem.]

001:41:26 Fullerton: Roger. You don't - you can't tie them to any other action or event there then? Is that right?

001:41:32 Scott: Negative.

001:41:33 Fullerton: Okay; thank you.

001:41:35 Scott: Okay.

[Comm break.]

[Like the computer in the Command Module, the computer in the IU can either accept data from the ground (via uptelemetry) or that data can be blocked, depending on a switch on Panel 2. The IU now has a more accurate knowledge of the vehicle's trajectory.]

001:43:26 Fullerton: 15, Houston. We'd like P00 and Accept.

001:43:31 Scott: P00 and Accept. You've got it.

[Comm break.]

[Now the Command Module's computer, the CMC, is set to receive the updated state vector. The CMC must be in an idle status (running P00, essentially a "do-nothing" program) with switches set to accept ground updates. P00 is commonly pronounced "pooh" by all the Apollo crews as in the character from A. A. Milne's book "Winnie the Pooh. As recounted in Murray & Cox's book, Apollo: The Race to the Moon, this program name even entered the daily lingo of the flight controllers. To 'go to poo' meant to go to sleep."]

[As an aside, the CMC has 39 programs available to the crew, numbered in octal (base eight) they are arranged into categories depending on their function.

01-07 Prelaunch

10-17 Boost

20-27 Navigation

30-37 Targeting

40-47 Thrusting

50-57 Guidance system alignment

60-67 Re-entry

70-77 Abort

Note that not all available numbers within these groups are used.]

001:45:27 Scott: Roger. CCM [means CMC] going to Block.

001:45:31 Fullerton: Roger. My mistake. Also have a short update for your TLI checklist ORDEAL angles because of the slight performance difference in the S-IVB. Over.

001:45:49 Scott: Okay; go ahead, Gordo.

001:45:51 Fullerton: Okay. On the launch checklist, page L2-30, bottom of the page. Tell me when you have it.

001:46:04 Scott: Go ahead, Gordo.

001:46:06 Fullerton: At 56 minutes, slew FDAI number 1 to pitch equals 17 degrees rather than 16; and, at the top of the next page, ensure FDAI number 1 pitch equal 14 degrees rather than 13. Over.

001:46:24 Scott: Roger. Copied. 17 degrees instead of 16, and 14 instead of the 13.

001:46:36 Fullerton: Okay; then on the next page, 2-32 at 59:55, change 7 degrees to 8 degrees, ensure FDAI number 1 pitch equal 8 degrees.

001:46:49 Scott: Copy 8 degrees.

001:46:50 Fullerton: One more on the cue card for TLI down slightly below the middle, the long cue card that the CDR uses at 54 minutes. The 24 degrees should be changed to 25 degrees. "Ordeal 300/Lunar, 25 degrees."

001:47:09 Scott: Okay, we've got that; 25 degrees.

001:47:15 Fullerton: And then there will be a 1 degree difference on the rest of the ORDEAL numbers.

001:47:19 Scott: Okay; looks like they all fit.

001:47:22 Fullerton: That's it.

[Comm break.]

001:48:53 Scott: All right; Roger. 2:25...

Public Affairs Officer - "This is Apollo Control. Apparently, we have had loss of signal through the Vanguard tracking ship in mid-Atlantic. During that pass over the United States, the numbers for the upcoming Translunar Injection maneuver were passed up to the crew. This maneuver, slightly over an hour from now, [is] planned at 2 hours, 50 minutes Ground Elapsed Time. The burn, lasting 5 minutes, 55 seconds of the S-IVB third stage, will place the spacecraft in [a] trajectory toward the Moon. It will increase the velocity by some 10,414 feet per second [actually 10,401.1 fps [3,170.3 m/s]]. The measurement of the Apollo 15 Earth orbit as it passed over the Texas Tracking Station; the display here in Mission Control showed the present orbit at 96.5 by 93.8 [nautical miles, 178.7 by 173.7 km]. During the launch phase, the heart rates of the crew of Apollo 15 were 110 for Scott, 104 for Worden and 115 for Irwin. We'll be communicating with the crew of Apollo 15 through the Carnarvon Station at Ground Elapsed Time of 2 hours, 24 minutes and some odd seconds and almost continuous communications through ARIA or Apollo Range Instrumented [means Instrumentation] Aircraft between Carnarvon and the Hawaii Tracking Station. The TLI burn begins just about the commencement of the pass over Hawaii. And at 1 hour, 51 minutes Ground Elapsed Time, this is Apollo Control."

[Flight Plan page 3-005.]

[The crew has moved on the "TLI Preparation" section of the launch checklist on page 2-29. They have settled into weightlessness easily and are not reporting any of the adaptation problems which other crews have experienced.]

[Scott, from the 1