048:01:52 Cernan: Hey, Charlie. Do you suppose a guy can really see 3,000 miles [5,500 km] with the naked eye in space? Something like the S-IVB?
048:02:03 Duke: Yes. Everybody is nodding their heads "yes" here. We think so. It - You ought to be able to see 4,000 miles [7,400 km] or so; that's a pretty big target out there, and we think you ought to be able to see it.
048:02:18 Cernan: Okay. Well, I - I could definitely see it. We've been seeing it for a couple of days I guess, and - with the monocular - and it looks more like, you know, it might really be the S-IVB.
048:02:32 Duke: Roger. FIDO said it's about 4,000 miles [7,400km]. I guess that's about the same plane as y'all are. FIDO says you'll have an update on your range...
048:02:47 Cernan: Yes, we see it...
048:02:50 Duke: Go ahead.
048:02:56 Cernan: We see it fairly regularly, I guess, if we look for it as we rotate through this PTC.
048:03:01 Duke: FIDO will have an update on the range in about an hour or so for you.
048:03:07 Cernan: Okay.
PAO: This is Gene Cernan in conversation with Charlie Duke.
Long comm break.
048:10:03 Stafford: Hello, Houston. Apollo 10.
048:10:06 Duke: Apollo 10, this is Houston. Over.
048:10:10 Stafford: Okay, We're going to go ahead and get the ECS redundant component check out of the way at this time. Then we're going to have our own little skull session in here about the lunar operations for about 2 or 3 hours. So, we won't be talking to you after this for a couple of hours unless we have some questions about the lunar operations.
The ECS redundant component check will involve checks of:
Both suit compressors.
Both suit demand regulators.
Both main O2 regulators.
Suit H2O accumulator.
Urine dump nozzle heaters.
Secondary glycol loop.
Primary glycol pumps.
Radiator heater.
048:10:29 Duke: Roger. We copy. We're working on an S-IVB location vector for you. Do you want us to send that up when we get it?
048:11:52 Young: Okay. Houston, if you are watching, we're going to do the main regulator checks here. [Long pause.]
048:12:12 Duke: Apollo 10, this is Houston. Can you hold off on the component check for another minute or so until we get the High Gain Antenna acquisition?
048:12:29 Young: Okay. We just - already started on it but...
048:12:30 Duke: Roger. We...
048:12:37 Duke: We're showing about - yaw about 270, pitch plus 30 on the High Gain Antenna.
Optimum pointing angles for the HGA.
048:12:48 Cernan: Ah so.
048:12:53 Duke: You should have acquisition right now. [Long pause.]
048:13:37 Young: Houston, 10. How do you read?
048:13:39 Duke: Roger. Loud and clear, and ready for you to proceed with the redundant component check.
048:13:45 Young: Okay.
Comm break.
048:15:57 Duke: Apollo 10, this is Houston. We copy the secondary evaporator operating now. We'd like you to let it run for 3 to 5 minutes this time if you would. Over.
048:16:13 Young: That's affirmative.
048:16:15 Duke: Very good.
Comm break.
048:18:57 Cernan: Hey, Bruce. How are things back there on the home front?
048:19:02 Duke: Oh, they are pretty good. Everybody is watching you all via TV and the newspapers, and things are going along nicely here.
048:19:12 Cernan: What about the home-home fronts? [Long pause.]
048:19:28 Duke: Roger. The two Barbaras were over here at Mission Control to watch the TV yesterday. Things seem to be going along pretty well.
048:19:40 Cernan: Okay. Thank you.
Comm break.
048:21:17 Cernan: Houston 10. If you are satisfied with the secondary loop I'll go ahead and deactivate it.
048:21:23 Duke: Roger. It looks good here. You can go ahead and deactivate, and we'll do a little checking on the - the home front situation for you and report back in a little while.
048:21:32 Cernan: Okay, fine. And the loop looks like it's operating pretty good here.
048:21:45 Duke: Roger. We concur.
Long comm break.
This is Apollo Control at 48 hours, 22 minutes. With the conclusion of that Environmental Control System component check the Apollo 10 crew has indicated they are going to spend the next couple of hours doing some homework for their lunar orbit activities. This is study time they've been doing every day since lift-off, and they've indicated they will not be, in all probability, doing much communicating during the next couple of hours. We will take the line down now and come back up if there is communications. At the present time, Apollo 10 is - distance from the Earth is 164,248 nautical miles [304,186 km]. Velocity; 3,626 feet per second [1,105 m/s]. We will take this loop down now after having been up live constantly for 3 hours and 27 minutes. We'll come back up if there are any communications. This is Mission Control, Houston.
This is Apollo Control at 48 hours, 27 minutes. Charlie Duke is talking to the crew.
048:26:24 Duke: Apollo 10, this is Houston. Stand by for the news from the home front. Over.
048:26:28 Duke: Hey, 10. We just talked to...
048:26:29 Cernan: Go ahead.
048:26:30 Duke: Okay, Gene-o. We just talked to Barbara Young, and she's the only one that's at home. The other two are at least not home. May be out to lunch or something or out spending all your money. But Barbara Young is the only one at home, and she says everything is all right, John, and said that she and Barbara Cernan almost fell out of the chair yesterday with your little demonstration of dynamics in zero g and thought it was real funny. But everything else is peachy keen at home, and we'll try to raise the other two gals later on today.
048:27:13 Cernan: Okay. Thank you, Charlie.
048:27:17 Duke: You're welcome.
048:27:18 Stafford: Tell mine to quit spending all the money. Okay?
048:27:21 Duke: Okay. We'll do that, Tom.
048:27:29 Cernan: I can see nothing's changed at my house.
048:27:30 Duke: Roger. [Pause.]
048:27:38 Duke: Apollo 10, this is Houston. Would you give us Omni Bravo and Manual on the High Gain Antenna? Over.
048:27:50 Cernan: Socking it to you. Here it comes.
048:27:54 Duke: Roger.
Very long comm break.
This is Apollo Control at 48 hours, 42 minutes and we are in communication with the Apollo 10 crew.
048:41:39 Duke: Apollo 10, Houston. [Pause.]
048:41:50 Cernan: Go ahead. Over.
048:41:51 Duke: Roger. Gene, just talked to Barbara and she said she was home and that I didn't let the phone ring long enough, so she's mad at me. She said she received your letter yesterday and she ruined her makeup after reading it, and that everything was really fine; she appreciated it very much, and that Tracy is fine, back in school, and they're really enjoying all your TV show. Over.
048:42:16 Cernan: Very good, Chas. Thank you.
048:42:18 Duke: Roger. Tom, we'll keep trying with Faye.
Comm break.
048:45:20 Duke: Hello. 10. Houston. We'll be having a handover to Goldstone in about 3 minutes.
048:45:29 Cernan: Roger, Charlie.
Very long comm break.
This is Apollo Control at 49 hours into the mission. Madrid is handing over acquisition of Apollo 10 to the Goldstone station at this time. Apollo 10 is 165,543 nautical miles [306,584 km] from Earth. Its velocity: 3,597 feet per second [1,097 m/s]. The only conversation we've had with Apollo 10 is to notify them of the acquisition handover. Here's the tapes on that.
This is Apollo Control at 49 hours, 9 minutes. The video tape of the television transmission recorded in Madrid will be flown to Houston. We will not use the satellite for transmission. Transport time is estimated at approximately 30 hours, so this video tape will be available in Houston sometime tomorrow evening. This is Mission Control Houston.
This is Apollo Control at 49 hours, 27 minutes. There has been no further conversation with the crew. Apollo 10 is now 166,435 nautical miles [308,236 km] from Earth and its velocity is 3,579 feet per second [1,091 m/s].
This is Apollo Control at 49 hours, 31 minutes and Gene Cernan is giving us a call.
049:30:38 Cernan: Hello, Houston. This is Apollo 10.
049:30:43 Duke: Roger, 10. Go.
049:30:47 Cernan: Charlie, I'm looking at the Earth now through the monocular, and I can see the west coast of Africa. I can see Spain and Gibraltar very, very well. I can see just about 90 percent of South America, up, through Central America. I can see the whole Gulf Coast all the way to California, and on this side now, Cuba is very visibly clear. All of Florida is clear. The whole Gulf Coast is clear. I can look up the East Coast maybe to about the Carolinas, and then it appears to get a little bit cloudy. And it appears that the Great Lakes, I think I can make out Lake Michigan and probably Lake Superior. And then there are some clouds up in the northwestern central United States.
049:31:43 Duke: Roger. We copy.
049:31:44 Cernan: Theres some. Okay. Coming out of the North Pole down into the Central Atlantic are some very weird, picturesque cloud formations. Swirls, not definite low areas, but big large swirls.
049:32:03 Duke: Roger. We copy.
049:32:04 Cernan: This is about the best view I think I've had...
049:32:08 Duke: Go ahead.
049:32:09 Cernan: It appears to be about the best view that I've been able to have of the whole Atlantic and South and North America from where I am, and it ought to be getting a little bit better as we go along.
049:32:19 Duke: Sounds pretty spectacular, 10. Can you distinguish the Bahamas region? In most of the photos it looked like it is definitely a greenish rather than a blue area. Can you pick out any of the islands or just - is Cuba the smallest - the largest - you can define?
049:32:42 Cernan: Charlie, she's out of my view right now. As soon as she comes in in the right-hand window, I'll take another look at it, but I think probably you can. Now there are some clouds down in there as you just go off of Miami and off the Keys. There are some scattered cloud coverage down in the Caribbean which may make it difficult to pick some of those islands out.
049:33:03 Duke: Roger. Just giving you an eye test.
049:33:06 Cernan: It's - Okay, it appears that the whole Gulf Coast all the way across Mexico through Arizona, from Florida to California, you know, up J2 and J86 is clear as a bell.
049:33:22 Duke:Roger. Copy. It was beautiful when we came to work this morning outside. I don't know what it's looking like now, though. Hold on.
049:33:36 Cernan: You don't even have to go out; I'll tell you.
049:33:39 Duke: Okay. Everybody - The front row standing here says it looks beautiful outside.
049:33:51 Cernan: We'll have it coming around here in the other window in just a few minutes.
049:33:55 Duke: Roger. [Pause.]
049:34:03 Duke: 10, can you comment on any other...
049:34:06 Cernan: How do you guys like it down there...
049:34:07 Duke: Say again, Gene; I cut you out.
049:34:08 Cernan: Go ahead, Charlie.
049:34:09 Duke: I was going to ask you, can you comment on any of the - you made a distinct comment on the Nile Delta and the Nile Valley; can you pick out any others as they come into view, say the Mississippi? Is it as clear and is as distinguishable as the Nile and the desert, or would you have a difficult time? Over.
049:34:37 Cernan: We'll take a look at it as she comes through the window over here.
049:34:40 Duke: Roger.
Long comm break.
049:39:21 Stafford: Hello, Houston. This is Apollo 10.
049:40:31 Stafford: Hello, Houston. Apollo 10. How do you read now? [Long pause.]
049:41:05 Stafford: Hello, Houston. Apollo 10.
049:41:07 Duke: Roger. 10. Go ahead. We switched antennas on you, 10, and you were cut out, Tom, right when you began your conversation. Go ahead.
049:41:17 Stafford: Okay. We're working through the Goldstone now. Right
049:41:26 Duke: 10, you're breaking up. Can you stand by about a minute until we get a better signal?
049:41:30 Stafford: Okay.
Comm break.
049:43:57 Duke: Apollo 10, Houston. How do you read now?
049:44:02 Stafford: Roger. Read you loud and clear. How me?
049:44:04 Duke:You're about three- to four-by, 10. Go ahead. I think we can read you now,
049:44:12 Stafford: Yes. Okay, Charlie. If you have a good contact with Goldstone, we might just show you - we've got some time to kill - we just might show you a quick 2 or 3 minutes of the Earth on TV you might never see on our normal transmission because we're way past here. We can get Africa, part of Europe, North and South America, and it's pretty good. If we can go High Gain into Goldstone, we could probably get it in about 10 minutes for you.
049:44:38 Duke: Roger. Stand by, We're at Goldstone active now. We'll see if we can configure the network and give you some angles. Stand by.
049:44:48 Cernan: Okay, Charlie. While you're doing that, your answer is I can see the Mississippi Delta very well as outlined against the Gulf of Mexico. Compared to the surrounding areas, it's a grayish area. You can't really see the river basin or anything that might be a delta, except the contour of the land.
049:45:14 Duke: Roger. We copy, 10.
049:45:18 Cernan: Okay. And your inlets from Florida all the way towards Trinidad. There's a lot of broken cloud coverage, but I can yet pick out islands other than Cuba down in that area all the way down through Trinidad, possibly islands in the areas of San Lucia and Martinique and down in that area.
049:45:41 Duke: Roger. You really got some eagle eyes up there. We'll be with you in a moment with some angles.
049:45:54 Cernan: Well, I'm cheating. I'm using a monocular. [Long pause.]
049:46:33 Cernan: I'll tell you one thing. Charlie. The map makers are pretty good.
049:46:44 Cernan: I can definitely see up in the Great Lakes region now.
049:46:48 Duke: Roger.
049:46:50 Cernan: Lake Superior and Lake Michigan are very clear. I can pick out one of the Eastern Lakes and then there is a big, long, thin cloudbank that runs from northeast to southwest, probably starts around the middle of Missouri and then goes on up into the northeastern part of the United States. That covers a couple of the other lakes.
049:47:13 Duke: Roger. Say, we're getting, better weather report than the 6 o'clock news.
049:47:21 Stafford: Okay. We've got the tube all set up. When you give us the angles, we can give you a quick 2 or 3 minutes of it and still continue with the PTC.
049:47:25 Duke: Roger. 10. The Goldstone is configured. Stand by. The EECOMs will have some angles for you in a second.
049:47:38 Cernan: You ought to get an outstanding picture of the Gulf of Mexico, Florida. The United States is almost 80 percent clear, and you'll get South America, and on the right-hand side near the terminator you ought to be looking, at Spain and the west coast of Africa.
049:47:52 Duke: Roger. We're configured now. Your angles are pitch 270 - correction - pitch 30, yaw 270, and it's a plus on the pitch, and these angles are good for 3 minutes from now, at 51.
HGA pointing angles.
049:48:08 Cernan: That was 030 on the pitch plus and 270 on the yaw. Right?
049:48:11 Duke: Roger. If you try it now, you can probably get it. Stand by. The EECOMs are shaking their heads "no" on that. Try 51, l0.
049:48:26 Cernan: At 51. Okay. [Pause.]
049:48:36 Cernan: Tell them I'm going to lead them, in a little bit, to see if we can do a little better than that.
049:48:42 Duke: 10, we don't have the lines in from Goldstone. It should be recorded at Goldstone, and we'll play it in as soon as we get the lines up for the live TV coming up at 54 hours.
049:48:55 Cernan: Okay, Charlie. Very good.
049:48:59 Duke: Since we don't see it down here, if you guys will give us a running commentary, we'd appreciate it.
049:49:07 Cernan: Okay. [Long pause.]
This is Apollo Control; we will play this video tape immediately following the live television pass this afternoon.
049:49:24 Duke: And, 10, if you've come up with any questions out of your 2-hour skull session on the lunar orbit work, if you'd like to pass them on, we'll get the experts working on them. Over.
049:49:39 Cernan: Okay.
Comm break.
049:51:08 Cernan: Houston, can you tell when we've got good High Gain lock?
049:51:11 Duke: Stand by.
049:51:16 Cernan: Doesn't appear here that we've got a solid lock.
049:51:24 Duke: Roger. We made an error in the calculations, l0. And we're estimating now at 53 before a good solid lock-on, on the main lobes.
049:54:51 Stafford: Hello, Houston. Apollo 10. How do you read on VOX?
Voice-operated relay (VOX) circuitry with externally controlled sensitivity. The VOX circuit will enable both the intercom and accessed transmitter keying circuits. The sensitivity of the VOX circuit can be adjusted by the crew.
049:54:55 Duke: I read you five-by on VOX, 10.
049:54:59 Stafford: Okay. I'll kind of narrate this, Charlie. I'm kind of at an odd angle to hold it out the window. Again, you can see the west coast of Africa, the Sahara Desert, they're all in orange. You can see the Atlantic Ocean with swirls of clouds over to the eastern part of Brazil. You can see the very weird cloud patterns that Gene described out over the northeastern part of the United States. Again, it looks like the North Pole and that whole area around Canada is completely socked in.
049:55:34 Duke: Roger.
049:55:36 Stafford: Again, the one thing that is really so amazing, as you look at the Earth, is the amount of cloud cover that we have down there. Over the tropical rain forest of South America, there's just numerous small cumulus clouds.
049:55:55 Duke: Roger. Can you describe the color as contrasted to say, the Andes or the American Desert?
049:56:03 Stafford: Roger. The color of the tropical rain forest there is more of a greenish brown. It's a greenish brown versus a brown-orange on the tropical - on the American Desert and the Sahara Desert.
049:56:18 Duke: Roger. Can you pick out the Amazons?
049:56:20 Stafford: I'm giving you...
049:56:22 Duke: Roger. Can you pick out the Amazon River?
049:56:23 Stafford: Negative. No. I can't pick out the Amazon. I am looking at it with my naked eye where Gene had the 28-power monocular. I do have the zoom on here, so you are seeing it a little bit bigger than we are on the standard vision, so the Earth as you see it there is bigger. And you can see the terminator, or nighttime, has moved over most of Africa at this time, and is starting to move over to Europe. It'll soon be nighttime in Spain, and also, it is getting daylight over in Hawaii, there. The cloud patterns are utterly fantastic as you look out at it.
049:57:04 Duke: Roger, 10. We copy. How about up around the clouds that I asked you about earlier up around the Bering Strait? Is it daylight over there yet?
049:57:13 Stafford: They are just starting to come into view and when we have our programmed TV pass, - that's through Goldstone, we should be able to take a look at that cloud frontal situation. It was a beautiful swirl yesterday.
049:57:26 Duke: Roger.
049:57:27 Stafford: But it's also amazing how some of the clouds are pure white and the other ones will look more of a brownish white - kind of a dirty white. Again, if you look you could see, by Mauritania going over to Brazil, the intertropical convergence zone that's always pictured on our weather map is just a straight line right around the Earth. It's really beautiful with occasional outcroppings of cumulus clouds.
049:57:54 Duke: Roger. Where are the brownish clouds located? Over the deserts, or just where, Tom?
049:58:01 Stafford: Right now the brownish clouds are over the tropical rain forest and the Atlantic Ocean.
049:58:09 Duke: Roger.
049:58:10 Stafford: ...tropical rain forest in Brazil.
049:58:11 Duke: Roger. Copy.
049:58:12 Stafford: We're about to lose you out our window.
049:58:17 Duke: We'll stand by. Goldstone and Madrid were both recording the TV. Get good signals both places.
049:58:24 Stafford: Okay.
049:58:25 Duke: Well stand by till you come out through the hatch window.
049:58:31 Stafford: Okay. As we say adios - disappeared behind our hatch window now. We will see you later.
049:58:37 Duke: Roger.
049:58:38 Stafford: Cut it.
049:58:40 Cernan: Roger.
049:58:46 Stafford: That VOX worked okay, I guess.
049:58:50 Duke: Hey, 10. That VOX was perfect. None of the words were clipped or anything. It was like talking to you in the same room, 10. It was really great.
049:59:04 Stafford: Okay. That's the first time, I guess, we've really used VOX. It seems to be okay up here, Charlie.
049:59:08 Duke: Roger. You're not clipped at all. We're real pleased with it here, 10. [Long pause.]
049:59:39 Duke: 10, Houston. We'll have you on the High Gain for about another 8 minutes. Over.
049:59:47 Stafford: [Garble] coverage on the Earth at all, now. You're completely out of view. John will be able to pick you up down in the optics.
049:59:54 Duke: Roger.
Long comm break.
050:04:43 Young: Houston, Apollo 10. Over.
050:04:45 Duke: Roger. Go ahead, John.
050:04:49 Young: Roger. In about another hour and a half, you ought to be right underneath us. And, boy, it ought to be the most remarkable picture of the United States ever made. The whole North American continent is just standing out. It's really - and there's not too much clouds, for a change; it's open.
050:05:06 Duke: Well, great.
050:05:08 Young: [Garble] see right down from Florida...
050:05:12 Duke: Go ahead.
050:05:13 Young: You can see Puerto Rico, Haiti, Jamaica, Cuba, Florida. The Bahamas are under cloud cover right now, but, in general, the whole United States, except for the New England states and a path cutting down through the middle of the United States, Wide open. You can see the Great Lakes very well.
050:05:42 Duke: Good show. We'll be looking forward to your TV show live here at - in a couple of hours, and we should be, as you say, about right underneath you and ought to get a good view. Thanks a lot.
050:05:56 Young: Roger. Mexico and the Yucatan peninsula and even some of Central America. I can't see Panama. I can see parts of Venezuela, Colombia, and, of course, most of Brazil is wide open. Chile seems to be open along the coast down there. Peru and Bolivia are probably under scattered clouds today.
050:06:19 Duke: Roger. You guys are giving us...
050:06:20 Young: You can sure see a lot.
050:06:21 Duke: ...great weather reports.
050:06:25 Young: You can sure see a lot of the world from up here.
050:06:28 Duke: Yes [laughter]. Like maybe all of it.
Comm break.
That's John Young giving that description.
050:08:02 Cernan: Charlie, I've got it out my window now, and, like John said, it's so remarkably clear. Lake Superior and Lake Michigan stand out very brightly. There's just a patch, a little patch of clouds, on the Chicago-Milwaukee area, or else there's snow on the ground. I really think it's probably cloud but you can almost pick out the states by the contour of the sea and the oceans and the lakes. And I can actually see the Mississippi, not see the river, but you can sort of see the Mississippi River Valley as it goes up on north from the delta
050:08:48 Duke: Is this through the monocular or naked eye, Gene?
050:08:52 Cernan: It's through the monocular, Charlie.
050:08:55 Duke: Roger. Well, it sounds like a spectacular sight. Wish we had had a stowaway up there with you.
050:09:08 Cernan: Hey, you know, you almost did until they wrote it in the OCP to get Joe Engle out of here.
050:09:11 Duke: Yes [laughter]. [Pause.]
050:09:18 Cernan: It's also very interesting just to watch the continents come out over the horizon as the world turns more towards us - as the U.S. continent turns more towards us.
050:09:33 Duke: Roger. We copy.
050:09:38 Cernan: And I agree now with John. You can see practically that whole island chain all the way down to Trini [Trinidad].
050:09:45 Duke: We copy. [Long pause.]
050:10:03 Cernan: It's hard to believe we is really here.
050:10:05 Duke: Yes, you guys are a long way away. We've got you at about 170,000 miles [315,000 km], little bit more than that right now.
050:10:13 Cernan: 170. Okay.
050:10:15 Duke: Roger. You're still below - If the drawing's right there, you're still below the Earth/Moon plane; and, be coming up at about 195,000 [nautical miles, 361,000 km], you'll be crossing through the plane and going a little above.
050:10:29 Duke: Hey. We're trying to get some angles...
050:10:31 Young: [Garble] Charlie [garble].
050:10:33 Duke: Go ahead, John.
050:10:38 Stafford: We're not much below it, right? We're pretty close.
050:10:42 Duke: Roger. Yes, real close. [Long pause.]
050:11:04 Stafford: Hey, you can watch the Earth through the optics plus or minus 57 and a half degrees in the sextant, so if you can pick it in time, you can follow it for over 100 degrees.
Comm break.
050:12:50 Duke: 10, Houston. We'd like you to select Omni Bravo and Manual on the High Gain. Over.
050:13:01 Stafford: Roger.
Very long comm break.
This is Apollo Control at 50 hours, 24 minutes. Apollo 10 is 168,353 nautical miles [311,788 km] from Earth, traveling at a velocity of 3,538 feet per second [1,079 m/s].
This is Apollo Control at 50 hours, 26 minutes. As an indication of how well this Passive Thermal Control mode is working, Apollo 10 has not had a thruster firing since an elapsed time of 29 hours, 53 minutes.
050:34:33 Duke: Hello, Apollo 10. Houston. Over.
050:34:39 Young: Go ahead, Charlie.
050:34:40 Duke: Roger, John. We're looking here ahead in the Flight Plan, and we'd like to give you your P27 update at 52:05 or thereabouts; and, hopefully, we won't have to kill the PTC for you to do this realignment. You did such a good job this morning, we think we can continue on in the PTC and let you do the realign; and we can get an update to you also in PTC mode. And we're suggesting, since this thing is going so great, that we just keep it going and put TV - that we could do TV also during PTC, since it seems to be working fine. And we'll have about - At the present roll rate, we'll probably have about 10 to 15 minutes coverage with the High Gain; so we can get the whole live TV, and it will be partial exterior and partially interior, and if that's agreeable with you guys, that's the way we'd like to play it.
P27 allows updates of the AGC from MCC-H. MCC-H are trying to ensure that its update can be transmitted without the need to stop the PTC to establish good communications via the HGA. They are trying to time the update so that the HGA will be pointing approximately in the correct direction and the crew can manually maintain the alignment of the antenna.
High Gain Antenna controls - Panel 2
050:35:43 Stafford: Okay, Charlie. But I - remember we were going to do a trunnion Cal here one of these days. And I guess today isn't the day.
050:35:52 Duke: Well...
050:35:53 Stafford: You can't do that unless you stop the PTC. Over.
050:35:59 Duke: Stand by. We'll see if that's worth stopping for. Hold on. [Long pause.]
050:36:30 Duke: 10, while we're waiting for the answer from the experts on the trunnion Cal, we'd like you to turn to the back of your Flight Plan to the mission rules summary, and like to talk about a few updates that we feel are justified at this time. Over.
050:36:55 Stafford: Okay. We're turning to them, Charlie.
050:36:57 Duke: Roger.
050:37:05 Stafford: Okay. We've got the Flight Plan out for this one. We're looking at it.
050:37:14 Duke: Roger. It's on the back page, Tom, on the LM stuff, primarily. Looks like the Command Module's side is in good shape. But on the LM side, if you'll notice under the column "Do Direct Return Abort For Loss Of," we have an X beside the primary loop. We'd like to change that to both loops, that we'd have to lose both loops before we did a direct return. Over.
050:37:46 Stafford: Okay. In other words, you said it can go secondary loop because you figure the PGNCS would last for a period of time?
050:37:57 Duke: Roger. If we went on the secondary, we would do the PDI abort sequence. But it's such a short time frame from between the DOI and the direct return that we don't think that we should go that route just for losing a primary loop and we feel we'd be satisfactory coming back on a secondary loop with a PDI abort. Over.
050:38:22 Stafford: Okay. That sounds good to us since we've seen from the - how the - the G&N system has worked in the altitude chamber without the cooler. We'll go along with that for sure.
The discussion above is in reference to the mission rule that would dictate a direct return abort of the LM to the CSM during the solo operations in lunar orbit, if the primary cooling loop in the LM fails. MCC-H has decided to amend the pre-flight mission rule for initiating a direct return abort from failure of just the primary coolant loop, to failure of both the primary and secondary loops. The main concern is cooling of the PGNCS (Primary Guidance Navigation and Control System]. MCC-H have decided the PGNCS would operate satisfactorily even if it only had the secondary loop cooling. In fact they believe it would cope even without cooling for the short time the abort back to the CSM would take.
Loss of a coolant loop is defined as sustained glycol temperature >500°F and rising except during coolant loop startup and dry out (sublimator lost) or glycol pump delta-P <6 psid (circulation lost) or known loss of the H2O feed capability to the sublimator(s).
On the Apollo 11 flight, a test of this scenario was made after the ascent stage of LM Eagle was jettisoned near the end of its mission. The PGNCS in the empty spacecraft was allowed to operate without coolant while being monitored from Earth. It was expected to last for little over an hour but in the event, it continued to function for over four hours.
050:38:30 Duke: Roger. These are suggestions, of course, and let y'all have time to cogitate over them and then you can come back with us if you - to us, if you disagree. And at the bottom of the page under the "Do Not Perform Rendezvous For Loss Of," next to the last line, we list RCS systems, and we had just an X. We say that we would not perform the rendezvous for loss of either RCS, A or B. Over.
050:39:02 Stafford: I think we agree with that completely, either one.
050:39:05 Duke: Roger. Well, that's just slight clarification. And, also, moving over under the same heading, RCS systems for the PDI abort sequence, we recommend that we do not go to that sequence for loss of one system. In other words, if we lose one RCS system, we continue with the nominal plan. Over.
050:39:32 Stafford: I think we ought to talk that one over.
050:39:35 Duke: Roger.
050:39:37 Stafford: Let us think about it for a little while. Okay?
050:39:38 Cernan: I'm a little bit lost, Charlie. You say do not perform rendezvous for loss of either RCS system, and then you say do PDI abort sequence for loss of either one? You continue the rendezvous, or what?
050:39:54 Duke: After you're committed to the rendezvous, is our feeling, that - In other words, once we've done DOI, that after you've committed to the rendezvous, then you would not change that sequence for loss of an RCS system, that we would continue on nominally. And that's a trade-off, though. If you need time to figure in all that stuff, when you look at it, we just think we're better off with a nominal time line once we're committed. Over.
050:40:21 Stafford: Yes. We certainly like the nominal time line, but the main thing is - depends on what you say the mean time to failure for that other system. If we lose attitude control, we could be in trouble,
050:40:32 Duke: Roger. We agree, 10. We'll go - It's 2 hours we're talking about, of course, and we'll go either way you guys want to go. This is strictly a recommendation.
050:40:48 Stafford: Okay. Let us think about it for a little while, Charlie.
050:40:50 Duke: Roger.
Comm break.
050:42:48 Cernan: Hey, Charlie. This failure is obviously between DOI and phasing, because once you've done phasing, you're committed to the nominal anyway.
050:42:59 Duke: That's affirmative, 10. We like - We look at also that - Really, we feel what you're talking about is just 2 hours of station keeping, because once you're past phasing and you're down to one system, then you're on the RCS for most of the burns anyway. I shouldn't say 2 more hours of station keeping; I should say 2 more hours of attitude control.
050:43:31 Stafford: Yes. [Pause.]
050:43:38 Cernan: I guess one reason or one question we have in mind, you know, is what caused you to lose that one ring. What was the circumstance that caused you to lose it, and what are the chances that 2 hours is going to make a difference, you know, in whether you do a PDI abort or whether you do the nominal.
050:43:58 Duke: Roger. We...
050:44:00 Stafford: Charlie, I...
050:44:01 Duke: Go ahead, Tom. I cut you out. Excuse me.
050:44:05 Stafford: Yes. I think you're [garble] the time [garble]. If it occurred earlier after DOI, we might [garble]. If it occurred real late [garble] real bad time [garble].
050:44:19 Duke: 10, you're fading out. Unreadable now. We'll switch the antennas on you. We'll be back in a moment.
Comm break.
050:45:46 Duke: 10, Houston. We're back; do you read me?
050:45:51 Stafford: Okay. How do you read now, Charlie?
050:45:53 Duke: Okay. Five-by, Tom. Look, we aren't just suggesting this. We feel like it's more of a real time situation here, and about what kind of failure we've had and how much time we've got, and we play it real time. There are certainly situations where you'd want to come back with a - doing a PDI abort sequence, so it was just something for you to think about; and I think it's more of a real time situation than a hard and fast rule, anyway. Over.
050:46:21 Stafford: Yes. That was just exactly what we were coming around to. It's awful hard to write that rule down on paper, and to say like, if it happened early, you can see what happens when you might do the PDI abort. But after - Later on where we'd be time-rushed to do the PDI abort in other combining circumstances, you would probably go ahead with the nominal.
050:46:38 Duke: Roger. We agree.
050:46:39 Stafford: So I'd just leave it up to real time.
MCC-H is also recommending a slight change to the pre-flight mission rule concerning the loss of one of the two independent LM RCS systems. They are advising it is satisfactory to continue with the nominal Flight Plan following the loss of one system, rather than initiating the PDI abort sequence as stipulated in the pre-flight mission rules.
Tom Stafford is concerned about losing redundancy of such an important sub system, which would undermine their ability to control the LM's attitude if the second system was also lost. The time period they are referring to is between the DOI (Descent Orbit Insertion) and phasing manoeuvres. They conclude that the decision should be made in real time if the failure occurs, so that they can assess the cause of the failure in one of the LM RCS systems and its impact on the likelihood of a similar failure in the other LM RCS system.
LM Reaction Control System (RCS) - Component location
The LM RCS consists of two parallel, independent systems (A & B) which normally function simultaneously. Each system has its own pressurized propellant supply that feed eight thrust chamber assembly's (TCA), two in each cluster. The arrangement of each TCA is such that either system, functioning alone, can provide complete control in all axes, with some translation effects. Propellant could be crossfed from one system to the other.
050:46:42 Duke: Roger. We agree 100 percent. We're with you.
050:46:48 Stafford: Alrighty. Fine.
050:46:49 Duke: And, 10, it looks more and more like the trunnion Cal is becoming less and less of a priority here. And we're recommending tentatively now that we continue the PTC on through that and get this later on, but we're checking with a few more experts on the problem. Over.
For details of sextant calibration see notes at 006:22:44.
050:47:13 Young: Okay. That's your decision.
050:47:15 Duke: Roger. We'll let you know, John. [Long pause.]
050:47:33 Stafford: Charlie, would you pass on the word to Christopher C. [Christopher C. Kraft Jnr, Director of Flight Operations] that we're saving all this fuel so we can get him some good landmark tracking.
050:47:39 Duke: Roger. We sure will. And, Tom, I talked to Faye on the telephone just a minute ago, and all's real fine at home, and they've really been enjoying your TV shows. And all three of the gals think they're married to a bunch of hams up there after yesterday's show; and they've really enjoyed it a lot, and everything's just real fine.
050:48:01 Stafford: Okay. Thank you.
050:48:06 Cernan: How can you be a ham when you're just trying to show that the world's round?
050:48:10 Duke: It's the interior shots that they were referring to, Im sure.
050:48:15 Cernan: Oh, were those live?
050:48:18 Duke: [Laughter.] Roger.
050:48:22 Cernan: Hey, Charlie, I want to talk you a bit about the data, since you were in charge of it. We've got some pretty interesting Flight Plan notes that were penciled and taped in at the last minute. We're wondering if you want to see some of those down there?
It appears that the backup commander, Gordon Cooper, backup Lunar Module Pilot Ed Mitchell and CapCom Charlie Duke, have inserted some unofficial notes or material into the onboard Flight Plan to amused the crew in flight.
050:48:37 Duke: Roger. It's up to you guys, whatever you think. Most of this goes out live, so if you want to show it, it will be fine.
050:48:49 Cernan: Well, since you did such a fine job on the data, we thought we'd like, you know, to express our thanks.
050:48:54 Duke: Roger. Well, I take really not much credit for that.
050:49:00 Stafford: You might have to clear that with Gordo [Cooper] and Ed [Mitchell].
050:49:02 Duke: Roger. Ed's sitting here right now grinning from ear to ear. We didn't think you guys were looking through...
050:49:10 Stafford: [Garble] grinning about another...
050:49:13 Duke: We didn't think you guys were...
050:49:14 Duke: [laughter] All right. [Pause.]
050:49:22 Stafford: Now we're trying to spare him. He's going to wade all the way through the Flight Plan to the end.
050:49:26 Duke: Roger, I'm glad to see you're reviewing all that data.
050:49:32 Stafford: We're trying to do our homework up here, Charlie.
050:49:35 Duke: Roger. [Long pause.]
Ed is Ed Mitchell, the Lunar Module Pilot on the backup crew, and Gordo, of course, is Gordon Cooper, the backup commander.
050:50:00 Duke: 10, Houston. We're Go without a trunnion Cal, and we'd like to say in PTC. Over.
050:50:10 Stafford: Okay. Sounds good to us, I don't think we've had a thruster fire in a long time.
050:50:14 Duke: Roger.
Long comm break.
This is Apollo Control at 50 hours, 53 minutes. Apollo 10 is 169,456 nautical miles [313,830 km] from Earth, traveling at a velocity of 3,514 feet per second [1,071 m/s]. Spacecraft weight is 93,267 pounds [42,402 kg].
050:57:39 Cernan: Hello. [Long pause.]
050:57:51 Cernan: Houston, were you trying to call 10?
050:57:54 Duke: Negative.
050:57:58 Cernan: Okay. You know, for information, I guess it caught me a little bit unexpected, but even with the S-band squelch on, you know we can hear this very fine, not annoying at all, but very fine, soft crackling in the background, but not typical loud S-band that drives you out of your mind.
050:58:19 Duke: Roger. Stand by.
050:58:24 Duke: Roger. We got this when we...
050:58:27 Cernan: Looks pretty much...
050:58:30 Duke: Go ahead, Gene.
050:58:32 Cernan: Go ahead, Charlie.
050:58:33 Duke: I was going to say, on this end, when you break lock, it really is grim. We've got to get synced up on this delay here.
050:58:43 Cernan: Yes. I know. When we cut each other out, I can hear my voice coming back to me that I said a second or two ago. But we don't - When we break lock or we're changing antennas or one thing or another, with that squelch on, we can tell it, but it's very acceptable. And even right now, I've got a very low crackling in the background. Normally, on a good lock-on, I don't.
050:59:07 Duke: Roger. I can hear that too down here in the MOCR. When we break lock, it really is loud down here. Of course, we don't have our equipment turned on, and when we start getting a bad signal, it really is deafening almost.
050:59:25 Cernan: I guess the only reason I mentioned it, I was surprised that I hear anything at all with that squelch on, but I do. And it's really very good, because it's acceptable and yet detectable.
050:59:33 Duke: Roger.
Very long comm break.
The S-band Squelch circuit removes unwanted noise from the S-band up-link signal. This switch and circuit was only fitted on CM-106 (Apollo 10) & CM-107 (Apollo 11).
051:09:49 Stafford: Houston, Apollo 10.
051:09:52 Duke: Go ahead, 10.
051:09:55 Stafford: Okay, Charlie. Looks like we finally drifted out of the deadband and fired a couple of thrusters.
051:10:00 Duke: Roger. We see you at 30 on the pitch here. [Long pause.]
051:10:30 Stafford: Okay, Charlie. Does it look like we should go back and start all over again or just continue on as is?
051:10:39 Duke: G&C says it looks good just the way it is. We just ought to continue in. And it looks like we're coming back into the deadband now, 10, so let's just leave it like it is and watch it for a while.
051:10:52 Stafford: Okay. I looks like - I'm guessing we've run about 20 hours without a thruster firing. That's pretty good.
051:10:58 Duke: Roger. We concur. It was great.
Long comm break.
Apollo 10 has been in PTC since approximately 030:00:00 GET. The 30-degree deadband has not been reach until now. The SM RCS are now beginning to fire to try to take the spacecraft attitude back inside the 30-degree deadband. The crew is enquiring whether they should damp the attitude excursions and then restart the PTC. MCC-H want to monitor the attitude excursions to see if they settle out again, before they recommend crew intervention.
This is Apollo Control; that thruster firing was at 51 hours, 10 minutes. The last thruster firing prior to that was at 29 hours, 53 minutes. At 51 hours, 12 minutes, Apollo 10's distance from the Earth is 170,089 miles [315,003 km], its velocity is 3,501 feet per second [1,067 m/s].
051:18:52 Stafford: Hello, Houston. Apollo 10.
051:18:55 Duke: Roger. Go ahead, 10.
051:19:00 Stafford: Roger. We seem to be waltzing off here against that yaw deadband, and the thrusters are continually firing
051:19:07 Duke: Roger. Copy. Stand by. We'll look at it. We might want you to start up again. Stand by.
051:19:16 Stafford: Okay.
Comm break.
051:20:37 Stafford: Houston, Apollo 10. I don't know if you can read our telemetry, but we've had about a steady stream of firing for the last 4 minutes.
051:20:45 Duke: Roger, 10. We're not copying your - We're in low bit rate. We're not copying your thruster firings. We noticed you're on the edge of the deadband; we're discussing this. Stand by.
051:20:57 Stafford: Okay. [Long pause.]
051:21:55 Stafford: Okay, Houston. Apollo 10. It's continuing to fire about once every 4 or 5 seconds.
051:22:02 Duke: Roger, 10. We copy. We're - Stand by just 1 more minute.
051:22:10 Stafford: Okay. [Long pause.]
051:22:23 Stafford: There we go again.
051:22:27 Duke: 10, Houston. We recommend you go Min Impulse, try to pulse it away from the edge of the deadband and then back to Rate Command, and then let's watch it. We're having a debate whether we should just stop PTC for a couple of hours or not. We're checking with the thermal people. Stand by.
Comm break.
Selection of RCS manual attitude control in Min Impulse would enable the crew to manually make small attitude corrections in any of the three axis. Once the manual inputs are completed the crew will return the manual attitude control switches (one for each axis) to the Rate CMD position which returns attitude control to the CMC.
051:24:59 Duke: Hello, 10. Houston.
051:25:05 Stafford: Go.
051:25:06 Duke: Roger. You can discontinue PTC at this time. And we recommend you select an attitude of pitch 90 and roll 307. Put us in a good TV attitude, and then you can go to - just drift, and we'll watch it for you. And if you start getting out of that attitude, then we can Min Impulse back. Over.
MCC-H have now monitored the attitude excursions and concluded that the PTC should be abandoned for a while and the crew should establish an inertial attitude that is best suited for the upcoming TV transmission.
051:25:33 Stafford: Roger. Pitch 90, yaw zero, and roll 307.
051:25:37 Duke: That's affirmative.
051:25:40 Stafford: Okay.
Comm break.
051:26:59 Duke: 10, Houston. In this attitude, we'll have a High Gain Antenna in a pitch of 023, yaw of 265.
051:27:15 Young: 023 and 265. Roger.
051:27:18 Duke: Affirmative. And, we're going to try and come up with some stars for you for P52, and then maybe a sextant correction; a trunnion Cal, too. We'll let you know on that.
051:27:33 Young: Roger.
Long comm break.
A P52 IMU alignment can now be scheduled as the PTC is being ceased.
051:34:40 Stafford: Okay, Houston. Apollo 10. We've maneuvered to roll 307, pitch 90, and yaw zero, and holding in that attitude.
051:34:48 Duke: Roger. [Long pause.]
051:35:34 Young: Houston, you want us to just turn the thrusters off now?
051:35:38 Duke: Stand by. We're discussing that right now, 10.
051:35:42 Young: We maneuvered there at wide deadband. If we turn them off now, we'll just go all over the place, I guess.
051:35:51 Duke: Roger. It's your choice. We'd like you to stay near this attitude, and we don't think you're going to use too much in wide deadband; so just keep them on, and we'll be in good shape.
051:36:03 Young: Roger.
051:36:04 Duke: John, it looks like you got a pretty good star for the trunnion Cal. We're coming up and rechecking it for you. And you'll probably do your P52 in this attitude, also, and we'll have some stars for you in just a minute.
Sextant trunnion calibration will be performed.
051:36:25 Duke: 10, Houston. Have you got a good view of the Earth out of one of your windows? That's why we came to this attitude.
051:36:35 Stafford: Yes, it's a beautiful view out of the left side window.
051:36:37 Duke: Roger.
051:36:38 Stafford: Couldn't ask for any better. And we're going to change our seats around here.
051:36:44 Duke: Roger, Tom.
051:36:49 Duke: And we're coming up about 9 minutes away from the waste-water dump. We're ready any time you guys are. [Long pause.]
051:37:45 Cernan: Hey, Charlie.
051:37:46 Duke: Stand by - Yes. Go ahead, 10.
051:37:51 Cernan: The nozzle on this bag is on the wrong end.
051:37:58 Duke: Roger. [Pause.]
051:38:05 Duke: You're defying the laws of physics.
051:38:09 Stafford: Yes. We'll show it to you in a little bit.
051:38:12 Duke: Okay. We're standing by.
051:38:17 Stafford: Okay. John is all set to start on his P52, here. And do you want the waste water dump first?
051:38:23 Duke: Negative. I think that'll ruin your P52. We're thinking about doing the P52 first. I don't think there's any really big sweat on the water dump, but if you'll just stand by 2 seconds - Go ahead. You can do your P52...
Duke is reminding Stafford of the obvious problem when trying to make sightings through the optics soon after a water or urine dump. The fluid instantly freezes as it escapes into the vacuum of space and forms thousands of ice particles which in sunlight cannot be distinguished from the stars the astronauts are trying to identify to take a mark on.
051:38:42 Stafford: Okay.
Comm break.
051:39:57 Duke: 10, Houston. We should be able to get the High Gain now with a pitch of 023 and a yaw of 265.
051:40:10 Stafford: Pitch 023 and yaw 265.
051:40:13 Duke: Roger.
Long comm break.
This is Apollo Control at 51 hours, 44 minutes, Apollo 10's distance from the Earth is 171,171 nautical miles [317,007 km], velocity is 3,479 feet per second [1,061 m/s]. We'll continue to stay up live for any voice transmission.
051:45:44 Duke: 10, Houston. We recommend for your trunnion Cal that we - Star number 31, Arcturus, probably requires just a little bit of maneuvering. It looks like the best to us. Over.
051:46:01 Stafford: Roger.
051:46:04 Duke: And, 10. Looks like - I think we passed on to you earlier today that we're skipping midcourse 3, and we probably will skip midcourse 4. It's in the order of 3.6 feet per second right now. And we're leaning towards skipping that one, also. Without the midcourses, we have a perigee of 60.7 nautical [miles, 112.4 km]; and, at LOI-1, we can achieve a 60 by 170 [111 x 315 km]. And with LOI-2, we can get a 60[-nautical-mile, 111 km] circular. So, it looks like we are leaning towards skipping midcourse 4, also.
051:46:47 Stafford: Okay. That sounds real good.
051:46:51 Duke: Roger. It looks like pretty good shooting here.
Long comm break.
The accuracy of the TLI burns and midcourse corrections (MCC) was astounding. Four MCC were planned for during the translunar coast. Apollo 8 and 14 required two MCC, Apollo 13 also performed two, but this was due to the need to return to a free return trajectory following the malfunction dictated the abandonment of the lunar landing mission. All other lunar bound Apollo missions only required one MCC during translunar coast. Any predicted nodal and pericynthion altitude deviations at the scheduled time of MCC-4 could usually be corrected for in the LOI burn.
051:52:45 Duke: 10, we copy your torquing angles and your star angle difference. [Long pause.]
051:55:06 Stafford: Houston, Apollo 10. You want us to go ahead with the calibration test at this time?
051:55:11 Duke: That's affirmative. We recommend star Arcturus, 31.
051:55:19 Stafford: Okay.
Long comm break.
This is Apollo Control at 52 hours, 1 minute. The Flight Surgeon reports that the heart rates for each of the crewmen has been averaging in the lower 60s throughout the day.
052:02:27 Stafford: Houston, Apollo 10. Have you copied Verb 06, Noun 87 there with us?
As part of the optics calibration CMC routine R57, the Verb 06 displays decimal in Register 1 or Register 1 & Register 2 or Register 1, Register 2 & Register 3 on the DSKY. For the trunnion calibration Register 1 & 2 will be used. Noun 87 displays the mark data in these registers; Optics Shaft Angle XXX.XX deg, Optics Trunnion Angle XX.XXX deg. Stafford is confirming that MCC-H have also been able to copy the angles displayed via telemetry.
052:02:32 Duke: Roger. We - Stand by. We copy it.
Comm break.
052:04:30 Duke:10, Houston. We're satisfied with the trunnion calibration. It's looking good to us. You needn't do any more.
This is Apollo Control.
052:05:11 Cernan: Okay, Houston. I believe that 89992 is probably the best number. These are right on the edge of the sextant. It's about to disappear out of it.
The number Cernan is referring to is Optics Trunnion Angle displayed in DSKY register 2, 89.992 deg. The scaling of this particular noun is such that a small negative angle will appear as a positive angle approaching 90.000 deg. The actual angle would be 90.000 deg minus the displayed angle, in this case 90.00 minus 89.992 resulting in an angle of 00.008 deg.
052:05:21 Duke: Roger, 10. We copy. It's looking good to us. You can discontinue that. We have a loaded site for you. If you'll give us P00 and Accept, we'll send you a state vector.
052:05:34 Cernan: Roger. I'll load - unload the 89992.
052:05:38 Duke: Roger. We copy. [Long pause.]
At 52 hours, 5 minutes, Apollo 10's distance is 171,898 nautical miles [318,353 km]. Velocity; 3,464 feet per second [1,064 m/s].
052:06:03 Stafford: Okay. You are in P00 and you have Accept.
052:06:07 Duke: Roger.
Long comm break.
052:09:37 Stafford: Houston, Apollo 10. When do you want our water dump?
052:09:40 Duke: 10, we're through with your update. You can go back to Block, and we are debating now on the dump. We got to get all the cameras configured. They want to try to photograph this again. We're looking probably at 52:15, but we'll have an exact figure in just a minute.
Photography of the waste water dump is required to ascertain the dispersion pattern, whether it was regular or whether some of the contents lingered near the vent valve outlet. This could lead to spacecraft exterior contamination or ice build-up at the outlet.
052:09:59 Stafford: Okay. [Long pause.]
052:10:14 Young: Houston, this is 10.
052:10:16 Duke: Go, 10.
052:10:20 Young: The reason for the delay in between the start of P52 and initiating it was, when I went to look at the sextant, the eyepiece had floated off; and, though we spent about 2 minutes scrambling around in here, and it was over behind Gene's sleeping bag, if you can believe that. How it got there, I don't know, because it couldn't have been gone - It couldn't have been off more than about 3 minutes.
052:10:48 Duke: Roger. You can sleep with it in your pocket tonight.
052:10:55 Young: Yes. We're taping it on, but that's the kind of thing I would think that ought to be sort of held in place by something better than tape.
(Left) A CM sextant eyepiece from Apollo 16. (Right) Sextant and telescope mounting plate with eyepieces - Image credits, the Smithsonian Institution, National Air and Space Museum
Cutaway diagram of the CM sextant.
052:11:03 Duke: Roger. We agree.
052:11:10 Young: I think that happened to Dave [Scott] on 9 [Apollo 9], too.
052:11:17 Duke: Roger.
That's John Young with that report.
052:11:57 Duke: 10, Houston. You can proceed with the dump at 52:15. Over.
052:12:07 Stafford: Roger. 52:15. [Long pause.]
052:12:49 Duke: 10, Houston. We'd like to give you a GET time back. We're coming up on 52:13, and it will be on my Mark, 52:13.
052:12:59 Duke: 10, Houston.
052:13:00 Duke: Mark.
052:13:01 Duke: 52:13.
052:13:05 Stafford: Roger. We are Synced.
052:13:06 Duke: Roger.
052:13:07 Cernan: Did you allow for the speed of light there, Charlie?
052:13:09 Duke:Yes, sir. I got it 1 second early, so you should have had it.
052:13:15 Young: Okay.
052:13:16 Duke: Me and the Retro can really count...
The spacecraft is now approximately 170,000 nautical miles [315,000 km] from Earth, so any voice calls from MCC-H to synchronise mission times have to be called out earlier than the actual time to allow for the voice signal to travel at the speed of light through the MSFN network links and up to the spacecraft to be received at the intended time.
052:13:18 Stafford: [Garble].
052:13:22 Stafford: Taking lots of lessons from Llewellyn there, huh?
052:13:25 Duke: Roger.
052:13:29 Stafford: Okay. I've got the CMC clock going. It looks Synced, here.
The CMC clock can be displayed by calling up Verb 06 Noun 65 which shows hours in register 1, minutes in register 2 and seconds (to 0.01 secs) in register 3.
052:13:32 Duke: Roger.
Comm break.
Apollo 10 is far enough out now that there's a one second delay in transmissions between the Control Center and the spacecraft and vice versa.
052:15:06 Stafford: Here comes the water dump.
052:15:07 Young: Houston, we're dumping.
052:15:09 Duke: Roger. Copy. [Long pause.]
052:16:06 Stafford: Houston, Apollo 10. Have any of the telescopes been able to see the water dump yet?
052:16:10 Duke: We haven't got word back on that yet, 10. It will probably be a while before they get their plates and things developed. I think they're taking pictures of everything, and it takes them a while to get all that information back. And, so far, we haven't heard where they've been able to see it or not. We'll keep trying to find out that word for you and let you know.
052:16:32 Stafford: Alrighty.
Long comm break.
Earth based telescopes are also attempting to photograph the spacecraft to establish the extent of the vapour cloud ejected from the CM and how long it takes for this cloud to dissipate.
This is Apollo Control at 52 hours, 21 minutes. Red Rover, who was most recently associated with Spider and Gumdrop is in the Control Center now monitoring the activities of Charlie Brown and Snoopy. Red Rover is also known as Rusty Schweickart, the Lunar Module Pilot on Apollo 9. Apollo 10 is 172,421 nautical miles [319,322 km] from Earth traveling at a velocity of 3,453 feet per second [1,053 m/s].
052:24:16 Stafford: Houston, Apollo 10. Did you transfer the CSM state vector to the LM slot, or do you want us to?
052:24:22 Duke: That's affirmative. We sure did.
The CMC had two areas in its memory where the state vector details could be held, the CSM slot and the LM slot. This enabled the computer to hold its own state vector in the CSM slot and the ground-calculated state vector in the LM slot. This ensured redundant state vector was always onboard. Verb 66 was used for the transfer from the CSM to LM slot.
052:24:26 Stafford: Okay. I didn't catch it until last.
052:24:29 Duke: Roger.
Long comm break.
052:27:43 Duke: 10, Houston. You can stop your dump now.
052:27:49 Stafford: Okay.
Very long comm break.
This is Apollo Control. The quantity of waste water dumped was 9½ pounds.
052:39:58 Duke: Apollo 10, Houston. John, we noticed after your trunnion bias check, when you entered the 89992, that - We saw a flashing 59 come up instead of a 92, and we don't think that number got in. It's not any big deal, but whatever the number is, is okay. But we don't think it went in - what you were trying to load.
052:40:38 Young: Let me think. [Pause.]
052:40:44 Young: Can you see that, Charlie? Or you guys gotten [garble] now.
052:40:47 Duke: Roger. We see those - We see your register. It looked like to us that when - that instead of the Proceed, you did a Verb 32. We saw the 59 down here when you entered that - entered that number, John.
The optics calibration is a sub routine R57. As part of this routine to take the calibration mark the crewman using the DSKY, keys Verb 59 Noun blank, looks on the DSKY for the Verb 59 to flash and then snap releases the Verb key to make the mark. This mark will store the trunnion angle in the computer's memory. To display this trunnion bias angle they should key Verb 06 Noun 87, the resulting angle will be displayed flashing in register 2. The crewman now has to inform the CMC whether they wish to incorporate this angle (for use in P23) by pushing the PRO(ceed) button or recycle to repeat the procedure by keying Verb 32 Enter. This will erase the mark data. MCC-H believe the procedure may have been carried out incorrectly.
052:41:06 Duke: Stand by on this display.
052:41:08 Young: Now, I just called up - I just called up 687. Didn't the second register 89? Whatever it was supposed to be?
052:41:17 Duke: Stand by. That's what it's supposed to be. I'm not sure - Hold on a minute, let me talk to the guidance guy.
052:41:30 Young: Please don't tell me it's not in there. [Long pause.]
052:41:51 Duke: 10, that location 87 is time-shared, and those numbers that we're looking at are results of marked data. The 89992 - We don't care whether it's in or not. The point was that - that - instead - to incorporate that, when you entered it, it appeared to us that a Verb 32 was done instead of Pro to incorporate, because we saw a 59 display instead of a 0692.
MCC-H are concluding their observations of the sextant trunnion angle calibration, pointing out that they believe that Verb 32 was keyed to recycle as they saw the Verb 59 to recommence the procedure. If Pro had been keyed they would have expected to see Verb 06 Noun 92 which displays the stored optics angles.
052:42:28 Young: Roger. Oh, yes. Okay.
052:42:32 Duke: And that's really all we were trying to say, John.
052:42:37 Young: Okay. Yes. I know that. Well, that's why I loaded it in there.
052:42:41 Duke: Roger.
052:42:43 Young: And the next time we do one, if I don't get a chance to do a trunnion CAL, I'll load that number.
052:42:50 Duke: Okay. Fine. That's great.
Very long comm break.
This is Apollo Control at 52 hours, 57 minutes. Apollo 10 is 173,614 nautical miles [321,531 km] from the Earth. Traveling at a velocity of 3,429 feet per second [1,045 m/s].
053:06:49 Stafford: Hello, Houston. Apollo 10.
053:06:54 Duke: Apollo 10, Houston. Go.
053:06:59 Stafford: Okay. John was asking earlier about that storm center over Alaska. It's finally started to rotate around and has developed into quite a system. We'll show it to you later on during the TV pass.
053:07:11 Eisele: Okay.
Don Eisele has briefly taken over the CapCom duties. Eisele is the Apollo 10 backup CMP. He flew on Apollo 7 also as CMP in the Earth orbit shakedown of the CM.
053:07:17 Young: How's it going, Donn?
053:07:21 Eisele: Oh, pretty good, John. How are you getting along up there?
053:07:26 Young: Great. This is just as great as you said it was, man.
053:07:29 Eisele: Kind of neat, isn't it.
053:07:33 Young: Man. Yes.
053:07:37 Stafford: Hey, Donn. For the first pass since we have been up, most of the United States is wide open today and will be in the middle of the Earth as you see it.
053:07:42 Eisele: Okay.
053:07:43 Stafford: Should be a pretty good view.
053:07:45 Eisele: All right. Thank you.
The CapCom now is Donn Eisele, the back-up Command Module pilot.
053:07:56 Eisele: You guys are getting close, coming up on 180K.
053:08:02 Stafford:Yes. we're about to pass over.
053:08:04 Eisele: Yes.
Comm break.
053:10:01 Young: Houston, this is 10. Over.
053:10:03 Duke: Go ahead.
053:10:08 Young: Roger. Yesterday, I asked them to give us a detailed briefing on how to use that water bag, on the theory that we are probably doing something wrong because it wasn't working. We never got that. Over.
053:10:21 Duke: Stand by.
Comm break.
That was John Young and Charlie Duke is back on the CapCom console. Donn Eisele is still at the console too.
053:12:15 Duke: Apollo 10, Houston.
053:12:18 Stafford: Go ahead.
053:12:20 Duke: Roger. About this water bag stuff. We've got a procedure here that we can read up to you, if you'd like to listen to it. As far - While it is not working, we got no ideas, other than reading this procedure to you. We'd like to see it on TV when the time comes I don't know whether that will help us or not, but watch you twirl it and see what happens, and maybe somebody will have a smart idea at that time . Right now, all we got to offer is a procedure that we can read up. Over.
As was experienced on earlier flights, the fuel cell water contained hydrogen. To alleviate the problems, a two-compartment bag with a handle for whirling the bag in a circular motion was provided. This bag had been developed rapidly with insufficient time for a complete test program. It did not function as intended in flight.
Water-Hydrogen seperation bag
Gene demonstrated the operation of the bag for the 16mm camera, magazine B.
053:12:56 Young: Okay. Why don't you do that? See if that's what we're doing. Maybe that's why it's not working.
053:13:00 Duke: Okay. Here we go. It says: step 1 is fill the bag to approximately one-half full of water using the water dispenser.
053:13:11 Young: We did that.
053:13:12 Duke: Okay.
053:13:13 Young: We did that.
053:13:14 Duke: I copied. You did that. Second step: squeeze the bag. [Laughter.]
053:13:15 Young: Yes, sir.
053:13:20 Duke: Squeeze the bag, Stand by.
053:13:30 Cernan: Yes. I was afraid it was going to sound about that smart.
053:13:35 Cernan: It's a pretty complicated mechanism we've got here.
053:13:40 Duke: Okay. Second step: squeeze the bag at the valve end to force the water into the opposite end of the bag. This will shorten the time task of collecting gas during the spinning operation. Okay. Third step: using the handle, spin the bag until separation is accomplished. This operation is to cause the gas to be collected in the valve end of the bag and the water at the opposite end. Number 4 is pinch off or fold across center seam to maintain the separation of gas and water. Okay. Then you open the probe valve and bleed the gas off and then close the valve, and they say that ought to do it. Over.
053:14:31 Cernan: Babe, that's quite a theory there. We'll give you a real-time evaluation right now, Charlie.
053:14:36 Duke: Okay. We can't wait for the TV. That's all - the only help we've got for the whole thing. Over.
053:14:45 Stafford: Just wait for the TV, Charlie.
053:14:47 Cernan: Charlie, you'll love it, babe; you'll love it.
053:14:50 Duke: Defies the laws of physics, huh?
053:14:55 Cernan: I found a way: we spin it...
053:14:57 Duke: Go ahead.
053:15:01 Cernan: We spin it until the air bubble goes to the bottom and then suck the water out around the bubble.
053:15:04 Duke: Roger. We copied. [Laughter.]
That was Gene Cernan.
053:15:09 Cernan: Try it, it works.
053:15:14 Duke: I don't know about you guys.
053:15:20 Duke: Hey, did you guys try just using one of the plain fruit juice bags to separate it out? How - Did you ever try that?
053:15:29 Stafford: Yes. And Donn, the water stays with the air. The bubbles condense from a thousand bubbles into one or two big bubbles but that's all she writes. You can't get it out.
053:15:43 Young: It's not clear how you get rid of the bubble, once you get the big bubble, you end up drinking it along with the water.
053:15:49 Cernan: Like I told Charlie, the valve's on the wrong end. I'm going to spin the other end.
053:15:56 Stafford: Would you believe that air is heavier than water?
053:16:19 Duke: It may be that the surface tension on the inside of that bag is enough to keep the water from flowing through that constriction very well.
053:16:31 Stafford: Well, at the end of the centrifuge turns, the big bubble is right in the bottom, quite a ways away from the constriction.
053:16:40 Duke: Roger.
053:16:41 Stafford: It wont condense all the bubbles in the water tubing.
053:16:44 Duke: Yes.
053:16:52 Duke: Looks like maybe the swing handle's on the wrong end of the bag, huh?
053:16:57 Cernan: The swing handle is on the right end, but the valve is on the wrong end.
053:17:01 Duke: Well, whichever.
Comm break.
053:18:04 Young: It's a very interesting thing to study these bubbles in this water.
053:18:09 Duke: Roger.
Long comm break.
Cernan has concluded that the bleed valve to evacuate the hydrogen once it had been separated from the water is at the wrong end of the sep bag. It should be situated by the outer compartment to vent the gas into the cabin.
053:22:44 Cernan: Houston, Apollo 10.
053:22:50 Duke: Go ahead, 10. Go ahead, 10. Go ahead. 10.
053:22:56 Cernan: Houston, Apollo 10.
053:23:03 Duke: Go ahead, l0.
053:23:06 Cernan: Okay. I mentioned this morning, earlier when we were looking at the Earth, just to give you a preview - John will describe it because it's out his window when we get there - But the eastern seaboard from about the Carolinas on up, just on the seaboard, is going to be covered with clouds and then into the Atlantic. I mentioned a cloud bank - Go ahead.
053:23:31 Duke: Go ahead. We're hearing you.
053:23:37 Cernan: Okay, Charlie. And I mentioned this morning there was a long cloud bank from the northeastern part of the United States into Missouri. It looks like now that that cloud bank goes from central Indiana up across Lake Erie, north-northeastward into Canada.
053:23:56 Duke: Roger.
053:23:57 Cernan: Michigan, Lake Superior, and the Midwest are very clear except for that cloud and there's some clouds which appear to be over - oh, maybe Kansas, Nebraska, I hate to say it, but Oklahoma. I may get some disagreement up here but I think it's Oklahoma, Colorado, Montana, up in that area; and then the West Coast is clear and the Southwest is all clear.
053:24:24 Duke: Roger, 10. We're looking at a weather map that was just brought in, and we cast our vote with you, Gene-o. The clouds are over Oklahoma and your description is excellent. It follows a - There's a low pressure up in the very far north turning from the Great Lakes northeastward into - and from - I guess it's up around the - almost to Greenland, it looks like here; and from there, the low pressure weather system with a front comes down into the United States and touches the panhandle of Texas and then goes back on up into Canada again pointing towards Alaska. And there's a band of clouds associated with that on this map, so your description is very accurate.
053:25:13 Cernan: Yes. Yes, I understand. I think you'll see that big swirl of clouds Tom was talking about up Alaska way.
053:25:21 Duke: Roger. There's a...
053:25:22 Cernan: Tom, you talk about the - Charlie, you asked Tom about the dense vegetation in South America. But if you look at the United States, the Mexican and greater American deserts are that orangish-brown as he described them; but when you look into the Midwest and into the East you go the greenish-brown. It's not the bright orange-brown, it's a darker, more subdued brown - maybe with subtle hints of dark green in it.
053:25:56 Duke: Roger. We copy that. It looks like this cloud system out in the Pacific is associated with another low-pressure system, that's sitting probably north of Hawaii at about 40 degrees latitude. It's located about 150 degrees west, so that's probably what's giving us the cloud pattern up off of Alaska.
053:26:21 Cernan: That's affirmative. That's going to be very easy to see.
053:26:24 Duke: Okay. We're all...
053:26:25 Cernan: And again, the San Joaquin Valley - the San Joaquin Valley looks like someone took a big spoon - and it seems to be the one thing at least that I'm able to pick out very easily every time we take a look at the States - looks like someone took a big spoon and just carved it right out of the coast.
053:26:42 Duke: Roger. [Pause.]
053:26:50 Duke: 10, through the monocular or through the sextant, were you able to distinguish the features around say, the San Francisco Bay area?
053:27:07 Cernan: Let me take a look, Charlie. [Pause.]
That is Gene Cernan giving the descriptions.
053:27:18 Cernan: There are lots of features down there. I sure ought to be able to distinguish some.
053:27:20 Duke: Okay. [Pause.]
053:27:26 Cernan: Charlie, it is sort of semi - appears semiclouded up north if you follow the coast past the San Joaquin Valley, and I can't really see anything that I can call San Francisco Bay from here.
053:27:40 Duke: Okay. Roger. Probably some haze - Is it pretty hazy out on the coast there, up along the California coast north of the San Joaquin?
053:27:51 Cernan: You've got some clouds just off the west coast of California that seem like they come just short of the coastline.
053:27:58 Duke: Roger. We copy. [Long pause.]
053:28:33 Cernan: Charlie, if I hold this monocular low enough, I can distinguish features up there on the coastline, up around the San Francisco area.
053:28:41 Duke: Okay. Roger, Gene. Copy.
053:28:46 Cernan: And I tell you, if we had an apple to drop, it would fall right on Houston from where we are. Right smack underneath us - right in the center of the world.
053:28:53 Duke: Roger. We are looking forward to this TV transmission, here.
053:29:05 Stafford: Okay. I wanted to ask you about that, Charlie. Were they planning to go live with us on the hour, or could we turn it on earlier? What do you want?
053:29:14 Duke: Stand by. We're seeing if Goldstone is configured for live. Stand by. Goldstone is ready. We are talking to PAO right now.
