|Window Geology||Preparations for EVA-1|
[Young, from the 1972 Technical Debrief - "When I unstowed the hammock and climbed on the top of the suits, I wasn't sleeping on a hammock, I was sleeping on a bed because the suits were right underneath me. The suits were up into the hammock about three inches. So I wasn't suspended, I was laying on top of the pressure suits. It's kind of an unusual position because of it; it gets right up under your back."]
[Duke, from the 1972 Technical Debrief - "As I reported, the first two nights I took a Seconal. It helped me (overcome the excitement and get to sleep). I slept really well all three nights on the lunar surface."]
[Young, from the 1972 Technical Debrief - "The first night, I was really warm and I had taken all the gear off and hung the FCS and WMS up to dry and slept in the sleeping bag with nothing on. I woke up in the middle of the night and my feet were freezing. So I turned around (that is, put his head toward the front of the cabin and his feet toward the rear) and put the ISA (Interim Stowage Assembly) over my feet and went right back to sleep. Worked like a charm. But the next couple of nights I slept in the LCG (Liquid Cooled Garment, but without water flow, obviously) because it was really cold at night."]
[Readers should note that the thermal differences in the cabin during the rest period are (1) some of the electrical equipment is powered down, (2) the shades are drawn to cut down on the reflected light entering the windows, and (3) the astronauts aren't moving around. In a small, confined space, reduction in such heat sources can have a dramatic temperature effect.]
[Duke, from the 1972 Technical Debrief - "(It was) chilly at night. You need a sleeping bag. Even with the LCG on, you needed a sleeping bag. You didn't need it when you started to sleep but, by the middle of the night...At least, I'd wake up in the middle of the night and I was cold and I wanted to get in that bag. The hammocks were great."]
[Young, from the 1972 Technical Debrief - "Yes, I thought so, too."]
[At a Ground Elapsed Time of about 114 hours, NASA's Public Affairs commentator tells the press that current plans call for three 7-hour EVAs, with EVA-1 starting at 119.28; EVA-2 at 141.43; EVA-3 at 165:30. Lift-off was originally scheduled for 171:45 but will now happen at about 177:28. The limiting factor is the water supply in the Descent Stage. At lift-off, there will be about a five-hour supply remaining, a reduction from the original margin.]
RealAudio clip by Siegfried Kessler
115:49:37 Duke: Houston, Orion. (No answer) Hello, Houston; Orion.
115:50:21 England: Good morning, Charlie; it's nice to hear your voice.
115:50:28 Duke: Nice to hear you guys. We're up. Did you guys have a site handover about 20 minutes ago?
115:50:35 England: Hold on, I'll check. (Pause) Okay; yes, I guess we did. Why, did you get keying there?
115:50:51 Duke: Okay, you...(Hears Tony) Well, you dropped the up-link in a big blast of static, and that's why I pegged out the EKG about 20 minutes ago.
115:51:09 England: Okay. The docs over here say, yeah, you did.
115:51:18 Duke: Yeah.
[The mission started at 17:54 GMT (Greenwich Mean Time) on April 16, 1972 and it is currently 13:45 GMT on April 21st. The Moon is about to set at the Honeysuckle Creek tracking station near Canberra and has just risen at the station near Madrid. Hamish Lindsay, who was on duty at Honeysuckle Creek for Apollo 16, notes that the handover was done at 23:21 Australian Eastern Standard Time / 13:21 GMT / 115:27 Ground Elapsed Time. Hamish writes "We were both close to our respective horizons at the time, which may explain the glitch in the handover signals."]115:51:19 Duke: Okay. Let me give you...Stand by. (Long Pause) Okay, Tony. If you're ready for the crew status report (as per Surface checklist page 3-7), I'll give it to you.
115:51:54 England: Okay, we're ready; go ahead.
115:51:58 Duke: Okay. For John on day 5, meal B, scratch the rye bread. He did not eat the rye bread. Ate everything else, and add a food stick into that also. For my meal, I ate everything but the rye bread; and add a drink bag and a food stick. That's the EVA beverage (32 ounces of Gatorade). Add that and the food stick. For medication, John had none, and he got 7-1/2 hours of good sleep. And for me, I had a Seconal and I slept for about 6-1/2 or 7 hours, I think; and it was real good. Over.
[NASA photo S72-19887 shows Apollo dietician Rita Rapp posing with some of the Apollo 16 food packages. The package in the center foreground is labeled 'Day 4, Meal A'. Details for the meals can be found in the LM Menu given in the Apollo 16 Press Kit ( 5.6 Mb PDF ).]115:52:58 England: Okay; we copy that. Sound real fine. You mean you got John to eat one of those food sticks?
115:53:06 Duke: Believe it or not.
115:53:08 England: Outstanding! (Pause)
115:53:16 Duke: In fact, he was sleeping so great that I just woke him up just a second ago, as a matter of fact. I couldn't stand it any longer.
115:53:33 England: (Chuckles) Very good. Well, you're right on the timeline. It's wake up time. (Long Pause)
[Duke - "I couldn't stand him sleeping any longer. I want to get him up and get going. I wanted to make sure we stayed on schedule."]115:53:56 Duke: Houston, we're ready to copy our lift-off times. Over.
[Jones - "Did you have a food list you could select meals from, or did somebody do it for you?"]
[Duke - "We had a list of foods; and the dietitian would recommend...Her name was Rita Rapp; and she would try to design a meal but you had a lot of variety within the meal. It was a balanced diet and a balanced meal, with so many calories was her target each day..."]
[Jones - "And low residue (to reduce the frequency of defecation)."]
[Duke - "And low residue. Yeah. So you had pea soup, you had cream-of-tomato soup, you had mushroom soup, maybe; and you had different kind of breads and you had the tuna spread and peanut butter spread and the ham spread. There were a variety of things. And these little food bars that we had, they were real high energy. I don't remember 'em being too bad; it seems like this implied John didn't like 'em. It was like a chewy granola - almost - except more chewy than that. Not crunchy at all."]
[Jones - "Anything about the rye bread?"]
[Duke - "I don't remember why we didn't eat it. I guess it was pretty dry and we were thirsty. That's probably the main reason. Because we tried all the food before we went and, if we didn't really like something, we didn't pick it. Rita had let us sample everything. Like I had some...I don't think we had any on the lunar surface, but I had her make some grits. I wanted to have some grits! She didn't have any grits for us southern boys. So I had some in the Command Module and, of course, we had hot water up there, so they were pretty good. But it took her two or three iterations to get the grits where they were worthwhile. Boy, the first bunch she came back (with) and they were just awful. It was terrible. But then, you know, a little bit of salt, a little bit of butter, and a little bit of here and a little bit there. By the time we got ready to fly, they were pretty good, so I ate all mine."]
[See, also, the Tech Debrief comments reproduced at 139:26:03.]
115:54:05 England: Okay. Stand by one. (Long Pause) Okay, Charlie. We've got the block data for the LM lift-off, LM Timeline Book. (Pause)
115:55:22 Duke: You speak.
[As John noted in the Tech Debrief, these emergency lift-off times were of little value with the Mission Timer turned off. See the discussion following 105:11:25.]115:55:23 England: Okay. T-22, 116:29:51; T-23, 118:28:22; T-24, 120:26:55; T-25, 122:25:28; T-26, 124:24:00; T-27, 126:22:32. This assumes GET update of 00:11:48, and Ken will be getting that update in about 2 hours.
115:56:27 Duke: Understand. Starting with 22: 116 plus 29 plus 51; 118 plus 28 plus 22; 120 plus 26 plus 55; 122 plus 25 plus 28; 124 plus 24 plus 00; 126 plus 22 plus 32; and that assumes the GET update of 11 minutes and 48 seconds for Casper. Over.
[Duke - "They would change the ground elapsed time for some reason to coordinate something or other. You know, time was arbitrary, anyway. And, so, they wanted to sync(hronize) something, and so they would change the GET - by 11 minutes and 48 seconds, for some reason."]115:56:54 England: Okay. That's a good readback. And we have an update to your Lunar Surface Checklist.
115:57:03 Duke: Go ahead.
115:57:05 England: Okay; on 11-1. (Pause)
115:57:14 Duke: Go ahead.
115:57:15 England: Okay; I guess we were too quick last night (at 107:41:02) in crossing out that "Pro, Hold until standby light off." We'd like you to put that back in.
115:57:27 Duke: Okay. Don't worry, we'd've (means "we would have") done that. Thank you much.
115:57:32 England: Okay; and then on page 11-2. (Pause)
115:57:44 Duke: Stand by.
115:57:45 England: Okay. (Pause)
115:57:56 Duke: Go ahead.
115:57:58 England: Okay. Under that T-ephemeris update, we'd like to have the note, (reads slowly) "T-ephemeris to be used only in the event of LGC/CMC clock sync is required." And for the registers: R1, 00011; R2, 13346; R3, 25621.
115:58:38 Duke: Okay; say R1 and R2 again.
115:58:40 England: Okay; R1, 00011; R2, 13346.
115:59:01 Duke: Okay; note is "T-ephemeris to be used only in event of LGC/CMC clock sync." Rl, 00011; R2, 13346; R3, 25621. And that's that we got loaded, or is that what we'd load if you wanted us to sync up?
115:59:28 England: Okay; that's what you'd have to load to sync up after they fix the CSM time.
115:59:35 Duke: Okay; thank you much.
115:59:37 England: Okay; and that's the end of that. And I'll brief you on the traverse whenever you're ready.
115:59:42 Duke: Let John get on the comm. It'll be a couple of minutes. We're going into the eat period, and we'll give you a call while we're eating.
115:59:53 England: All right.
[Very Long Comm Break]
[Jones - "With reference to your "let John get on comm", the only comm you had in the cabin was the earpieces on the Snoopy headgear? There was no speaker?"]
[Duke - "No; we didn't have a speaker. You had to put on your hat."]
RealAudio clip by Siegfried Kessler
116:12:46 Young: Hello, Houston. Good morning.
116:12:48 England: Good morning, John. (Pause)
116:12:57 Young: Did you work all night too, Tony?
116:12:59 England: No, no. I've been home and sacked out.
116:13:06 Young: Good. (Pause)
[Duke - "He lived almost right across the street from us. In El Lago. If I remember...No, he didn't live over there."]116:13:11 Young: Okay. Go ahead with your EVA stuff.
[Jones - "But it was close?"]
[Duke - "Yeah; a couple of miles away."]
[Traverse map EVA-I, III 1 of 3 shows the planned EVA-1 traverse route. The following is taken from the Final Lunar Surface Procedures volume and describes pre-flight thinking about the landing site.]116:13:12 England: Okay. (Pause) Now these are the Backroom's best guess. The Spook sampling may be compromised by that ray from South Ray that you described, and since we're mostly interested in local Cayley on EVA-1, you'll probably have to spend a little time trying to differentiate between secondaries coming in from South Ray and local material. You described most of the (South) Ray material as being very angular. One of the clues may be rounded blocks, for local material. At Flag (Crater at CB/73 on EVA-I, III 1 of 3), again, you may have that same problem. Since we couldn't see over there, we really couldn't tell; and we don't want you to feel bound to Plum Crater there at Flag; if there's another place on the rim of Flag where you're more likely to get local material, feel free to head for it.
["The lunar highlands appear to consist of three major types of deposits: (1) undivided pre-Imbrium materials and older, degraded crater materials, (2) ejecta blankets composed of material by the major basin-forming events - e.g., Mare Imbrium formation - that are typified by the Apollo 14 Fra Mauro and Apollo 15 Apennine Mountains highland areas, and (3) volcanic constructional materials that are exemplified by the Descartes highland region, the Apollo 16 lunar landing site."]
["The Descartes area is an outstanding location to sample and study the petrochemistry of two volcanic constructional units of the lunar highlands: the Cayley formation unit and the Kant Plateau unit, of which two separate and distinct portions are present."]
["Fresh craters of various sizes, also present within the candidate landing area, allow sampling of these highland units to various depths. The mounded floors of craters within this landing area - up to 1 kilometer in diameter - suggest that a lower layer of unknown origin has been penetrated."]
[Kiva Crater, at CX/73 on EVA-I, III 2 of 2, is one of these craters with a central dome.]
["The Cayley formation unit is highlands plains material consisting mostly of smooth to undulating terrain, probably resulting from fluid volcanic flow rock and pyroclastic detritus. This unit is the largest single identifiable rock unit on the near side of the Moon - covers 7 percent of (the) Nearside - except for mare regions. The Descartes Mountains (including Stone Mountain) - (which form the western) edge of the Kant Plateau unit - are composed of hilly and furrowed highland plateau material that is probably the product of more viscous volcanic flow rock, pyroclastics, and their associated cones. This type of unit covers 4.3 percent of the near side of the Moon. This landing site provides a unique opportunity to accomplish dating and other studies of the morphological evolution of young, bright-rayed craters. The geological information obtained can be applied to infer ages of other visible craters of apparently similar construction."]
["The specific geological features recommended for sampling in the proposed landing area (site 2 on Figure 2.5-3) are as follows: (a) Cayley Plains which include young, bright-rayed craters (such as) North Ray, South Ray; (b) South Descartes Mountains, (specifically) Stone Mountain; (c) North Descartes Mountains, (specifically) Smoky Mountain; and (d) subdued craters and crater chains."]
[Figure 2.5-4 from the Lunar Surface Procedures volume shows the pre-flight Geological Units in (the) Descartes Landing Area.]
116:14:15 Young: Okay; will do. But the color of the ray material is a pretty good gouge (meaning "indicator"); it's all white.
116:14:24 England: Right. And the...
116:14:26 Young: At least, I think it is. That's the way it...(Stops to listen)
116:14:29 England: I'm sorry, John; go ahead.
116:14:35 Young: It sure looked all white at pitchover, there.
116:14:39 England: Right. And I guess we'd like you to go ahead on a normal EVA-1 there, and not worry too much about the local blocks in the LM-ALSEP area. We'll try to pick them up at the end of EVA-1 or at Station 10 (near the LM) in EVA-2.
116:14:59 Young: Roger.
116:15:01 England: And, again, on the traverse itself, we'll skip the TV getting out, since we won't have AC and all and the high gain. And, so, you don't have to worry about deploying the TV and tripod; and we'll leave the TV for Charlie when he gets the LCRU out. We will need a few more words during the ALSEP deploy or, correction, during the LRV deploy, since we won't be able to watch it. And, our best guess on an ALSEP area is still sort of northwest of you there. But it will be completely up to you; whatever looks best. And again, the use of the UV camera, we'll...
116:15:42 Young: Okay.
116:15:43 England: ...give you real-time updates on that.
116:15:48 Young: Okay. I guess we're going to have to put the UV a little closer to the vehicle because of the current...Probably won't make a lot of difference there.
[They will use the UV camera to take photographs of various astronomical targets.]116:15:59 England: Okay. And if you guys are all for it and everything, we're still trying to crowd in three EVAs.
[Duke - "We had a restriction. The thing had to be in the (LM) shadow, but they wanted it far enough away from the Lunar Module...I don't know whether it was a field-of-view problem or it was a contamination problem from dust on the lens or something. I don't remember, exactly; but, with the higher sun angle, it left the shadow shorter. And so we had to move the camera back in closer because of the length-of-the-shadow problem. But I don't remember the details of their concerns."]
[As shown in Figure 2.3-1 in the Lunar Surface Procedures volume, had they started EVA-1 at the planned time of 103 hours, the sun elevation would have been about 11 degrees. They will actually start the EVA at about 119 hours and the sun elevation at that time will be about 22 degrees. Because the LM is approximately 7 meters tall, the shadow lengths at sun elevations of 11 and 22 degrees are 36 and 17 meters, respectively. Because the UV camera is about 1.4 meters tall, to be in complete shadow it has to be placed closer to the LM than these figures would indicate. See AS16-113- 18339 for the EVA-1 UV camera placement. The camera is near the LM ladder, just to the right of the airborne John Young.]
116:16:11 Duke: What do you mean, are we all for it?!
116:16:15 England: (Laughing) Well, I just thought I'd give you a chance to put your vote in.
116:16:25 Young: I'm not for crowding 'em in, but let's do three of them! (Long Pause)
116:17:08 Duke: Tony, Charlie. Please pass on to the ALFMED P.I. (R.E. Benson and L.S Pinsky) in the Science Room that you can see those light flashes on the lunar surface just like Translunar coast, and you can also see them in the lunar orbit. During the sleep periods. Over.
[Here, Charlie is referring to flashes of light that were reported by all of the crews starting with Apollo 11. When they had their eyes closed, the astronauts saw occasional flashes of light (a few per minute) which, it was quickly realized, were probably caused by cosmic rays entering their eyes. The ALFMED (Apollo Light-Flash Moving-Emulsion Detector) was flown on Apollo 16 to determine the precise mechanism involved. The device is shown in Figures 27-17, 27-18, and 27-19 from the Apollo 16 Preliminary Science Report and contained sets of photographic plates which were used to determine the characteristics of the cosmic ray particles that excited flashes what were verbally reported by an astronaut while wearing the device. Charlie wore the ALFMED for one hour on the Translunar portion of the mission and, as well, for an hour during the TransEarth coast. During those same times, John wore eye shades and reported any flashes he saw. The subject wearing an ALFMED in Figure 27-19 may be E. (Buzz) Aldrin, who left NASA in July 1971.]116:17:28 England: Okay, did you notice any change in frequency?
[Journal Contributor David Woods calls our attention to the following from Apollo 11 CMP Michael Collins' superb Carrying the Fire: "(I) did not notice any in flight...but now I can make my imagination work either for or against the idea and conjure up a darkness which is either absolute or penetrated occasionally by a tiny white streak crossing my retina. Unable to make an honest contribution, I stay out of the conversation."]
116:17:34 Duke: They're about the same (on the surface) as the...They're less than that experiment we ran (on the way to the Moon), but they were about the same as they were in lunar orbit.
116:17:42 England: Okay; understand. They were less than in the experiment, but about the same as in orbit.
116:17:51 Duke: Yeah, and I think there was about...Let me say, I maybe saw 10 before I went to sleep, and I think I got to sleep pretty fast. So, they aren't really too numerous, but you can see them.
116:18:06 England: Okay, very good.
[Very Long Comm Break]116:42:16 Young: Okay, Houston. We think we're down to 117:03 (in the checklist) now. What time have you got?
[Because Charlie loaded the Equipment Transfer Bag (ETB) as per checklist page 2-1 prior to the rest period, once he and John finish breakfast, they will don the suits are per checklist page 3-8.]
116:42:25 England: I'm sorry, John. Say again?
116:42:28 Young: I say, we're down to 117 hours and 3 minutes (which is Step 10 in the handwritten alterations to page 3-8). We're ready to don suits. What time have you got?
116:42:36 England: 116:42.
116:42:38 Young: Okay. We're going to go ahead and do it, with the understanding that when we get them donned and get the PLSS on, we'll depress (the cabin) and go ahead and get out, because we don't have a very good way to keep time in here.
116:42:53 England: Okay; understand. We do have a procedure here. We'd like for you to mess with your steerable antenna a little bit, there.
116:43:07 Young: Okay, do you want me to do that now?
116:43:09 Duke: (To John) Yeah, let's do it.
116:43:11 England: If you're ready.
116:43:15 Young: We're ready.
116:43:18 England: Okay. Circuit breaker panel 11 ( CB(11) ), AC Bus B, S-Band Antenna, Close.
116:43:26 Young: It's closed.
116:43:27 England: Okay. Panel 16 ( CB(16) ), on the Comm, S-Band Antenna, closed.
116:43:35 Young: Closed.
116:43:37 England: Displays, closed.
116:43:40 Young: Displays, closed.
116:43:41 England: And Heaters, S-Band Antenna, closed.
116:43:47 Young: S-Band Antenna Heater breaker, closed.
116:43:49 England: Okay. On the steerable manual controls, match the indicated angles. (Pause)
116:43:57 Young: Okay.
116:44:01 England: Okay; the Track Mode to Slew. (Pause)
116:44:14 Young: Track Mode to Slew.
116:44:15 England: Stand by a second, please. (Long Pause)
[Houston is trying to get the high-gain antenna to work.]116:44:43 Duke: I think it might be working, John. I just got a jump on my needle here.
116:44:51 Young: On the yaw needle?
116:44:52 Duke: Yeah. It's always been stuck on 12 before, and now it's on minus 75. But (in the antenna shadow) it doesn't look like it's 75 out there. Of course, you don't know with the pitch. (Pause)
116:45:15 Young: (To Houston) Okay; what do you want to do with it now, Houston?
116:45:18 England: Stand by one on that. We're working on another problem here. (Pause)
116:45:28 Young: (To Charlie, somewhat incredulous) Working another problem?
116:45:30 England: Okay. We'd like you to close Inverter 2 circuit breaker, and select Inverter 2.
116:45:40 Duke: Okay, you got it. (To John) That's what I was afraid of. Now it's back to 12.
116:45:51 England: Okay; we'll press on with the procedure here. We had the Track Mode to Slew, set the Pitch control knob fully counter-clockwise.
116:46:02 Duke: It is.
116:46:04 England: Okay; Track Mode, Off. (Pause)
116:46:10 Duke: It's Off.
116:46:12 England: Okay, now set both Pitch and Yaw knobs fully clockwise. (Pause)
116:46:21 Duke: It is.
116:46:23 England: Okay; go to Track Mode, Slew. (Pause)
116:46:31 Duke: Okay....
116:46:32 England: Let us know.
116:46:33 Duke: ...And the antenna didn't move.
116:46:39 England: Okay; we understand. It did not move.
116:46:45 Duke: Negative; either in pitch or yaw. (Long Pause)
116:47:02 England: Okay. Look on your panel 16, and see if the S-Band Antenna circuit breaker's open or closed.
116:47:10 Duke: It's closed. (Long Pause) (Annoyed) What a bunch of bullshit! Dadgone it (garbled)
116:47:36 England: Okay; we're just going to back out of that procedure. Let's go Track Mode, Off. (Pause)
116:47:48 Young: It did something in yaw then, Charlie.
116:47:51 England: And match the indicated angles; Track Mode switch, Slew.
116:48:01 Duke: Tony, with the Track Mode to Off, both indicators are minus 75
116:48:10 England: Okay. (Pause) Okay. Set your Pitch at 180 and the Yaw at minus 12. (Pause)
116:48:32 Duke: It's set.
116:48:35 England: Okay. And go through, and we'll pull the circuit breakers that you have set for this procedure. That's on panel 11, S-Band Antenna, Closed. Pull it open.
116:48:48 Young: Okay, it's open.
116:48:49 England: Okay. On 16, S-Band Antenna, open.
116:48:51 Young: Okay, Tony.
116:48:54 England: Okay, John?
116:48:57 Duke: Go ahead.
116:48:58 England: Okay, the S-Band Antenna, open.
116:48:59 Duke: Go ahead.
116:49:00 England: Okay. Displays, open; and the Heaters, open.
116:49:04 Duke: It's open.
116:49:05 England: Okay. Inverter 2 circuit breaker, open; and Inverter 2, Off.
116:49:14 Duke: Rog. That's done.
116:49:16 England: Okay, let's press on with your suits.
116:49:21 Duke: Okay, Tony. What are the nominal angles for lock-on error and...on this attitude?
116:49:32 England: I'll get those. (Pause)
116:49:41 Duke: Okay. (Garbled)
116:49:47 England: Okay. The 180 and minus 12 we gave you should be good angles. (Pause) And that's for photography, not for lockon. We're going to have you take a picture of it when you get out.
116:50:07 Young: Roger.
116:50:09 Young: When Charlie moves the needles in yaw, he can get it to oscillate - plus or minus what? - plus or minus 3 degrees. (Pause) The antenna doesn't sound like it's moving. I thought it sounded jiggly. (Pause) Whatcha doing now, Charlie? (Pause)
116:50:50 England: Okay, John and Charlie. We'd like you to press on with the EVA work. If we mess with that S-band any more, we'll do after the EVA. I've got a note here. I don't know whether it's right or not, but it says that you won't be able to hear the yaw motor. (Pause)
116:51:16 Young: Okay; but Charlie is looking at it (meaning the antenna shadow) out the window, and it's not moving.
116:51:22 England: Okay. There's a latching mechanism in the thing there that should have released when the thing was unstowed, and we're going to try to have you take a picture of it. There's a lever that pokes out there, and we can tell from the picture whether that latch released. And there should be a little bit of slop in there so...
116:51:38 Young: I understand.
116:51:40 England: ...maybe he could drive it a little bit. (Long Pause)
[Duke - "I remember taking a picture of that antenna (AS16-113- 18336, 18337, and 18338). When we first docked with the Lunar Module following trans-lunar insertion, there was a lot of white stuff floating into space. It turned out that it was some paint peeling off. So, when we looked up to take a picture of the antenna, I saw this paint that was curled up. It looked like the sun had hit it, you know? It was peeling off. So that came out in the picture. I don't remember whether this latching mechanism showed up or not."]
[Figure 14-29 from the Mission Report shows the steerable antenna and latch that failed to release in lunar orbit prior to the landing. See the discussion prior to PDI.]
|Window Geology||Apollo 16 Journal||Preparations for EVA-1|