Young: Activation Through Separaton. Command Module Power Transfer. We got this half hour head start and we were all suited up, and we were running 20 minutes ahead of the time line and we asked them if we could go ahead and power up. They said, sure, go to it because we had plenty of power and everything. The first thing that happened is that Charlie leaped in there, and there was no grind (?) from the yaw antenna and the high gain.
Mattingly: I think the only comment you can say about our part of it was that we got tight on bleeding the tunnel down. Other than that, I think we did everything fine on the undocking.
Young: Tunnel Cloeeout. You didnÂ’t have any trouble witn that?
Mattingly: No problems with that. Everything worked.
Young: Maneuvering to Undocking. You didnÂ’t have any problem with it?
Mattingly: No. Undocking and separation were nominal. I remember when you backed off, and you said thatÂ’s as far as sheÂ’s going. And I thought, here we go again and you hit thosc other things, and we separatcd. Well, the idea was to let it hang on the capture latches, and we did, and it gave a bigger "clunk" than I anticipated when it got to the end of the probe. There were no dynamics at all. It was just waiting for them to stabilize, and they were just steady as a rock. It just takes a little squirt of RCS and we were gone. I thought that all worked super. Somewhere in here, we did a VHF check and we had some trouble getting together on B Duplex most of the time. It turned out to have better comm on A Simplex, although the VHF generally sounded super. Maybe you understand what happened. I really donÂ’t know.
Duke: It was either our B receiver or your B transmitter. They ought to be able to check the B transmitter in the spacecraft. We could isolate that. We had VHF problems before flight and they changed out both VHFs.
Young: It was almost unreadable at first, and .then it seemed to get better.
Duke: We were clear to Ken but on our B receiver on voice ranging; and then on B simplex, it was a little garbled. It sounded like he was in the bottom of a cave. But it did get better. So it would be wise to have ASPO check that out.
Young: Formation Flight. Looked like you were doing a great job there.
Mattingly: The time line after undocking. I didnÂ’t do any formation driving around after we undocked. We went ahead with the Flight Plan, and went to do our landmark tracking and the P52 and all of those things. Everything there worked super. We did skip the transponder check.
Young: We skipped the transponder check because we just couldnÂ’t fit it in. It wasn't necessary anyway because we were going to go whether it worked or not. It may give you a warm feeling, but if your mission rules say you go without it, and itÂ’s something that youÂ’re tight on, to me thatÂ’s the first thing that you leave out.
Mattingly: LM Inspection Photography. I took a couple of pictures of you as we separated, but we didnÂ’t do any maneuvers or anything. You could see the gear and I guess that was really all I was looking for. I didnÂ’t see anything hanging off anywhere. IÂ’d like to comment on the fact that we had two comm loops, and I think that was really super. That made life so much easier because Charlie could get his pads when they were convenient for him, and I could get my pads when they were convenient for me. I donÂ’t know what it cost the MOCR guys to run two comm loops, but on our end, it was really a big help.
Young: It really is bad when youÂ’re trying to cough up two sets of pads during that period of time.
Mattingly: That really helped. I canÂ’t say enough nice things about that. Stu really pushed on that.
Young: Is there anything you can say about the fuel cell purge?
Mattingly: I can say I didnÂ’t do one. Okay, we skipped the radar check. I also skipped the COAS alignment, again, because it looked to me like I wanted to have the extra time to get ready for the circ burn. The only thing we were doing different from normal was that we were going to start it at eight minutes, instead of six minutes, so that you would have time to take 509 out of the computer. I think I probably started it at about 8:30. I was really intent on making sure that the circ burn went on schedule. When we got to the secondary yaw gimbal check, it was unstable and diverging as soon as I touched the thumbwheels for a trim check. There was no question about it being a real live thing, because the spacecraft was wagging its tail just like the indicator, and it was diverging. I shut it down and in succession I tried it in Auto SCS, then I tried it in Rate SCS. I failed to try it in Accel Command. I tried it in PVC. I tried it in CMC and got exactly the same response. Whenever you turned the gimbal on; it was stable. The first thing that moved the gimbal excited a diversion oscillation, whether it was in SCS or CMC. We got a change to the mission rules document about a week before launch and I was almost too mad about it to read it. Now I donÂ’t know if I was glad I read. it or not. One of the things was you had to have four servo loops to do circ.
Young: Ken asked me about it and I said I didnÂ’t think you should burn.
Mattingly: The thing that had bothered me about it was the point that Charlie raised later, and the only thing we had done differently was to run those gimbal motors for 20 minutes before LOI and 20 more minutes before DOI. We had always been so careful. We researched this point and we talked about it. One of the SIM problems we talked about was what do you do if your gimbal motor gets stuck on. Do you kill the bus or do you let it run? They researched it and came to what I thought was a surprising conclusion. Just let the thing run. ItÂ’s unlimited in lifetime. My concern was that this might not be a a random failure of the yaw gimbal, but maybe running this extra time had heated something up. I might have temporarily been a hero if I had let you go land on that rev, but if I didnÂ’t bring you home you werenÂ’t going to like me very much. ThatÂ’s got to be the toughest decision I had to make.
Young: You were not by yourself, because I didnÂ’t want you to do it either until we understood what we were doing.
Mattingly: Let me say something about what we did after that. Again, it was one of those things where, fortunately, weÂ’d been down this road before. We had talked in data priority about what you do if you donÂ’t do a circ burn. It was one of those things where you never could really get your heart into it because we could never figure out how you were not going to do circ. But we had talked about it and they had come up with a TPI rendezvous scheme, which didnÂ’t seem to make any sense to me because of the navigation at those ranges. So we tried it and we flew some of these things on a one-rev, no-circ, re-rendezvous. And with the kind of separation maneuver we have you can expect to be somewhere around 1200 feet separation. You just wait until youÂ’re that far apart and then brute force it. And it costs you a few percent, 5-foot-per-second Delta-V. In retrospect, I think we probably made a mistake, because without any direction from somebody, I should have rejoined on the LM at the first opportunity.
Young: Yes, Ken asked me what to do and I told him I didnÂ’t know.
Mattingly: I didnÂ’t do it, and all I can say, in retrospect, is I think I should have. At the time, I decided, well, there is still a chance we might get to land and I donÂ’t want to waste any gas that might cut into that RCS budget until we have to.
Young: I guess the thought that was sticking in my mind was that when we would come to that time that we would be go for PDI, and if they could figure out what was the matter, weÂ’d go ahead and land without having to re-rendezvous. And 1200 feet wouldnÂ’t make any difference in the phasing at that point. When we came around that side we were ready to go for PDI because we had done everything that we had missed before.
Mattingly: We knew we couldnÂ’t do PDI with me in the same orbit.
Duke: You couldnÂ’t do that.
Mattingly: We knew that point. Let me just say that I think I should have joined up on you without any call from anybody and I didnÂ’t do that. I didnÂ’t know you couldnÂ’t do DOI with us in the same orbit. Yes, sir, because you donÂ’t have any abort targeting.
Duke: We were at least at PDI-2 now.
Young: I can get to that LM from any place in the sky, if itÂ’s got the Delta-V to get there.
Mattingly: There is no mission rule that covers this specific case. I think there ought to be. Okay, then we came around and we didnÂ’t do anything. Then they called us and said go ahead and do your join-up just the way weÂ’ve done it. Stu had flown one and I had flown one at the Cape and they said do it just like that when your closest point of approach is at some time, which I fail to remember. And it turned out that at that time, which was supposed to be our closest point of approach, we were still opening. So I lost confidence that they really had a good handle on our relative trajectory. And they said just brute force it. Well, I put in 3 feet per second towards you, at the time they gave us. And we started opening. We were opening at the time I put it in, I put in 3 feet per second and the opening rate increased. It turned out that the 3 feet per second was retrograde. You pointed that out and I got to thinking that that's retrograde and weÂ’re closer to apogee than to perigee, and is that really the thing to be doing? I tried to figure out a clever way to do this and let orbital mechanics work for us. I finally took it back out just to get ourselves safe. About that time we picked up the ground and I felt that the ground never really understood the question I was asking them. Did I have a good state vector? I showed a 6.3 perilune. I figured that if I had a good state vector when it started I was still safe and thatÂ’s no sweat. But their numbers were showing me in a 9-mile perilune and I began to wonder if maybe I had a bad state vector to start with. Finally, they had us brute force at the bottom. I was reluctant to brute force from anywhere. I felt that we had opened up to over a mile then and, at that point, I was ready to go and do a regular rendezvous, if they wanted to put us together; and let us use orbital mechanics instead of fighting it and still save the gas. When they told us to brute force it, I guess in my own mind I felt that weÂ’d lost the ballgame. We were going to get back together for good. The flight guys are going to have to give us the data on how much gas it would cost. It was a pretty expensive thing. It turned out that using JohnÂ’s rendezvous radar, for line of sight, gave me a faster jump than I could get out the window. We just never let it get away from us. We did whatever we had to. I had wondered what it would be like getting into the dark and doing this and we quickly found out.
Young: He was 600 feet out and he could see us because he was in the earthshine. He could see us perfectly.
Mattingly: You could see the outline of the LM. The tracker light is beautiful. You could see the outline and if I had known that I would get there before earthshine stopped, I would have told them to turn out the tracker light because it was so nice. I kept worrying about when earthshine was going to quit and what was out there. And throughout the entire thing, the only sensation of closure rate I had was JohnÂ’s reading them out. The EMS and the radar were uncannily close together. couldnÂ’t believe how close they were. But it was somewhat easier for John to read me the range rate than for me to have to take my stopwatch out and measure the closure rate. And there was never a sensation, even when we were right together.
Young: WeÂ’re talking about closure rates like a foot a second. ItÂ’s fabulous. ThatÂ’s really fantastic gear.
Mattingly: I turned my spotlight on so I could see him. And you guys saw the spotlight, and knew it was on. I turned it on at 500 feet and we were still in earthshine and I couldnÂ’t tell it was on. So I said, well, probably earthshine is too bright. Well, then the earthshine disappeared and we were somewhere between 300 and 500 feet, I donÂ’t remember where, but the spotlight didnÂ’t do anything. We had to be inside 300 feet for the spotlight to be effective. At 300 feet, I could tell that the LM was there. I could see a shape. And then, inside of that, the old spotlight was just fine. And they finally turned the tracking light on and I could see it.
Young: ThatÂ’s the old Gemini light like we used on Agena.
Mattingly: But I was surprised that you had to be that close to get anything from it. Stationkeeping? If flying airplanes in formation could be as simple as flying two spacecraft, the whole world would be aviators because you could kill a rate. I donÂ’t know how long we sat there without my touching a thruster. We just came up there and sat there and that was it. Stationkeeping in the dark, they asked us to dump the water and I really had no qualms about leaving the couch and going down and dumping the water. We started that in the dark and that was when you noticed that we had been dead in the water with each other. I put the dump on and that spacecraft translated away. Did you see that thing? Right out the side.
Young: ThatÂ’s a real gap of water coming out. Yes, just moved right out.
Mattingly: Really did.
Young: I couldnÂ’t believe it.
Mattingly: Not fast, but it was unmistakable that thatÂ’s what it was doing. And didnÂ’t take much to counteract it, but that was sure there, so I guess IÂ’m more of a believer in FDO data now, than I was.
Young: Yes, we saw it, relatively speaking.
Mattingly: I guess this is an appropriate time to make a comment on if you ever have to do a night rendezvous. Docking at night is going to be an absolute piece of cake. It just couldnÂ’t be simpler. The rendezvous, I think, because of the absolute lack of any sensation of motion along the line of sight. Now, we didnÂ’t see big rates. But five feet a second, IÂ’m sure I could not have seen. And thatÂ’s kind of uncomfortable in the dark. YouÂ’ve got to have one of those rate systems going. Radar preferably. And without that you donÂ’t really want to commit to this. Because I think what will happen is youÂ’ll be worried that you arenÂ’t closing fast enough and then all of a sudden the angular size of that thing is just going to grow and with that big marshmallow youÂ’d never stop it.
Young: I agree with you. YouÂ’d get the little marshmallow out of the way, hopefully.
Mattingly: Yes, that would have to be your technique. YouÂ’d have to dump. Because that big marshmallow just glides right on by. We did our separation burn on the next rev, after weÂ’d gotten into stationkeep and all that. And again I think we got out of sync and maybe should have done. I was trying to save gas at all costs and when they gave me the separation burn, they gave me an attitude to go to. And I got the feeling that maybe they were unhappy that I elected to burn at three axes and burn in the attitude I was in.
Young: I think that with the small differences you can afford not to do that. SomebodyÂ’s got to keep somebody in sight.
Mattingly: When they told us the time was coming up, we had just a few minutes and the only way to get to the attitude they gave me was to go real fast and I just felt like my obligation was to save gas at that point. I went three axes and kept you in sight. I would do it again.
Young: I think itÂ’s a good head, man. You donÂ’t want to run two of those things together out there.
Mattingly: The circ burn after that was just super nominal, didnÂ’t bring the secondary yaw gimbal on until after the gimbal check and then brought it on for redundancy. And we did roll 90 degrees so that I had the two good gimbals in the yaw in the middle gimbal plane. I made that one change to it, which was no problem at all. We had some residuals which were higher than I anticipated, in fact, I got quite a bit of attitude excursion on the burn initially. I was surprised that it didnÂ’t run as stable as any of the other burns. And you could see the gimbal swing and the pitch attitude. Pitch and yaw were both moving.
Young: You may not have changed your weight, because of the RCS maybe.
Mattingly: Well, if thatÂ’s the case, IÂ’m surprised how sensitive it is. But we ended with some residuals as a result of this attitude excursion.
Young: You had to roll to get them out.
Mattingly: And I got both residuals in the two axes I couldnÂ’t burn. And I had to take one out and then roll and take the other one out again, to keep from firing over the SIM bay. I was just surprised at the magnitude of the residuals in all of the three axes. I didnÂ’t anticipate that. After that, the rest of it was all nominal. Why donÂ’t you pick up your side?
Young: I wanted to say I thought Ken handled that thing beautifully. I think IÂ’m the guy that coerced him into taking that Delta-V out that he put in, retrograde, because I was really nervous about that. I didnÂ’t really know. I think I remember you saying three feet a second but I wasnÂ’t really sure and we were too close to apogee to be doing that, and I just didnÂ’t want to see the Command Module disappear behind one of those hills. I donÂ’t think it would have ever happened but I didnÂ’t want to see it.
Mattingly: IÂ’m sure if we had done it we would have been safe. My intent was that once I committed myself to that path, I didnÂ’t care how much gas it cost, I was going to finish it. But, I was worried about sagging below you, thrusting up toward you and going underneath. You talked me out of that.
Young: It was a good rendezvous. I donÂ’t see how you could have played it any better. The closure rate was so slow, but the inertial line of sight rates were just perfect. All the way.
Mattingly: I guess itÂ’s worth saying that we have different impressions here, but itÂ’s my impression here that inside of half a mile my COAS gave me better line of sight rates than the radar. Outside of that, your radar was good.
Young: If you correct for what the needles are telling you to do, you could be doing the wrong thing. It wouldnÂ’t amount to a hill of beans in the LM because you just take it right out again. On the Command Service Module, you would be squirting out gas to fix something that really didnÂ’t need to be fixed. YouÂ’re going to fix it anyhow.
Mattingly: And then youÂ’re going to take it out later.
Young: So I reverted to the COAS when we started diverging and I think itÂ’s the right way. There, we were 20 minutes ahead and I figured we had that time line just beat to shreds. I figured we were going to be ready to go down to PDI minus 1.
Duke: Everything worked except the S-Band steerable. Eighty-two was nominal except the steerable and it would not move in yaw. So that threw us behind on the up-links. And we had to manually do the P27s, which impacted the P52 dock. We missed everything else we did on order here. Everything else was nominal, except for the ECS; the RCS activation we had a double reg failure in system A.
Young: And the first words were, "Open the ascent feeds." Charlie didnÂ’t hear that so I opened the ascent feeds before Charlie realized what IÂ’d done and he said, "WhatÂ’d you do that for?" Because we just had a sim that blew the whole mission when we opened the ascent feeds.
Duke: So I closed them.
Young: So Charlie closed them and it turned out to be the right thing to do. If weÂ’d left them open any longer weÂ’d have probably overpressurized the APS, or gone too high on the APS pressure. People donÂ’t realize that. And then after weÂ’d done that they called up and said donÂ’t let the APS pressure get above 180, which we hadnÂ’t even looked at.
Duke: But those were the only two problems we had, the S-Band steerable and the RCS System A.
Young: We tried working the P27 together. Charlie would call it out and IÂ’d punch it in, but we were getting in each otherÂ’s way; so Charlie finally took the P27 and I went and pressurized the RCS. We were working the time line in parallel, something I could do on my side I would do at the same time Charlie could do on his side. I think thatÂ’s the only way we stayed up on it. The PGNCS Activation and Self Test was nominal. The Suit Loop Checkout was nominal. Everything was nominal except that yaw steerable. It was like somebody forgot to take out the "Remove before flight" pin or something. ThatÂ’s the way it looked to me.
Duke: The Landing Radar Self Test, we did that after undocking and that didnÂ’t work the first time.
Young: It didnÂ’t work the second time either. We were in a communications attitude and we were at perigee and I donÂ’t know what it was but it was reading erroneous numbers. The first time it read on the tapemeter, it read 8000 feet and itÂ’s supposed to read something like 494 on the range rate. It was reading totally erroneous on the range rate, and the next time, the VERB 63 radar self test where you set the gnomon flag and everything, was totally wrong, and then we tried it again and it read the right range rate, but the wrong altitude. And then, we got to an attitude where we werenÂ’t pointed at the ground and the thing worked like a champ.
Duke: It was locked up, but we had such a super radar, that it locked up on the ground. Because on PDI we were locked up at 50 000. So we think thatÂ’s what happened.
Young: I donÂ’t know what happened, but it sure flunked.
Duke: We didnÂ’t do the Lunar Landmark Recognition because we were behind. The MSFN Relay we never exercised. Their comm up- link was loud and clear the whole time, but I guess poor Jim had his hands full hearing us on the down-link on the Omni, until we got the 210 up.
Young: DAP Loads were nominal. The Rendezvous Radar Checkout we didnÂ’t do, we tried it one time.
Duke: Now wait a minute, this was just before undocking, John. This was the rendezvous checkout. That worked fine.
Young: Deployment of the Landing Gear was just a clunk and it was down and thereÂ’s no doubt in anybodyÂ’s mind. Undocking was nominal. Separation was nominal. Like you say, we didnÂ’t do the Landmark Recognition and the MSFN Relay.
Mattingly: We skipped the landmark tracking that we did after DOl. I guess that deserves a couple of words. When we get through, IÂ’ll come back to that.
Mattingly: I guess it was significant that we were able to get both the training landmark and the landing site on the same rev and track them both. The auto optics and all that really worked like a champ. The thing that surprised me and, I donÂ’t know if anyone has mentioned it and I just didnÂ’t listen, but when you look through those optics at the Moon, youÂ’re really getting a dose of heat in your eyeball. I think you should never do more than two landmarks together, and you really should do only one, on any rev, because your eyes were very sensitive to looking at that bright concentrated light. And you could feel the heat when you put your eye to the telescope.
Young: Let me tell you what Ken did the day before we started all this, into low Sun angle. He tracked landmark 16-3 the day before, on OJT training day and how many marks did you get it - four, five? Ten? HeÂ’d been set up to track the OJT landmark. He tracked that one and then without changing attitude he put in the new landmark for the 16-3, which is right at the landing site and tracked that son of a gun, the day before we were supposed to go down and land at the low Sun angle. I donÂ’t know how the ground will use that data, but if they had been able to collect that data instead of the OJT landmark data, man, weÂ’d been in Fat City. I donÂ’t know if they did collect it.
Mattingly: The reason we didnÂ’t plan to do it that way, was that when we set up the Flight Plan originally, the landing site was going to be in the dark on DOI and then with the month slip the landing site slipped out in the daylight so that it was infeasible to do that. That was a pen-and-ink thing I wrote in because I wanted to look at the landing site early and we stuck it in there.
Young: My suggestion would be if the landmark is going to be in daylight at all, get the landmark at the landing site, rather than fooling around with something. Even if he doesnÂ’t get the data that will give him a chance to do some landing site recognition, which heÂ’s going to need for the next day. After he gets the data, thereÂ’s one big block you could forget about worrying about.
Mattingly: That P24 sure is a smooth running program. The auto optics did not put us on any of the targets, directly. We always had to correct them, but once you got going on it, that thing was really nice and smooth. Super easy thing to do; the only difficulty you have at low altitude is target identification.
Young: IÂ’d be willing to see what your landmarks tracking did for the state vector.