Young: Lift-off was nominal. The pitchover was on time and we flew the most beautiful profile I ever saw. Shutdown was on time. There was one thing that we did differently.
Duke: We closed the main shutoff in system A before ascent.
Young: Before we turned on the ascent feed, the main shutoff in system A was closed. When we got into orbit, we used system B and crossfeed, which effectively gave us two systems. It worked beautifully. I never had any doubt that this rascal was going to work properly. The control system is just a champ. The insertion was nominal. I forget what the residuals were, but there was nothing to trim.
Duke: Less than 1.
Young: Two feet a second and asked for 10 up. We pitched up and locked on to the spacecraft a lot sooner than I thought we would. We were about 150 miles out. They redid that table in the time line. Charlie saw the Command and Service Module in reflected sunlight first. This was right after we pitched up, which must have been 2 or 3 minutes after insertion.
Duke: We inserted 170 miles behind and closing at 492.
Young: By the time we were at 150, Charlie saw that star out the window. It turned out to be the Command and Service Module. I could not see it through the COAS. If I moved to the side of the COAS, after we had radar locked on, he was right in the middle. I was glad to get that data point, because everybody had been asking, can you see him in the reflected sunlight? And I answered, "Yes, I can see him at 150 miles." We kept an eye on him until he went into darkness. ThatÂ’s a good. way to be able to check the state vector and make sure you donÂ’t have a bent radar.
Duke: Once we got locked on the PGNCS needles, the 50/18 needles, the AGS needles, the radar needles were centered. I forget how many marks we ended up with but it was about 25.
Young: It was a lot more marks than we needed. In fact, they said we could proceed if we wanted to.
Duke: So we did, 2 minutes early.
Young: Two minutes early. The TPI solution for the PGNCS is the one we burned. I forget what the numbers were, but it was right down the track.
Duke: We lost radar lock when we did the burn. It was right at the edge of the limit, and when we lit the engine, we lost radar lock. Until that time, we hadn’t lost lock. And of course, all we did was call up P35 and reacquire. When it changed the W matrix in P35, I either hit the enter button too fast or hit another button, and the W matrix didn’t get changed. When I called it up again to look at it, it was the same as it was before PPI. I redid it and that resulted in our getting a few less marks for the first midcourse. I think it was 5 as opposed to 7. Five is adequate. All the TPI solutions agreed perfectly. Our onboard TPIs and the ground agreed within a couple of feet per second, so we decided to burn the PGNCS. At the first midcourse in all three axes, the biggest one was 0.9. We burned the first midcourse on the PGNCS, and there was no disagreement between us and the Command and Service Module. On the second midcourse, the numbers were so small that we shouldn’t have burned, but we went ahead and burned them anyway. I would think that it wouldn’t be that smart, but maybe it was. I did not make a line of sight correction until we were at 7000 feet. Beautiful targeting. I probably could have waited until I was closer in than that, but I didn’t really feel too good about it. The braking velocity was 29 feet a second and that’s exactly what it was. Line of sight control was just beautiful all the way in, and what the needles were saying agreed very well with what was happening on the Lunar Module until we were close in. Then as you noticed, we went out to the north about 70 or 80 feet and brought it back in. When we were about 600 feet out, I could see down the side of the Service Module, so I knew we were out just a little to the side. As opposed to the usual Kamikaze brake that I usually make, we kept it very conservative. We talked about that before the mission. We decided that we would always keep the braking within something that the Command and Service Module could do. This means that, contrary to the braking gates that we use in the LM, you sort of have to lead them. In other words, at the range that you want to be at, you almost have to be at the braking velocity to give the Command and Service Module a fighting chance in case it has to do it. I never had any doubt that we would do it all ourselves because that machine was working so beautifully. We just closed in and it was so good I wanted to do it again. It was really slick. After you finished your maneuver, they wanted us to do the 360—degree yaw. We talked them out of that because I was already in position, and all I had to do was the 360 yaw. We did that first and then you did your pitchover to the attitude where we took the pictures of the bubbles on the Command and Service Module. You did the roll over and then went to the docking attitude. I think that the 16—millimeter camera doesn’t really reflect on those bubbles to well, unless somebody studies it very carefully. There were sure a lot of bubbles out there on the thermal coat and on the surface. Then we went to the docking attitude and came in and docked.
Young: PGNCS and AGS were in perfect agreement. The nav was beautiful. WeÂ’ll get the numbers for this at a later time.
Mattingly: The things that I did differently on the Command Module side, as it turned out, didnÂ’t really have any effect on the rendezvous. Because of the concern for the glitch in the IMU, we did all the attitude maneuvers for all the attitude controls in the SCS, and the navigation was being done by the CMC IMU. They worked those procedures out, we talked about them, and I wrote down some notes that Stu gave to me. It was a very straightforward thing. It was very similar to the way we would handle a no-IMU rendezvous. We had practiced that kind of thing, and the only thing that was different was when you needed to know a precise angle, we only had to go to the IMU and fly to that angle. So you had the precision but you used the procedures that we had gone through on some of these failed IMU malfunctions. So it turned out that we could draw on background experience, and it worked out real nicely. We got a lot of marks. I had 20 and 22 marks prior to TPI. I really thought I was going to pick you up at insertion. I think without a better state vector I wasnÂ’t going to find them. YouÂ’d never find it in the telescope. With the sextant, I think I would have seen you at insertion with the Sun angle, had you been in the field of view. IÂ’m not at all sure I could have tracked it because the auto optics chatter was just enough to make it difficult to track. And I kept searching but I never did find it. There was a little dot near the middle of the sextant, which apparently was part of the sextant optics, and I tracked that guy for a while. I was sure being super because it was always in the center, no matter what I did. This is before you did your tweak. And then I caught it.
Young: While we were sitting up before we got into orbit, we heard the VHF radar lockup. Were you locking on us?
Mattingly: I talked to you on VHF.
Young: But we heard the tone; I forget where it was.
Mattingly: Before we got into orbit?
Young: Yes.
Mattingly: Yes, I locked up on you just prior to the insertion. I gave it a try, not anticipating any success. You were chattering and I figured IÂ’d just do it for drill, and it locked up. I blocked the inputs until I received a comparison with your radar. But it had been correct. And you didnÂ’t stop talking. You were talking in the middle of my lockup tone.
Young: I know it.
Mattingly: I didnÂ’t think it would work, and it worked just super.
Young: I was really surprised.
Mattingly: And the correlation between the VHF and the radar I thought was amazing.
Young: Yes, it was really beautiful.
Mattingly: Everything on my side was just better than I've ever seen it in a simulator. I received a state vector from the ground, and as soon as you moved into the darkness, I picked you up in the sextant. It was a flashing light. noticed I didnÂ’t pick you up in the telescope until I had you in the sextant at 100 miles. I picked your flashing light up in the telescope at 70 miles. And that was the first time IÂ’d been able to recognize it in the telescope as being your beam.
Young: That old 1400—mile beacon is pretty good.
Mattingly: With the sextant, it was just beautiful. ItÂ’s like a star. And at 50 miles, I had the Earth in there along with you and it still showed up nicely, even though the Earth was right in the field of view, which some people had worried about. I had 10 and 13 marks for the midcourse 1.
Young: Yours was better than ours.
Mattingly: Everything was working so well that the marks were just pouring in. And I made a correlation of the boresight between the telescope and the sextant and where you boresighted. In the telescope, you were located at the bottom and about one line at the bottom of the crosshair pattern of the sextant and about one line width to the right. And I thought that was super agreement between those two instruments.
Speaker: Something less than 0.2 of a degree.
Young: Yes, I think down at the bottom is 0.1.
Mattingly: It really surprised me how well it worked. And everything else we did on the rendezvous itself was nominal. Docking — We got out of sync with ourselves on this business of taking the photo sequence. I think we really did the right sequence, taking you first. I got the impression that both you and the ground were getting very impatient about getting started on docking, and it had been my plan before flight, my stated intention, that 15 minutes before darkness I was going to start my approach. I would do the photos and all that up until that point. And then it seemed like everybody thought I was being superconservative, but I had 20 minutes before darkness and everybody was getting ginchy that I wasn’t making the approach.
Young: I thought we made our approach right away.
Mattingly: I guess I wasnÂ’t concerned about the approach in the dark after a previous experience. There was no reason to waste gas hurrying. So I didnÂ’t. And we got there about 5 minutes before dark. And the only thing I would change by doing it again, I would approach faster. It was very obvious that you could see the LM attitude dead band. I was trying to play it cool and not chase the line of sights. But IÂ’d. lose my courage. Every time you get a little bit off, IÂ’d go right over and several times I caught myself moving back and forth, chasing your attitude dead band. Y0UG When you approached, I was looking right at you, and you were really lined up well through the COAS. I could see you through the COAS. And as a matter of fact, if they painted a line underneath the window with a mark down it, you wouldnÂ’t need that docking adapter. You could dock with the line and make it every time.
Mattingly: I had that impression. I had the impression that if the target had fallen off the LM, it would have made very little difference in docking. The one thing IÂ’d do differently is IÂ’d approach faster. ItÂ’ll make your line of sight rates less expensive to control. They arenÂ’t going to be big; theyÂ’re going to be dead band kind of things. The other one was that I got contact and I was anticipating hearing it like everyone had said you would. Apparently, I approached slowly enough that I didnÂ’t hear anything. I saw the LM jiggle a little bit, and I donÂ’t know if you heard me contact.
Young: I didnÂ’t hear it either. We didnÂ’t feel it either.
Duke: I felt it; it rattled a little bit.
Mattingly: Nothing happened, so I thought, guess weÂ’re going to do something else. I decided IÂ’d thrust at it but nothing happened. I didnÂ’t feel any motion and I was just ready to thrust again when the barber pole came up. So I must have just had it laying there, and it just needed a little push to get the capture latches in. And again, I think a faster closure rate would have made more positive docking.
Young: You could have pushed the LM4 backwards.
Mattingly: But there was no rebound on the part of the LM. And they always talked about if you donÂ’t hit it hard enough to capture it, youÂ’ll knock it away. But it didnÂ’t. It just lay on the nose there, and all I had to do was push it a little bit.
Young: As soon as you said barber pole, I shut the PGNCS off and we were there. No thruster, no extra thrust applied, none of this fighting each other.
Mattingly: I went to free as soon as we contacted. The retract was just like the original one.
Young: Very slow until it got there, a hangup on the edge, and all of a sudden the docking lights just appeared.
Mattingly: Same pattern. For some reason, we didnÂ’t take photographs of this. I donÂ’t know why. The ground called and said donÂ’t take photos.
Duke: We did one thing procedurally at insertion. We had a lot of dust and pebbles floating around in the cockpit with us. We did turn on the cabin fan and left helmets and gloves on until docking, because we had so much dust in there.
Young: That didnÂ’t clear any dust out because you have to open the inflow valve to get any of that stuff in the suit loop to clean it out.
Speaker: It just circulates it around. It has a filter behind it.
Speaker: Does it have a filter behind it? Well, it didnÂ’t clean much of the dust out.