MSC-07631 12. Lift-off, rendezvous and docking

Cernan

LM powerup and launch preparation went well. We did not do the P22. Everything else just went as advertised on the LM. She powered up beautifully. The lift-off was normal. Obviously, we got all our pyros, and we lost no changeover, Parker valves, or anything. Very soon after lift-off, we had apparent loss of comm, a lot of noise in the S-band. It turned out that we were down-linking, but there was something wrong with the up-link. So the CDR watched most of the guidance and would call out, in the blind, altitudes and GOs and what have you as we pitched over and pressed on up. For about the first 2 or 3 minutes, the lunar module pilot had to concern himself with trying to get comm back.

Schmitt

Apparently , Goldstone dropped the up-link. When they were getting it back, I was switching omnis, and for a while there, it was just completely out of phase. They had a continuous down-link on us.

Cernan

It was a very inopportune time, I might say, because it happened just right after ignition. I think that's something, though, that the INCOs are going to be able to clarify. We certainly can't give you the details. It's just that there was essentially no comm on all the antennas.

We flew into a trajectory that appeared to be nominal. The AGS showed us slightly out of plane. As a result, our tweak at 9 ft/sec was minus 4, minus 9, and plus 1. We burned out X, Z, Y, in that order.

Schmitt

It was about 7 ft/sec, a little over 7 ft/sec.

Cernan

It looked like we might have had a g-sensitive drift in our Y-accelerometer in the PGNCS. The tweak was excellent because our rendezvous was just as nominal a rendezvous and as nominal a trajectory profile as I've ever been involved with. The drift in accelerometer did not bother us anywhere else in the tracking or in the rendezvous at all.

Rendezvous navigation followed the checklist; we got right off the form very well. We got all the updates into the AGS. The residuals in the TPI burn were greater than what I had expected. We did not record them because I wanted to get them nulled out just as soon as possible. I don't know the tenths, but they were minus 7 in X, and they were 14 and 4, and I'm not sure whether they were plus or minus in Y and Z. They were large, larger than I'd expected. They were minus 7 and 4-point something and a 4-point something. We reduced those to less than 0.2 ft/sec. From then on, we continued to plot right through the midcourses right up the pike on a nominal trajectory.

Schmitt

The comm was good. I have a couple of comments about the AGS. Early after insertion, I always checked the accelerometer. They looked real good. About 5 or 10 minutes later (I can't remember exactly) , I looked and I'd accumulated maybe a foot and a half per second in X. I did a gyro cal, and after that, there was no significant accumulation in X. It went very well. I did that without talking to the ground, but I felt I had an understanding with them on that.

On the TPI solution, the AGS was essentially within 2 or 3 ft/sec, a good TPI solution after six marks. The insertion solution was not very good. It was off by a number of feet per second in X and even more in Z. This was the first one of 17 marks. The PGNCS recycle and PGNCS final were very close, within a couple of feet per second.

Cernan

Midcourse Solutions - The first midcourse solution agreed effectively all systems, except AGS out of plane was a little bit high. The decision was made to burn the onboard PGNCS solution out of the LM, which was minus 1.2, plus 0.4, and plus 0.3. We continued to track right up the pike. Midcourse 2 came up, and we again prepared all the solutions. The AGS out of plane was still a little bit high and actually in the opposite direction from the PGNCS. We had a slight variation in the CSM solution in Z. I don't know why. It came up with plus 5.4 ft/sec in Z. So we really didn't get a very good correlation between the CSM and the LM on the second midcourse. But the PGNCS was still performing, the radar was still performing, and based upon our trajectory plot and based upon our following a nominal inertial line of sight rate, we decided to burn the onboard PGNCS solution in the LM. It was minus 0.4, minus 0.7, and minus 1.6.

From there on out, we just continued to follow the inertial line of sight angles. There was very little tweaking in either Y or Z. We just sort of floated right through the braking gates. At 1 mile, I think we took about 6 or 7 ft/sec off to hit 30. We met all the gates as prescribed and just came moving very slowly into the final stationkeeping.

We went into a formation flight around the CSM. We got a good inspection of the spacecraft and the SIM bay, the report of which is in the transcript. Everything looked good to us The command module maneuvered to the docking attitude. The LM just took its docking attitude, gave stationkeeping control to the command module, did pitch and yaw maneuvers, and stood by for docking.

Evans

One of the noticeable differences between this docking and the docking with the S-IVB is the fact that the ascent stage did dance a lot more than the S-IVB did. The S-IVB is steady as a rock. The LM dead band would change attitude, and you'd try to follow it. On the first attempt, I must have had less than 0.1 ft/sec, just barely closing. I was just taking it nice and easy. We made contact and did not get capture. As soon as we didn't get capture, it was obvious we were closing too slowly. We backed off a couple or 3 feet, renulled the rates, initiated the closing rates, and got capture. As soon as we got capture, both vehicles went to CMC FREE I looked out, and I had some rates in the Old and I'm sure that the LM had rates also. He must have had.

Cernan

We went FREE Upon capture, the LM went FREE The CSM trying to null the rates ended up perturbating the LM and giving us rates.

Evans

We finally gave up on that mode and had the LM go to ATTITUDE HOLD. Once you get ATTITUDE HOLD, the CSM could null the rates. We got it lined up and attempted the hard docking. There was no problem. The probe retract came back. This time, it didn't sound like it was as much of a ripple fire. It was more of a "phhtt." It was a quicker hard dock than it was the previous time.

Cernan

I want to say something about the visual sighting during rendezvous. From the LM, I was able to see the command module when it was sunlit at somewhere around 100 miles. I definitely defined that that was the command module. After the command module went into darkness, I could not pick up his tracking lights until we were well within about 40 miles. I could not pick up the docking light, the rendezvous light, of the command module until we were well within 40 miles. It was initially a very dim, faint flash. I was able to verify on board that the LM tracking light was working. I finally figured out how; it was reflecting off the underside of the EVA handrail on the left forward side of the LM. I could see the LM tracking light flashing. There were some particles we took with us that stayed with the spacecraft, and you could see the sequential flash off the particles as the result of our LM tracking light.

Schmitt

Regarding the television and photography from the LM, we'll just have to wait and see how it turned out. I took a lot of footage. We put it on not only the ascent mag, but we put it on the other mag. That includes the SIMbay. Right or wrong, we did have a Hasselblad on board, so we have a lot of Hasselblad photography.

Edits and errors by Eric Hartwell are licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 2.5 license. The original NASA material is copyright-free.