Spacelog Apollo 8

The next voice you hear will be that of the smiling Irishman.

Apollo 8, Houston. Over.

Go ahead.

Good morning, James.

Oh, it's Michael Collins, is it? Good morning to you.

Righto. And we're looking at your pitch CDU readout down here and looks to us like you are about 25 degrees off the 180 for your PTC, and we were just wondering how come?

We've been looking at that, too. It keeps wandering off in pitch for some reason more than yaw. I was just about ready to go back to it again. I had to go back one time, and I was just seeing how far she would drift. I thought it would drift out a ways and come back by itself, but it is not doing it.

Okay.

Houston, Apollo 8. We're in the process of doing the trunnion bias check; then we will go to P23.

Roger. Thank you, Frank.

Houston, Apollo 8.

Apollo 8, Houston. Go.

We like to have the PTC attitude to comply with P23 requirement.

Roger, Frank. Stand by.

Apollo 8, Houston.

Go ahead.

Any time you want to start on those P23's is just fine.

Okay. I was just checking. I just wanted to know how our thermal control was going before we left.

Apollo 8, Houston. Over.

Go ahead, Houston. Apollo 8.

Your temperatures are looking good, Frank. There is still a differential temperature between quads, but nothing that would cause us in the slightest to worry about doing P23.

Apollo 8, Houston. Over.

Go ahead.

Roger, Jim. We've been looking at these stars that we gave you this time for P23. It looks like the second star, number 11, has a trunnion angle right out to the limit, about 49.7 degrees. And we're thinking it might be a good idea to switch you over to star 1, which has a much smaller trunnion angle. What do you think? Star 1 is Alpheratz.

Fine with me; I would just as soon take star 1.

Okay. That will be then in place of star 11, star 1, and in place of lunar far horizon, lunar near horizon; and it remains two sets. Over.

Roger. Star 1, lunar near horizon, two sets.

Apollo 8, Houston. Over.

Apollo 8, Houston. Over.

Go ahead, Houston. Apollo 8.

Roger. Fine. Old golden fingers there is getting so swift we missed some marks on the downlink. I wonder—if you hand recorded them, could you read us your three marks—trunnion angles, your three trunnion angles on star 2 and the last four trunnion angles on star 1. Over.

Do you read me still, Mike?

Stand by. We're not reading you good enough, so we'll wait until you get a better OMNI.

That ought to be a good one.

That is a good one. That's loud and clear.

Okay. Star 2 trunnion angle, first one 05245, second one 05243, next one 05241; last 4 trunnion angles 04133, 04133, 04132, 04132.

Apollo 8, Houston. Over.

Go ahead, Mike.

Okay. We're predicting at the nominal time of your next midcourse, which is entry interface minus 2 hours—we're predicting 1.4 foot per second burn which changes your gamma at entry interface by a tenth of a degree. Right now with no further maneuvers, your gamma is minus 6.39 degrees, and we're going to steepen it up very slightly to hit the center of the target line, and it will be after the maneuver minus 6.51. Over.

Very good.

Anything else you want like that?

No. I just wondered—we hadn't heard whether we were going to do it or not and so on.

Roger.