Spacelog Apollo 8

Roger. We're reading you much better now. Jim can go ahead with his transmission to the guidance troops. They have one question before he starts. They would like to know what his GERU was at TIG, 114 hours. Over.

Roger. Wait one. The GERU at TIG was plus 07972.

Roger. Plus 07972.

Apollo 8, this is Houston. We are ready to copy your data. Over.

Okay, Houston. Based on the P37 with minus MA solution, I got an impact longitude of minus 160.95. I biased it to get an impact latitude—longitude of 163.75. I wanted to change my impact point 30 degrees to the east, and I tried to determine what my P30 burn parameters would be to do this, and I got a DELTA-V_X burn of minus 11.6 and a DELTA-V_C of plus 600, DELTA-V_{Y of zero. Now that changed my previous DELTA-VX burn from minus 50.2. I just want to know whether that meets with their approval.}

Roger, Jim. We copy and will run it through the mill and give you an answer.

Apollo 8, Houston.

Go ahead, Houston. Apollo 8.

Apollo 8, this is Houston with a flight plan update.

Go ahead.

Roger. At 100 hours 30 minutes, change star number 02 from one set to two set. Over.

Roger. Star 02 from one set to two set.

Roger. Also, set number 2, set number 2, change star number 11 to star number 7. Over.

Roger. Eleven to 7.

Roger. Then after star set number 3, initiate PTC again; pitch 10, yaw 45. Over.

Pitch 10, yaw 45.

Roger. Then at 101 hours 30 minutes, delete the earth horizon settings. Over.

101:30, delete the earth horizons sightings.

That's affirmative. The folks here are evaluating the thermal situation. Looks like you will be out of PTC rather at an extended period of time. That's the reason we have you initiating PTC again there around 101 as soon as you finish those three star sightings. We are still working on the—about the next 10 hours after 100 hours. We are looking at the thermal situation, and the star sighting situation, and we will be giving you more updates later on. Over.

Roger. We don't have a thermal problem at all now, do we? All our indications here are normal in here.

Roger. Everything looks okay. I think they're just kinda trying to look down the track aways.

I'm all for keeping it that way.

Roger.

We deleted them.

Apollo 8, Houston.

Go ahead, Houston.

Roger. Frank, I would like to talk to you for a minute or two about the AUTO OPTICS funnies that you have been seeing throughout the mission. Over.

Go ahead.

Roger. The problems you have run into so far are due to some unknown source, probably EMI or the like loading your CMC trunnion cell which is now 91, so it doesn't really represent your true trunnion angle. Now this loading problem we don't feel implies any decrease in the reliability in your CMC at all. We think that the best way to circumvent the problem is to cycle the OPTICS ZERO switch first to OFF and then ON prior to using the optics for any purpose. And with that procedure, I think you probably won't have any more problems. Over.

Roger, Jerry. Understand. I do notice one difference. We did preferred REFSMMAT's. The first we had trouble with; the last one worked out as expected. I noticed for the first one that when the option came up, it was for nominal option, whereas for the very same procedure for this last REFSMMAT change, we got … preferred REFSMMAT option. …

Apollo 8, this is Houston with a comeback on your entry navigation calculations. Over.

Go ahead.

Roger. We went through the charts and got exactly the same answer as you got. Looks like your procedure is very good; looks like it was real good head. You remembered to average out the velocity. We also went ahead and computed the problem to verify the chart and got a good solution. Over.

Roger.

Thank you very much.

You're welcome.

Now if we can get our state vectors to agree, we'll be in business.

Apollo 8, Houston.

Apollo 8, Houston.

Go ahead.

Roger, Frank. Is Jim listening?

Listening.

Roger. On your question about the option: PROGRAM 40 sets the preferred flag such that the next P52 will come up option 1, subsequent alignments after that come up option 2. Over.

Roger. Understand. So 40 will have to come up with a TIG burn with an option 1 for us.

Roger. Now concerning your restart that happened in lunar orbit, for the peace of mind of the computer people and the MIT folks, we have a question. Did VERB 34 ENTER to a flashing VERB 51 in P22 cause your restart? Over.

Yes. That sounds like it was it.

Roger. Thank you, Jim.

That must be a “no, no”.