Spacelog Apollo 13

Apollo 13, Houston.

Go ahead, …

Roger, You're coming in a little weak. Have a recommended roll rate for this PTC, if you could copy.

Alright. Go ahead.

Okay. Recommend that you put in R₁ the following: 03750, and that should give you exactly a rate of 0.3 degrees per second. Over.

Okay. Enter 03750. Is plus or minus our choice?

Roger. The same direction you rolled the last time, which I believe is plus.

Hey, Vance, would you monitor our rates and kind of give an idea of when you think they're stable enough to start PTC.

Roger, Jack. We'll take a look and let you know as soon as they look stable enough.

Okay. I've got quads A and B disabled here.

Roger.

Have they come up with an idea of how much fuel I used on the docking and also the P23 session at 5 hours or 6 hours.

I think we can give you something. Stand by a minute.

Apollo 13, Houston.

Go ahead.

Okay. It's looking good so far as RCS consumables are concerned, Jack. You're standing about 20 pounds above the curve right now. Looking at the TD&E, you expended 65 pounds or—Stand by—55 pounds, correction on that.

How much?

And 14 pounds on P23s. You used a little more out of quad A than out of the others.

Okay. Thanks, Vance.

Roger.

Hey, could you say again the TD&E fuel? We've got a different—we all heard different things.

I said 65 and then corrected that to 55 pounds.

Apollo 13, Houston.

Go ahead, Houston.

Okay, Jim. Your rates look good. It's okay to start the roll again, if you'd like.

Hello, Houston; Apollo 13.

Apollo 13, go ahead.

Okay. Ready for a little count here, Vance, and I'll shoot another picture. We found the Earth again.

Okay. We'll be standing by, Fred.

A 3, 2, 1 -

MARK.

Hey, Houston, 13.

3, 2, 1 -

MARK.

Apollo 13, Houston.

Go ahead, Houston.

Jim, Houston here. Two items: first of all, your PTC is looking very good and it should carry you through the night; second point, have a procedure to give you, if you're ready to copy. We'd like to set three bits in the computer, and I'll explain why.

Go ahead, Vance, we're ready to copy.

Okay. The procedure is as follows: VERB 25, NOUN 07, ENTER; 1331, ENTER; 7, ENTER; and ENTER. Explanation as follows. During the P23s, there was one time when VERB 37 was entered into the computer at about 16 seconds after the OPTICS ZERO switch was flicked to ZERO. This is a very uncommon anomaly in that, if you do this during—0.4-second interval at around 16 seconds after you zero the optics, some OPT-mode bits are reset; and this would mean that, if you had a OCDU fail, it wouldn't be indicated; so all this procedure is doing is setting these three bits back again where they should be.

Okay, Vance, and I guess I'll try to be slower on that VERB 37.

Yes. Actually slower or faster, either one, I guess. Well, yes, slower. It's a very unusual thing to have that happen.