Spacelog Apollo 13

Go ahead.

On the P33, just like to verify that you changed the NOUN 88 values for this last star. It looks like they haven't been changed. Over.

Okay, Vance.

That's better. Let's read you what we—what we have. We have what they had in the flight plan, and if it's been changed from the flight plan, we don't have it.

Stand by 1.

We think you're right, Vance. It looks like they used the same set of NOUN 88 for both stars by mistake.

Apollo 13, Houston.

Go ahead.

Go ahead.

Okay. We have several items, here. First, is a reminder on the PTC that R₁ should be 375—0.375 degrees as last night, to get 0.3-degree rotation rate. The second one —

Okay. Copy that.

Okay. The second one, at 32 hours looking at Bennett's Comet—we want the pictures taken when the spacecraft is as stable as it's going to be before starting PTC. The stability requirement is very high. We weren't sure if you understood that from what we passed up. In addition, the photographs might not show as much as the eye can see of the comet, so if you see anything interesting about the structure of the comet, why, sketching it is in order and is encouraged. Over.

Okay, Vance. What we'll do is, when we get to attitude, we'll disable the quads and do like we did last night; we'll let GUIDO and you people down there tell us when you think we are stable enough; then we'll do all this work with the DAC on the sextant, first; and then when we get that done, we'll go back and put the sextant eyepiece back on and see what we can observe visually.

Okay. That sounds good. Also, while you are waiting for the vehicle to stabilize, it might be interesting to have the eyepiece on and be looking at it visually. Okay. Next item: your SPS burn had no anomalies whatsoever. It was a very good burn.

Okay. Very good.

Next item: request hydrogen tank 1 HEATER OFF for balancing purposes.

And Apollo 13, another item: something that we have observed and you might be seeing is a slight TCE fluctuation on fuel cell 3. This fluctuation has been going from about 152 to 160 over a 37-second period. It has been seen on other flights in the past. No one is worried about it, but the usual fluctuation is about 1-1/2 degrees instead of 7 seconds, so I thought you should be aware of it.

Okay, Vance. And one other slight distinction we've noted is the flow of hydrogen versus the oxygen is not exactly matched on fuel cell 3 either.

Okay. We copy. And the last item: we'd like to send you an IRIG update, so at your convenience, request P00 and ACCEPT.

Okay. We are in P00 and ACCEPT, Vance.

Okay.

Quad C and D are disabled, Vance.

Roger. Disabled. And down here, we see that your hydrogen and oxygen on the fuel cell are exactly matched, so we suspect it's purely a spacecraft read-out problem.

Okay, Vance, let us know when you're through with the DSKY so we can load NOUN 88?

Roger. We'll let you know, Jack.

Okay. You're go for the pictures.

Okay, Vance. We tried our AUTO OPTICS and couldn't pick it up there. We're pointing pretty much right into the Sun, and things are pretty well washed out. And I've gone to MANUAL OPTICS and I'm trying to get 0.8, 12.5 on the shaft and trunnion, and I still can't pick it up. So—it's very light in the sextant, so I kind of think maybe we're too near the Sun to see it.

That's right, Vance. The sextant is all—it's—it's all milky and it—any comet that could be seen through there is just going to be missed in the background.

Okay, we copy that. We got some discussion. Stand by.

Okay, Vance, it isn't—we're not looking into the Sun—what we are getting is a large reflection from the Sun behind us off the LM; and it is—it is coming on that quad 1 there, and that quad is reflecting back into the sextant.

Okay, Jack. Understand. Just a question: if you look through the telescope, can you see the comet at all? Over.

No, I can't, Vance. It's—it's still too light.

Say, Vance?

Roger. Go ahead.

Are the flowers blooming yet?

Gee, I sure haven't seen any.

Okay.

Hey, we've—we've got quite a discussion down here on your trying to observe the comet, and this reflection is not unexpected. And give us another minute, and we'll be back with you on something on that.

Okay. I doubt very seriously though, if we take any photographs with high-speed black and white with the light coming into the sextant that you're going to get anything out of it.