Spacelog Apollo 13

But, Joe, assuming the S-IVB is still stable. The object I was looking at was definitely tumbling.

Okay, Fred. As I recall, it was stable then, although it's tumbling now.

Okay. It probably was the SLA panel I picked up.

Right. Incidentally, I guess the guys in building 6 —

Oh and I think we -

Go ahead, Jim.

I—I think we answer to number 9. We—at around 5:32, I think, was when we think the number 5 light came on in the S-II, and a definite vibration which was more than just a high-frequency vibration we got with the normal S-IV burn, and then the light came on. I called ECO thinking from the training that it was 7:42 and looked up at the time and realized it was early. And then, soon after the light came on, the vibration stopped and the engine or the booster smoothed down. It was very smooth from there on.

Okay. This may be a stupid question, but do you have any idea what the frequency of it was?

Only to say that it was much higher—I couldn't really guess now. It was rather a rapid longitudinal vibration.

Okay, Jim. Stand by now for a minute, we're going to switch OMNI.

Houston, 13, …

13, Houston. I read you. We still have quite a bit of noise on the loop.

I'll stand by. Roger.

Okay, Jim. It should be pretty good now. We copied you answering question number 9.

Do you want any more comments on the S-IVB vibrations?

I don't think so. When you get all done, I'll—I'll make a quick check to see if the booster people have any—any additional questions. You skipped number 8, Jim; could you go back to that for a second?

Okay, stand by.

Our only comment there, Joe, was that the burn on TLI, to our knowledge, was about 3-3/4 second longer than had been predicted and that was the only thing that we really noticed; otherwise, looked like PI [?] was nominal at cut-off.

Okay, understand.

Okay, on comparing the flight of 13 to Apollo 8, lift-off was about the same amount of vibration as I noticed on 8, but at the beginning of the flight, there was less of the sideways motion than we experienced on Apollo 8. The S-IC separation felt more violent on 13 than it did on 8, maybe that's because I was in a different seat, I don't know. But there was about three sharp transients of the cut-off and a couple of big bangs where we were thrown backwards longitudinally on our straps before the S-II went off. And the S-II was, of course, just as smooth on 13 as 8 except for the number 5 engine. And we did not experience the vibration that we experienced on 8 towards the end of the S-II burn. And the S-IVB was—had more vibration than we had on 8.

Okay, Jim, got all that.

The up—the update on the ORDEAL ball was a good one. At the burn, we were about—just about 8 degrees. We had to pitch down. The yaw was right on all the way through the entire burn, and just towards the end of the burn, the ball started going black in pitch a little bit.

Okay, sounds good, we'll give Mike Wash a gold star on that one. Okay, Jim, stand by 1 while I see if we have any extra questions.

Jim, while we're waiting to see if they have any more questions, I'd like to read you the booster people's preliminary analysis on the—the S-II cut-off. Over.

That would be very interesting. Go ahead.

Okay, preliminary analysis of the data indicates that the center S-II engine vibrated at a somewhat higher amplitude than we've seen on previous flights, and it started at about 160 seconds into the S-II burn. As a result of these vibrations, the engine chamber pressure decreased to the level where the two low-level thrust sensors, the thrust-okay sensors, initiated center engine cut-off. Early evaluation of data indicates that no damage occurred to the engine, and the cause of the increased vibration amplitude is still under investigation. Over.

I thought it was the center engine.

Yes, right.

Joe, do you have any word on what marks we had for TLI?

At the time of TLI, as I recall, you had 6 seconds longer than the nominal burn which was 3 seconds longer than the B-sigma low burn, and you were also GO for a second-opportunity TLI if we had required one.

Okay, we were just wondering because it appeared to us that we had a longer TLI burn than had been predicted.

Yes, you did. We confirmed that—that—that cut-off time just about as you saw it, and I don't have an explanation for it, but it was within the B-sigma margin.

13, Houston.

Go ahead.

Roger, we have no further questions. All the answers were clear and satisfactory, and we thank you very much. You can press on with the rest of your busy day.

And, Houston; 13.

13, Houston. Go ahead.

Okay, Joe. Out window 5, I just picked up the tumbling object again so, for sure, it must have been a SLA panel. I don't think we could still be in the proximity of the S-IV at this time.

I don't think so, Fred. It's several hundred miles aft of you. 700 miles is—is the number, I'm told. And since the SLA panel didn't make the midcourse correction, that might be it.

Yes, it's, I can't really tell for sure even through the monocular that it is, but it looks the same relative position to the stars. And the best I can tell about the same intensity and still about the same distance from us.

Can you see it tumbling. Does it have a shape, or is it a point?

No. I can tell it's tumbling; I guess the flat side not only is facing me, it's not only much brighter, it also grows larger.

Okay. Very interesting. We'll see if we can figure out where that's relative to you. They keep updating the S-IV impact on us a little bit. The last guess we had was that it will impact about the same longitude we gave you but close to zero latitude and a little bit later. You still won't be able to see it. And they're saying it might make a —

Roger.

— they're saying it might make a 100 to 120 foot crater, too.

It'll still be past the terminator for us for awhile.

Right. It will be at about the REV 20 terminator, so it will be late in your lunar orbit activities before you will be able to photograph it, and FAO is looking at whether we can work that in or not.

The objects in the foreground are parts of the LM that you're looking at.

The camera is now going to …

We can just barely see those parts of the LM. They must be in a shadow.

Okay. Now you are looking at a thruster quad at the lower part of your screen.

I've got the f-stop all the way open now, Vance; that's quad—quad 1 you're looking at with the LM should—The Moon should be in view just over the top of the quad.

Right. We see the nozzle of the quad, but it's dark and it's not easy to see.

13, Houston. INCO suggests you try AVERAGE if you're in PEAK to see if that gives us a better picture.

Okay. We're in AVERAGE now.

I think that helps out. We can see it better.

Okay. Now, 13, request you either move it away from the bright area or else move it back to PEAK. Over.

Okay, Vance. I cranked the focus down a little bit. Is the quad coming in any better now?

It's coming in about the same, Fred, and you're a little weak now on the COMM.

We could see when you went back to PEAK.

And I'm now … all the way out.

Okay. We could see you zoom in on the Moon, and it's near the center of our screen, just a little to the left. Very clear.

Yes. I show it just about at 38.

We can't tell if it's gray or light brown, though.

Do you have your grid down there, Vance?

That's negative, Fred.

Okay.

I don't know if you can make out the features there, Vance, on the Moon, but it looks like the terminators are at central plains area somewhere around Descartes, maybe.

Okay. We're—We see it just as a bright portion of the lunar disk, and it looks a lot like you see it from Earth. Very bright. We are unable to see any features at all.

It's pretty much the same with the eyeballs in here, and it looks a little bigger now. But the only way I could see it very good at all was with the monocular, a little while ago.

Okay, Fred. Very good. We'd be interested to seeing the cabin when you get ready for that, too.

Okay. I'll set up now.

And, Vance, we're counting down to midcourse-2, we're up to, in our checklist, to minus 6 minutes to go.

Roger. Minus 6 minutes. Understand you're about ready to turn on the gimbal motors and all that sort of thing. Okay. We see the computer now in the upper middle part of the—the panel. I think we see somebody's checklist in the center couch. It must be Jim holding the checklist.

Right. And what Jim's holding now, he's got a pen in his hand we've rigged on a string, as sort of a simple-minded accelerometer. This burn's pretty short and I'm not sure even that's going to show very much. But we'll see if it'll stretch out at the end of its string.

Yes. We see the pencil at the top of the picture floating around. And Jack's coming into view now.

And I've gone back—Okay, I've gone back to AVERAGE now and … pitch up.

Now in a few minutes, Vance, I guess we'll see how about the only system we haven't used yet works. Everything else sure has worked mighty fine.

Right. The spacecraft's really working nicely. Okay. We're picking up panel 2 now. Still a little bit of the checklist.

Wondering if you can pick up the caution array there?

Right. We just saw your—your testing of the caution and warning system at the left-hand side of the panel on our TV. See the lights all flash on. You're doing it again.

You mission timer's showing up as a—a brilliant green in the upper left-hand part of the picture.

Roger. I got the camera kind of canted on you here, Vance.

Vance, Jim's going to go to VOX now.

Vance, how do you —

Roger. Read you loud and clear, Jim.

Okay. We'll—what we'll do—We'll be on VOX for the remainder of the burn and preburn countdown.

…

… And what we're waiting for is 54 minutes on our counter or 20 which would be minus —

Jim, we hear clipping on your VOX. Could you adjust it so that you're coming in continuously all the time?

Okay. Stand by 1.

1, 2, 3, 4, 5. How's that, Vance?

Okay. That's better.

Vance, how do you read the CMP on VOX?