Spacelog Apollo 13

Yes, everybody wondered if you would remember that; by golly, you did.

Hey, Jim, I got a little bit more information—maneuver pad, I got LAT/LONG range to go, VERB 10 and GET; if you got a place to copy that down, I'll give it to you for EMS.

Okay. Stand by.

Go ahead.

Okay, Jim. I just have the last three blocks. NOUN 61: latitude, minus 021.62; longitude, minus 265.37; range to go, 2162.9; VERB 10:36291: GET of .05g is 142:41:30; read back.

I didn't get the latitude, but the longitude is minus 165.67; range to go, 11629; velocity 36291; 142:41:30.

Okay, Jim. The latitude is minus 021.62; I have a correction on the longitude—minus 165.37. Go ahead.

Roger, Jack. The latitude is minus 21.62; longitude is minus 165.37, and this goes in conjunction with that midcourse 7 pad you gave us.

That's affirmative. That means no maneuvers between now and midcourse 7. And this is a horizontal in-plane burn, plus X, toward the Sun, 19.3 feet per second.

Roger. …

And, Jim, on the—Setting up the AGS, right after you do the 400 plus 5, you should do a 400 plus all balls. And one other point we want to clarify is that we know that you're sure that this burn will be made with the plus X-axis pointing at the Sun to make the entry angle steeper. You got it?

That's right, Jack. What I'm going to do is—We'll stop with the Earth in the commander's window, the COAS down, and then I'm going to maneuver the spacecraft so that I have the lighted portion of the Earth at the top of the window; that is, the COAS will be along the plus-Y of the spacecraft and the top of the window—of the rendezvous window, I should be looking into the Sun. That means I'll be burning towards the Sun and steepening the angle.

That's affirm, Jim. I—You got the attitude right, and did you copy about doing a 400 plus all balls after—you do the 400 plus 5? That is, a 400 plus 5 and a 400 plus all zeros back to back.

Roger. I have copied that.

Jack—this is Aquarius. I'm not too sure how long or with what force the venting is going to do to our trajectory. However, you might keep a check on that. It may have been going on for some time.

Roger, Jim. We've been taking a look at it. We haven't been able to detect it on the Doppler, however.

Roger.

And, Houston, Aquarius.

Go ahead, Aquarius.

Jack, would you give me a time hack on an even GET so I can start my watch.

Okay. Coming up on 87 hours and 35 minutes, we will be there in 30 seconds. Set it for 87.35.

Just give me a hack at 88 hours.

Okay. I'll give you a hack at 88 hours. That'll be another 25 minutes.

Houston, Aquarius.

Go ahead, Aquarius.

Okay, Jack. Let's just talk over how I'm going to get to the attitude and then do the burn. What I'm talking about is the control techniques. The way it looks now I'll try to stop the spacecraft in yaw with the Earth out my window, then we'll be in GUIDANCE or we'll be AGS CONTROL; we'll be in—yaw will be in MODE CONTROL. Then we'll be using the TTCAs to control the pitch and then control the roll. I don't see another way we can control the combination that we have here without using the TTCAs. Then we will also use the TTCA during engine burn. Do you people concur with that technique?

Jim, that sounds like the one that is best to use to me. Let me talk it over with the rest of the guys here, and we'll advise you.

Jim, in that control mode, that sounds like the best way to go. The only thing you'll have to do is to get ATTITUDE HOLD in the AGS, and so before you start to maneuver, you'll have to bring the AGS up, and get a 400 plus all zeros in there, and then AGS will respond in yaw when you go to MODE CONTROL. That is, AGS will control your yaw in MODE CONTROL and your pitch and roll can be taken care of in PULSE with a TTCA. After you get in attitude, then, you'll have to re-do an AGS body axis aline which is 400 plus 5, then go back to 400 plus all zeros again.

Right, Jack. That was my next question. I don't want to aline the AGS ball 000 until I am in position, so we use that as a primary attitude burn monitor device.

And, Jim, you can do a 400 plus all zeros any time you want to; that just tells the AGS that you want it to control your attitude should you go to ATTITUDE HOLD in MODE CONTROL.

Roger. I understand, but after we get to the attitude, we'll do a 400 plus 5 to get the AGS aline ball, and then we'll do a 400 plus zero.

Affirmative.

Another thing, Jim, is while you're maneuvering to that attitude using AGS to control your yaw, if you find out enroute to that attitude that you didn't quite have the yaw where you wanted it to be, you can use your ACA and tweak up the yaw, and your AGS needles go right back to zero because you zero the attitude errors.

Roger. Sounds good.

Jim, you'll be splashing down about 560 miles southeast of Samoa at about 0800 local time. The weather forecast for the area is good; 1500, scattered, high broken, 10-mile visibility. The seas will be 5-foot waves, 15 knots, and you'll be going to Samoa by boat and/or aircraft. You'll spend either the night on the boat or in Samoa and return to Ellington by 141 on Saturday, the following day.

Roger. Would you tell the people of the LRL to turn it off.

Oh, no. We're going to do the whole bit.

And don't forget my hack at 88 hours, Jack.

Say again, please, Aquarius.

I want to get my time hack at 88 hours.

Roger. That will be in about 6-1/2 more minutes.

Roger.

MARK.

How are you doing, Jim?

Pretty good, Jack. Say, you might have the people look at our DPS burn card to see what changes have to be made on it for the burn.

Heard you say look at the DPS burn; you'll have to say what about it again, please.

Roger, Jack. You might take a look at our DPS burn card, our checklist card that we have in the LM, and see what changes might have to be put in that checklist.

How're you doing there, Jim?

Okay, Jack. It appears that we're going—funny diversion here, the PTC attitude in—in pitch. I'm going to do a LPD check now, but the last time the Moon went around, it was above—way away above the LPD angle and I see the Earth coming around now which is going to be pretty low. They oscillate back and forth, but each time they seem to get a little farther away from the center line. You might think of some procedure to reestablish PTC, if it's necessary.

Okay.

Jim, the only way we know of getting the as good or a better PTC than you've got right now is to crank up the G & N and we—We don't want to do that. So our plan is to just take whatever we get out of this, and later on, it may turn out by the time you get to burn attitude, you'll be right where you want to be.

Houston, Aquarius.

Go ahead.

What's our course of action to set up PTC after this midcourse at 107?

We thought you'd ask that.

The only thing we can try to do, Jim, is to get the thing up manually and see what happens. There must be a better answer than that —

Okay.

— and one course of action is to omit the midcourse and make a total midcourse, say, about 8 hours before entry. We haven't decided yet.

Right now we're talking about a 7-foot-per-second midcourse at 104 hours. And extrapolate that down to about 8 hours before entry. We gave you a pad for that—that's about, only 19 feet per second, so if it doesn't change too much—and we can get all kinds of DPS.

Houston, Aquarius.

Go ahead, Aquarius.

Can you think of any normal venting phenomena that might occur like maybe—a hydrogen tank that's over-pressurized relieving in the window?

Yes, we thought of that, Jim.

That is one possibility that we've though of, Jim, because—We heated up that tank, and we haven't been using any hydrogen and, therefore, it could be venting in the overboard release.

Right. The only other thing I can think of when I look at it through the AOT is—it did appear to be coming from one spot; but that's the only difference although I can't see where it is coming from because it's beyond the curvature of the command module. But, it appears like it might be coming from more than this one spot.

Okay. Thank you. We hope that when we crank up the command module tomorrow that we'll be able to—or later on today—that we will be able to identify more closely what it's been coming from. But, the guidance guys say that they haven't been able to see the results of any venting in their data and it would take a very, very small amount to perturb their data.

Well, that's a note of encouragement.

(Music)

You got a Chinese band going up there?

Oh, sorry. I forgot all about hot mike.

Jim, we've had you scheduled for an eat period about an hour ago. I suppose you've taken care of that. The other thing is we're kind of interested in knowing how long you're going to be at stick there, or if you're going to go back to bed or what?

Okay, Jack. We're—We're going to set up a regular watch and sleep period here. Fred was up for a long time, so I got up a little bit early to relieve him. Jack and Fred are now asleep, so I'm going to let them sleep as long as they can, and then we'll have an eat period and then I'll go back to bed for a bit. And we'll separate the schedule.

Okay. We're right at the point now where, according to the flight plan that we had made up for you, that you would have all finished eating and you and Jack would have the duty while Fred went to sleep. So, essentially, according to the plan we've got, you got up about 3 or 4 hours early. And—The next time that we have that as a rest period for you is at 96 hours, which is 7 hours from now, and an hour before that, say at 95 hours, all three of you would eat, and then you and Jack would hit the sack again and Fred would have the duty until 102 hours. We'd be glad to take care of this work-rest cycle for you.

Okay. That's good. Let me—Let me wait until they get up, or at least Jack gets up. He should be getting up before Fred. And we'll try to get back on the schedule. I hate to wake everybody up right now though, if they're sleeping.

Okay. Your choice on that. As soon as Jack gets up, I'd suggest we go ahead and break up these lithium hydroxide canisters and make a couple of them. Jack could work on that. It's going to take four sets of hands, I think.

Aquarius, Houston. Over.

Go ahead, Houston.

Hi, Jim. We've got a flight handover in about 2 minutes, and we'll have a temporary loss of COMM. You don't need to switch antennas. Over.

Aquarius, Houston through Madrid for a COMM check. How do you read?

Loud and clear, Joe. How me?

… asleep?