Spacelog Apollo 13

And we just went on to the secondary CO₂ canister. Fred swapped out the primary, but we want to stay on the secondary until it is all used up.

Okay. I'm going to use the tape … CO₂.

We're reading a partial pressure CO₂ of 4.2 millimeters. We're cleared to use the secondary until it reaches 15.

Aquarius, in comparing our initial estimates of water usage and electrical power usage, it appears that we're right on the money on water usage, and we're using a little less amperes than we had originally expected in our first analysis, so we're either right on the money or just a little bit ahead of the game in that regard.

Well, that sounds encouraging, Jack.

And there are a few temperatures that we're watching for you. You have the heaters powered down. We're looking at them, and those include the PIPAs, the ASA, the quad temps, and your propellants, except for the DPS propellant.

Okay. I've got them here.

We have, as you probably know, several groups working on procedures from here on out. We have a group working on midcourse corrections to determine a system, the attitudes, how to do it, alinement techniques, and so forth. We have a group working on the entry, including how and when we're going to activate the CSM. We have a group working on the CSM system status, and in a few hours—Later on tomorrow, from where we see it, we're going to go to some base configuration on the CSM and we're going to conduct a MAIN BUS B check. Right now the COMM is kind of degrading, and I can't hear what you're about to say very well. But I just want to keep you advised as to how things are going here. And remember you've got duty on the antennas.

Aquarius, are you reading Houston?

…

Okay, Jim. I can hear you talking but I can't tell what you're saying because you're way down in the background noise.

Okay. Can you hear Aquarius now? Over.

Oh, yes. That's much better. Did you get my report on the various types of people and what they're doing around here?

Roger. Sounds like you had things well organized. You might also consider what kind of a stowage configuration … and what we can leave behind in Aquarius.

Okay, Jim. I didn't catch that suggestion on account of the background noise; maybe we can pass it on when it gets more favorable.

I'm thinking in terms of stowage. Whether we would leave the suit. … the Hycon camera in Aquarius, prior to …

Okay. I heard you say something about using the Hycon camera in Aquarius.

Negative, Jack. I'm thinking of reentry stowage attitude. Whether we should—what we should leave behind in Aquarius. Leave the suits behind; leaving such big items as the Hycon cameras in Aquarius. Over.

Oh, understand. You're thinking about stowage. What'll we leave behind in Aquarius when we fall back into Odyssey. Is that right?

That's affirmative.

Okay. We've people working on that, too.

And we presently are tracking you at 22 500 miles from the Moon, moving out at 4400 feet a second.

And, Jim, earlier in the evening, we thought there was a misunderstanding about the amount of potable water you can drink, but we want to advise you that you can drink as much water as you want to. There's 38 pounds in the potable tank, and that's about all you'll need. The doctors suggest you drink as much fruit juices as you want, too.

Jim, earlier in the evening, Fred-o reported some venting out of window number 1 in the command module. He also reported a piece of loose metal about 4 inches square, silver, floating by, and one thing we were trying to establish is whether or not this is a new venting or whether this is part of the residual venting of our original problem. Do you have any more words or comments? And one thing he was doing was taking some photographs and we authorized photographs, targets of opportunity, using the lunar-surface camera number 1, and use the setting of 1/250 of a second, and not knowing precisely what f-stop to use, we suggested taking three of each, using settings of f:4, f:5.6, and f:8. Over.

Roger, Jack. The venting really seems to … I reported earlier, I also spotted the large piece go by and prior to our … burn … The venting you see now is much greater … went into the dark mode, you could easily distinguish stars and didn't have the bright articles and bright objects, and I also have the camera here to take photographs. …

Okay, Jim. Once again I hear you talking back there but I can only pick out a few words; maybe we'll have a better time.

Aquarius, we're trying to improve our communications. Could you turn the BIOMED off and give us a voice check, please?

Voice check follows: 1, 2, 3, 4, 5, 5, 4, 3, 2, 1; voice check out.

How are you doing there, Aquarius?

We're doing good, Jack.

Okay. Sometime when you get two guys available there and you could construct one of these lithium hydroxide rigs, I'd like to have you get the materials together, and we'll go through the steps together.

Okay. Sounds good. And how do you read me now?

Well, there is a lot of background noise, and sometimes it is worse than others and right now I hear you better than I have in the past.

Okay, Jack. I'm kind of curious the amount of perturbations our PTC attitude is taking. I notice that we are getting off attitude, and I'm just kind of curious how far we can let this go.

We were tracking the attitudes with Fred earlier and it looked like what we were doing was oscillating about some point, but coming back. Are you detecting some kind of divergence now?

Not too much. I notice that it's different than when I went to sleep. We are more at an angle now with the terminator of the Earth, so when we started out, we were just about parallel with the terminator, and now we are canted off somewhat. I haven't seen any trends, though, of going back and forth.

And, Jim, our current plan is to not correct the PTC. We're going to take whatever we get and live with it. And we can kind of keep track of what's going on a little better if when you swing past the Earth and swing past the center of the Moon, if you could read off the LPD angles for the center of the Earth and the center of the Moon. Over.

Roger. Will do, Jack. And I'm looking into the AOT now to the right—No, the number 4 detent, and we are venting something back there; I can see particles moving on past the command module. What it is, I don't know.

Okay. Can you identify the quadrant?

Well, I'm looking through the right rear reticle now of the AOT, and when I was back in the command module, I could see it out of the CM 1 window. The particles are rather small, but they are coming out with some force. That's probably what is disturbing our PTC attitude.

Yes, that sounds quite probable, Jim. That's about the same report we got from Fred, but we haven't been able to identify what they might be and probably won't be able to until we crank up the CSM. If there's any change in that status, why, we just want to keep advised of it.

Roger. Understand.

And, Aquarius, we are setting a pretty good vector on you now. And it looks like you're a little bit outside of the corridor. We're looking at a 7-foot-per-second midcourse at 104 hours. We are going to come up with an entry interface minus 8 pad to use in the event of a loss of COMM situation

Roger. Understand, and I hope you have that procedure for attitude.

We are ginning up a procedure for attitude for you, Jim. For the no-COMM case, it may be a little different than what the guys working on the procedures come up with for the burn at 104 hours.

Houston, Aquarius. The Earth is going through the 10-degree line or angle of the LPD.

Okay, We copied 10 degrees. Is that Earth or Moon, Jim?

That is Earth.

And, Houston … As we … No! … has an angle of about 24 degrees on the LPD.

Okay. We read 24, Jim.

Jack, … the LPD on the Moon now is 22 degrees.

Okay. I'm reading you better, Jim. Say again, please.

Roger. The LPD now on the Moon is 22 degrees. I missed the Earth last time. I'll get it this time.

Okay. Twenty-two degrees, and looks like we've come up with a procedure for the attitude control on the upcoming burns. Probably the ones that we'll use from here on out.

Okay, Jack. Stand by 1.

It's going to be a few minutes before I'm ready to read it up to you.

Jack, on the first of the LPD angles is about a minus 2 degrees and just slightly above the top line.

Okay. Just went by minus 2 degrees. Is that on the Earth?

That's the Earth. Now, I don't know whether we're oscillating back and forth or not, Jack, or whether it's a continual motion. We'll have to see here.

Okay, Jack. The Moon now has an LPD angle of 10 degrees

Roger. The Moon at 10 degrees.

Okay, Jim. Just as kind of a lead-in to this procedure that we're going to use for the mid-course to use AGS and it's going to be a manual burn. The attitude will be controlled manually; the start/stop on the engine will be controlled manually. So we have a pretty good vector on you now, and it turns out you're coming in a little bit too shallow. So what that means is we're going to make our burn to come in a little more steeply, and we're going to be coming in around the dark side of the Earth. Therefore, to come in more steep, our thrust should be in the direction of the Sun. Does that all make sense to you?

I think so. We're going to use AGS for a burn monitor. The burns are going to be manual, and they're going to be started manually and stopped manually.

Okay. And your reentry is around the dark side of the Earth, and since we're coming in shallow, we're going to have to burn toward the Sun to make it steeper. Do you follow that?

That's affirm. Especially these burns will be perpendicular to our flight path and to the Sun giving a steeper entry angle.

Okay, Jim. I heard you say perpendicular to your flight path, which is affirmative, and I didn't get the rest of your statement.

I understand the technique, Jack. We're burning to give us time to steepen our entry angle, and it will be perpendicular to our flight path for corridor control.

Okay. That's affirmative. So, in general terms, what we're going to have to do is to power up the AGS and bring up the AGS eight-ball, and then to set up your attitude, put the COAS in the front window, and guidance control will be in AGS, of course. But manually orient the spacecraft to place the center of the Earth directly out the Z-axis. Then rotate about the Z-axis to place the point of the crescent on the Y-axis of the COAS. And this will have your plus X-axis in the direction of the Sun as we discussed before. So the crescent will be up with the point down. Copy that?

Okay, Jack. We'll have to go over what again. The COAS will be out front window; we'll place the Earth in the center of the COAS, and, let's see, the center of the Earth right now is parallel to the LPD which is about parallel to our X-axis. And we'll have to rotate about 90 degrees

Okay, Jim. So we want to get the Y-axis of the spacecraft parallel to the terminator by putting the points of the crescent on the Y-axis.

Roger. Understand.

Seriously, Jack, when I stop the spacecraft looking at—at the Earth, I'm going to have to roll—in LM terms, roll the spacecraft 90 degrees to get the tip of the Earth all on the Y-axis.

That's affirmative, Jim. You're going to have to roll 90 degrees to point your plus X-axis at the Sun and put the crescent—the points of the crescent on the Y-axis. The points of the crescent on the Y-axis with the COAS pointed at the center of the Earth will take care of your yaw and your pitch.

Roger.

Okay, Jim. After you get that orientation to come in a little more steeply, we perform an AGS body-axis aline which is at 400 plus 5 on the DEDA. If the AGS ball is up at this time, the AGS ball will go to 000. We can talk more about control modes later, but we'd recommend doing this, of course, in AGS ATTITUDE HOLD—ATTITUDE HOLD. Put your YAW to MODE CONTROL and leave PITCH and ROLL in PULSE, therefore, controlling your attitude with the TTCA. We don't want to use the gimbal, so have ENGINE GIMBAL OFF. We'll make these burns at 10-percent thrust. We'll use a manual start and stop. For ullage, we'll use the PLUS-X TRANSLATIONAL button, and ullage will be for 10 seconds. Over.

Okay. I understand what you're saying, but you'll have to repeat it here.

Okay. We'll perform the burn in GUIDANCE CONTROL to AGS. And MODE CONTROL to ATTITUDE HOLD. Your ATTITUDE CONTROL switches will be ROLL to PULSE, PITCH to PULSE, and YAW to MODE CONTROL. So the AGS will control your yaw and you will use the TTCA to control pitch and roll. ENGINE GIMBAL OFF; 10-percent thrust. Start and stop manual. For ullage, use the plus-X translational button; 10 seconds ullage. Over.

Okay. For the burn there will be go to GUIDANCE CONTROL AGS, MODE CONTROL ATT HOLD, ATTITUDE CONTROL switches will be ROLL PULSE, PITCH PULSE, YAW MODE CONTROL. We'll use TTCA control for pitch and roll. ENGINE GIMBAL will be OFF; we'll be using 10-percent thrust; we'll start and stop manually, the … control ullage will be a PLUS-X TRANSLATIONAL button. And also our thrust will still be, but before that we are going to do an AGS aline … ball …

That's affirmative, Jim. After you get oriented in the attitude you want to burn in, do an AGS aline which is—an AGS body-axis aline which is 400 plus 5. When you get ENTER, this will bring ball up to 000, and I want to confirm that you—that you said ENGINE GIMBAL OFF. O-F-F. Over.

Roger. Confirm that ENGINE GIMBAL will be off.

And, Jack, how long do you estimate the length of the burns will be?

Okay. The length of the burns are going to be probably less than a minute. And we want you to have cut-off based on time. So we will give you a burn time. And I have a P30 maneuver pad for midcourse-7 in the event that we lose COMM if you are ready to copy.

Okay, Jack. Ready to copy.

Okay, Jim. P30 LM maneuver pad: the purpose is midcourse-7. NOUN 33 is 134:59:42.98. NOUN 81 is N/A. H_A is N/A. H_P is plus 0020.5. DELTA-V R is 0019.3. Burn time, 0:39; 008, 000; the rest is N/A; thrust will be at 10 percent. Read back.

All right. This is midcourse-7 corridor control, and it's in case we lose COMM: 134:59:42.98; NOUN 81 is N/A; 42, N/A; plus 0020.5; 0019.3. Burn time, 0:39; 008, 000. All the rest is N/A: thrust 10 percent.

Okay, Jim. That's a good readback, and in the event of lost COMM, use the procedures that I gave you. It may be that between now and tomorrow these procedures will change a little bit, so we'll go with what we've got now, and stand by for something better if it comes. Over.

Okay, Jack. I'm looking at your burn pad and I see that the … total gimbal … 19.3 feet per second.

Okay, Jim. We verify 19.3 feet per second for 39 seconds.

The old midcourse technique sounds like something that we came up with on Apollo 8.