Spacelog Apollo 13

Okay. Understand; and do you want some sort of a PTC mode, Jack?

Affirmative. We'll take whatever PTC mode you can set up, Jim.

Okay. And since you know our approximate attitude, how about just getting me something to find you on the DSKY for a southerly plus X-direction.

Roger. Stand by 1.

And one other question, Houston. When you say power down the DSKY or the LGC, do you mean going into 06 or multiple circuit breaker?

Stand by on powering down the DSKY, Jim. We'll give you the procedure for that. The procedure that we —

Okay.

— the procedure that we have is listed in several places. It's in the Contingency checklist under “Power down” on page 1, second paragraph.

And we'll give you that word when we want you to do that. That's LGC only, not to power down the IMU. But we'd like to have you hold off on that until we send you the word. Over.

And, Aquarius, while we're working on this, we have a proposed flight plan update for your working and resting cycles. And—You ready to copy?

Okay. Do you want me to write this in the flight plan, per se, Jack?

You can probably write it on a piece of scratch paper. This is pretty easy.

Okay. Go ahead. We got a lot of scratch paper.

Okay, Jack. As I read that, the LMP is to go to sleep at 63:00 for about 6 hours. During that period, the CDR and CMP should try to get a bite to eat. I'm to awake at 69 hours. CDR and CMP sleep at 70 hours, and they are to awake at 76 hours. And we should plan on doing our P51, P52 at 76 hours or 76:30. At 78:30, we're going to load a P30 and aline AGS to PGNS. Second maneuver is to take place at 79:25:26.5 for ignition time. Then we're all to eat at 81 to 82 hours.

Okay. With a minor modification, your P51, P52 will be about 77 hours, and that's the period of darkness. And the commander and the CMP ought to eat around 68 to 69 hours, and you should eat between 69 to 70 hours just after you get up. We have left an hour in there where everybody is awake together to talk things over. Go ahead.

Okay. I'll eat after I wake up between 69 and 70.

All right we have additional —

— and I've got the correction to P —

Go ahead, Fred.

Yes. We got the word the P51, P52 is going to be done around 77 hours, while we're in darkness.

That's affirmative. And we have a work-rest cycle laid out for further on, which we can relay to you later.

Okay.

Okay. And, Houston, you have advice on what attitude you want me to go to.

Okay. That'll be the next bit of information. I'll get that for you, Jim.

Okay.

And, Aquarius, just to get you thinking in that direction, we've run a fairly thorough analysis, and we've found out that it's going to be cheaper to keep the LGC and the DSKY up and turn the inverter and the ball off. It's going to save us 1 amp and also some water, so it looks like what we're going to do. And we'll have to monitor the middle gimbal angle. And we'll get the procedure on that, and it'll also be an easier control mode where we'll be able to use the TTCA through the—through the DAP.

Aquarius, Houston. We've got a procedure for you. Ready to copy?

Ready to copy.

Okay. It's pretty easy. We see you've already got VERB 16 NOUN 20 called up there and so we want you to, in maneuver and PGNS ATTITUDE HOLD, use the TTCA. We want you to, on the commander's ball, pitch to 267.5 and yaw to minus 4.5. And when you do this in VERB 16 NOUN 20, on the DSKY, you ought to read plus 00120, plus 26750, and plus 00450. Go ahead.

Okay. We're to drive the commander's ball to a pitch of 267.5, yaw minus 4.5. And we should have in 16 20 at that time, plus 00120, plus 26750, plus 00450.

Houston, Aquarius.

Go ahead, Aquarius.

Roger. You didn't mention roll on the ball. Do you want roll zero?

The roll ought to be plus 1.2, Jim.

Houston, Aquarius.

Go ahead, Jim.

Okay. We're just about there in pitch and in … middle gimbal angle, but that other gimbal angle didn't look like it pulled the right way. I tried both methods.

Yes. I been looking at that, too, and we're asking why, and we'll get an answer for you.

Yes. Houston, I wonder if you're accounting for being a bit off the bellyband here, and I've gone through GASTA.

And, Fred-o, I know you're supposed to start sleeping here pretty soon, but we got a new PC plus 2 pad, P30 maneuver pad for you.

Stand by.

Okay. Go ahead, Jack.

Okay. DPS, pericynthion plus 2 into the MPL, 079, 27, 4013, plus 08144, minus 00443, minus 00226, N/A, plus 00205, 08455, 4 plus 20, 268, 261, plus 08155, minus 00443, minus 021, 2187, N/A. GDA should be okay as is, which hopefully is pitch 5.85, yaw 6.74. Two-jet ullage for 10 seconds, the DPS throttle 10 percent for 5 seconds, 40 percent for 21 seconds, 100 percent for the rest of the burn. And this should put us into the water at 142 plus 47.

Okay. Good readback.

Somehow that didn't add up with the DELTA-V_X to give a DELTA-V_R of that magnitude. It seems like it'd been bigger.

Okay, Houston. I'm not having too much luck holding this particular attitude.

Okay, Jim. Stand by 1.

Okay, Aquarius. When you get her pretty much in attitude there, and it looks like you're as close as we need to be, we'd like to try a control mode and see if it will work; sort of a semi-PTC. We'll leave the ball powered up for this, and if this doesn't work, why, we'll have to revert to ATTITUDE HOLD mode. But—Stand by 1, please.

We'd like you to think about this control mode, Jim, and see if you think it might work from what you know right now. We're a little skeptical, but we'd like to put it to you. So, once you get in a pretty good attitude, monitor in VERB 16 NOUN 20, go to PGNS MINIMUM IMPULSE, VERB 76, as we have, and set up a yaw rate—yaw rate to the right. Monitor the middle gimbal on R₃ on the DSKY and see if she'll kind of stabilize out. If not, the only other suggestion we've got is to go to PGNS ATTITUDE HOLD. We'll keep the ball up until you make this evaluation.

Okay, Houston. You cut out, say again.

Okay. Where'd you lose me, Jim?

I lost you when you said try the control mode; you're a little skeptical.

Okay. From what you say, we have to be a little skeptical of this procedure, but we'd like to have you try it and have you evaluate it. You can monitor the middle gimbal on R₃. Before we power down the ball, we want your evaluation. The next best choice is PGNS ATTITUDE HOLD. Over.

Okay. I'll try it.

Okay. Go ahead with the control mode procedure.

Hello, Houston; Aquarius.

Go ahead, Aquarius.

Okay. I'm not … you. I can monitor register 3. I can probably keep it out of …—going into gimbal lock.

Roger. How are pitch and roll?

Okay. I think I can control the gimbal angles in 16 20 with the compressors the way they are, but I'll have to try MINIMUM IMPULSE—just a minute.

Okay, Jack. I've a question—one more question about Odyssey.

Go ahead.

Okay, I still have the PYRO A sequence A and PYRO B sequence B circuit breakers in. Do you want those out?

Stand by 1.

Odyssey, Houston. The two circuit breakers you referred to, leave them in.

Okay. Copy. Leave them in.

Okay, Houston. I can control yaw in minimum impulse, but stand by on pitch.

And, Fred-o, the DELTA-V_R resultant computes with the components.

Fred's off the COMM now, Jack.

Roger. Your PAD is good.

And, Jack, we didn't get that whole sentence there.

Okay. I said that the DELTA-V_R that Fred questioned computes well with the component—its rms.

Okay. Copy.

Okay, now. Jack, let's go over this once more. You wanted me to try out control of the spacecraft in the PULSE mode. Is that correct?

That's affirmative. Set up a yaw rate and monitor the middle gimbal angle.

Okay. I can do that. I'm not too sure whether I can control roll or pitch in pulse, but I can control yaw in pulse—yaw in pulse on the ball.

Roger. And remember we're not going to have a ball there, so that we're going to be monitoring CDUs on the DSKY, and if we get it off, it will be pretty hard to figure out where to fly back to; and, well, in addition, have to control the OMNIs while we're doing this.

Roger.

Without the ball, I still have use of the TTCA for control of the—angles.

Affirmative. You'll have the TTCA for pitch and roll.

Okay. I think I can do that without the ball, and if you just give me the TTCAs I think I can control the spacecraft using 16 20.

I'm going to yaw right.

Okay, Jack. I am now—The REGISTER 1 is in the DECREASE mode.

And, Houston, do you see anything wrong with this spacecraft motion?

We have a data drop on right now, Jim; we'll look at it as soon as it comes up.

Okay, Aquarius. We're going to dispense with this control mode. We'd like you to fly the machine back to the original attitude that you had, and we'll go PGNS ATTITUDE HOLD, and then we've got to get that ball off the line to save some power. And then, in order to keep even heating, every 15 or 30 minutes, we'll give you a call to give us 90 or 180 degrees of roll—of yaw.

Okay, Houston; Aquarius. I'm flying it back over towards the initial angles you gave me of a pitch of 257. I'll get near the bellyband in roll and yaw; then I'll go to PGNS ATT HOLD.

That's affirmative, Jim. And then we're going to have you go through a powerdown procedure.

Okay.

And you'll need VERB 77 with ATT HOLD when you get there.