Spacelog Apollo 13

Okay. Turning to the next page and the last page, Jim, 34. Top of the page, “Monitor DELTA-V_X via 470.” Scratch next two lines, “When propellant quantity equals 37” and the “DESCENT HELIUM REG.” Scratch “TTCA commander, reduce to 10 percent.” Now we want you to add a line; “shut”—It's a shutdown criteria, “shutdown on burn time minus 1 second.” Over.

Okay, “The shutdown is on burn time minus 1 second.” Let me give you an example. If we have a 30-second burn, we're going to shut down at 29 seconds. Is that correct?

That's affirmative. We'll give you the pad, be coming up here from FIDO in a couple of hours, I guess, when we stabilize out on our tracking. The reason for—If you're ready to copy out a couple of more steps, and then I'll explain the reason we want to shut down on this burn time minus 1 second. Picking up on "When DELTA-V_X —

Okay.

“— When DELTA-V_X equal to the final DELTA-V_X,” scratch that line. Scratch “ATTITUDE CONTROL: YAW, to PULSE.” Add—Correction, scratch “Damp excessive rates via LM Y, Z translation” and add at that point “Null” error needles. Trim address 470 to 0.1 foot per second." Over.

Okay, going through. After the “Shutdown on burn time minus 1 second,” we scratch the next line; and we scratch “ATTITUDE CONTROL: YAW, to PULSE”; we scratch “Damp excessive rates via LM Y, Z translation”; we add the line “Null” error needles, trim—Null the error needles and trim address 470 to—What was the value there, Charlie?

“0.1 foot per second.” The reason we are shutting down on the burn time is, since the ASA breaker has been out for so long, we're not real confident that our AGS PIPAs are going to be super-sharp. So we want to make sure that we just get a burn time—no overburn; so we're shutting down on burn time minus 1 second. And then that will allow us a plus-X translation to trim 470 if it looks okay. If we had an overburn, we'd be in —

Okay.

— if we had an overburn, we'd be impinging on our command module to try to trim it out, so that's our reasoning there. Over.

Okay. Understand.

Okay. Picking up in the middle of the page, that—a block “CMS resume attitude control,” scratch. Scratch the next line; “PRO VERB 96.” Scratch the third line; “PROPELLANT QUANTITY MONITOR, OFF.” Over.

Okay. We'll scratch the blocks, and we'll scratch the “PRO VERB 96”; then we'll scratch “PROPELLANT QUANTITY MONITOR, OFF.”

Roger. Now, at the bottom of that page, I have a procedure for you to reestablish PTC. Over.

To reestablish PTC. Go ahead.

Okay. First line, “ATTITUDE CONTROL, three to PULSE”; line 2, “Roll with the TTCA until attitude is roll, plus or minus 90; pitch, 0; yaw, 0.” Over.

Okay. Step 1, “ATTITUDE CONTROL, three to PULSE”; 2, “Roll with the TTCA … pitch is 0 and yaw is 0,” and I think that will be on the AGS ball.

That's affirmative. You broke up there for a minute, Jim. We'll do that on the AGS ball from the burn attitude. We just want you to roll either way 90 degrees, keep pitch 0 and yaw 0. Now, step 3; “When at—when at attitude, ACA out of detent.” Step 4; “ATTITUDE CONTROL: YAW, to MODE CONTROL. When rates are less than 0.05, ATTITUDE CONTROL: YAW, to PULSE.”

Okay, Charlie. Can you hold up here a second? I lost you.

Roger.

Start with step 3 again. “When attitude—When at attitude, ACA out of detent.”

That's Roger. Next step, step 4: “ATTITUDE CONTROL to YAW”—Correction, “ATTITUDE CONTROL: YAW, to MODE CONTROL.” Over.

Okay. Step 4 is “ATTITUDE CONTROL: YAW, to MODE CONTROL.”

Roger. Step 5: “When rates are less than 0.05 degrees per second, ATTITUDE CONTROL: YAW, to PULSE.”

Okay. “When rates are less than 0.05 degrees per second, ATTITUDE CONTROL: YAW, to PULSE.”

Roger. Step 6: “Spin up to 0.3 degree per second in yaw,” and that takes about 21 pulses. Step 7—Yes.

Okay. Go ahead.

Okay. Step 7: “MODE CONTROL, AGS, OFF.”

Okay. Step 6 was “Spin up to 0.3 degrees per second in yaw”; that's about 21 pulses. Step 7 was “MODE CONTROL, AGS, to OFF.”

That's affirm. Step 8: “Power down per power”—Correction, “Power down per contingency checklist page Power 5.” Over.

Okay. And step 8 is Power down per contingency checklist Power 5," and I take it that's been revamped considering our situation. Okay.

That's affirmative, Jim. That's the one we gave you last night after the big burn, and we'll use that one as modified by—by us. This—we tried this PTC under AGS in the simulator and, of course, no slosh or anything, but it seemed to work pretty good by nulling the rates using the TTCA in pitch and roll and letting the ACS do it in yaw. You null the rates by looking at the error needles and just watching those, and when they don't—when they stop moving, then you got it within the limits of what we want. Over.

Okay. And I guess, Charlie, you have no—Do you have a ATT hold mode in pitch and roll at all in this configuration we're in, or do we have to use the TTCA?

We feel like we have to use the TTCA. The AGS gains are not too good in pitch and roll in this configuration. It'll hold it in yaw but it won't in pitch and roll. Over.

Okay.

And you'll have—During the burn, of course, you'll be controlling pitch and roll via the error needles with the TTCA also, and it's the little scheme that we've practiced in some of the SIMs. Over.

Right. Understand.

And, Houston, want to make sure that we allow enough time to get to the proper attitude for the burn so that we can be sure we establish the proper attitude and don't have to rush the burn.

Roger, Jim. We -we're looking right now, tentatively, at starting this about 45 minutes before the burn and our sensitivity is—not too bad on this burn. We can go 30 minutes either way and not affect our DELTA-V. Over.

Okay. Fine. And do you have a handle on just how long the burn will be? In time?

It's looking like at about 7.8 seconds and about 15—Correction, 7.8 feet per second and about 15 seconds. Over.

In about 18 seconds?

Negative. 15. 1 5.

1 5. Okay.

And one other point is that we'd like to remind you that this is going to be in blowdown and both REGs B closed but we've got plenty at the 10 percent.

Understand.

And, Jim, in the simulator with our configuration that we had here, the thing is real stable at 10 percent, so we don't think you'll have to tweak very much at all using the TTCAs. Over.

Okay. Understand.

And I'll give you back to Vance. Thank you.

And thank you.

Okay. Concerning number 2 battery, you think it might be a sensor failure because you haven't seen any changes, and you're going to put the battery back on the line in about 10 minutes.

That's affirm.

Houston, Aquarius.

Go ahead, Jim.

For information, Vance, about a half hour ago, I guess, Jack and I couldn't see constellations at certain spacecraft attitudes, stars. We could see the—Scorpio and Sagittarius and we could see Altair or Acrux and Alpha Centuri, Vega, stars of that magnitude, and our venting has stopped which allows us now to differentiate between the particles and the stars.

Roger; copy. Understand you can see the stars pretty well. Were you, at that time, in an attitude facing away from the Sun? I presume this is very attitude critical.

Yes. It is somewhat, Vance. If we have the Sun shining off the quads, it sort of ruins our vision; and also, if the Earth or the Moon are in the general field of view, we can't see anything.

Okay. Thank you.

Aquarius, Houston.

Go ahead, Vance.

Jim, we're ready to put that battery back on the line. Request you open the CROSS TIE BAL LOAD circuit breaker, panel 16, and then put back—BAT 2 back on the line.

Okay. First of all, we'll open the BALANCE CROSS TIE breaker on panel 16.

That's affirm.

Okay. The CROSS TIE BALANCE LOAD circuit breakers is in now, Vance. Now you want us to put battery 2 back on. Is that affirm?

Did you say it was in, or did you pull it out?

No. It's in; do you want it out?

That's affirm. We'd like it out, and then BAT 2 on the line.

Okay. Coming up. BAT 2 is on the line. We have a MASTER ALARM and a BATTERY light.

Aquarius, Houston.

Go ahead, Houston.

Jim, it looks to us like your battery is good, that this is in fact a sensor problem; therefore, request you close the CROSS TIE BAL LOADs on—circuit breaker on panel 16. Advise —

Okay.

— advise that you will not have any malfunction indication on any of your batteries now, but we can watch it from the ground. Over.

Okay. We'll close the CROSS TIE BALANCE LOAD circuit breaker at this time.

Roger. Copy.

That's closed, and we don't have any warning on any of the batteries, but you can monitor from the ground.

That's affirm.

And, Jim, we have a lengthy procedure here for powering up the CSM and turning on instrumentation so we can check the TM, and this will take a large piece of scratch paper whenever you're ready to copy.

This is to power up the CSM?

That's affirm.

Okay. I'll tell you what, I'll have Jack get configured. He can copy that down and I'll have him—we'll get the stuff. Stand by.

Okay.

Okay, Vance, how do you read the Aquarius?

Okay, read you loud and clear, Aquarius. Is it cool in there now?

Okay. Yes, it's pretty cool. This is the third officer on this LM crew here. Ready to copy.

Okay. Jack, this is a lengthy procedure, take probably two or three pages. It assumes that you are in your nominal configuration, which was sent up—or in your day-flying configuration, which was sent up to you earlier today.

Okay. I can verify that we are in that configuration with the exception of panel 382, the water accumulator, which I've left off in case we wanted to get some more drinking water out of the command module, and I'll put those in the proper configuration before we do anything.

Okay. Ready to copy?

Okay. Go ahead.

Okay, Vance. Are you with me?

Roger. Why don't you read that group back, and then we'll proceed on.

Okay, sounds good. Because I don't know where I—how far I lost you. Okay, panel 4; TELCOMM, GROUP 1, to AC1. On panel 5, close the following circuit breakers: ECS, PRESSURE GROUP 1, MAIN B; ECS, PRESSURE GROUP 2, MAIN B; ECS, TEMP, MAIN B; ECS, SECONDARY LOOP TRANSDUCER, MAIN B; ECS RAD, CONTROL/HEATERS, MAIN B; BAT RELAY BUS, BAT B; BAT CHARGER, BAT B; INVERTER CONTROL, 2; INVERTER CONTROL, 1; EPS SENSOR SIGNAL, AC1; EPS SENSOR SIGNAL, MAIN B; EPS SENSOR UNIT, AC1; WASTE/POTABLE H₂O, MAIN B; INSTRUMENTATION, ESSENTIAL, MAIN B.

Okay; That's all correct. Is that reading rate okay for you?

Yes, that's fine.

Okay, and leave a little space if you can to the right of these because when we talk about the backup procedure, why then we can just use the same listing, and I'll—I'll tell you open instead of close these circuit breakers, or at least most of them. Over.