Spacelog Apollo 13

Fred, Houston. That is verified. You can go ahead with the yaw maneuver.

Okay. Just made another maneuver. We allowed for a little too much roll, there. I wonder if that's too much, or should I try to take it out now that I got it stopped.

Fred, this is Houston. —

Twenty degrees roll left—Yes. All right; go ahead.

Okay, Fred. I didn't copy the beginning of your message.

Okay, I—I was talking to Jim, there.

Aquarius, Houston. Over.

Go ahead, Joe.

Roger. Listen, Charlie Duke wants to talk to you—to you about the AOT star check; and, so that we can have good COMM, I'd like to reconfigure with the POWER AMPLIFIER circuit breaker in and the VOICE FUNCTION switch to VOICE and while we're at it, we'd like the RANGING FUNCTION switch to RANGING. Over.

Okay.

Aquarius, Houston. Over.

Houston, Aquarius.

Roger, Fred-o. Reading you —

Okay, Houston, Aquarius. Go ahead.

Okay, Fred-o. Reading you 5-by. The procedure I'm going to read up to you is a Sun check for the—to see if we're going to need an alinement or not. If you'll get out your G&N dictionary and open it to P52, page 34, we'll start at the bottom. Over.

Okay. Stand by 1.

Sounds like you broke out, Charlie.

Yes, finally, Fred-o. I've no longer got the red spots.

Okay. Stand by, Aquarius. We'll be back with you momentarily.

Okay.

Aquarius, Houston. You ready with your G&N dictionary? Over.

Okay. I'm on page 34 now, looking at P52.

Okay, Fred-o. At the bottom of the page, we want step 1, on the flashing 0406, we want an option 3, and that'll pull us over to 6; and, on the 5025, we want you to do the ENTER on the 5025, and that'll bring up flashing 0170, and load in R₁ 200. Over.

Okay. Let me see if I'm with you. We call up P52 and, on the flashing 0406, we PRO on a 3 REFSMMAT which leads us to a flashing 5025. We ENTER on that. On the flashing 0170, we want to ENTER a 200.

That's affirmative; and after that, you PRO on that, and you come up with a flashing 0688, and we'll have to load NOUN 88. And if you're ready to copy, I have the Sun half-unit vectors at 74 hours GET. Over.

Okay. Go ahead.

Okay. At Sun half-unit vectors, X, R₁, is plus 0.45498, Y plus 19024, Z plus 08250. Over.

Okay. We PRO on—after entering the 200. We'll get a flashing 0688. We then load the Sun unit vectors for 74 hours, which are R₁ plus 5—correction, plus 45498, R₂ plus 19024, R₃ plus 08250.

Roger. That's good, Fred-o. And that'll bring you to step 8, and you get a flashing 5018 when you PRO on the NOUN 88. Okay. At 5018, we want to do an AUTO maneuver to—to the attitude, so just do the—the PRO with the GUIDANCE CONTROL, PNGS; MODE CONTROL, PNGS, AUTO; and we'll take this attitude. Now, that's going to put us at—at attitude for the Sun check. Now, we're being a 1.4-degree deadband in this program in a docked configuration; so, to help you out, you could call VERB 62 to get your needles—and it—when the needles go through zero or null out and—in that deadband—then you take a look in the AOT and see how close the Sun is. And we want within plus or minus 1 degree. Over.

Okay. So we PRO on the NOUN 88, and we end up with a flashing 5018; and you want an AUTO maneuver here rather than using the TTCA, so we PRO with GUIDANCE, PNGS; MODE CONTROL, AUTO. We've got a 1.4-degree deadband with a VERB 62 will give us the needles to try to zero them in and, at that time I look through the AOT and, if it's like Apollo 11 Sun check, all we've got to have is the Sun somewhere in the—out there somewhere on the Sun as it passes. Is that correct?

I think that's a little tight; that's about a quarter degree. We can go a little bit out of that. Stand by 1. Fred, we'll get you an answer on that one. And also, if you'll stand by, we'll give you a DAP load for this maneuver. Over.

Okay. We'll—You'll give us a DAP load.

Roger. Stand by.

Aquarius, Houston. Fred-o, on that—to pass that check, the Sun is at—will subtend an arc of one-half degree in the AOT, so you can be two diameters off and still pass the check. Over.

Okay. It's a half a degree, and so we can be two Sun diameters off and still pass.

That's affirmative. And we want you to maneuver with a DAP of 0.2 of a degree a second. Over.

Okay. You want us to use a DAP of 0.2.

Okay. That DAP load, Fred-o, is 31120. Over.

Okay. 31120.

Roger. Now, if we pass that check, you can just terminate P52 right there, and we'll give you an attitude to go to a burn attitude, and from this we can get a star check. If you don't pass, we'd like you to do an alinement at 75 hours. And, if you're ready to copy, we have some Sun half-unit vectors and some Earth half-unit vectors at 75 hours. Over.

Stand by 1, Charlie.

Okay. Go ahead for 75 hours—Sun and Earth half-unit vectors.

Roger. First with the Sun; for X, plus 45483; for Y, plus 19053; for Zebra, plus 08262; Earth half-unit vector at 75 hours, plus 32120, minus 34155, minus 17370. Over.

Okay. Sun half-unit vectors: R₁ plus 45483, R₂ plus 19053, R₃ plus 08262; Earth half-unit vectors: R₁ plus 32120, R₂ minus 34155, R₃ minus 17370.

Roger, Fred-o. Good readback. Now, on the Earth, we estimate it—if you have to do this alinement, that the Earth will be about a 2-degree Earth. And it'll be approximately three-quarters lighted. Now, to mark on the Earth, we'd like you to take an imaginary line between the horns of the crescent and mark midway between the horns. Over.

Okay. We got a 2-degree Earth that's three-quarter lighted, and we're to imagine a line between the horns of the Earth and mark right in the center of that line.

That's affirmative. Now, on—on this star check—correction, the Sun check, Fred, at—On the 5018, I got some FDAI angles for you if you're ready to copy. Over.

Okay. You're talking about the check at 74 hours GET, right?

Roger. Okay. At 74 hours when you start this maneuver, the 5018 should look like R₁ of 2703 degrees, pitch R₂ is 0903, and R₃ of 2908. Over.

Okay. How about making those all five digit readouts; read them again, Charlie.