Spacelog Apollo 8

I guess we are between 500 to 1000 feet.

Roger.

Herb Alpert seems pretty good.

Houston, Apollo 8.

Apollo 8, Houston.

Roger. I believe we are going to have to vent or thrust away from this thing; we seem to be getting closer.

Roger. Understand, Frank; go ahead whenever—just give us some idea of when you did it and how much.

Roger.

Apollo 8, Houston. Could you stand by one? We are working on something here.

Apollo 8, Houston.

Apollo 8, this is Houston. Over.

Apollo 8, this is Houston. Over.

You are loud and clear, Mike. Go ahead.

Okay, Frank. On your additional separation maneuver, we recommend that you make a radial burn, point your plus X-axis toward the earth, and thrust minus X for 3 feet per second. Over.

I don't want to do that; I'll lose sight of the S-IVB.

Okay. The reason we want a radial burn is to increase your midcourse correction so we can use the SPS. Stand by on it.

Apollo 8, Houston.

Go ahead.

How close to a radial burn can you get without losing sight of the S-IVB, Frank?

Well, I don't know because I can't see the earth now, Mike.

Okay.

We can pitch down some. Jim has the earth in the optics so we could pitch some and get pretty close to one, I guess.

Apollo 8, Houston.

Go ahead, Houston. Apollo 8.

We can give you a pitch gimbal angle on radial direction if that would be a help. It's 181 degrees; pitch gimbal angle would be exactly radial at 4 hours and 10 minutes. I don't know whether that solves your visibility problem or not.

181?

That's affirmative.

Well, then zero would be just as good, wouldn't it?

Frank, if you use zero, then make the SEP if possible in the plus X thrusters. That's the direction of the burn we'd like.

Well, can't do that. I'll thrust right square into that S-IVB.

Yes, okay. Understand.

What will he maneuver to as far as the gimbal angle for his blowdown?

Apollo 8, Houston. At blowdown, that S-IVB should be oriented to perform a retrograde blowdown along the local horizontal.

Okay.

Is it still chasing? Does it look like it is closing on you, Frank?

It is about the same. The trouble is it is pointed at us pretty well.

Roger. Understand.

Frank, what we want to do is get a radial upward burn; and as long as you can, through the optics or some other means out the window, figure out where the earth is, then use the appropriate thrusters to thrust upward, radially upward for 3 feet per second. That is what we are looking for for trajectory reasons.

Okay. Understand. I just—as I say, I just can't very well do that now. I don't want to lose sight of this S-IVB.

Roger. We concur with that. I just thought perhaps Jim, through his optics, or you could get some feel for where the earth is. That's what we want to do, is radially upward.

Okay. As soon as we find the earth, we will do it.

Thank you.

Houston. The venting on the S-IVB is terminated.

Apollo 8, Houston.

Go ahead, Houston. Apollo 8.

Roger. Frank, do you think you are going to be able to do this burn radially? We would like to add to its magnitude if you are going to make it in some other direction. Over.

No, I am not even sure we are going to do it yet, Mike. If I can get—we seem to be drifting away from this thing a little bit, although it is still pointing at us quite closer than I'd like.

Roger. Understand.

Apollo 8, Houston. We would like you to do some additional maneuver; it is just a question of how much and in which direction.

Okay. Right now, our gimbal angles are about—roll's about 190 and pitch is about 320 and yaw is about 340. We could certainly do it in this position. That would be alright.

Apollo 8, Houston.

Go ahead, Houston. Apollo 8.

Roger, Frank. You could help us out if you would explain where you are relative to the booster. In other words, with respect to the earth and the radius back there, are you above or below or one side, or where exactly is the booster relative to you?

Well, it's as I said before. We can't definitely find the earth. I think we are in front and a little bit above—a little bit above the—almost in front of the—directly in the front of the booster.

Roger. Understand; almost directly in front of the booster.

Perhaps a little bit horizontally displaced towards the—let's see—Houston, to help you, we are looking right directly above the S-IVB with the sun—it's on the right side of the S-IVB and on our—coming in our left number 1 window.

Okay. Understand; the sun is on the right side of the S-IVB and coming in your number 1 window. And are you—when you give us those angles, that means that your plus X-axis is pointed at it with those angles. Is that affirm?

Roger.

Okay.

The earth is in our plus Y, plus Z-direction now, Mike.

Thank you. Earth is plus Y, plus Z.

Right, and a little minus X.

Okay.

Houston, for information. I am looking through the scanning telescope now, and I see millions of stars; most of them—the venting from the S-IVB.

Right. Are you having any trouble telling which are the stars and which are the S-IVB particles?

Definitely; we are in sunlight, and it looks like they are all S-IVB, but we don't know. I am going to attempt a P52 realign at this time and see what I can do.

Mike, anything more on this separation maneuver you're on?

We are working on it, Frank. We are trying to compute what radially outward will be in close terms. Now, you still have the earth—as I understand plus Y and plus Z quadrant. In other words, it's down below you on your right and slightly to your rear? Is that still true?

That's right. Quite a bit to our rear and down below us. Off to the right.