Spacelog Apollo 8

Go ahead, Apollo 8.

Roger. With the delay in burn, do you mind if we have a urine dump the—before the burn? Will that foul your tracking up?

Okay. Stand by. Let me run that one by.

Apollo 8, Houston. We don't have any objections to going ahead with the urine dump now. And for your information, the waste water dump—our schedule, we plan to put it off until about 11:30, and this will get you up to approximately 90 percent in your waste tank. It's a little higher than normal, but we wanted to put this off until after the burn was completed; and some of the other things that we've got coming up, about 9 hours you have oxygen fuel cell purge; and we've already mentioned the deletion of the star landmark sightings. From 10 to 11 we have put aside for the burn preparations. And a final score is 31 to 20.

Cleveland won over Dallas, huh?

How about that?

Houston, how do the circuit margins on the S-band look as compared to your preflight calculations?

Okay, Apollo 8. It's a little bit early to give you any real numbers on your COMM performance. Looks like it's working as good as predicted, and everything else seems to be doing better, so this may be doing better, too, after we have done our next COMM checks some of these other things will have a better hack on; I can give you a quantitative answer to your question.

Houston, Apollo 8. How do you read?

Loud and clear, Apollo 8.

Roger. Sure got a nice view of the earth from here. We can see Baja California and about where San Diego ought to be.

Very good.

I can't see my dad's flagpole out there today, though.

Apollo 8, Houston.

Go ahead, Houston.

Okay. We dropped off of high gain on the OMNI there for a bit and went to a low bit rate, and we're getting ready to command you back to a high bit rate. Do you want us to keep you posted every time we change tape speeds?

We're not recording now anyway, Houston.

Roger. Understand; but when we go to high bit rate, do you want to be kept informed every time we transfer? We hadn't planned on it.

If we think it we need the recorder, we'll ask you on that deal.

Apollo 8.

Go ahead.

Roger. How does your tracking look on us?

Fido, FLIGHT.

Apollo 8, tracking still in progress and a little too soon to give you a firm answer on the results, but everything looks nominal so far.

Is it working okay?

Seems to be.

Apollo 8.

Go ahead.

Okay. Sometime when it's convenient for you now, I would like to see an oxygen fuel cell purge. And do you have any estimate on when you might be getting around to this COMM test?

Right now we're right in the middle of trying to get something to eat, Ken. We can—I guess we can do the fuel cell purge.

Apollo 8, there's no rush. Just didn't know what you were doing at the time and—Give us a call when you have a free moment; we'll pick up.

We can start the O₂ purge now, if you wish.

Okay. That'd be fine, and I'll keep track of the time for you.

Okay. That'd be good. Now I'll turn on O₂ now on fuel cell 1.

Apollo 8, Houston. That's about 2 minutes on your first fuel cell.

Roger. It's up, and number 2 is on now.

Roger.

Houston, Apollo 8.

Houston. Go ahead.

While I'm waiting for my turn at the water gun, I might give some comments on the optics. There seems to be quite a band of light that goes all way across the scanning telescope anywhere in the vicinity of the sun. Just a little while ago we were in the position where I could pick up the moon in the scanning telescope. And then I looked at it in the sextant and the sky—the space around the moon was a very light blue, just about as light blue as we have it back on earth. And it's not black—that sun angle with the moon.

Understand. This light blue was—showed up in the sextant.

That's affirmative. I maneuvered the optics so I could pick up the moon in the sextant, and the—the space around the moon is light blue.

Roger. Can you make any kind of estimate about the proportion of the radius, how far out that seems to extend?

Well, it extends the full length of the sextant. Actually, I could see us coming as we moved across, because the band of light in the scanning telescope cut across where the moon was, and it moved in this area. I believe it's caused by the refractional light inside the optics themselves.

Roger.

No problem seeing the moon. When I looked for the star landmark line of sight, I—It's a very thin crescent, but it was very visible.

Roger. Does the area illuminated in earthshine show up?

Not at this altitude, and that's strange. I thought I could see that. At this altitude, the refraction of the light in the optics themselves, due to the reflection of the sunlight I suspect, or earth's light, completely blanked out the dark side of the moon to this altitude.

How about that.

Maybe we have an atmosphere around the moon.

Okay, Apollo 8. Looks like that ought to terminate the fuel cell purging.

Houston, Apollo 8.

Go ahead, Apollo 8.

Do you want to get started here around 10 hours? Is that what you said?

Well, what we had planned was to use the 10- to 11-hour period as your preburn preparation just as we would have done normally, and —

That's fine. We can go ahead and do that.

— and if you can work in this COMM check before that, it would be desirable, but that's not a constraint.

What do you want in the way of a COMM check, George?

Again, what do you want?

Okay. What we've got here is a couple of DTO COMM checks. We'll be switching around to five different modes, and only one of them will interrupt your activities. In that case, we'll be switching to the uplink backup voice, and that's the one time that you might lose temporary uplink voice COMM. You'll have downlink voice COMM throughout the entire procedure, and it ought to take you, I guess, 10 to 15 minutes MAX, the only requirement being that we should stay on a high-gain antenna.

Why don't we go ahead and start now then?

Okay. That sounds pretty good.

- whenever -

Okay, Apollo 8. Another couple of minutes and we'll be ready to go into our—our COMM check. And, for your information, looks like the signal strength is 3 to 4 dB better than expected on the wide range, on the WIDE BEAM mode, and approximately that gives you 1.4 increase in your range.

Roger. Let's not increase it by 1.4 more, though.

Okay.

Something else you might take a look at: as you go through the PTC, we have some who would like to know if you can see any detectable effect on the windows in the form of their fogging. Particularly, does the sun seem to vary fog intensity or does it increase it or decrease it or make it go in patches or anything like that that you might be able to notice?

The sun doesn't seem to change it much; however, the different incidences of the sun's rays magnify the—the fogging, or at least change it.

Okay, Apollo 8. I'm sorry. Would you say again, please?

The sun doesn't stem to have any effect on the windows themselves, but the different inci—angles of incidence of the sun rays change the relative amount of obscuration caused by the fogging.

Okay.

Okay, Apollo 8. We're ready to go into the COMM check now, and it's your option. We can call out switches and let you position them, or we can command it from the ground. In either event, there will be a couple of switches that you'll have to throw for us.

We'll have to command them, and we'll throw what we have—what you want.

Okay. And I'll keep you posted on what we're doing. The first test is an uplink voice and ranging with full downlink which is essentially what you're doing right now, is to be used for a baseline.

Roger.

Okay. We're starting on test number 1, and if you would verify that S-band NORMAL mode switch is in VOICE.

Roger. We're in VOICE.

Okay.

… Charlie.

And the up-telemetry DATA to DATA.

Roger. DATA.

Okay. And up-telemetry COMMAND to NORMAL.

Normal.

Roger. How about high-gain antenna track to AUTO?

We're on OMNI D now; we've got to wait till we get around the other way.

Okay. What's your estimate?

We're at 15 minutes from it.

Okay.

Maybe we'd better hold the COMM check till after the midcourse, because we'd better get fired here at 10 if we want to burn at 9.

That's affirm. We're viewing that right now.

… means we're on two vertical level.

Okay, Apollo 8. We're postponing the COMM test until after the burn.

Thank you.