Spacelog Apollo 8

Roger. Do you have any problems seeing the moon?

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.

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.