PASSIVE THERMAL CONTROL

The REFSMMAT for the translunar coast used the ecliptic, which is the plane in which Earth orbits the Sun: two of the three axes of the REFSMMAT were relative to the ecliptic, and the third was aligned along the Earth-Moon line at the time of TLI. To prevent one side of the spacecraft roasting and the opposite side freezing in the constant sunlight of cislunar space, it was to be oriented with its principal axis perpendicular to the ecliptic, then set rolling on a 20-minute cycle for passive thermal control (PTC) in a regime more popularly known as the barbecue mode. This had to be established before the astronauts could retire for the night. There were four options in the flight plan for midcourse corrections to refine the trajectory for lunar orbit insertion. The first was scheduled 9 hours after TLI, but since the delta-V was only 17 feet per second the burn was deleted, and the initiation of PTC advanced. Ten hours into the mission, after orienting the spacecraft perpendicular to the ecliptic, Collins gave the computer 20 minutes in which to fire the RCS thrusters as necessary to eliminate any axial wobble.

While waiting, Aldrin enquired about their altitude, which was 50,000 nautical miles. “It’s a beautiful sight,” he enthused, referring to Earth. “I can see snow on the mountains of California. It looks like LA doesn’t have much of a smog problem today. With the monocular, I can discern a definite green cast to the San Fernando Valley.’’

“How’s Baja California look, Buzz?’’ Duke asked.

“It has got some clouds up and down it, and there is a pretty good circulation system a couple of hundred miles off the west coast of California.’’

“Your rates look really great, now,’’ Duke called a few minutes later. “You can start your PTC.’’

“If you would like to delay PTC for 10 minutes or so, we can shoot you some television of a seven-eighths-phase Earth,’’ Armstrong offered.

Duke checked whether Goldstone was configured to receive television; it was. “It will be recorded at Goldstone and then replayed over here, Neil. Any time you want to turn her on, we’re ready.’’

“We’re sending a picture of Earth right now. Let us know if they’re receiving at Goldstone.’’

“Goldstone says it looks great,’’ Duke confirmed.

Armstrong was pointing the camera through the window beside his couch, and they had put up shades to prevent the Sun entering the other windows and causing internal reflections. He zoomed in until Earth filled the screen, and was pleased to observe that the automatic gain control adjusted the aperture to compensate.

“We’d like 10 minutes’ worth of television,’’ Duke requested. “And we’d like a narrative on the exterior shots. We also suggest you might try an interior position.’’

“We’re seeing the eastern Pacific Ocean,’’ replied Armstrong. “We’ve not been able to visually pick up the Hawaiian Island chain, but we can clearly see the western coast of North America – the United States, the San Joaquin Valley, the High Sierras, Baja California, and Mexico down as far as Acapulco and the Yucatan peninsula. And you can see on through Central America to the northern coast of

South America, Venezuela and Colombia. I’m not sure you’ll be able to see all that on your screen down there.’’

“Roger, Neil,’’ acknowledged Duke. “We wanted a narrative so that when we get the playback we can correlate what we’re seeing.’’

Although Armstrong and Aldrin had each remarked on the diminishing view of Earth, Collins had been too busy sighting on stars and operating the computer. “I haven’t seen anything but the DSKY so far,’’ he pointed out.

“It looks like they’re hogging the windows,’’ Duke consoled.

“You’re right,’’ Collins confirmed.

There was a distinct sense of distance – Earth and the Moon were both far off – but the distances were so immense that, in the absence of points of reference along the way, there was no sensation of movement despite the spacecraft’s high speed.

After 15 minutes, Duke announced, “You can terminate the television at your convenience, and then initiate PTC.’’ The impromptu telecast had verified that the television system was working beautifully.

Collins initiated the roll. With the Sun, Earth and Moon passing in procession by the windows, the illumination in the cabin became very dynamic.

As the camera was packed away, Armstrong gave a crew status report, reading their individual radiation monitors, noting that they had not taken any medications, and saying that in his opinion they were “fit as a fiddle’’, by which he meant they had not developed any symptoms of ‘space sickness’.

“As far as we can see,’’ Duke agreed, ‘‘you’re cleared for some zzzz’s.’’ In fact, as a result of having deleted midcourse correction 1, they were two hours ahead on the time line.

When testing the CSM with Apollo 7, Wally Schirra’s crew had maintained a staggered sleeping cycle in which there was always one man awake to monitor the spacecraft. On Apollo 8 Frank Borman’s crew had done the same, with the result that they slept poorly and were exhausted on entering lunar orbit. It was therefore decided that future crews should adopt a single sleep cycle. Armstrong was eager for his crew to conserve their energies in transit, to ensure that they would be alert on arrival in lunar orbit. In fact, it had been agreed that he and Aldrin would act as passengers because their mission would not start until they were in lunar orbit, and Collins would act as the chauffeur for the translunar coast. Although Duke signed off early, the crew did not retire until 10.30 pm on their Houston-time watches. Having arisen very early to prepare for launch, it had been a long day, and in their last few hours they were feeling distinctly drowsy. They had their supper, placed shades over the windows to block out the Sun and dimmed the internal lamps. Armstrong and Aldrin then disconnected their communications links and snuggled into enclosed hammocks – in effect mesh sleeping bags slung beneath the side couches – while Collins, the ‘watch keeper’, donned a lightweight headset with its earpiece on low volume, in case of a call from Mission Control, and strapped into the left-hand couch using a lap belt; as he rested, he realised that he no longer had any discomfort in his knee.

Cliff Charlesworth, Gene Kranz and Glynn Lunney were to rotate 8-hour shifts during the translunar coast. The ‘graveyard’ shift was handled by Lunney’s Black

Team. For the first 24 hours of a mission, flight controllers maintain a particularly close eye on the telemetry in order to identify the quirks of the new craft early on, and to establish norms and consumable rates.

Goldstone sent the taped telecast to Houston by a land line, where the signal was fed through conversion equipment for display on the wall screen and release to the media. On arriving home from the Cape and finding the press on her lawn, Jan Armstrong informed them that it had been a long day and she really needed to sleep, but happened to switch on her television as the networks started to run the telecast; the other wives missed it.