Richard Lawrence - The Mammoth Book of Space Exploration and Disaster

Manual control of the spacecraft yaw attitude using external references has proven to be more difficult and time-consuming than pitch and roll alignment, particularly as external lighting diminishes… Ground terrain drift provided the best daylight reference in yaw. However, a terrestrial reference at night was useful in controlling yaw attitudes only when sufficiently illuminated by moonlight. In the absence of moonlight, the pilot reported that the only satisfactory yaw reference was a known star complex nearer the orbital plane.

But Mercury Control had requested an attitude check, and I complied, first reporting that I had to get back within “scanner limits,” that is, to an attitude in which the horizon was visible to the pitch horizon scanner. That required more maneuvering, which required more fuel. I was still trying to cram in more observations.

Capcom asked: “Can we get a blood pressure from you, Scott?”

I sent the blood pressure, reported on the transmission, and continued voice reports on the experiments: the behavior of the “fireflies”; the balloon, still shadowing Aurora 7 like a stray animal, was oscillating some. Just before LOS, I reported I was going to “gyros normal. Gyros normal now.” Hawaii Capcom replied: “Roger, TM [telemetry] indicates your-zero pitch.” And then “LOS, Scott, we’ve had LOS.”

Loss of signal. I was moving on to voice contact with Al Shepard, California Capcom, and approaching the start of my final, most perilous circumnavigation of the planet.

Kris Stoever continued:

The pilot of Aurora 7 speeded toward California, where Al Shepard was capcom, in charge of ground communications. Scott first gave Al his short report on fuel, cabin-air temperature, and control mode (“manual, gyros normal, maneuver off”). But then the important issue: the suit steam-exhaust temperatures. They were “still reading,” he told Al dispiritedly, “70 degrees.”

But Al had good news:

“Understand you’re GO for orbit three.”

While the GO business was nice to hear, it was really hot in the cabin, and Scott still had lots of work to do. As it happened, more than the MA-7 cabin temperatures were hot. From all reports, Kraft was full-out fuming as Scott approached the continental United States. The flight director appears to have concluded, erroneously, that the pilot of MA-7 had deliberately ignored his request for an attitude check over Hawaii. Now, in addition to his anxieties about fuel use, Kraft was nursing a grudge about a snub that never took place.

In his memoir, he writes that as Carpenter approached California, he directed Al Shepard, the California Capcom, to set things right. Al’s new job, Kraft told the famously self-possessed Navy commander, was “to find what the hell was going on up there,” adding that he left the California Capcom with “no doubt” about his “frustration” with Carpenter. Kraft was in fact bellowing through the earpieces of Al’s headset.

The flight director told Al he needed two things from Scott: an attitude check and a tight curb on fuel use. In an exercise of judgment as California Capcom, Shepard relayed just one of Kraft’s two requests:

“General Kraft is still somewhat concerned about your auto fuel. Use as little auto – use no auto fuel unless you have to prior to retrosequence time.”

Shepard then turned to the matter at hand, which was the heat in the cabin and an apparently malfunctioning heat exchanger in Scott’s suit. He suggested another, more comfortable setting. He omitted Kraft’s request for an attitude check. Al then did unto Scott as he hoped others might one day to unto him, offered the pilot a little time, a little quiet, and some encouragement:

“Roger. You’re sounding good here. Give you a period of quiet while I send Z and R cal.”

The two men carried out these quiet space chores over the next three and a half minutes. Then Al gathered information. Either he knew enough to ask, or he was prompted by the flight surgeon:

“Do you – have you… have you stopped perspiring at the moment?”

No, Scott told him, he was “still perspiring.” A good sign. No impending heat stroke. Catching the drift of the conversation, Scott reported he might open his visor “and take a drink of water.”

Capcom acknowledged: “Roger. Sounds like a good idea.”

He let Scott drink. Sixteen quiet seconds passed. Then Al asked a question. Note the man’s impeccable manners:

“Seven, would you give us a blood pressure, please, in between swallows.”

It was a remarkable moment of earth-to-space human solicitude. A minute later, a refreshed Scott reported:

“Twenty swallows of water. Tasted pretty good.”

Capcom replied: “Roger, Seven, we’re sure of that.”

In a final, reassuring exchange before LOS, the California Capcom would send Aurora 7 on her way:

“Seven, this is California. Do you still read?”

Carpenter replied: “Roger, loud and clear.”

Capcom: “Roger, we have no further inquiries. See you next time.”

The “next time” would bring the two men, Shepard and Carpenter, together again in an even more life-saving conspiracy of astronauts.

After four hours in orbit and a long period of drifting flight, Aurora 7’s cabin temperature had dropped to 101 degrees Fahrenheit; the vexing problems with the suit temperature were being resolved. The balky camera was now a memory. Scott had succeed in shooting all the M.I.T. film for the “flattened sun” photographs. The experiment on the behavior of liquids in zero-G was a success. Capillary action can pump liquids in space. Over Woomera, Scott described and analyzed various successful valve settings for his suit – in-flight observations that would assist with a later redesign of the Mercury suit; he also took photometry readings and measurements on Phecda, a star in the Big Dipper, then sinking into the haze layer of the horizon. His short report had good news:

“I’m quite comfortable. Cabin temperature is 101… fuel reads 46 and 40 percent. I am in drifting flight. I have had plenty of water to drink.”

For the next eleven minutes of spaceflight Scott transmitted an uninterrupted flow of observations. The partially inflated balloon, which had failed to jettison as planned over the Canaries, still bumped along behind the capsule. It kept “a constant bearing,” Scott reported, “at all times.” Still transmitting to Woomera:

“I have 22 minutes and 20 seconds left for retrofire. I think I will try to get some of this equipment stowed at this time.”

Coming up on sunrise, rich with “observables,” the pilot of Aurora prepared for one final observation of the airglow phenomenon, reporting for the tape recorder:

“There is the horizon band again; this time from the moonlit side.”

Carpenter complained once more about the light leak:

“Visor coming open now. It’s impossible to get dark-adapted in here.”

NASA had molded an eye patch for John Glenn so he could keep an eye covered through daytime on one orbit and emerge on the night side with a dark-adapted eye. But the small cabin was so dusty the sticky tape (designed to keep the patch secured over his eye socket) became covered with dust and would not stick to his skin. NASA did not reattempt this dark-adaption patch with MA-7. Managing to get a good view through the filter, Scott continued: “Haze layer is very bright through the air glow filter. Very bright.” He then concentrated on the photometer measurements, reporting with some puzzlement that the width of the airglow layer was exactly equal to the width of the X inscribed on the lens. “I can’t explain it – I’ll have to – to—”

And then the sunrise, at 04 19 22. Scott would remember the sunrises and sunsets as the most beautiful and spectacular events of his flight aboard Aurora 7. “Stretching away for hundreds of miles to the north and the south,” they presented “a glittering, iridescent arc” of colors that, he later wrote, resolved into a “magnificent purplish-blue” blending, finally, with the total blackness of space. Thinking the camera might help with the air-glow measurement, he quickly grabbed for it and in doing so inadvertently rapped the spacecraft hatch.