The Mammoth Book of Space Exploration and Disasters

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.

A cloud of tiny, luminous particles swarmed past the window.

“Ahhhhhhhh!” he exclaimed, to the tape recorder. “Beautiful lighted fireflies that time,” explaining, “it was luminous that time.” Banging repeatedly on the hatch, he was rewarded with explosions of cloud after cloud of luminous particles from the spacecraft.

“If anybody reads,” Scott explained excitedly, “I have the fireflies. They are very bright. They are,” he announced with triumph, “capsule emanating!” He quickly explained the cause and effect that proved his finding: “I can rap the hatch and stir off hundreds of them. Rap the side of the capsule: huge streams come out.”

He would yaw around the other way to get a better view, he reported. With his photometer handy, Scott estimated that the fireflies might register at a nine on the device and proposed to find out. “I’ll rap,” he told Woomera, now out of range. “Let’s see.”

The official NASA history of Project Mercury notes that:

Until Aurora 7 reached the communication range of the Hawaiian station on the third pass, Christopher Kraft, directing the flight from the Florida control center, considered this mission the most successful to date; everything had gone perfectly except for some overexpenditure of hydrogen peroxide fuel.