295. Space Walks (1)

260px-ed_white_first_american_spacewalker_-_gpn-2000-001180EVAs (extravehicular activities) or space walks are commonplace today. It wasn’t always that way. In the early days of space exploration, every space walk was a brush with death. The Russians denied that reality and the American’s downplayed it. But the fact was, in the words of Gene Cernan (see also 293. the Last Man on the Moon), “. . . we didn’t know diddly-squat about walking in space when I popped my hatch open on Gemini 9. . . It’s a sobering reflection when I think about it now, and I thank God that I lived through the experience.”

It was life threatening from the beginning. Alexey Leonov nearly died on man’s first spacewalk (see 116. Spacecraft Threatened by Bears). Three months later, Ed White’s space walk was exhilarating until it came time to reenter his Gemini craft. Then he found getting back in to be nearly impossible. Nothing is as easy as it looks in space.

There are basically three problems with spacewalks – vacuum, vacuum, and weightlessness. Vacuum outside and pressure inside makes space suits incredibly difficult to bend. Reaching over to flip a switch, which a bedfast child could do on Earth, takes great strength when suited up and in vacuum. Vacuum also provides insulation. When a spacewalking astronaut is working hard to bend in his pressure suit, the vacuum of space is keeping his body heat from dissipating. Finally, weightlessness makes it impossible to get purchase to exert one’s strength.

Both Leonov and White floated happily, but when it came time to reenter their vehicles, they found it hard to maneuver, hard to bend, and they both overheated.

Cernan’s spacewalk, the third ever attempted, was worse. He was given an impossible series of tasks to perform. Nevertheless, he was determined to perform them. People who fail, don’t remain in the astronaut corps, and trying to do the impossible nearly killed him.

First, the two astronauts fully suited up and opened the hatch. This meant that not only Cernan was suddenly encased in a “garment made of hardened plaster of paris”, but so was Stafford, reducing his ability to help. They released the “snake”, their term for the umbilical cord that carried electricity, oxygen, and communications. Ed White had also been on the end of an umbilical, but he had had a hand powered jet that he used for mobility. Cernan’s first experiment was to see if he could move around space, simply tugging on the umbilical.

He couldn’t.

The snake uncoiled and recoiled, subject to internal stresses. Any time Cernan tried to move by tugging on it, he ended up being spun out of control. This went on for half an hour until it was clear that no astronaut would ever be able to use his umbilical to maneuver.

Cernan clung to the hatch to catch his breath, then began the second experiment. The MMU was a backpack style manned maneuvering unit designed for an astronaut to fly freely at the end of  a safety line. It was a great idea, but there was no place in the Gemini to store it, so it had been fastened into a recess in the very base of the vehicle.

Now he just had to get there. concluded tomorrow


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