Wednesday, March 18, 2015

50 Years Ago: Soviet Cosmonaut Walks in Space

Hero of the Soviet Union Alexei Leonov.

Fifty years ago on March 18, 1965 the Soviet Union again pulled ahead of the United States in the Great Space Race. From Baikonur in the province of Kazakhstan, a forerunner of the Soyuz rocket lifted off carrying the two-man Voskhod 2 capsule. Aboard the spacecraft were cosmonauts Alexei Leonov and Commander Pavel Belyayev. The Voskhod 2 had been modified for this flight with the addition of a special airlock in preparation for the first EVA, or Extra-Vehicular-Activity (spacewalk).

Comparison of the Voskhod 1 and version 2 with undeployed airlock.

Once the spacecraft reached orbit, the special airlock was inflated so that the outer hatch was moved a distance from the descent module. In the EVA plan, a cosmonaut would pressurize the extended airlock, then enter the airlock, named Volga. The hatch to the cabin would then be closed, and the airlock depressurized. This was necessary because the Voskhod controls and avionics were air-cooled, and would not function properly if the cabin were depressurized.

Illustration of the EVA elements.

In the actual event, post-flight statements from the Soviet government that the EVA went perfectly turned out not to be true. After leaving the airlock, Leonov floated to the end of his umbilical hose, and his pressure suit began to "balloon" and stiffen due to over pressurization. Finding it very difficult to move freely, he was unable to activate a switch on his suit that would allow him to take pictures from a chest-mounted camera. He was also unable to control his movements enough to retrieve an exterior-mounted camera recording his EVA. After 12 minutes he finally managed to re-enter the airlock, but had entered head-first, not according to procedure. He became stuck trying to turn around, and finally solved the problem by risking "the bends" by lowering his suit pressure so that he could bend. Supposedly, Leonov could have been ejected with the airlock if he could not recover and the commander would return alone. The EVA was so difficult that doctors later reported that Leonov could have suffered from heatstroke, and he admitted later that he was sweating profusely so much that water "sloshed" in his spacesuit. Fortunately, he did manage to return, repressurize the airlock, and then re-enter the cabin.

Leonov outside the airlock entrance.

Before re-entry, the airlock was jettisoned. Unlike the earlier Vostok capsules, the Voskhod had no escape method and so instead of parachuting to ground after re-entry, the crew would ride the descent module to a harder landing with retro-rockets just before touchdown. The crew did land safely despite a problem with the descent module not separating cleanly from the service and instrument sections. They landed in the Ural mountains area so far from their rescue teams that they had to spend the night in their capsule, while wolves were heard outside.

Leonov, second from right, in Salt Lake City in 2005.

These days, Alexei Leonov is a great promoter of space exploration, a businessman, and is an artist as well. In 2005 he attended the XIX COngress of the Association of Space Explorers held in Salt Lake CIty, UT. As part of the ceremonies, our Space Center staff was able to participate and later meet with the astronauts from around the world. I took the picture above of Leonov standing with cosmonauts from the former Soviet Union, and of course I got his autograph.

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