Astronauts Take Spacewalk to Find Ammonia Leak

The International Station Expedition 33/34 crew members, Russian cosmonaut Oleg Novitskiy, front left, NASA astronaut Kevin Ford, front center, and Russian cosmonaut Evgeny Tarelkin, front right, talk with family members via phone from the Russian Mission Control Center in Korolev, Russia.

The International Station Expedition 33/34 crew members, Russian cosmonaut Oleg Novitskiy, front left, NASA astronaut Kevin Ford, front center, and Russian cosmonaut Evgeny Tarelkin, front right, talk with family members via phone from the Russian Mission Control Center in Korolev, Russia.

Associated Press + More

By MARCIA DUNN, Associated Press

CAPE CANAVERAL, Fla. (AP) — Two astronauts are spacewalking outside the International Space Station in an attempt to find an ammonia leak in a critical radiator system.

Station commander Sunita Williams and Japanese crewmate Akihiko Hoshide ventured out Thursday morning. They will isolate plumbing to help flight controllers locate the leak and open a spare radiator.

[READ: Dragon Ship Back on Earth After Space Station Trip]

Their spacewalk got under way just hours after the orbiting lab had to dodge a piece of space junk.

On Wednesday evening, thrusters on a docked Russian supply ship were fired to move the space station out of harm's way. But a computer error caused the thrusters to malfunction, and the station did not reach the desired altitude.

[PHOTOS: Space Shuttle Endeavour Hits the Streets]

NASA says the station and its six residents are safe despite their lower-than-intended orbit. The menacing debris is a satellite fragment.

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