Estimated read time: Less than a minute
This archived news story is available only for your personal, non-commercial use. Information in the story may be outdated or superseded by additional information. Reading or replaying the story in its archived form does not constitute a republication of the story.
CAPE CANAVERAL, Fla. (AP) - Astronauts have stepped out on the first of a series of urgent repair spacewalks at the International Space Station.
The two Americans on the crew floated outside Saturday morning. They will disconnect an ammonia pump that contains a bad valve. The breakdown has crippled the space station's critical cooling system for the past 1 1/2 weeks.
The pump replacement is a huge undertaking attempted only once before, in 2010. NASA has ordered up three spacewalks to complete the job. The next one will be Monday.
Astronauts Rick Mastracchio (Muh-STRACK-ee-oh) and Michael Hopkins will go back out again Christmas Day, if any work remains.
The six-man crew had to turn off all nonessential equipment inside the orbiting lab following the malfunction on Dec. 11. Scientific research came to a near-halt.
(Copyright 2013 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)