NASA plans another spacewalk this week after a repair mission to fix a broken cooling pump on the International Space Station was unsuccessful.
NASA announced plans for another spacewalk after weekend attempts to
repair a broken ammonia pump module aboard the International Space
Station failed. The space agency reported the next spacewalk
would take place no earlier than Aug. 11. Expedition 24 Flight
Engineers Doug Wheelock and Tracy Caldwell Dyson completed the first
spacewalk to remove and replace the pump module on Aug. 7, however,
the day's tasks were only partially completed.
As the result of an ammonia leak in the final line that needed to be
disconnected from the failed pump module, the decision was made to
reconnect the line on the pump module and install a spool positioning
device to maintain proper pressure internal to the ammonia line. NASA
reported the completion of the process would most likely require at
least two additional spacewalks.
Though the repair mission was not a complete success, it added another
record to NASA's history books: Aug. 7's excursion lasted 8 hours, 3
minutes, making it the longest expedition crew spacewalk in history and
the sixth longest in human spaceflight history. Wheelock conducted the
fourth spacewalk of his career, while Caldwell Dyson made her first
spacewalk. Flight Engineer Shannon Walker operated Canadarm2, the
station's robotic arm, and assisted the spacewalkers from inside the
station, according to a NASA report.
"After the loss of one of two cooling loops July 31, ground controllers
powered down and readjusted numerous systems to provide maximum
redundancy aboard the orbiting laboratory," the space agency posted to
its Website. "The International Space Station is in a stable
configuration, the crew is safe and engineers continue reviewing data
from the failed pump."
A NASA report explained one of two Control Moment Gyroscopes (CMG 1)
that was taken off line was spun up once again, enabling
the station to operate with three of four CMGs to electrically control
the orientation of the outpost. "Temperatures on the Main Bus Switching
Units, which route power to various systems, are a little higher than
normal, but well within normal parameters and are stable," the report
The space agency noted the tasks originally planned for Aug. 12's
previously scheduled spacewalk by Wheelock and Caldwell Dyson to
install a power extension cable to the Unity module prior to the
delivery of the Permanent Multipurpose Module on the STS-133 mission in
November and to install a Power and Data Grapple Fixture to the Zarya
module to support future robotics work would be deferred to a later
Nathan Eddy is Associate Editor, Midmarket, at eWEEK.com. Before joining eWEEK.com, Nate was a writer with ChannelWeb and he served as an editor at FierceMarkets. He is a graduate of the Medill School of Journalism at Northwestern University.