By Irene Klotz, Reuters, Published December 21 2013
Astronauts nail first spacewalk to fix station’s cooling system
The spacewalk, which was broadcast live on NASA Television, was the first for NASA since July when the spacesuit helmet worn by Italian astronaut Luca Parmitano began filling with water, a situation that could have caused him to drown.
No such leaks were detected in today’s spacewalk, the first of two or possibly three that will be needed to complete the cooling system repair.
The operation was prompted by the Dec. 11 shutdown of one of the station’s two U.S. ammonia cooling systems, which forced the crew to turn off non-essential equipment and shut down dozens of science experiments.
While the six-member crew is not in danger, the remaining cooling system cannot support the three laboratories and other modules on the U.S. side of the $100 billion station, a project of 15 nations. The Russian side of the station has a separate cooling system.
Engineers at the Johnson Space Center in Houston tried devising ways to bypass a suspected faulty pump valve, but with time running short, managers decided to have astronauts replace the pump, located outside the station, with a spare.
The work, which began shortly after 7 a.m. EST, went smoothly, with station flight engineers Rick Mastracchio and Mike Hopkins finishing up an hour earlier than expected.
They were able to not only disconnect the old pump, but also remove it from its pallet on the station’s exterior truss, a task originally slated for a second spacewalk on Monday. A third spacewalk, if needed, is scheduled for Wednesday.
“Beautiful day. Awesome view,” Mastracchio, a veteran of six previous spacewalks, said as opened the airlock’s hatch and saw the view from 260 miles above the southern Atlantic Ocean.
He and Hopkins wore spacesuits that were modi-fied to protect them from another possible water leak. The problem in July was traced to contamination in piece of equipment called a fan pump separator that circulates water and air in the spacesuit and removes moisture from air.
How the water-separator portion of the device became clogged remains under investigation.