Saturday, November 7, 2015

NASA Astronauts Complete Complex Spacewalk

Astronauts Scott Kelly and Kjell Lindgren translate along the port truss structure back to the Quest airlock after completing cooling system servicing work. Credit: NASA TV

Space station commander Scott Kelly and Kjell Lindgren carried out a busy but mostly trouble-free spacewalk Friday, routing ammonia coolant back to the prime radiator used by one of the lab's solar arrays and bypassing a secondary radiator that was activated three years ago to help pinpoint a coolant leak. "Going off grid for spacewalk," Kelly said via Twitter before heading out. "I'll be back w you again soon!"

The astronauts ended their spacewalk at 2:10 p.m. EST with the repressurization of the U.S. Quest airlock. The astronauts restored the port truss (P6) ammonia cooling system to its original configuration, the main task for today’s spacewalk. They also returned ammonia to the desired levels in both the prime and back-up systems.

"You guys worked really hard," radioed Kimiya Yui, a Japanese astronaut assisting the spacewalkers from inside the station, once they had returned inside the Quest airlock. "Great job and welcome back."



In a minor departure from the planned tasks, the astronauts ran out of time to cinch and cover a spare radiator known as the Trailing Thermal Control Radiator. The radiator, which Lindgren retracted earlier in the spacewalk, was fully redeployed and locked into place in a dormant state.

The radiator had been deployed during a November 2012 spacewalk by astronauts Sunita Williams and Aki Hoshide as they tried to isolate a leak in the truss’ cooling supply by re-plumbing the system to the backup radiator. The leak persisted and was subsequently traced to a different component that was replaced during a spacewalk in May 2013.

The 7 hour and 48 minute spacewalk was the second for both astronauts, and the 190th in support of assembly and maintenance of the orbiting laboratory. Crew members have now spent a total of 1,192 hours and 4 minutes working outside the orbital laboratory.

Their shorter spacewalk on Oct. 28 featured a robot-arm lube job and other mundane maintenance.

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