U.S. astronauts conduct spacewalk to perform maintenance work

A pair of U.S. astronauts floated outside the International Space Station Thursday for a six-and-a-half hour spacewalk to perform maintenance work, including retracting a thermal control radiator that is no longer in use.

Commander Jeff Williams and Flight Engineer Kate Rubins switched their spacesuits to battery power at 7:53 a.m. EDT (1153 GMT) aboard the space station to begin the spacewalk, the second for the duo in just 13 days, U.S. space agency NASA said.

The main task of the spacewalk was to retract a thermal radiator that is part of the space station's cooling system. The radiator is a backup that had been deployed previously as part of an effort to fix an ammonia coolant leak.

Williams and Rubins will also tighten bolts on a joint that enables one of the station's solar arrays to rotate, and install the first of several enhanced high-definition television cameras that will be used to monitor activities outside the station, including the comings and goings of visiting cargo and crew vehicles.

This is the fifth spacewalk in Williams' career and the second for Rubins. They installed the first International Docking Adapter on the station during their previous spacewalk on Aug. 19. The adapter will allow new U.S. commercial crew vehicles to link up to the complex in the future.

(APD)