Two astronauts aboard the orbiting International Space Station on Wednesday replaced an electric motor on one of three solar wings that provide power to the station during a seven-hour-long spacewalk, NASA said.
The 90.8-kilogram (200-pound) Bearing Motor Roll Ring Module (BMRRM), called the "broom," drives the starboard solar wings as they tilt along their axis to follow the sun for optimal power generation. It broke down on December 8.
Commander Peggy Whitson and Flight Engineer Dan Tani spent from 0956 GMT to 1700 GMT on the repair, mostly during night part of the orbit when less dangerous voltage is generated by the solar wings than when they are exposed to the sun.
The ISS's three solar wings have to be fully operational to allow construction work on the station to continue.
In February, the shuttle Atlantis is scheduled to deliver the European Columbus laboratory to the ISS, followed by another shuttle mission in mid-March to deliver the Kibo Japanese laboratory.
Whitson and Tani also inspected the Solar Alpha Rotary Joint of another ISS solar wing that showed indications of debris-caused friction inside its mechanism. The joint rotates the solar wing to keep it pointed toward the sun.
The National Aeronautics and Space Administration aims to complete the construction of the orbiting station, planned as a jumping-off point for deeper space exploration, by September 30, 2010, when it is due to take its three space shuttles out of service.
It is planning a dozen more shuttle missions to complete the ISS and to repair the orbiting Hubble Space Telescope.
