Two Discovery astronauts have completed the major tasks of their spacewalk, the mission's last, and are moving on to odd jobs with some remaining time. Danny Olivas and Christer Fulgesang routed a pair of 60-foot long power and data cables that will be used by the U.S. Tranquility module when it is added to the station in February.
Dealing with the stiff, 1.5- to 2-inch diameter cables in zero gravity is a challenge, said Zeb Scoville, the mission's lead spacewalk officer, before the mission. "They can get to be a bit like a bundle of snakes," he said in a news conference. "They're really stiff. If you bend them, they'll hold that shape pretty well."
Despite that challenge, Olivas and Fuglesang arranged the cables ahead of schedule, for the most part. Working between Starboard 0 truss segment and Unity node, they uncoiled small sections and secured them with copper wire ties.
Scoville said Friday that because NASA had not actually settled which Unity port would house Tranquility (it was expected to be the port side), the cables wouldn't be routed all the way to preserve flexibility for future missions. Olivas and Fuglesang did struggle to connect the primary power cable to the S0 truss. If it couldn't be mated properly, they planned to place a protective sleave over the connector and leave it for a later mission.
Olivas began working on another "get-ahead" task preparing for Tranquility, removing a slide wire on Unity.
The wire helps spacewalkers move around outside the station, but will interfere with the new module and is no longer needed in that position.
Mission controllers cautioned that the wire is damaged and could present a sharp edge.
Earlier, the team deployed a spare parts holder, replaced a failed circuit breaker and gyroscope rate assembly and installed two Global Positioning System antennas.
The spacewalk started at 4:39 p.m. and is scheduled to last six-and-a-half hours.
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