The International Space Station has a new control moment gyroscope, which is in the process of being checked out by Mission Control.

Mission Specialists Dave Williams and Rick Mastracchio completed a spacewalk that has been in the works since one of the station's four gyroscopes - which control orientation - failed in October. Williams carried the 600-pound replacement to its new home on the Z1 segment of the station truss, and stored the failed equipment on the outside of the station. It will be returned home on a future shuttle mission.

The second of four spacewalks scheduled for Endeavour's mission, this was the 90th spacewalk devoted to station maintenance and construction. Williams and Mastracchio left the station at 10:32 a.m. and spent 6 hours and 28 minutes outside.

The Expedition 15 crew and the visiting STS-118 crew continue joint operations aboard the International Space Station.

Since the seven STS-118 astronauts arrived on Aug. 10, the station has grown in size and received a new attitude control gyroscope during two spacewalks. The Starboard 5 (S5) truss segment was attached Saturday during STS-118's first spacewalk. The S5 will serve as a spacer segment between the Starboard 4 and 6 (S6) segments. The S6 and its solar arrays will be attached during a future shuttle mission.

http://www.amsat.org/amsat/archive/sarex/48hour/msg00944.html

The International Space Station will get a new control moment gyroscope today, courtesy of the space shuttle Endeavour and spacewalking astronauts Rick Mastracchio and Dave Williams.

The second spacewalk of Endeavour's flight to the station is scheduled to begin just after 10:30 a.m. CDT.

The Endeavour crew, Commander Scott Kelly, Pilot Charles Hobaugh, and Mission Specialists Tracy Caldwell, Mastracchio, Williams, Barbara Morgan and Alvin Drew, and station crew members, Commander Fyodor Yurchikhin and Flight Engineers Oleg Kotov and Clay Anderson, were awakened for spacewalk day at 5:46 a.m. CDT by "Outta Space" performed by Billy Preston. It was played for Drew.