Spacewalkers Install S5 Truss, Work Ahead of Schedule

Image: Mission Specialist Rick Mastracchio participates in the first spacewalk of the STS-118 mission. Image: NASA TV

STS-118’s first spacewalk continues to run smoothly and ahead of schedule.

The crew quickly went to work after starting the excursion at 12:28 p.m. EDT. With spacewalkers Rick Mastracchio and Dave Williams assisting, Pilot Charles Hobaugh used the station’s robotic arm to attach the S5 about 1:35 p.m. The spacewalkers then completed the task of permanently bolting the S5 in place on the end of the Starboard 4 truss segment.

Mastracchio and Williams are performing some scheduled and get-ahead tasks to prepare the S5 for the arrival of the Starboard 6 truss next year.

The next major task of the spacewalk is the retraction of a radiator on the Port 6 (P6) truss. After the radiator is folded, Mastracchio and Williams will secure it. The P6 will be relocated from atop the station to the end of the Port 5 truss during a future shuttle mission.

Mastracchio and Williams are scheduled to wrap up at about 6:58 p.m. STS-118 Mission Specialist Tracy Caldwell is the spacewalk coordinator, and Expedition 15 Flight Engineer Clay Anderson is assisting Hobaugh at the controls of the station’s Canadian-built robotic arm.

The Station-to-Shuttle Power Transfer System, which was activated after Friday’s docking, has been shut down as a precaution during the spacewalk. It will be brought back online after the conclusion of the excursion. The transfer system may allow Space Shuttle Endeavour and the STS-118 crew to stay at the station longer. A decision on a possible mission extension to 14 days is expected to be made Sunday.