The work culminated in a 6 hour, 15 minute spacewalk by shuttle astronauts Jim Reilly and Danny Olivas, who focused on final attachment of bolts, cables, and connectors to begin the activation of the truss and ready it for deployment of its solar arrays.
The spacewalk began at 3:02 p.m. CDT and ended at 9:17 p.m. CDT and was the 84th devoted to station assembly and maintenance totaling 515 hours, 20 minutes.
The spacewalk was delayed for about an hour after the station temporarily lost attitude control when the stationís control moment gyroscopes went offline due to the mass of the new truss segment in the final stage of its attachment. The loss was not unexpected because of the stationís skewed asymmetry as the 17.8 ton bus-size S3/S4 truss was being moved toward the S1 truss.
Pilot Lee Archambault, Mission Specialist Patrick Forrester and Expedition 15 Flight Engineer Oleg Kotov tightened the final of four bolts permanently mating the new 45-foot truss to the outboard end of the S1 truss. The installation paved the way for the start of the spacewalk Ė the fourth for Reilly and first for Olivas. Once completed, the truss will stretch 356 feet from end to end.
Once the spacewalk began, Reilly and Olivas moved quickly through their tasks of releasing the launch restraints on the four Solar Array Blanket Boxes, which house the folded solar arrays. Their work sets the stage for the deployment of the solar arrays Tuesday.