The International Space Station is a construction site in orbit once again as Space Shuttle Atlantis and Expedition Five crewmembers today prepare to install the next segment of the station's backbone – the Starboard One (S1) Truss.
Expedition Five's Peggy Whitson and Atlantis' Sandy Magnus will use the station's Canadarm2 robotic arm to install the 45-foot long, 15-ton structure beginning about 5:30 this morning. Simultaneously, Astronauts Dave Wolf and Piers Sellers will prepare for the first of three spacewalks to attach plumbing, data and electrical lines to bring S1 to life. They plan to exit the Quest Airlock at about 9:40 a.m. and can easily be identified while outside. Wolf will wear a suit with solid red stripes, while Sellers will wear an all white spacesuit.
Throughout the spacewalk, Pilot Pam Melroy will be inside offering guidance and advice to the spacewalkers and keeping them on schedule. Shuttle Commander Jeff Ashby will operate the shuttle robotic arm providing camera views for documentation.
Following grapple of the S1, Magnus and Whitson will move it into position at the starboard end of the first truss segment where it will be secured in place by four remotely operated bolts. That first segment was delivered on a shuttle flight earlier this year.
In addition to hooking up power, data and fluid lines, Wolf and Sellers will release locks on a beam allowing S1's radiators to be oriented for optimal cooling. They also will deploy an antenna and release restraints on a handcar, which can be used to move spacewalkers and equipment along the truss. The next spacewalk, or Extravehicular Activity (EVA) is planned for Saturday to continue hooking S1 connections to the station.
S1 is the third of what will be 11 segments of the Integrated Truss delivered to the station. The truss eventually will stretch 356 feet from end to end and will support four huge solar wing assemblies, one pair of which is already atop the station's P6 Truss. The truss also will support cooling radiators and the first railroad in space, capable of carrying the robotic arm to assembly and maintenance sites around the station.
The workday began at 3 a.m. with a musical wakeup call to Atlantis' crew from Mission Control, Houston. The "medley of childhood songs" was played for Magnus from her family. The Expedition Five crew, Commander Valery Korzun, Whitson and Cosmonaut Sergei Treschev, woke aboard the station at the same time.
The crew is scheduled to go to bed about 8 o'clock this evening, and the next status report will be issued about 5 p.m. today, or earlier if events warrant.
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