Shown here is the International Space Station (ISS) S1 Truss in preparation for installation in the payload bay of the Space Shuttle Atlantis at NASA's Kennedy Space Center )KSC)in Florida. The truss launched October 7, 2002 on the STS-112 mission and will be attached during three spacewalks. Constructed primarily of aluminum, it measures 45 feet long, 15 feet wide, 10 feet tall, and weighs over 27,000 pounds. It is one of nine similar truss segments that, combined, will serve as the Station's main backbone, measuring 356 feet from end to end upon completion. Manufactured by the Boeing Company in Huntington Beach, California, the truss was flown to the Marshall Space Flight Center, in Huntsville, Alabama where brackets, cable trays, fluid tubing, and other secondary components and outfitting items were added. In Huntsville, it was screened for manufacturing flaws, including pressure and leak checking tubing, and electrical checks for cabling, before being shipped to KSC for final hardware installation and testing. The Space Station's labs, living modules, solar arrays, heat radiators, and other main components will be attached to the truss.