(06/12/1999) -- The 'Super Guppy' transport aircraft approaches the runway at the KSC's Shuttle Landing Facility. On board is the S0 (S Zero) truss segment, from Boeing in Huntington Beach, Calif. The truss segment, which will become the backbone of the orbiting International Space Station (ISS), is a 44- by 15-foot structure weighing 30,800 pounds when fully outfitted and ready for launch. It will be at the center of the 10-truss, girderlike structure that will ultimately extend the length of a football field on the ISS. Eventually the S0 truss will be attached to the U.S. Lab, 'Destiny,' scheduled to be added to the ISS in April 2000. Later, other trusses will be attached to the S0 truss on-orbit. During processing at KSC, the S0 truss will have installed the Canadian Mobile Transporter, power distribution system modules, a heat pipe radiator for cooling, computers, and a pair of rate gyroscopes. Four Global Positioning System antennas are already installed. The S0 truss is scheduled to be launched in the first quarter of 2001 on mission STS-108