(06/12/1999) -- Workers in the O&C Bldg. watch as the S0 truss is lowered onto a workstand. The S0 truss will undergo processing in the O&C during which the Canadian Mobile Transporter, power distribution system modules, a heat pipe radiator for cooling, computers, and a pair of rate gyroscopes will be installed. Four Global Positioning System antennas are already installed. A 44by 15-foot structure weighing 30,800 pounds when fully outfitted and ready for launch, the truss will be at the center of the ISS 10-truss, girderlike structure that will ultimately extend the length of a football field. Eventually the S0 truss will be attached to the U.S. Lab, 'Destiny,' which is scheduled to be added to the ISS in April 2000. Later, other trusses will be attached to the S0 on-orbit. The S0 truss is scheduled to be launched in the first quarter of 2001 on mission STS-108