Workers in the Operations and Checkout Building watch as the Integrated Truss Structure S0 is lowered into the payload canister. The S0 truss will soon be on its way to the launch pad for mission STS-110. Part of the payload on Space Shuttle Atlantis, the S0 truss will be attached to the U.S. Lab, "Destiny," on the 11-day mission, becoming the backbone of the orbiting International Space Station (ISS). Launch is scheduled for April 4