In the payload changeout room workers watch as the doors of the payload canister open to reveal the S0 Integrated Truss Structure.

In the payload changeout room, workers watch as the doors of the payload canister open to reveal the S0 Integrated Truss Structure. The truss will be moved into the PCR and then transferred to Space Shuttle Atlantis's payload bay. Part of the payload on mission STS-110, the S0 truss will become the backbone of the orbiting International Space Station (ISS). The S0 truss will be attached to the U.S. Lab, "Destiny," on the 11-day mission. Launch is scheduled for April 4