STS-112 PAYLOADS
International Space Station Flight 9A

Payload Bay

S1 Truss

STS-112's primary payload is the S1 (S-One) Truss, which will be attached to the International Space Station and outfitted during three spacewalks. The S1 is 13.7 meters (45 feet) long and weighs about 13.6 metric tons (15 tons). It will be the third component of the 11-piece Integrated Truss Structure delivered to the station and will allow for the outward expansion of the station. The S1 will be attached to the S0 (S-Zero) Truss' starboard side.

The large truss contains: a new external cooling system for the station that is slated to be activated in 2003; a second S-Band communications system to provide enhanced and extended voice and data capability; a cart that will serve as a mobile work platform for future spacewalkers; two new external television cameras; and the first Thermal Radiator Rotary Joint, which will provide the mechanical and electrical energy for rotating the station's heat-rejecting radiators based on various system requirements.

The S1's attachment to the station is slated to occur during Flight Day 4.