The backbone of International Space Station is formed by five pre-integrated truss segments. Each segment will provide the foundation for subsystem hardware installation, utility distribution power generation, heat rejection, and external payload accommodations. When it is completed, the truss will be the length of a football field, with its axis perpendicular to the Station's main axis. Its simple, girder-like appearance will mask its multiple ISS roles. Labs, living quarters, payloads and systems equipment will be directly or indirectly connected to it. U.S. solar arrays supplying 105 kW of ISS power -- enough to light a town -- will be attached to it.