US astronauts will conduct back-to-back EVAs to fit the Integrated Truss Structure Z1 (pictured) in its temporary location on the International Space Station's (ISS) Unity node module, during mission STS 92 Discovery - the Space Shuttle's 100th mission which is to be launched on 5th October. The truss is the exterior framework that will support the solar arrays which will provide early power to the ISS. The arrays will be attached to the ISS during the following Shuttle mission in November.
Source: Flight International