During the scheduled 6.5-hour spacewalk U.S. astronaut Clay Anderson and Russian cosmonaut Fyodor Yurchikhin will install a television camera stanchion on the station's main truss, reconfigure a power supply for an S-Band antenna assembly, and replace a remote power controller module.
They will also disconnect and jettison the Early Ammonia Servicer, an ammonia reservoir that was installed on the ISS in August 2001, but has never been used and is no longer needed following the activation of the permanent cooling system last December, NASA said.
The current spacewalk will be the first for Anderson and the third for Yurchikhin.
Following the spacewalk, a docked Progress 25 cargo craft will fire its thrusters twice raising the ISS orbit to ensure a proper rendezvous and docking with the Progress 26 spacecraft, scheduled for launch August 2 and space shuttle Endeavour whose lift off is planned for August 8.
