Pilot Paul Lockhart will coordinate the spacewalk from the aft flight deck of Endeavour. The station's robotic arm, the Canadarm2, will be operated at varying times by Expedition Five Flight Engineer Peggy Whitson, Expedition Six Commander Ken Bowersox and Expedition Six NASA ISS Science Officer Don Pettit. Commander Jim Wetherbee will provide TV and photo support.
The spacewalkers will begin by installing 33 spool positioning devices on various locations around the outside of the station. The clamp-like devices ensure that the quick disconnect fittings in the station's ammonia coolant lines release as designed.
Other spacewalk tasks include connecting the Ammonia Tank Assembly umbilicals and reconfiguring a circuit breaker on the Main Bus Switching Unit. If time allows, the two also will reconfigure the Squib Firing Unit, a pyrotechnic device designed to release the Port One truss radiator panels when they are deployed next year.
Before the spacewalk begins, Whitson and Bowersox will command the Canadarm2 to walk off its current location on the Destiny Laboratory to its mobile base on the P1 truss. Whitson will operate the robotic arm with Pettit assisting during some of the spacewalk activities. When Herrington is finished, Whitson and Bowersox will command the Canadarm2 to return to a Power and Data Grapple Fixture on the Destiny Laboratory.
During the spacewalk, Expedition Five Commander Valery Korzun and Flight Engineer Sergei Treschev will continue handover activities with Bowersox and Expedition Six Flight Engineer Nikolai Budarin. Korzun and Treschev also will complete their final sessions in the Lower Body Negative Pressure suit, a Russian device to help the cosmonauts prepare for their return to Earth's gravity.