Endeavour Mission Specialists Mike Lopez-Alegria and John Herrington will exit the station's Quest airlock for a second time during this mission to begin a 61/2-hour spacewalk. Scheduled to begin about 1:20 p.m. central time, the work outside the station today will see Lopez-Alegria and Herrington connect fluid lines from the new Port One (P1) truss segment to the Starboard Zero (S0) truss; install a second wireless video antenna system to the P1; relocate stanchions that were used to hold the P1 in place during launch; and move a Crew Equipment Translation Aid railway handcar from the P1 to the Starboard One (S1) truss.
Endeavour Pilot Paul Lockhart will coordinate the spacewalk from the orbiter's flight deck and Endeavour Commander Jim Wetherbee will provide photo and TV support. From the ISS, Expedition Five NASA Science Officer Peggy Whitson will provide robotic arm support using the station's Canadarm2, and will be assisted by Expedition Six NASA ISS Science Officer Don Pettit.
Expedition Five Commander Valery Korzun, Whitson and Flight Engineer Sergei Treschev will also continue their handover and training briefings for Expedition Six Commander Ken Bowersox, Flight Engineer Nikolai Budarin and Pettit.
Whitson and Bowersox will take some time today to test the station's bicycle ergometer, which experienced some trouble over the weekend. In addition to being used for exercise, it is used as part of a pre-spacewalk protocol to purge nitrogen from crewmembers' bodies. Testing of the Carbon Dioxide Removal Assembly in the station's Destiny laboratory continued overnight and showed that maintenance work performed by the crew on Wednesday had resolved a faulty valve problem with the system.