The Shuttle crew's day began at 4:04 p.m. with a wake-up call from Mission Control, playing the song "Space Cowboy" by N'Sync for Mission Specialist Janet Kavandi. On board the Space Station, Commander Yury Usachev and Flight Engineers Jim Voss and Susan Helms also awoke at 4:04 p.m.
During tonight's space walk, Gernhardt, designated EV1, will be identifiable by the red stripes around the legs of his spacesuit, while Reilly, EV2, will be wearing an all-white space suit. Atlantis' pilot Charlie Hobaugh will coordinate the space walk from within the shuttle cabin.
Gernhardt will begin the space walk by removing an insulating cover, nicknamed the "shower cap," from the airlock's berthing mechanism, as well as protective covers from the mechanism's seals. Reilly will work to install bars on the airlock that will be used to attach four High-Pressure Gas Tanks during two subsequent space walks later in the mission. Gernhardt will then disconnect heater cables that kept the airlock warm while in the payload bay, which Reilly will stow along with the shower cap and berthing mechanism covers.
When the airlock is ready for installation, Helms, from a control panel in the station and assisted by crewmate Voss, will attach the Canadarm2 to the Quest airlock and lift it out of Atlantis' payload bay. Grappling of the airlock by the station's robotic arm is scheduled to occur at 11:04 p.m., with removal of the airlock from the payload bay at 11:19 p.m. The airlock is scheduled to be attached to the right side of the Unity module at 2:04 a.m.
Throughout the space walk, Atlantis astronaut Janet Kavandi will operate the shuttle's robotic arm, using it to maneuver the two space walkers around the space station and to provide camera views to assist Helms and Voss with their work.