Station Expedition Two crewmember Susan Helms lifted the airlock from the cargo bay of Atlantis using the station's Canadarm2 at 12:10 a.m. CDT. After a slow and carefully planned series of maneuvers with the arm, the airlock was maneuvered to the berthing port on the station's Unity node.
Spacewalkers Mike Gernhardt and Jim Reilly observed the berthing procedure from above and below, providing additional guidance for Helms. The airlock was berthed to the station at 2:40 a.m. Gernhardt then attached cables from the station to its new airlock to provide heating for Quest while Reilly pre-positioned foot restraints for the second spacewalk scheduled for Tuesday.
The spacewalk, coordinated by Atlantis' pilot Charlie Hobaugh in the shuttle's cabin, began at 10:10 p.m. Saturday with the shuttle and the station 237 statute miles above the South Pacific east of New Zealand. After moving into the cargo bay, Gernhardt removed an insulating cover, called the "shower cap," from the airlock's berthing mechanism and other covers from its seals. Reilly installed bars on the 6½-ton airlock which will serve as attachment points for four high-pressure tanks, two oxygen and two nitrogen. The tanks will be installed during the two subsequent spacewalks. The mission's third and final spacewalk will be conducted from the new airlock itself.
After the airlock was securely attached and after installation of the cable to power its heaters, Gernhardt and Reilly returned to the shuttle's airlock after flight controllers confirmed that the airlock's heaters were functioning.
Official end of the spacewalk occurred with repressurization of Atlantis' airlock at 4:09 a.m. today. The spacewalk lasted 5 hours and 59 minutes.
Later, Expedition Two crewmembers Yury Usachev, Jim Voss and Helms opened the hatch to the airlock vestibule, the small area between the station and Quest's largest compartment, and began its outfitting.