During the mission's third spacewalk, Gernhardt and Reilly will install a second nitrogen tank on the Quest airlock. Three other tanks, two oxygen and one nitrogen, were installed during a previous spacewalk. Expedition Two Flight Engineer Jim Voss, assisted by Flight Engineer Susan Helms, will lift the final gas tank from the payload bay of Atlantis around 10:40 p.m. and slowly deliver it to Gernhardt and Reilly, who will be awaiting its arrival at the Quest airlock.
Atlantis Pilot Charlie Hobaugh assisted by Station Commander Yury Usachev will coordinate the nearly five-hour spacewalk. Commander Steve Lindsey will operate the shuttle's robotic arm.
The Atlantis crew was awakened at 4:04 p.m. by the song "I Could Write A Book" from the motion picture When Harry Met Sally. The song was played for Lindsey. All systems aboard both Atlantis and the International Space Station continue to function normally as the two spacecraft orbit the Earth at an average altitude of 240 statute miles.