STS-104, Mission Control Center Status Report # 20 Saturday, July 21, 2001 – 6 p.m. CDT

The crews of Atlantis and the International Space Station will bid one another farewell and close the
hatches between the vehicles at about 9 p.m. on Saturday. Undocking is scheduled for 11:54 p.m., to be
followed by an hour-long fly around of the station by Pilot Charlie Hobaugh. The final separation burn that
will move Atlantis away from the station to begin its journey home is scheduled for 1:14 a.m. Sunday.

The Atlantis crew, Commander Steve Lindsey, Hobaugh and Mission Specialists Janet Kavandi, Mike
Gernhardt and Jim Reilly, will leave behind the Expedition Two crew of Commander Yury Usachev and Flight
Engineers Jim Voss and Susan Helms, who are in their 136th day in space.

The Expedition Three crew, Commander Frank Culbertson and Flight Engineers Vladimir Dezhurov and
Mikail Tyurin, will replace the Expedition Two crew next month during the STS-105 mission.

Atlantis will undock from an International Space Station that is ready to begin independent operations.
Since July 2000, 77 tons of hardware has been added to the station, including the Zvezda module, the Z1
Truss Assembly, Pressurized Mating Adapter 3, the P6 Truss and its 240-foot long solar arrays, the U.S.
laboratory Destiny, the Canadarm2 and the Quest airlock.

The Atlantis crew was awakened at 4:14 p.m. Saturday by the song “Who Let The Dogs Out” sung by the
Baha Men. The song was played for Hobaugh. 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.

The next mission status report will be issued about 6 a.m. Sunday or as events warrant.