Fast Facts: Countdown for Atlantis Launch

Official countdown for NASA's Space Shuttle Atlantis (all times ET):

11:04:55 a.m. Countdown resumes for Terminal Count (T-minus 9 min)

11:06:55 a.m. Orbiter access arm retraction

11:09:55 a.m. APU start

11:10 a.m. Terminate LO2 replenish

11:10:55 a.m. Purge sequence 4 hydraulic test

11:11 a.m. IMUs to inertial

11:11:05 a.m. Aerosurface profile test

11:11:35 a.m. Main engine steering test

11:12:05 a.m. LO2 tank pressurization

11:12:25 a.m. Fuel cells to internal reactants

11:12:30 a.m. Clear caution-and-warning memory

11:12:55 a.m. Crew closes visors

11:12:58 a.m. LH2 tank pressurization

11:14:05 a.m. SRB joint heater deactivation

11:14:24 a.m. Shuttle GPCs take control of countdown (auto sequence start)

11:14:49 a.m. Main engine start (T-6.6 seconds)

11:14:55 a.m. LAUNCH