Space Shuttle Launch Schedule 2009: Atlantis’s Timeline

The space shuttle Atlantis is set to launch at 2:01 p.m. EDT today. The coming few hours will be jam-packed for NASA as crew members go about the busy space shuttle launch schedule. A full breakdown of key events follows.

You can read more about Atlantis’s mission on our Shuttle Launch Live 2009: Atlantis Webcast page. There, you’ll also find live streaming coverage of Atlantis from the Kennedy Space Center.

Space Shuttle Launch Schedule 2009

The next major milestone in Atlantis’s space shuttle launch schedule starts at T-3 hours and holding. Assuming everything stays on-schedule (as of mid-morning, NASA is estimating a 90 percent chance of good conditions), the following timeline will occur:

T-3 hours and holding
This built-in hold typically lasts two hours.
* Perform inertial measurement unit preflight calibration
* Align Merritt Island Launch Area (MILA) tracking antennas
* Final Inspection Team proceeds to the launch pad to conduct a detailed analysis of the vehicle as the team walks up and down the entire launch tower
* Closeout Crew proceeds to the launch pad to configure the crew module for countdown and launch and assist the astronauts with entry into the orbiter

T-3 hours and counting
* Crew departs for the launch pad and, upon arriving at the pad, begins entry into the orbiter via the White Room
* Complete close-out preparations in the launch pad’s White Room
* Check cockpit switch configurations
* Astronauts perform air-to-ground voice checks with Launch Control (Kennedy Space Center) and Mission Control (Johnson Space Center)
* Close the orbiter’s crew hatch and check for leaks
* Complete White Room close-out
* Close-out crew retreats to fallback area

T-20 minutes and holding
This built-in hold typically lasts 10 minutes.
* Shuttle Test Director conducts final launch team briefings
* Complete inertial measurement unit preflight alignments

T-20 minutes and counting
* Transition the orbiter’s onboard computers to launch configuration
* Start fuel cell thermal conditioning
* Close orbiter cabin vent valves
* Transition backup flight system to launch configuration

T-9 minutes and holding
This is the final built-in hold, and varies in length depending on the mission.
* The Launch Director, Mission Management Team and Shuttle Test Director poll their teams for a go/no go for launch

T-9 minutes and counting
* Start automatic ground launch sequencer
* Retract orbiter access arm (T-7 minutes, 30 seconds)
* Start auxiliary power units (T-5 minutes, 0 seconds)
* Arm solid rocket booster range safety safe and arm devices (T-5 minutes, 0 seconds)
* Start orbiter aerosurface profile test, followed by main engine gimbal profile test (T-3 minutes, 55 seconds)
* Retract gaseous oxygen vent arm, or “beanie cap”

T-2 minutes, 55 seconds
* Crew members close and lock their visors

T-2 minutes, 0 seconds
* Orbiter transfers from ground to internal power

T-50 seconds
* Ground launch sequencer is go for auto sequence start (T-31 seconds)
* Activate launch pad sound suppression system

T-16 seconds
* Activate main engine hydrogen burnoff system

T-10 seconds)
* Main engine start (T-6.6 seconds)

T-0
* Solid rocket booster ignition and liftoff!