NASA will begin the countdown for launch of Space Shuttle Columbia on mission STS-109 Feb. 25 at 10 a.m. EST at the T-43 hour mark. This mission marks the fourth Shuttle servicing mission to the Hubble Space Telescope and the first Shuttle mission in 2002. The KSC launch team will conduct the countdown from Firing Room 1 of the Launch Control Center.

The countdown includes 26 hours and 36 minutes of built-in hold time leading to a preferred launch time at about 6:48 a.m. on Feb. 28 with a launch window extending about 66 minutes. The exact location of the orbiting Hubble Space Telescope (ISS) will be determined during the T-9 minute built-in hold. The flight director will at that time determine the exact time of launch.

Mission STS-109 is the 27th flight of the orbiter Columbia and the 108th flight overall in NASA’s Space Shuttle program. STS-109 is scheduled to last about 11 days with a planned KSC landing at about 5:01 a.m. EST on March 11.

Columbia rolled into KSC’s Orbiter Processing Facility on May 29, 2001, after returning from its Orbiter Maintenance and Down Period in California. Columbia last flew on mission STS-93 in July 1999. The orbiter rolled out of OPF bay 3 and into the VAB on Jan. 16, 2002. While in VAB high bay 3, Columbia was mated to the external tank and solid rocket boosters. The entire SpaMEAhuttle stack was transferred to Launch Pad 39A on Jan. 28.

On mission STS-109, the seven-member crew will capture the Hubble Space Telescope using the Shuttle’s robotic arm and secure it on a workstand in Columbia’s payload bay. Four mission specialists will perform five scheduled spacewalks to complete system upgrades to the telescope. More durable solar arrays, a large gyroscopic assembly to help point the telescope properly, a new telescope power control unit, and a cooling system to restore the use of a key infrared camera and spectrometer unit, which has been dormant since 1999, will all be installed. In addition, the telescope’s view of the Universe will be improved with the addition of the Advanced Camera for Surveys (ACS), which replaces the Faint Object Camera, the last of Hubble’s original instruments.

The STS-109 crew includes Commander Scott D. Altman, Pilot Duane G. Carey, and Mission Specialists John M. Grunsfeld, Nancy J. Currie, James H. Newman, Richard M. Linnehan and Michael J. Massimino.

(end of general release)

COUNTDOWN MILESTONES
*all times are Eastern

Launch-3 Days (Monday, Feb. 25)

*	Prepare for the start of the STS-109 launch countdown
*	Perform the call-to-stations (9:30 a.m.)
*	Countdown begins at the T-43 hour mark (10 a.m.)
*	Begin final vehicle and facility close-outs for launch
*	Check out back-up flight systems
*	Review flight software stored in mass memory units and display systems
*	Load backup flight system software into Columbia's general purpose computers
*	Remove mid-deck and flight-deck platforms (6 p.m.)
*	Activate and test navigational systems (11 p.m.)
*
*	Launch-2 Days (Tuesday, Feb. 26)
*
*	Complete preparation to load power reactant storage and distribution system (1 a.m.)
*	Flight deck preliminary inspections complete (2 a.m.)
*
*	Enter first built-in hold at T-27 hours for duration of 4 hours (2 a.m.)
*
*	Clear launch pad of all non-essential personnel
*	Perform test of the vehicle's pyrotechnic initiator controllers (3 a.m.)
*
*	Resume countdown (6 a.m.)
*
*	Begin operations to load cryogenic reactants into Columbia's fuel cell storage tanks
*	     (6 a.m. - 2 p.m.)
*
*	Enter 4-hour built-in hold at T-19 hours (2 p.m.)
*
*	Begin filling pad sound suppression system water tank (2 p.m.)
*	Demate orbiter mid-body umbilical unit (2:30 p.m.)
*	Resume orbiter and ground support equipment close-outs
*
*	Resume countdown (6 p.m.)
*
*	Final preparations of the Shuttle's three main engines for main propellant tanking and flight (6 p.m.)
*	Pad sound suppression system water tank filling complete (7 p.m.)
*	Close out the tail service masts on the mobile launcher platform
*
*	Launch-1 Day (Wednesday, Feb. 27)
*
*	Enter planned hold at T-11 hours for 12 hours, 58 minutes (2 a.m.)
*
*	Begin star tracker functional checks (3 a.m.)
*	Activate orbiter's inertial measurement units
*	Activate the orbiter's communications systems
*	Install film in numerous cameras on the launch pad (4:50 a.m.)
*	Flight crew equipment late stow (7:20 a.m.)
*	Move Rotating Service Structure (RSS) to the park position (11 a.m.)
*	Perform ascent switch list
*	Fuel cell flow-through purge complete
*
*	Resume countdown at T-11 hours (2:58 p.m.)
*
*	Activate the orbiter's fuel cells  (4:08 p.m.)
*	Clear the blast danger area of all non-essential personnel
*	Switch Columbia's purge air to gaseous nitrogen (4:43 p.m.)
*
*	Enter planned 2-hour built-in hold at the T-6 hour mark (7:58 p.m.)
*
*	Launch team verifies no violations of launch commit criteria prior to cryogenic loading of the external tank
*	Clear pad of all personnel
*
*	Resume countdown (9:58 p.m.)
*
*	Chilldown of propellant transfer lines (9:28 p.m.)
*	Begin loading the external tank with about 500,000 gallons of cryogenic propellants (about 9:58 p.m.)
*
*	Launch Day (Thursday, Feb. 28)
*
*	Complete filling the external tank with its flight load of liquid hydrogen and liquid oxygen propellants (about 12:58 a.m.)
*	Final Inspection Team proceed to launch pad
*
*	Enter planned 2-hour built-in hold at T-3 hours (12:58 a.m.)
*
*	Perform inertial measurement unit preflight calibration
*	Align Merritt Island Launch Area (MILA) tracking antennas
*	Perform open loop test with Eastern Range
*
*	Resume countdown at T-3 hours (2:58 a.m.)
*
*	Crew departs Operations and Checkout Building for the pad (3:04 a.m.)
*	Complete close-out preparations in the white room
*	Check cockpit switch configurations
*	Flight crew begins entry into the orbiter (about 3:34 a.m.)
*	Astronauts perform air-to-ground voice checks with Launch and Mission Control
*	Close Columbia's crew hatch (about 4:48 a.m.)
*	Begin Eastern Range final network open loop command checks
*	Perform hatch seal and cabin leak checks
*	Complete white room close-out
*	Close-out crew moves to fallback area
*	Primary ascent guidance data is transferred to the backup flight system
*
*	Enter planned 10-minute hold at T-20 minutes (5:38 a.m.)
*
*	NASA Test Director conducts final launch team briefings
*	Complete inertial measurement unit preflight alignments
*
*	Resume countdown at T-20 minutes (5:48 a.m.)
*
*	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
*
*	Enter estimated 40-minute hold at T-9 minutes (5:59 a.m.)
*
*	Launch Director, Mission Management Team and NASA Test Director conduct final polls for go/no go to launch
*
*	Resume countdown at T-9 minutes (about 6:39 a.m.)
*	Start automatic ground launch sequencer (T-9:00 minutes)
*	Retract orbiter crew access arm (T-7:30)
*	Start mission recorders (T-6:15)
*	Start Auxiliary Power Units (T-5:00)
*	Arm SRB and ET range safety safe and arm devices (T-5:00)
*	Start liquid oxygen drainback (T-4:55)
*	Start orbiter aerosurface profile test (T-3:55)
*	Start main engine gimbal profile test (T-3:30)
*	Pressurize liquid oxygen tank (T-2:55)
*	Begin retraction of the gaseous oxygen vent arm (T-2:55)
*	Fuel cells to internal reactants (T-2:35)
*	Pressurize liquid hydrogen tank (T-1:57)
*	Deactivate SRB joint heaters (T-1:00)
*	Orbiter transfers from ground to internal power (T-0:50 seconds)
*	Ground Launch Sequencer go for auto sequence start (T-0:31 seconds)
*	SRB gimbal profile (T-0:21 seconds)
*	Ignition of three Space Shuttle main engines (T-6.6 seconds)
*	SRB ignition and liftoff (T-0)

CREW FOR MISSION STS-109
Commander (CDR): 	Scott D. Altman
Pilot (PLT):	Duane G. Carey
Payload Commander (MS1):	John M. Grunsfeld
Mission Specialist (MS2):	Nancy Jane Currie
Mission Specialist (MS3):	Richard M. Linnehan
Mission Specialist (MS4):	James H. Newman
Mission Specialist (MS5):	Michael J. Massimino

SUMMARY OF STS-109 LAUNCH DAY CREW ACTIVITIES

Wednesday, Feb. 27
9 p.m.	          Crew wake up
10:15 p.m.	Breakfast

Thursday, Feb. 28
*1:00 a.m.	Snack and photo opportunity
2:24 a.m.	Weather Briefing (CDR, PLT, MS2)
*2:24 a.m.	Don flight suits (MS1, MS3, MS4, MS5)
*2:34 a.m.	Don flight suits (CDR, PLT, MS2)
*3:04 a.m.	Depart for launch pad
*3:34 a.m.	Arrive at white room and begin ingress
*4:48 a.m.	Close crew hatch
*6:48 a.m.	Launch

* Televised events (times may vary slightly)
All times Eastern