The countdown includes 26 hours and 45 minutes of built-in hold time leading to a preferred launch time at about 8:45 a.m. on Sept. 8. A preferred launch window of 2 � minutes exists inside a 10-minute window. The exact location of the orbiting International Space Station (ISS) will be determined during the T-9 minute built-in hold. The launch director will at that time determine the exact time of launch.

Mission STS-106 is the 22nd flight of the orbiter Atlantis and the 99th flight overall in NASA's Space Shuttle program. STS-106 is scheduled to last 10 days, 19 hours and 9 minutes with a planned KSC landing at about 3:54 a.m. on Sept. 19.

Following Atlantis' previous flight, STS-101, the orbiter underwent an accelerated processing turnaround for this mission. Atlantis arrived in KSC's Orbiter Processing Facility (OPF) bay 3 May 29. It rolled out of the OPF on Aug. 7 to be mated with the external tank and solid rocket boosters in the Vehicle Assembly Building (VAB). The entire Space Shuttle stack rolled out to Launch Pad 39B Aug. 13 to undergo final launch preparations.

On mission STS-106, the seven-member crew will prepare ISS for the arrival of its first international crew later this year. During the flight, the crew of Atlantis will outfit the newly arrived Zvezda Service Module with supplies carried to orbit in the double SPACEHAB cargo module and from a Russian Progress craft currently docked to Zvezda. The mission includes a single space walk to connect electrical lines and data cables between Zvezda and the rest of the Station.

The STS-106 crew includes: Commander Terrence Wilcutt, Pilot Scott Altman, and Mission Specialists Yuri Malenchenko, Boris Morukov, Daniel Burbank, Edward Lu and Richard Mastracchio.

    
COUNTDOWN MILESTONES
*all times are Eastern
Launch - 3 Days (Tuesday, Sept. 5)


*       Prepare for the start of the STS-106 launch countdown 
*       Perform the call-to-stations (10:30 a.m.)
*       Countdown begins at the T-43 hour mark (11 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 Atlantis' general purpose
computers
*       Remove mid-deck and flight-deck platforms (7 p.m.)


Launch - 2 Days (Wednesday, Sept. 6)


*       Activate and test navigational systems 
*       Mid-deck and flight deck preliminary inspections complete (12:30
a.m.)
*       Complete preparation to load power reactant storage and distribution
system (2 a.m.)


Enter first built-in hold at T-27 hours for duration of 4 hours (3 a.m.)


*       Clear launch pad of all non-essential personnel
*       Perform test of the vehicle's pyrotechnic initiator controllers (4
a.m.)


Resume countdown (7 a.m.)


*       Begin operations to load cryogenic reactants into Atlantis' fuel
cell storage tanks 
     (7 a.m. - 3 p.m.) 


Enter 4-hour built-in hold at T-19 hours (3 p.m.)


*       Begin filling pad sound suppression system water tank 
*       Demate orbiter mid-body umbilical unit 
*       Resume orbiter and ground support equipment close-outs
*       Pad sound suppression system water tank filling complete (6:30 p.m.)
 
Resume countdown (7 p.m.)


*       Final preparations of the Shuttle's three main engines for main
propellant tanking and flight (7 - 9 p.m.)


Launch -1 Day (Thursday, Sept. 7)


*       Close out the tail service masts on the mobile launcher platform (3
a.m.)



Enter planned hold at T-11 hours for 13 hours, 50 minutes (3 a.m.)


*       Begin star tracker functional checks (4 a.m.)
*       Activate orbiter's inertial measurement units
*       Activate the orbiter's communications systems 
*       Install film in numerous cameras on the launch pad (7 a.m.)
*       Flight crew equipment late stow (10:50 a.m.)
*       Move Rotating Service Structure (RSS) to the park position (12:30
p.m.)
*       Perform ascent switch list
*       Fuel cell flow-through purge complete (3 p.m.)


Resume countdown (4:50 p.m.)


*       Activate the orbiter's fuel cells (6 p.m.)
*       Clear the blast danger area of all non-essential personnel
*       Switch Atlantis' purge air to gaseous nitrogen (7:05 p.m.) 


Enter planned 2-hour built-in hold at the T-6 hour mark (9:50 p.m.)
*       Launch team verifies no violations of launch commit criteria prior
to cryogenic loading of the external tank 
*       Clear pad of all personnel
*       Chilldown of propellant transfer lines
*       Begin loading the external tank with about 500,000 gallons of
cryogenic propellants (about 11:20 p.m.)


Resume countdown (11:50 p.m.)


Launch Day (Friday, Sept. 8)


*       Complete filling the external tank with its flight load of liquid
hydrogen and liquid oxygen propellants (about 2:20 a.m.)
*       Final Inspection Team proceed to launch pad


Enter planned 2-hour built-in hold at T-3 hours (2:50 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 (4:50 a.m.)


*       Crew departs Operations and Checkout Building for the pad (at about
5 a.m.)
*       Complete close-out preparations in the white room
*       Check cockpit switch configurations 
*       Flight crew begins entry into the orbiter (about 5:30 a.m.)
*       Astronauts perform air-to-ground voice checks with Launch and
Mission Control
*       Close Atlantis' crew hatch (about 6:45 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 (7:30 a.m.)


*       NASA Test Director conducts final launch team briefings
*       Complete inertial measurement unit preflight alignments


Resume countdown (7:40 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 45-minute hold at T-9 minutes (7:51 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 (8:36 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)



SUMMARY OF BUILT-IN HOLDS FOR STS-106


T-TIME                 LENGTH OF HOLD               HOLD BEGINS
HOLD ENDS 
T-27 hours              4 hours                 3 a.m. Wed.
7 a.m. Wed.     
T-19 hours              4 hours                 3 p.m. Wed.
7 p.m. Wed.     
T-11 hours              13 hours, 50 minutes    3 a.m. Thurs.
4:50 p.m. Thurs.        
T-6 hours               2 hours                 9:50 p.m. Thurs.
11:50 p.m. Thurs.       
T-3 hours               2 hours                 2:50 a.m. Fri.
4:50 a.m. Fri.  
T-20 minutes            10 minutes                      7:30 a.m. Fri.
7:40 a.m. Fri.  
T-9 minutes             about 45 minutes                7:51 a.m. Fri.
8:36 a.m. Fri.  



CREW FOR MISSION STS-106
Commander (CDR): Terrence Wilcutt               
Pilot (PLT):    Scott Altman            
Mission Specialist (MS1):       Edward Lu               
Mission Specialist (MS2):       Richard Mastracchio             
Mission Specialist (MS3):       Daniel Burbank          
Mission Specialist (MS4): Yuri Malenchenko
Mission Specialist (MS5): Boris Morukov                 
                        
                        
SUMMARY OF STS-106 LAUNCH DAY CREW ACTIVITIES


Thursday, Sept. 7


7:30 p.m.           Crew wake up
8 p.m.              Breakfast


Friday, Sept. 8 
                
3:50 a.m.       Light dinner and crew photo                             
4:20 a.m.       Weather briefing (CDR, PLT, MS2)        
4:20 a.m.       Don launch and entry suits (MS1, MS3, MS4 & MS5)        
*4:30 a.m.      Don launch and entry suits (CDR, PLT, MS2)      
*5 a.m. Depart for Launch Pad 39B       
*5:30 a.m.      Arrive at white room and begin ingress  
*6:45 a.m.      Close crew hatch 
*8:45 a.m.      Launch  
* Televised events (times may vary slightly)
All times Eastern