NASA will begin the countdown for launch of Space Shuttle Atlantis on the fourth mission to dock with Russia's space station Mir on the morning of Friday, Sept. 13 at 12 a.m.(midnight) at the T-43 hour mark. The KSC launch team will conduct the countdown from Firing Room 1 of the Launch Control Center.
The countdown includes 33 hours and 53 minutes of built-in hold time leading to the opening of the launch window at about 4:54 a.m. (EDT) on Sept. 16. The launch window extends for about 7 minutes, possibly less, depending on final orbiter performance evaluations. The exact time of launch will be determined about 90 minutes before liftoff based on the location of the Mir space station. (Controllers are preparing for launch as early as 4:53 a.m. and that is the time reflected in the countdown bar-charts.)
In order to accommodate the short window necessary to rendezvous and dock with Mir, some changes have been made to the standard launch countdown. Most significant is the addition of an extra 30 minutes to the normal 10 minute built-in hold at T-9 minutes. Also, tanking is scheduled to begin about 30 minutes earlier than normal, at about 7:30 p.m. Sunday.
STS-79 is the sixth Space Shuttle mission of 1996. This will be the 17th flight of the orbiter Atlantis and the 79th flight overall in NASA's Space Shuttle program. Atlantis last flew on the second Shuttle/Mir docking flight in November 1995.
This flow has been unusual in that Atlantis was twice returned to the Vehicle Assembly Building (VAB) from the pad due to hardware and weather concerns. Atlantis was first rolled out of Orbiter Processing Facility bay 1 on June 24 and mated with the external tank and solid rocket boosters in the VAB. The Shuttle stack was then transported to Pad 39A on July 1.
On July 10, Atlantis was returned to the VAB due to threats from Hurricane Bertha. Two days later, managers decided to keep Atlantis off the pad in order to replace the solid rocket boosters before launch. Atlantis was destacked from the original set of boosters and returned to the OPF. Once the new boosters were prepared, Atlantis was again rolled over to the VAB on Aug. 13 and mated to the replacement booster/external tank configuration. On Aug. 20, Atlantis was returned to the pad for the second time.
Two weeks later, on Sept. 4, Hurricane Fran threatened Florida and managers decided to return Atlantis once again to the safety of the VAB. The threat quickly passed and the next day Atlantis was moved back out to the pad for the third time.
On mission STS-79, Atlantis will carry into orbit a six member crew. Mission Specialist John Blaha will replace Shannon Lucid on the Mir space. He will remain there until Atlantis again docks with Mir next January. Lucid will return to Earth with the rest of the STS-79 crew.
The STS-79 crew are: Commander Bill Readdy; Pilot Terry Wilcutt; and Mission Specialists Jay Apt, Tom Akers, Carl Walz and John Blaha. All members of the STS-79 crew are veteran Shuttle flyers.
The crew are scheduled to arrive at KSC at about 12:01 a.m. Friday, Sept. 13. Their activities at KSC prior to launch will include equipment fit checks, medical examinations and opportunities to fly in the Shuttle Training Aircraft.
(The countdown will target launch for 4:53 a.m. The exact launch time will be adjusted at the T-9 minute hold.)
Prepare for the start of the STS-79 launch countdown
Perform the call-to-stations (11:30 p.m. Thursday, Sept. 12)
All members of the launch team report to their respective consoles in
Firing Room 1 in the Launch Control Center for the start of the
countdown.
Countdown begins at the T-43 hour mark (12 a.m.)
Start preparations for servicing fuel cell storage tanks
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
Begin stowage of flight crew equipment
Inspect the orbiter's mid-deck and flight-deck and remove crew module
platforms
Enter first planned built-in hold at T-27 hours for duration of four hours (4 p.m.)
Clear launch pad of all non-essential personnel
Perform test of the vehicle's pyrotechnic initiator controllers
Resume countdown (8 p.m.)
Clear launch pad of all personnel
Begin operations to load cryogenic reactants into Atlantis' fuel cell
storage tanks (8 p.m. - 4 a.m.)
After cryogenic loading operations, re-open the pad
Enter four-hour built-in hold at T-19 hours (4 a.m.)
Resume orbiter and ground support equipment close-outs
Demate orbiter mid-body umbilical unit and retract into fixed service
structure
Power-up Spacehab and prepare for final stowage
Resume countdown (8 a.m.)
Start final preparations of the Shuttle's three main engines for main
propellant tanking and flight
Activate the orbiter's flight controls and navigation systems
Install mission specialists' seats in crew cabin
Close-out the tail service masts on the mobile launcher platform
Enter planned hold at T-11 hours for 21 hours, 3 minutes (4 p.m.)
Complete final stowage of Spacehab
Perform orbiter ascent switch list in crew cabin
Install film in numerous cameras on the launch pad
Activate the orbiter's communications systems
Activate orbiter's inertial measurement units
Fill pad sound suppression system water tank
Safety personnel conduct debris walkdown
Move Rotating Service Structure (RSS) to the park position (11 a.m.)
Following the RSS move, begin final stowage of mid-deck experiments
and flight crew equipment
Resume countdown (1:03 p.m.)
Continue installation of time critical flight crew equipment
Perform pre-ingress switch list
Start fuel cell flow-through purge
Activate the orbiter's fuel cells
Configure communications at Mission Control, Houston, for launch
Clear the blast danger area of all non-essential personnel
Switch Atlantis' purge air to gaseous nitrogen
Enter planned two-hour built-in hold at the T-6 hour mark (6:03 p.m.)
Launch team verifies no violations of launch commit criteria prior to
cryogenic loading of the external tank
Clear pad of all personnel
Begin loading the external tank with about 500,000 gallons of
cryogenic propellants (about 7:30 p.m.)
Resume countdown (8:03 p.m.)
Complete filling the external tank with its flight load of liquid
hydrogen and liquid oxygen propellants (about 10:30 p.m.)
Perform inertial measurement unit preflight calibration
Align Merritt Island Launch Area (MILA) tracking antennas
Perform open loop test with Eastern Range
Conduct gimbal profile checks of orbital maneuvering system engines
Enter two-hour hold at T-3 hours (11:03 p.m.)
Close-out crew and Final Inspection Team proceeds to Launch Pad 39A
Resume countdown at T-3 hours (1:03 a.m.)
Crew departs Operations and Checkout Building for the pad (about 1:08 a.m.)
Complete close-out preparations in the white room
Check cockpit switch configurations
Flight crew begins entry into the orbiter (about 1:48 a.m.)
Astronauts perform air-to-ground voice checks with Launch Control and
Mission Control
Close Atlantis' crew hatch (about 3:03 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 (3:43 a.m.)
NASA Test Director conducts final launch team briefings
Resume countdown (3:53 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 40-minute hold at T-9 minutes (4:04 a.m.)
(This is the last planned built-in hold. Other hold options are
available if necessary. During this hold, the exact launch time will
be determined based on the exact location of the Mir space station.
The hold time will likely vary by a minute or two.)
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 4:44 a.m.)
Start automatic ground launch sequencer (T-9:00 minutes)
Retract orbiter crew access arm (T-7:30)
Start mission recorders (T-5:30)
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-79
T-TIME LENGTH OF HOLD HOLD BEGINS HOLD ENDS
T-27 hours 4 hours 4:00 p.m. Fri. 8:00 p.m. Fri.
T-19 hours 4 hours 4:00 a.m. Sat. 8:00 a.m. Sat.
T-11 hours 21 hours, 3 minutes 4:00 p.m. Sat. 1:03 p.m. Sun.
T-6 hours 2 hours 6:03 p.m. Sun. 8:03 p.m. Sun.
T-3 hours 2 hours 11:03 p.m. Sun. 1:03 a.m. Sun.
T-20 minutes 10 minutes 3:43 a.m. Sun. 3:53 a.m. Sun.
T-9 minutes about 40 minutes 4:04 a.m. Sun. 4:44 a.m. Sun.
CREW FOR MISSION STS-79
Commander (CDR): Bill Readdy
Pilot (PLT): Terry Wilcutt
Mission Specialist (MS1): Jay Apt
Mission Specialist (MS2): Tom Akers
Mission Specialist (MS3): Carl Walz
Mission Specialist (MS4): John Blaha (up)
Mission Specialist (MS4): Shannon Lucid (down)
SUMMARY OF STS-79 LAUNCH DAY CREW ACTIVITIES
Sunday, Sept. 15
6:00 p.m. Wake up
6:30 p.m. Breakfast
* 11:58 p.m. Lunch and crew photo
Monday, Sept. 16
12:28 a.m. Weather briefing (CDR, PLT, MS2)
12:28 a.m. Don launch and entry suits (MS1, MS3, MS4)
12:38 a.m. Don launch and entry suits (CDR, PLT, MS2)
* 12:50 a.m. Crew suiting photo
* 1:08 a.m. Depart for launch pad 39A
* 1:48 a.m. Arrive at white room and begin ingress
* 3:03 a.m. Close crew hatch
* 4:54 a.m. Launch
* Televised events (times may vary slightly)
All times Eastern