Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/STSKITS/STS_50.LAU

Text File | 1992-06-23 | 16KB | 379 lines

6/19/92: STS-50 COUNTDOWN SCHEDULED TO BEGIN JUNE 22




Bruce Buckingham                             June 19, 1992



KSC Release No. 79 - 92


     The countdown to launch for the Space Shuttle Columbia on
mission STS-50 is scheduled to begin at 8:00 a.m. EDT on Monday,
June 22, at the T-43 hour mark. This launch will be the 12th for
the orbiter Columbia and the 48th overall in the Space Shuttle
program. The countdown includes 33 hours and 7 minutes of built-
in hold time leading up to the opening of the launch window at
12:07 p.m. (EDT) on Thursday, June 25.  The launch window extends
until 2:37 p.m.

     Columbia will carry into orbit the United States
Microgravity Laboratory-1 on a 13-day mission.

     At the start of the countdown, the launch team in Firing
Room 3 in the Launch Control Center will verify that the Shuttle
vehicle is powered up and that the data processing system and
backup flight control system are operating without problem.
Verifications will also be conducted to ensure that a review of
the flight software stored in the orbiter's twin memory banks is
being conducted, computer controlled display systems are being
activated, and the backup flight system general purpose computer
is being loaded.

     This weekend, final ordnance operations will be conducted at
the pad and the aft orbiter compartment will be closed for
flight. Following countdown commencement on Monday, operations
will begin to prepare the main propulsion system and orbiter's
main engines for cryogenic loading, orbiter navigation aids will
be turned on and tested and the inertial measurement units will
be activated.

     Also performed on Monday will be final storage of mid-deck
and flight deck supplies and payloads, microbial sampling of
drinking water and water level adjustment of the crew waste
management system.

     At T-27 hours, the countdown will enter its first built-in
hold. This is a four-hour hold lasting from 12:00 midnight to
4:00 a.m. Tuesday. When the countdown resumes, the launch pad
will be cleared of all personnel in preparation for cryogenic
fuel loading of the Power Reactant and Storage Distribution
system tanks and the Extended Duration Orbiter (EDO) tanks in the
payload bay. These tanks hold the super-cold liquid hydrogen and
liquid oxygen reactants used by the fuel cells to provide
electricity to the orbiter and drinking water for the crew.

     Cryogenic flow is scheduled to start at the T-25 hour mark.
Servicing activities will take approximately 11 hours.

      As servicing of the cryogenic tanks continues, the clock
will enter another built-in hold at the T-19 hour mark. This hold
will last for 12 hours. Normally, this is a four-hour hold.
However, an additional eight hours was added into the schedule to
allow extra time to complete the loading of the EDO tanks in the
payload bay. This hold is scheduled to last from 12:00 noon to
12:00 midnight Tuesday.

     Following cryogenic loading operations, the pad will be
reopened for normal work and the orbiter mid-body umbilical unit
used to load the super-cold reactants into the orbiter's fuel
cell tanks will be demated.

     When the countdown resumes, technicians will complete final
vehicle and facility closeouts and begin activating the orbiter's
communications systems and configuring Columbia's cockpit for
flight. The orbiter's flight control system and navigation aids
will be activated. The stowable mission specialist and payload
specialist seats will be installed in the flight and mid-decks.
Also, a trace contaminant purge on the United States Microgravity
Laboratory will be concluded.

     The countdown will enter a standard built-in hold at the T-
11 hour mark at 8:00 a.m. Wednesday. The 13-hour, 47-minute hold
will extend to 9:47 p.m. Wednesday. During this hold, time
critical equipment will be installed in the orbiter's cockpit and
the inertial measurement units will be activated and warmed up.
At about 11:00 a.m. Wednesday, the Rotating Service Structure is
scheduled to be moved away from the vehicle to the launch
position.

     At T-9 hours (11:47 p.m. Wednesday), the onboard fuel cells
will be activated. At T-8 hours, the launch team will begin
evacuating the blast danger area. At T-7 hours, 30 minutes,
conditioned air that is flowing through the orbiter's payload bay
and other areas will be switched to gaseous nitrogen in
preparation for loading the external tank with super-cold liquid
propellants. The inertial measurement units will transition from
the warm up stage to the operate/attitude determination mode at
T-6 hours and 45 minutes.

     The countdown will enter another planned built-in hold at
the T-6 hour mark at approximately 2:47 a.m. Thursday. During
this one-hour hold, final preparations for loading the external
tank will be completed and a pre-tanking weather briefing will be
conducted.

     Chilldown of the lines that carry the cryogenic propellants
to the external tank begins approximately when the clock starts
counting again at 3:47 a.m. Thursday. Filling and topping of the
external tank should be complete at the beginning of the next
planned hold at T-3 hours or 6:47 a.m.

     During the two-hour planned hold, an ice inspection team
will perform a survey of the tank's outer insulation, and the
closeout crew will begin configuring the crew module and white
room for the flight crew's arrival. Liquid oxygen and liquid
hydrogen will be in a stable replenish mode during this time to
replace any propellant that "boils" off.

     During the hold at T-3 hours, the seven-member STS-50 crew
will be awakened at about 6:30 a.m.

     Following breakfast, the crew will receive a briefing on
weather conditions both here at KSC and around the world via
satellite from Mission Control-Houston.

     The flight crew will suit up in their partial-pressure
suits, then leave the Operations and Checkout Building at about
8:52 a.m., at T-2 hours and 55 minutes. They will arrive at the
pad white room at about 9:22 a.m. where they will be assisted by
white room personnel in getting into the crew cabin.

     Just prior to the T-1 hour mark, the test team and the
flight crew will get another weather update, including
observations from an astronaut flying in a Shuttle Training
Aircraft in the KSC area.

     The last two built-in holds will be 10 minutes in duration
and will occur at the T-20 minute mark or at 11:27 a.m. and at
the T-9 minute mark or at 11:48 a.m. During the final hold, the
flight crew and ground team receive the NASA Launch Director's
and the Mission Management Team's final "go" for launch.

     Milestones after the T-9 minute mark include start of the
ground launch sequencer; retraction of the orbiter access arm at
T-7 minutes, 30 seconds; start of the orbiter's auxiliary power
units at T-5 minutes; pressurization of the liquid oxygen tank
inside the external tank at T-2 minutes, 55 seconds;
pressurization of the liquid hydrogen tank at T-1 minute, 57
seconds; and the electronic "go" to Atlantis' onboard computers
to start their own terminal countdown sequence at T-31 seconds.
The orbiter's three main engines will start at T-6.6 seconds.

                      COUNTDOWN MILESTONES

                Launch - 3 Days (Monday, June 22)

     Prepare for the start of the STS-50 launch countdown and
perform the call-to-stations at the T-43 hour mark. Countdown
will begin at 8:00 a.m. All members of the launch team will
report to their respective consoles in Firing Room 3 of the
Launch Control Center for the start of the countdown.

               Launch  - 2 Days (Tuesday, June 23)

     Enter first planned built-in hold at T-27 hours for a
duration of four hours.

     Check out backup flight system and review flight software
stored in mass memory units and display systems. Load backup
flight system software into Columbia's general purpose computers.

     Begin stowage of flight crew equipment. Inspect the
orbiter's mid and flight decks and remove crew module platforms.
Start external tank loading preparations and prepare Shuttle main
engines for main propellant tanking and flight. Complete Spacelab
trace contaminant purge.

     Resume countdown. Start preparations for servicing fuel cell
storage tanks and begin final vehicle and facility closeouts for
launch.

     Clear launch pad of all personnel and begin loading liquid
oxygen and liquid hydrogen reactants into Columbia's fuel cell
storage tanks and the EDO pallet tanks in the payload bay.

     After the loading operation, the pad will be reopened for
normal work and orbiter and ground support equipment closeouts
will resume.

     Enter planned built-in hold at T-19 hours for a duration of
12 hours.

     Demate orbiter mid-body umbilical unit used during fuel cell
loading.

               Launch - 1 Day (Wednesday, June 24)

     Resume countdown. Activate orbiter communications systems,
flight control and navigation systems. Install mission and
payload specialist seats in crew cabin. The tail service masts on
the mobile launcher platform will be closed out for launch.

     Enter planned hold at T-11 hours for a duration of 13 hours
and 47 minutes.

     Perform orbiter ascent switch list in crew cabin. During
this hold, the orbiter's inertial measurement units will be
activated and kept in the "warm up" mode and film will be
installed in the numerous cameras on the launch pad. In addition,
safety personnel will conduct a debris walkdown and the pad sound
suppression system water tank will be filled.

     The Rotating Service Structure will be moved to the park
position during this hold at about 11:00 a.m.

     Resume Countdown. Install time critical flight crew
equipment and perform the pre-ingress switch list. Start fuel
cell flow-through purge.


                 Launch Day (Thursday, June 25)

     Activate orbiter fuel cells. Configure communications at
Mission Control Houston for launch. Clear the blast danger area
of all non-essential personnel and switch Atlantis' purge air to
gaseous nitrogen.

     Enter one-hour planned built-in hold at T-6 hours.

     Resume countdown. Launch team verifies there are no
violations of launch commit criteria prior to cryogenic servicing
of the external tank. Clear pad of all personnel. Start loading
the external tank with cryogenic propellants. Loading is
scheduled to begin at 3:47 a.m.

     Complete filling the external tank with its flight load of
liquid hydrogen and liquid oxygen propellants. Perform open loop
test with Eastern Space and Missile Center and conduct gimbal
profile checks of orbital maneuvering system engines.

     Perform inertial measurement unit preflight calibration and
align Merritt Island Launch Area tracking antennas.

     Enter two hour hold at T-3 hours. Wake flight crew. Closeout
crew and ice inspection team proceeds to Launch Pad 39-A.

     Resume countdown at T-3 hours. Complete closeout
preparations in the white room and cockpit switch configurations.
Crew departs Operations and Checkout Building for the pad.

     Flight crew enters orbiter. Astronauts perform air-to-ground
voice checks with Mission Control Houston. Close Columbia's crew
hatch. Begin Eastern Space and Missile Center final network open
loop command check, perform hatch seal and cabin leak checks, and
begin the inertial measurement unit preflight alignment and range
safety closed loop test. The white room is closed out and the
closeout 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. NASA Test
Director conducts final briefing

     Resume countdown. Transition orbiter onboard computers to
launch configuration and start fuel cell thermal conditioning.
Close orbiter cabin vent valves. Backup flight system transitions
to launch configuration.

     Enter planned 10 minute hold at T-9 minutes. Launch Director
and Mission Management Team complete final polls for launch.

     Resume countdown.

Start automatic ground launch sequencer (T-9 minutes)
Retract orbiter crew access arm (T-7:30)
Start mission recorders (T-5:30)
Start APU's. Arm SRB and ET range safety safe and arm devices (T-5)
Start liquid oxygen drainback (T-4:55)
Start orbiter aerosurface profile test (T-3:55)
Orbiter transfers to internal power (T-3:30)
Start MPS gimbal profile test (T-3:30)
Pressurize liquid oxygen tank/retract gaseous oxygen vent arm (T-2:55)
Fuel cells to internal reactants (T-2:35)
Pressurize liquid hydrogen (LH2) tank (T-1:57)
Deactivate SRB joint heaters (T-1:00)
LPS go for start of orbiter automatic sequence (T-0:31 seconds)
Ignition of Shuttle's three main engines (T-6.6 seconds)
SRB ignition and liftoff (T-0)



              SUMMARY OF HOLDS AND HOLD TIMES FOR STS-50

T-27 hours --- 4 hour hold ----------- Tuesday, 12 midnight - 4:00 am
T-19 hours --- 12 hour hold ---------- Tuesday, 12 noon - 12 midnight
T-11 hours --- 13 hour, 47 min. hold - Wednesday, 8:00 am - 9:47 pm
T-6 hours ---- 1 hour hold ----------- Thursday, 2:47 am - 3:47 am
T-3 hours ---- 2 hour hold ----------- Thursday, 6:47 am - 8:47 am
T-20 minutes - 10 minute hold -------- Thursday, 11:27 am - 11:37 am
T-9 minutes -- 10 minute hold -------- Thursday, 11:48 am - 11:58 am





             SUMMARY OF STS-50 LAUNCH DAY CREW ACTIVITIES

Thursday June 25:

6:30 am        Wake Up
7:30 am        Breakfast/Dinner
8:12 am        Weather Briefing (CDR, PLT, MS2)
8:12 am        Don Flight Equipment (MS1, MS2, PS1, PS2)
8:22 am        Don Flight Equipment (CDR, PLT, MS2)
8:52 am        Depart for Pad 39-A
9:22 am        Arrive at White Room
12:07 pm       Launch


     The seven crew members who will be launched aboard Columbia on
Space Shuttle mission STS-50 are:
     Commander Richard Richards
     Pilot Kenneth Bowersox
     Mission Specialists: Bonnie Dunbar, Ellen Baker, Carl Meade
     Payload Specialists: Lawrence DeLucas, Eugene Trinh



                            #   #   #   #





6/9/92: STS-50 LAUNCH ADVISORY

Mark Hess
Headquarters, Washington, D.C.       June 9, 1992

Lisa Malone
Kennedy Space Center, Fla.


    NASA will launch Space Shuttle Columbia on a 13 day
mission on June 25, 1992.  NASA officials selected the
launch date at the conclusion of the Flight Readiness
Review held today at the Kennedy Space Center, Fla.

     Mission STS-50, planned to be the longest flight
to date in the Shuttle program, will carry the United
States Microgravity Laboratory-1 payload into orbit.  A
Spacelab long module will serve as an in-orbit
laboratory for seven crewmembers and 31 experiments
devoted to materials science, fluid physics, combustion
science and biotechnology.

    Columbia will be launched into a 184 statute mile
circular orbit inclined 28.5 degrees to the Equator from
Pad 39-A.  The launch window on June 25 opens at 12:07
p.m. EDT and closes at 2:37 p.m. EDT.  Columbia will end
its mission with a landing at Dryden Flight Research
Facility, Calif.  The mission duration is planned for 12
days, 20 hours and 29 minutes.

    Commanding the mission will be Richard Richards.
Columbia's pilot will be Ken Bowersox.  Mission
specialists are Bonnie Dunbar, Ellen Baker, and Carl
Meade.  Payload specialists are Larry DeLucas and Gene
Trinh.


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