February 24, 1995

KSC Release No. 18-95

SPACE SHUTTLE MISSION STS-67 LAUNCH COUNTDOWN TO BEGIN MONDAY 

	The countdown for launch of the Space Shuttle Endeavour on mission
STS-67 is scheduled to begin Monday, Feb. 27 at 2 a.m. EST, at the T-43
hour mark.

	The countdown includes 28 hours and 37 minutes of built-in hold
time leading to the opening of the launch window at 1:37 a.m. (EST) on
March 2. The launch window extends for 2 1/2 hours, through 4:07 a.m.

	STS-67 is the second of eight missions scheduled for 1995. This
will be the 8th flight of the Shuttle Endeavour and the 68th flight
overall in NASA's Space Shuttle program.

	The primary purpose of mission STS-67 is to support the Astro-2
payload, a series of ultraviolet telescopes that will study the evolution
and composition of stars and galaxies and the interstellar dust between
galaxies. The Astro-2 telescopes will also look at the planet Jupiter in
hopes of observing any changes in the planet's upper atmosphere resulting
from the Shoemaker-Levy 9 comet impacts last summer.

	The three telescopes flying on Astro-2 are: Hopkins Ultraviolet
Telescope (HUT), Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE)
and Ultraviolet Imaging Telescope (UIT).

	Other payloads located on the middeck are two Protein Crystal
Growth investigations, the Commercial Materials Dispersion Apparatus
Instrumentation Technology Associates Experiments (CMIX), and the Shuttle
Amateur Radio Experiment (SAREX-II).

	Endeavour was rolled out of Orbiter Processing Facility bay 1 on
Feb. 3 and mated with the external tank and solid rocket boosters in the
Vehicle Assembly Building. The Shuttle stack was then transported to
Pad 39A on Feb. 8. Endeavour last flew in September/October 1994.

	The STS-67 crew are: Commander Stephen Oswald, Pilot William
Gregory, Payload Commander/Mission Specialist Tamara Jernigan, Mission
Specialists John Grunsfeld and Wendy Lawrence, and Payload Specialists
Samuel Durrance and Ronald Parise.

	The crew is scheduled to arrive at KSC at about 11:15 p.m. Sunday,
Feb. 26. Their activities at KSC prior to launch will include equipment
fit checks, medical examinations and opportunities to fly in the Shuttle
Training Aircraft.

	As the countdown begins, the KSC launch team in Firing Room 3 of
the Launch Control Center will verify all systems to assure the Shuttle is
properly powered up and the data processing and backup flight control
systems are operating trouble free.

	Verifications conducted throughout the launch countdown ensure
continuous reviews are made of the flight software stored in the orbiter's
twin memory banks. Computer controlled display systems will be activated
and the backup flight system general purpose computer will be loaded.

	Operations will also begin to prepare the orbiter for on-board
cryogenic loading. Later, orbiter navigation aids will be turned on and
tested and the inertial measurement units activated. Ground crews will
make the final storage of mid-deck and flight deck supplies, perform
microbial samplings of the flight crew's drinking water and check water
levels in the waste management system.

	At T-27 hours, the countdown enters its first scheduled hold.
This is a four-hour hold lasting from 6 p.m.-10 p.m. Monday, Feb. 27.

	When the countdown resumes, the launch pad will be cleared of all
personnel for loading cryogenic reactants. Reactants are loaded into the
power reactant storage and distribution system tanks located under the
payload bay lining and the extended duration orbiter pallet tanks in the
aft end of the payload bay. The reactants are used by the orbiter's fuel
cells to provide electricity to the orbiter and drinking water for the
crew. Cryogenic flow operations are scheduled to start at about 10 p.m.
Monday and continue for about 12 hours.

	As servicing of the cryogenic tanks nears completion, the clock
will enter an eight-hour built-in hold at the T-19 hour mark. This hold
will last from 6 a.m.-2 p.m. Tuesday.

	Following cryogenic loading operations, the pad will be re-opened
for scheduled pre-launch activities. The orbiter mid-body umbilical unit,
used to load the super-cold reactants in the orbiter's fuel cell tanks,
will be demated and retracted into the launch structure.

	When the countdown resumes, technicians will complete final vehicle
and facility close-outs and begin configuring Endeavour's cockpit for
flight. The orbiter's flight control system and navigation aids will be
activated. The stowable crew seats will be installed in the flight and
mid-decks.

	The countdown will enter another built-in hold at the T-11 hour
mark at 10 p.m. Tuesday. This 13-hour, 17-minute hold will last until
11:17 a.m. Wednesday. During this hold, time critical equipment will be
installed in the orbiter's cockpit. The inertial measurement units and the
orbiter's communications systems will be activated.

	At about 8:30 a.m. Wednesday, the Rotating Service Structure is
scheduled to be moved away from the vehicle and placed in launch position.

	At T-9 hours (1:17 p.m. Wednesday) the onboard fuel cells will be
activated. At T-8 hours, the launch team will evacuate the blast danger
area and clear the pad for loading the external tank with the cryogenic
propellants for the orbiter's main engines. At T-7 hours, 30 minutes,
conditioned air that is flowing through the orbiter's payload bay and
other areas on the orbiter will be switched to gaseous nitrogen in
preparation for fueling the external tank. The inertial measurement units
will transition from the warm-up stage to the operate/attitude
determination mode at T-6 hours, 45 minutes.

	The countdown will enter another planned built-in hold at the T-6
hour mark at 4:17 p.m. Wednesday. During this one-hour hold, final
preparations for loading the external tank will be completed. Also, a
pre-tanking weather briefing will be conducted for the benefit of the
Mission Management Team prior to their giving approval to begin tanking
operations.

	Chilldown of the lines that carry the cryogenic propellants to
the external tank begins when the clock starts counting again at 5:17 p.m.
Wednesday. Filling and topping off the external tank should be complete
about three hours later at the beginning of the next planned hold at T-3
hours, or 8:17 p.m. Wednesday.

	During the two-hour hold at the T-3 hour mark, the Final Inspection
Team will conduct a final survey of the pad and various Shuttle components
ensuring their readiness for flight. Also, the close-out crew will be
dispatched to the pad and 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.

	The seven flight crew members will be awakened at about 8:42 p.m.
Wednesday and seated for their final meal before launch at about 9:12 p.m.
Following their meal, the crew will receive a briefing on weather conditions
at KSC and at the TransOceanic Abort Landing sites.

	The flight crew will suit-up in their partial-pressure suits, then
leave the Operations and Checkout Building at about 10:22 p.m. Wednesday.
They will arrive at the Pad 39A white room at about 10:52 p.m. and be
assisted into the crew cabin by white room personnel.

	Just prior to the T-60 minute mark, the test team and the flight
crew will get another weather update, including observations from
astronaut Bob Cabana flying in a Shuttle Training Aircraft in the KSC area.

	The next built-in hold occurs at the T-20 minute mark (12:57 a.m.
Thursday) and lasts for 10 minutes. The final built-in hold occurs at the
T-9 minute mark (1:18 a.m.) and extends for 10 minutes. 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; ground power disconnection from the orbiter at T-50
seconds; and the electronic "go" to Endeavour's 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, Feb. 27)
 
* Prepare for the start of the STS-67 launch countdown 
* Perform the call-to-stations at the T-43 hour mark 
* All members of the launch team report to their respective consoles in
Firing Room 3 in the Launch Control Center for the start of the countdown.
* Countdown begins at 2 a.m. EST
* Start preparations for servicing fuel cell storage tanks
* Begin final vehicle and facility close-outs for launch

Enter first planned built-in hold at T-27 hours for duration of four hours
(6 p.m.)

* Check out back-up flight systems
* Review flight software stored in mass memory units and display systems
* Load backup flight system software into Endeavour's general purpose
computers
* Begin stowage of flight crew equipment
* Inspect the orbiter's mid-deck and flight-deck and remove crew module
platforms
* Perform test of the vehicle's pyrotechnic initiator controllers

Resume countdown (10 p.m.)
 
* Clear launch pad of all personnel
* Begin the 12 hour operation to load cryogenic reactants into Endeavour's
fuel cell storage tanks and the extended duration orbiter pallet

Launch - 2 Days (Tuesday, Feb. 28)

Enter eight-hour built-in hold at T-19 hours (6 a.m.)

* After cryogenic loading operations, re-open the pad
* Resume orbiter and ground support equipment close-outs
* Demate orbiter mid-body umbilical unit and retract into fixed service
structure


Resume countdown (2 p.m.)

* Start final preparations of the Shuttle's main engines for main
propellant tanking and flight
* Activate 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 13 hours, 17 minutes (10 p.m.)

* 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

Launch -1 Day (Wednesday, March 1)
 
* Safety personnel conduct debris walkdown
* Move Rotating Service Structure (RSS) to the park position at about
8:30 a.m.
* Following the RSS move, begin final stowage of mid-deck experiments and
flight crew equipment

Resume countdown (11:17 a.m.)

* Install 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 Endeavour's purge air to gaseous nitrogen

Enter planned one-hour built-in hold at the T-6 hour mark (4:17 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 (5:17 p.m.)

* Begin loading the external tank with cryogenic propellants (5:17 p.m.)
* Perform inertial measurement unit preflight calibration
* Align Merritt Island Launch Area (MILA) tracking antennas
* Complete filling the external tank with its flight load of liquid
hydrogen and liquid oxygen propellants (8:12 p.m.)

Enter two-hour hold at T-3 hours (8:17 p.m.)

* Perform open loop test with Eastern Range
* Conduct gimbal profile checks of orbital maneuvering system engines
* Close-out crew and Final Inspection Team proceeds to Launch Pad 39A

Resume countdown at T-3 hours (10:17 p.m.)

* Crew departs Operations and Checkout Building for the pad at 10:22 p.m.
* Complete close-out preparations in the white room
* Check cockpit switch configurations 
* Flight crew enters orbiter
 
Launch Day (Thursday, March. 2)
 
* Astronauts perform air-to-ground voice checks with Launch Control and
Mission Control
* Close Endeavour's crew hatch
* 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 (12:57 a.m.)

* NASA Test Director conducts final launch team briefings

Resume countdown (1:07 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 final 10-minute hold at T-9 minutes (1:18 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 (1:28 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 MPS 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)
* 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 BUILT-IN HOLDS FOR STS-67

T-TIME --------- LENGTH OF HOLD -------- HOLD BEGINS -------- HOLD ENDS 

T-27 hours ---------4 hours ----------6:00 p.m. Mon.------10:00 p.m. Mon.
T-19 hours ---------8 hours ----------6:00 a.m. Tues.------2:00 p.m. Tues.
T-11 hours --------13 hrs.,17 mins.--10:00 p.m. Tues.-----11:17 a.m. Wed.
T-6  hours ---------1 hours ----------4:17 p.m. Wed.-------5:17 p.m. Wed.
T-3  hours ---------2 hours ----------8:17 p.m. Wed.------10:17 p.m. Wed.
T-20 minutes ------10 minutes -------12:57 a.m. Thurs.-----1:07 a.m. Thurs.
T-9  minutes ------10 minutes --------1:18 a.m. Thurs.-----1:28 a.m. Thurs.



CREW FOR MISSION STS-67

Commander (CDR): Stephen Oswald (Red Team)
Pilot (PLT): William Gregory (Red Team)
Payload Commander/Mission Specialist (MS3): Tamara Jernigan (Blue Team)
Mission Specialist (MS1): John Grunsfeld (Red Team)
Mission Specialist (MS2): Wendy Lawrence (Blue Team)
Payload Specialist (PS1): Samuel Durrance (Blue Team)
Payload Specialist (PS2): Ronald Parise (Red Team)


SUMMARY OF STS-67 LAUNCH DAY CREW ACTIVITIES


Wednesday, March 1

 8:42 p.m.	Wake up
 9:12 p.m.	Dinner/Breakfast and crew photo
 9:42 p.m.	Weather briefing (CDR, PLT, MS2)
 9:42 p.m.	Don flight equipment (MS1, MS3, PS1, PS2)
 9:52 p.m.	Don flight equipment (CDR, PLT, MS2)
10:22 p.m.	Depart for launch pad 39A
10:52 p.m.	Arrive at white room and begin ingress

Thursday, March 2, 1995

12:07 a.m.	Close crew hatch
 1:37 a.m.	Launch