Conference 7.286::space

               SPACE SHUTTLE WEEKLY STATUS SUMMARY
                   Thursday, January 7, 1993

George H. Diller
Kennedy Space Center
 
                            STS-56

Vehicle: OV-103/Discovery   Mission Number: STS-56
Location: OPF Bay 3
Payloads: ATLAS-2/ODERACS/SSBUV/SPARTAN/SUVE
Launch timeframe: March, wk 3   Crew Size: 5
Mission Duration: 8 days   Inclination: 57 degrees
Nominal Landing Site: KSC


STS-56 IN WORK:

- inspections of 17-inch quick disconnect
- liquid oxygen main propulsion system leak checks
- reinstall wheel and tire assembly
- orbiter hydraulic servicing
- Ku band antenna testing
- radar altimter testing
- potable water servicing
- tile removal and replacement/tile repairs


STS-56 WORK COMPLETED:

- remove and inspect drag chute hardware
- flush and drain waste management system
- removal of forward reaction control system


STS-56 WORK SCHEDULED:

- hypergolic deservicing this weekend
- reconfigure payload bay for ATLAS-2
- humidity separator flow performance testing


ISSUES AND CONCERNS:

                  SPACE SHUTTLE STATUS SUMMARY
                    Friday, January 8, 1993

Lisa Malone
Kennedy Space Center
 
             STS-56/ ATLAS-2 - DISCOVERY (0V 103) - OPF BAY 3

IN WORK TODAY:
-  pulse purges of the main propulsion system
-  preparations for removing auxiliary power unit ferry flight plugs
-  voltage test of the fuel cells
-  troubleshooting the Ku-band antenna
-  inspections of the 17-inch umbilicals

WORK SCHEDULED:
-  inspections of the orbital maneuvering system thrusters
-  removal of the main engine heat shields

WORK COMPLETED:
-  installed all flight tires on the main and nose landing gears
 

                SPACE SHUTTLE WEEKLY STATUS SUMMARY
                   Friday, January 15, 1993

George H. Diller
Kennedy Space Center
 
                         STS-56

Vehicle: OV-103/Discovery   Mission Number: STS-56
Location: OPF Bay 3
Payloads: ATLAS-2/ODERACS/SSBUV/SPARTAN/SUVE
Launch timeframe: March, wk 4   Crew Size: 5
Mission Duration: 8 days   Inclination: 57 degrees
Nominal Landing Site: KSC

STS-56 IN WORK:

- preparations for main engine removal
- fuel cell and PRSD system testing
- OMS pod thruster checkout
- auxiliary power unit lube oil deservicing
- solid rocket booster stacking in the Vehicle Assembly Building


STS-56 WORK COMPLETED:

- remove & replace mass memory unit #2
- reload MMU #2 software
- reinstall general purpose computer
- main engine drying


STS-56 WORK SCHEDULED:

- main engine removal
- aft main propulsion system leak and functional checks
- retest MMU #2
- install remote manipulator arm
- head-up display system checkout
- S-band air-to-ground antenna testing
- auxilary power unit leak and functional testing
- install drag chute morter and chute retractor
- install drag chute

              SPACE SHUTTLE WEEKLY STATUS SUMMARY
                   Friday, January 22, 1993

George H. Diller
Kennedy Space Center
 
                            STS-56

Vehicle: OV-103/Discovery   Mission Number: STS-56
Location: OPF Bay 3
Payloads: ATLAS-2/ODERACS/SSBUV/SPARTAN/SUVE
Launch timeframe: March, wk 4   Crew Size: 5
Mission Duration: 8 days   Inclination: 57 degrees
Nominal Landing Site: KSC

STS-56 IN WORK:

- preparations for left OMS pod removal
- connections of waste containment system
- Ku-band antenna testing
- stacking solid rocket boosters in the VAB
- main propulsion system functional testing



STS-56 WORK COMPLETED:

- head-up display system checkout
- tests of S-band air-to-ground antenna
- auxiliary power unit leak and functional checks




STS-56 DISCOVERY WORK SCHEDULED:

- main engine installation
- right OMS pod functional
- forward reaction control system installation
- solid rocket booster stacking continues
- Ku-band antenna testing continues
- potable water servicing
- drag chute installation
- crew hatch seal leak check
- testing of flight deck data display systems
- auxiliary power unit lube oil servicing


 

              SPACE SHUTTLE WEEKLY STATUS SUMMARY
                   Friday, January 29, 1993

George H. Diller
Kennedy Space Center
 
                        STS-56

Vehicle: OV-103/Discovery   Mission Number: STS-56
Location: OPF Bay 3
Payloads: ATLAS-2/ODERACS/SSBUV/SPARTAN/SUVE
Launch timeframe: March, wk 4   Crew Size: 5
Mission Duration: 8 days   Inclination: 57 degrees
Nominal Landing Site: KSC

STS-56 IN WORK:

- sleep station installation
- preparations for payload installation
- preparations for main engine installation
- radiator functional checks
- waste containment system functional checks
- potable water servicing
- Ku-band antenna testing
- vertical tail closeouts
- OMS pod removal
- tile water proofing
- stacking solid rocket boosters in the VAB

STS-56 DISCOVERY WORK COMPLETED:

- OMS pod functional checks
- initial auxilary power unit lube oil servicing
- auxilary power unit leak and functional check
- drag chute installation
- tests of S-band air-to-ground antenna

STS-56 WORK SCHEDULED:

- heads up display system checkout
- payload bay cleaning
- main engine installation
- heat shield installation
- checks of air data system
- TACAN checkout
- heads up display system checkout
- crew hatch seal leak check
- main computer display system checkout
- remove and replace spare general purpose computer
- liquid hydrogen system leak and functional check
- forward reaction control system installation
- potable water servicing
- crew hatch seal leak check
- testing of cockpit data display systems
- auxiliary power unit lube oil servicing


 

              SPACE SHUTTLE WEEKLY STATUS SUMMARY
                   Friday, February 5, 1993

George H. Diller
Kennedy Space Center
 
                             STS-56

Vehicle: OV-103/Discovery
Location: OPF Bay 3                    Mission Number: STS-56
Payloads: ATLAS-2/SSBUV/SPARTAN/SUVE   Crew Size: 5
Launch timeframe: NET March 23         Orbital Altitude: 184 sm
Mission Duration: 9 days 6 hours       Inclination: 57 degrees
Nominal Landing Site: KSC/April 1


STS-56 IN WORK:

- left OMS pod installation
- SUVE Interface Verification Test
- potable water servicing
- S-band air-to-ground transmitter checks
- TACAN testing
- payload bay cleaning
- preparation of payload bay for ATLAS-2 payload installation
- installation of ATLAS-2 into payload transport canister at O&C
- stacking solid rocket boosters in the VAB


STS-56 WORK COMPLETED:

- installation of main engines
- initial ammonia boiler servicing
- payload bay door inspections
- payload bay door cycle tests
- radiator inspections
- fuel cell testing
- range rate radar receiver testing


STS-56 WORK SCHEDULED:

- fuel cell changeout
- ATLAS-2 payload installation
- installation of forward reaction control system
- MSBLS checkout
- checkout of data display systems on the flight deck
- ammonia boiler servicing
- main engine electrical interface checks
- open external tank doors
- OMS/RCS flight control checkout
- brake anti-skid test
- deploy remote manipulator arm for testing
- liquid hydrogen system leak and functional tests
- checkout of orbiter crew cabin and payload bay lighting system


 

              SPACE SHUTTLE WEEKLY STATUS SUMMARY
                   Friday, February 12, 1993

George H. Diller
Kennedy Space Center
 
                           STS-56

Vehicle: OV-103/Discovery
Location: OPF Bay 3                    Mission Number: STS-56
Payloads: ATLAS-2/SSBUV/SPARTAN/SUVE   Crew Size: 5
Launch timeframe: NET April wk 1       Orbital Altitude: 184 sm
Mission Duration: 9 days 6 hours       Inclination: 57 degrees
Nominal Landing Site: KSC

STS-56 IN WORK:

- tile repair
- tile waterproofing
- remote manipulator arm installation
- configuring payload bay for Spacehab
- payload bay door radiator repair


STS-56 WORK COMPLETED:

- SUVE Interface Verification Test
- airlock crew hatch functional test
- potable water servicing
- installation of forward reaction control system
- S-band air-to-ground transmitter checks
- installation of main engines
- TACAN testing
- potable water sampling
- payload bay cleaning
- payload bay door inspections
- payload bay door cycle tests
- stacking solid rocket boosters in the VAB
- radiator inspections
- fuel cell testing
- range rate radar receiver testing
- installation of forward reaction control system
- MSBLS checkout


STS-56 WORK SCHEDULED:

- OMS/RCS cross-feed connections this weekend
- ATLAS/SPARTAN Interface Verification Test on Monday
- OMS thruster inspections
- air data system functional test
- main engine electrical interface checks
- potable water servicing
- fuel cell changeout
- remote manipulator arm testing

 

               SPACE SHUTTLE WEEKLY STATUS SUMMARY
                   Friday, February 19, 1993

George H. Diller
Kennedy Space Center
407/867-2468
 
                        STS-56

Vehicle: OV-103/Discovery
Location: OPF Bay 3                    Mission Number: STS-56
Payloads: ATLAS-2/SSBUV/SPARTAN/SUVE   Crew Size: 5
Launch timeframe: April wk 1           Orbital Altitude: 184 sm
Mission Duration: 8 days 6 hours       Inclination: 57 degrees
Nominal Landing Site: KSC

STS-56 IN WORK:

- removal of main engine heat shields
- closeouts of main propulsion system
- potable water system leak check
- closeouts of midbody
- remote manipulator arm deployment check
- gaseous nitrogen servicing
- tile repair
- tile waterproofing
- payload bay liner installation
- external tank door latch pull test


STS-56 WORK COMPLETED:

- hydrogen propulsion system leak check
- MSBLS checkout
- payload bay door bulb seal repair
- ATLAS/SPARTAN Interface Verification Test
- Crew Equipment Interface Test (CEIT)
- remote manipulator arm installation
- water spray boiler checkout
- water spray boiler servicing
- potable water servicing
- OMS/RCS electrical checks
- fuel cell changeout
- fuel cell checkout
- forward reaction control system checkout


STS-56 WORK SCHEDULED:

- ammonia boiler servicing this weekend
- OMS/RCS cross-feed connections this weekend
- final radiator inspections on Sunday
- crew hatch functional check on Sunday
- air data probe/system functional check
- potable water servicing
- orbiter/external tank door functional test
- flight controls functional check
- closeouts of crew compartment
- final payload bay cleaning
- close payload bay doors
- tile closeouts
- close payload bay doors/remove strongbacks
- final nose gear/main landing gear tire pressure checks


SPECIAL TOPICS:  As a result of the turbopump inspection
requirement, Discovery's engines will be removed next week in the
orbiter processing facility.  They will be reinstalled in the
Vehicle Assembly Building using other engines presently in the
main engine maintenance facility.  Two of the turbopumps recently
removed from Columbia will be used, and the third one from the
remaining engine has already been inspected and reinstalled.

 

               SPACE SHUTTLE WEEKLY STATUS SUMMARY
                   Friday, February 26, 1993

George H. Diller
Kennedy Space Center
 
                          STS-56

Vehicle: OV-103/Discovery              Mission Number: STS-56
Location: OPF Bay 3                    Orbital altitude: 184 sm
Payloads: ATLAS-2/SSBUV/SPARTAN/SUVE   Inclination: 57 degrees
Launch timeframe: NET April 3          Nominal Landing Site: KSC
Mission Duration: 8 days 6 hours       Crew Size: 5


STS-56 IN WORK:

- orbiter aft main engine compartment closeouts
- crew module closeouts
- payload bay door closure
- crew hatch closure
- structural leak checks
- final tile work

STS-56 WORK COMPLETED:

- removal of main engines
- external tank door functional test
- landing gear functional test
- OMS/RCS flight control checks
- OMS/RCS system leak checks
- final check and securing of orbiter flight controls
- final payload bay cleaning
- thermal protection system tile work
- remote manipulator arm checkout
- MSBLS testing
- Ku-band antenna testing
- potable water supply system leak checks
- tests of air data probe

 STS-56 DISCOVERY WORK SCHEDULED:

- landing gear strut pressurization Saturday
- completion of tile closeouts Saturday
- weight and center of gravity determination Monday
- install orbiter on orbiter transporter Tuesday
- rollover to VAB on Wednesday

 

                 SPACE SHUTTLE DAILY STATUS
                   Tuesday, March 2, 1993


George H. Diller
Kennedy Space Center
 
                            STS-56

SPECIAL TOPICS

Discovery is scheduled for rollover from OPF Bay 3 to the VAB transfer
aisle this afternoon at approximately 5 p.m.  Mating to the external tank/solid
rocket booster stack will occur overnight.  The two-day Shuttle Interface Test
will follow.

     Installation of Discovery's three main engines is targeted to start on
March 8. (The engines were removed in the OPF because of the turbopump seal
retainer issue.) A rollout to Pad 39-B will occur sometime in the mid-March
time frame with a more definite date to be determined later.

 

                  SPACE SHUTTLE DAILY STATUS
                   Wednesday, March 3, 1993

                      (UPDATED 4:30 p.m.)

George H. Diller
Kennedy Space Center
 
                                 STS-56
SPECIAL TOPICS:

Discovery's rollover from OPF Bay 3 to the VAB transfer aisle occurred
at 5:41 p.m. last night and the orbiter was hoisted for mating to the external
tank/solid rocket booster stack at 1:50 a.m. this morning.  Soft mate is
complete with hard mate in work.

              SPACE SHUTTLE WEEKLY STATUS REPORT
                      Friday, March 5, 1993

Mitch Varnes
Kennedy Space Center, Fla.
 
                            STS-56

VEHICLE: OV-103/ Orbiter Discovery               MISSION: STS-56
Current location: Vehicle Assembly Building


STS-56 IN-WORK:

- Orbiter/external tank mate is continuing.
- Preparations for installing main engines into orbiter.



STS-56 WORK SCHEDULED:

- Installation of main engines set to begin on Monday.



STS-56 WORK COMPLETED:

- Mating of liquid hydrogen and liquid  oxygen  connection  lines
between external tank and orbiter.

 

                 SPACE SHUTTLE DAILY STATUS
                  Thursday, March 11, 1993

George H. Diller
Kennedy Space Center

 
                        STS-56

SPECIAL TOPICS:

     Discovery's rollout from the Vehicle Assembly Building to Launch Pad 39-B
has been rescheduled for 12 Noon on Friday, March 12.  This decision was made
to avoid inclement weather which is expected in central Florida on Friday night
and Saturday morning, and also because Discovery will be ready for rollout.

              SPACE SHUTTLE WEEKLY STATUS SUMMARY
                   Friday, March 12, 1993

George H. Diller
Kennedy Space Center
 
                         STS-56

Vehicle: OV-103/Discovery              Mission Number: STS-56
Location: VAB-Bay 1                    Orbital altitude: 184 sm
Payloads: ATLAS-2/SSBUV/SPARTAN/SUVE   Inclination: 57 degrees
Launch timeframe: NET April 3          Nominal Landing Site: KSC
Mission Duration: 8 days 6 hours       Crew Size: 5



STS-56 IN WORK:

- preparations for rollout to Pad 39-B


STS-56 WORK COMPLETED:

- installed main engines
- installed main engine heat shields
- Shuttle Interface Test


 STS-56 DISCOVERY WORK SCHEDULED:

- move rotating service strucuture around vehicle on Monday afternoon
- extend weather protection panels Monday afternoon
- establish launch vehicle access  Monday/Tuesday
- establish electrical connections with launch pad Mon./Tues.
- open payload bay doors/establish payload bay access Tuesday
- Terminal Countdown Demonstration Test (TCDT) Wed./Thurs.


SPECIAL TOPICS: Rollout of Discovery has been rescheduled for Monday at 6 a.m.
due to weather concerns tonight and Saturday.

 

                          SPACE SHUTTLE DAILY STATUS
                            Monday, March 15, 1993
George H. Diller
Kennedy Space Center

 
                            STS-56

SPECIAL TOPICS:

 (STS-56)

     Discovery's rollout from the Vehicle Assembly Building to
Launch Pad 39-B began at 7:28 a.m. this morning.  The astronauts
are scheduled to arrive at 3:30 p.m. this afternoon to begin the
required launch pad safety training and for the Terminal
Countdown Demonstration Test which will be conducted on Wednesday
and Thursday.


 

                 SPACE SHUTTLE DAILY STATUS
                  Tuesday, March 16, 1993

George H. Diller
Kennedy Space Center

 
                             STS-56

SPECIAL TOPICS:

(STS-56)

     Discovery's rollout from the VAB began at 7:28 a.m. yesterday; arrival at
Launch Pad 39-B occurred at 1:49 p.m.; hard down atop the launch pad pedestals
was at 2:28 p.m.  The astronauts arrived at the Shuttle Landing Facility at
4:30 p.m. yesterday.  Today they begin launch pad safety training.  The
countdown for the Terminal Countdown Demonstration Test will begin at 8 a.m.
Wednesday and conclude at 11 a.m.  Thursday.


 

                SPACE SHUTTLE DAILY STATUS REPORT
                     Tuesday, March 23, 1993

George H. Diller
Kennedy Space Center
 
                            STS-56

SPECIAL TOPICS:

     At Pad 39-B, loading of storable hypergolic propellants is in work today
and Wednesday. The pad is closed to all other work during this activity.

 

                SPACE SHUTTLE DAILY STATUS REPORT
                    Wednesday, March 24, 1993

Mitch Varnes
NASA Kennedy Space Center
 
                             STS-56

OTHER BUSINESS:

STS-56/ATLAS-2                                OV-103/Discovery

Loading of Discovery's storable hypergolic propellants is con- tinuing at
launch pad 39-B.  This operation will continue throughout today.

Space Shuttle managers will convene at KSC tomorrow for the STS- 56 Flight
Readiness Review. The announcement of a launch date is possible but not
expected to be released following the conclusion of the meeting.

 

Atmospheric Laboratory for Applications and Science - 2

An Educational Publication of the National Aeronautics and Space Administration


One of the linchpins of NASA's Mission to Planet Earth is the series of
Atmospheric Laboratory for Applications and Science (ATLAS) missions to be
flown on the Space Shuttle. Mission to Planet Earth is NASA's contribution to
the United States Global Change Research Program, a unified study of the planet
and its components, from its interior to its outermost atmospheric regions.  In
turn, Mission to Planet Earth is a cooperative element of the International
Geosphere/Biosphere Research Program, one of the most comprehensive scientific
undertakings of all time.

        The primary goal of the ATLAS program is to help scientists
characterize the chemical and physical components of the middle part of Earth's
atmosphere, including the effect of the Sun's energy on those components. (The
middle atmosphere or stratosphere and mesosphere contain Earth's protective
ozone layer.  Chemical processes there contribute to problems such as ozone
depletion and global warming.)

        Because no single space mission can provide enough information to
accomplish this goal or provide data on possible long-term changes, NASA has
planned a series of ATLAS missions. (ATLAS-1 flew between March 24 through
April 2, 1992.) Each mission will carry a core of seven instruments designed to
gather data under a variety of atmospheric conditions over both the Northern
and Southern Hemispheres. Some of the instruments focus primarily on
atmospheric observations while others measure solar energy.  Both sets of data
are essential for proper interpretation of the conditions and processes at work
in the middle atmosphere.

ATLAS-2 Mission

The ATLAS-2 mission, planned for spring of 1993, features a core payload of six
instruments that are carried to space on a Spacelab pallet and one instrument
that is carried in two cannisters mounted to the payload bay wall.  The pallet,
a U-shaped cradle, fits inside the payload bay of the Space Shuttle Discovery
like a back porch.  As a mounting platform, the pallet exposes instruments
directly to the conditions of outer space.  Normally, the instruments will be
operated by radio control from the ground, but crewmembers may also operate the
instruments from within the orbiter's cabin.  Attached to the pallet in the bay
is the Spacelab igloo.  The igloo is a white cannister that houses Spacelab
subsystems, pumps, and power boxes to provide the science equipment with power,
communication links, and environmental control.

        Liftoff of the eight day mission is planned for nighttime to make
sunrise observations at high northern latitudes.  NASA managers will decide
during the mission if an extra day can be flown for additional science
observations.

ATLAS-2 Instruments

The Atmospheric Trace Molecule Spectroscopy (ATMOS) instrument will survey
concentrations of trace molecules by measuring absorption of solar infrared
radiation.  This instrument will help scientists determine what chemicals are
present in the middle atmosphere, what their concentrations are, where they are
located, and what chemical reactions they influence.

        The Millimeter-wave Atmospheric Sounder (MAS) will also study
atmospheric constituents.  MAS will measure ozone concentrations, temperatures,
water vapors and chlorine monoxide in the middle atmosphere.  Chlorine monoxide
is a key trace molecule involved in the destruction of ozone.

        Two instruments, the Solar Spectrum Measurement (SOLSPEC) and the Solar
Ultraviolet Spectral Irradiance Monitor (SUSIM) will characterize the solar
radiation that drives chemical reactions in the middle atmosphere.  The SUSIM
will only measure ultraviolet radiation, but will cover a broader range of
ultraviolet radiation (120-400 NM) than will the SOLSPEC instrument. (A
nanometer is a metric unit equal to one-billionth of a meter.  The SOLSPEC
instrument's range of 180 to 3,200 nanometers covers the electromagnetic
spectrum from ultraviolet to infrared radiation.) Both instruments, when flown
over many missions, will yield long-term records of solar radiation and its
variations.

        The Shuttle Solar Backscatter Ultraviolet (SSBUV) instrument measures
both solar ultra-violet output and stratospheric ozone.  This instrument has
flown previously on four other Space Shuttle missions.

        Two other ATLAS instruments measure the total solar irradiance.  The
Active Cavity Radiometer Irradiance Monitor (ACRIM) and the Measurement of
Solar Constant (SOLCON) seek to measure the total amount of energy the Sun
delivers to the Earth. This amount is referred to as the solar constant,
although it varies by a small amount from year to year.  The variance in the
solar constant is significant because small changes in incoming energy can have
dramatic effects on the climate.  By measuring incoming energy above the
atmosphere, scientists can get more precise data.

        In addition to taking measurements, the instruments on this mission are
invaluable for calibrating similar instruments on scientific satellites.  The
longer a satellite operates in space, the greater is the chance that
high-energy radiation or other harsh conditions can damage the hardware and
skew the data gathered.  Comparison of the ATLAS data with that of free-flying
satellites can help scientists recalibrate their instruments on the satellites
and ensure their long term accuracy.  In particular, ATLAS-2 will underfly the
Upper Atmosphere Research Satellite (UARS) to enhance its data.

Unique Science Opportunities

Measurements taken by ATLAS-2 are particularly crucial in light of recent
atmospheric conditions.  Data gathered from the UARS and from an airborne
sampling mission in the Arctic indicate unprecedented levels of the chemical
chlorine monoxide at high northern latitudes during the winter of 1991-1992.
Given these high concentrations, atmospheric models suggest that, under
appropriate meteorological conditions, significant ozone depletion over the
Arctic is possible. (The ozone layer serves as a filter that blocks harmful
ultraviolet radiation from the Sun. When ozone amounts decrease, more
ultraviolet radiation can reach Earth's surface and damage living things.)

        Chlorine monoxide is a key compound in a cyclic process where small
amounts of chlorine may efficiently destroy much larger amounts of ozone in the
stratosphere.  Sunrise is the best time to measure the concentration of several
stratospheric molecules.  Since these molecules form at night and are destroyed
during the day, the concentration is largest at sunrise.

Other Mission Objectives

On flight day 3, the crew will deploy the Spartan Solar Wind Physics
Experiment. The Spartan is a free- flying platform that is deployed by the
orbiter's Remote Manipulator System (RMS) for independent operations.  Two
instruments onboard Spartan will gather data about the corona, the outer most
layer of the Sun, and the acceleration of the solar wind (charged particle
streams emanating from the Sun) in a variety of locations in the Sun's corona.
The RMS will retrieve Spartan after about 40 hours of operation in space.

        Other mission activities include biological and medical experiments,
radiation studies, materials processing experiments, and contact with amateur
radio operators through Shuttle Amateur Radio Experiment (SAREX).

        In their continuing support of education, the crewmembers will
videotape a variety of preplanned scenes on living in space to be used for an
elementary level educational videotape.  The tape will be available to teachers
through the NASA Teacher Resource Center network later in the year.


STS-56 Quick Facts

Crew:   Kenneth D. Cameron (COL, USMC) - Commander
        Stephen S. Oswald - Pilot
        Michael Foale (Ph.D.) - Mission Specialist
        Kenneth D. Cockrell - Mission Specialist
        Ellen Ochoa (Ph.D.)  - Mission Specialist

Vehicle:        OV-103, Discovery       Mission Duration:       8+1 days
Orbital Inclination:    57 degrees      Orbital Altitude:       296 km
Primary Payload
and Experiments:

        ATLAS-2         Atmospheric Laboratory for Applications and Science
        SSBUV/A-02      Shuttle Solar Backscatter Ultraviolet experiment
        SPTN-201        Shuttle Pointed Autonomous Research Tool for Astronomy
        CMIX            Commercial Materials Dispersions Apparatus Assembly
        PARE            Physiological and Anatomical Rodent Experiment
        STL             Space Tissue Loss
        CREAM           Cosmic Ray Effects and Activation Monitor
        SUVE            Solar Ultraviolet Experiment
        RME III         Radiation Monitoring Experiment III
        HERCULES        Hand-held, Earth-oriented, Real-time, Cooperative,
                        User-friendly, Location targeting, and Environmental
                        System
        SAREX           Shuttle Amateur Radio Experiment


Educational Activities: Videotaping for an elementary level program on living
                        in space.



Classroom Activities and Questions

1.  The entire progress of the mission from launch to landing can be observed
on television if your school has a satellite dish.  Direct the dish to the
SATCOM F2R satellite at 72 degrees west longitude.  Tune in to NASA Select,
transponder 13, 3960 megahertz.  If your school does not have a satellite dish
but does have a cable television hookup, call your local cable company and
request that they receive NASA Select and either distribute it on one of their
channels or tape it for your use.  Check local news services for updates on
Discovery's liftoff or call the NASA Kennedy Space Center at 407-867-2525 for a
recorded message.

2.  Collect current newspaper and magazine articles on environmental problems
relating to Earth's atmosphere.  Contact NASA SPACELINK (see below) for
additional information.

3.  What are some of the consequences of atmospheric ozone depletion and global
warming?  What are the sources of chemicals that trigger ozone depletion?

4.  Contact the American Radio Relay League for the name of a local amateur
radio operator who might be willing to provide a SAREX demonstration for your
classroom.  The league coordinates educational activities related to the
experiment, which is expected to fly again on several future Shuttle missions.

        American Radio Relay League
        225 Main Street
        Newington, CT 06111


References and Resources

� To request copies of the publications below, write:

NASA Education Division
Code FET
NASA Headquarters
Washington, DC 20546

� Publication text is also available from NASA SPACELINK. See references and
resources section below.

NASA (1992), The Atmosphere Below (videotape), Liftoff to Learning series.
Comes with a video resource guide for the teacher.  NASA Education Division,
Washington, D.C.

NASA (1992), ATLAS Educator Slide Set, NASA Education Division, Washington,
D.C.

NASA (1991), Earth's Mysterious Atmosphere - ATLAS 1 Teacher's Guide with
Activities, EP-282/11-91,

NASA Education Division, Washington, D.C.

NASA (1989), The Upper Atmosphere, A Program to Study Global Ozone Change,
3/89:20K.

NASA SPACELINK provides information about current and historic NASA programs,
lesson plans, the text from previous Mission Watch and Mission Highlights fact
sheets.  Anyone with a personal computer, modem, communications software, and a
long distance telephone line can communicate directly with NASA SPACELINK. Use
your computer to dial 205-895-0028 (8 data bits, no parity, and 1 stop bit).


Mission Patch for STS-56

The STS-56 patch is a pictorial representation of the STS-56/ATLAS-2 mission as
seen from the crew's viewpoint.  The payload bay is depicted with the ATLAS-2
pallet, Shuttle Solar Backscatter Ultra Violet (SSBUV) experiment, and Spartan,
the primary scientific payloads on the flight.  ATLAS-2 is a "Mission To Planet
Earth," so the Earth is featured prominently.  The mission's two primary areas
of study are the atmosphere and the Sun. To highlight this, the Earth's
atmosphere is depicted as a stylized visible spectrum and the sunrise is
depicted with an enlarged two-colored corona.  The commander's and pilot's
names are written in the Earth field and the names of the mission specialists
are in the space background.

     Source:NASA Spacelink    Modem:205-895-0028  Internet:192.149.89.61

                SPACE SHUTTLE WEEKLY STATUS SUMMARY
                    Friday, March 26, 1993
George H. Diller
Kennedy Space Center
 
                           STS-56

Vehicle:  OV-103/Discovery              Mission Number:  STS-56
Location: Pad 39-B                      Orbital altitude: 184 sm
Primary payload: ATLAS-2                Inclination: 57 degrees
Launch timeframe: Apr. 6-7              Nominal landing site: KSC
Mission duration: 8 days                Crew Size: 5


IN WORK:

- Flight Readiness Test (FRT) of main engines and flight controls
- checkout of contingency EVA spacesuits

WORK SCHEDULED:

- begin main engine check valve testing tonight
- install main engine foam insulation Saturday-Monday
- begin crew cabin stowage of flight crew mission items Monday
- initial orbiter aft confidence test Monday
- begin orbiter aft compartment closeouts Monday
- mate orbiter mid-body umbilical unit (OMBUU) Monday
- open payload bay doors Monday morning
- perform final payload walkdown and contamination inspections Monday
- close payload bay doors for flight Monday night
- ordnance installation and connection Wednesday
- external tank purges Thursday
- final orbiter aft confidence test Friday

STS-56 WORK COMPLETED:

- loaded storable hypergolic propellants into orbiter storage tanks

ISSUES AND CONCERNS: A full set of leak checks and confidence tests are
scheduled to be run on Discovery's main engine check valves.  This will be done
in parallel with other scheduled main engine prelaunch preparations.

 

               DAILY SPACE SHUTTLE STATUS REPORT
                         March 30, 1993
George H. Diller
Kennedy Space Center
 
                              STS-56

Vehicle:  OV-103/Discovery               Mission number: STS-56
Location:  Pad 39-B                      Orbital altitude: 184 sm
Primary payload: ATLAS-2                 Inclination: 57 degrees
Launch timeframe: NET April 6            Landing site: KSC
Mission duration: 8 days                 Crew size: 5


STS-56 IN WORK:

- installation of replacement check valve on main engine #1
- orbiter aft compartment closeouts
- avionics bay closeouts
- mate and leak check orbiter mid-body umbilical unit
- stowage of flight crew mission items into crew compartment
- troubleshooting crew cabin instrument panel electrical system
- countdown preparations in Firing Room 3


STS-56 WORK SCHEDULED:

- leak check replacement check valve tonight
- ordnance installation and connections Wednesday
- pressurization of hypergolic propellant tanks Wednesday
- external tank purges Thursday
- final orbiter aft confidence test Friday
- remove main engine protective covers Friday
- install aft compartment flight doors Friday

STS-56 WORK COMPLETED:

- completed removal of leaking check valve on main engine #1
- completed ATLAS-2 payload closeouts
- closed payload bay doors for flight
- installed crew escape pole
- performed crew hatch functional check
- topped off pad liquid oxygen storage sphere



ISSUES AND CONCERNS

STS-56:

     In repeating the combined test as well as individual leak
checks of Discovery's #1 main engine check valves yesterday, one
valve did not pass these tests.  While it is the same valve which
failed on Columbia it is not known at this time if there is any
correlation.  Overnight it was removed and today it is being
flown to Rocketdyne in California for failure analysis.  A spare
valve is being installed today and will be leak checked tonight.


 

Ed Campion
Headquarters, Washington, D.C.         March 30, 1993


LAUNCH ADVISORY

     NASA today announced that Space Shuttle Discovery with the
STS-56/ATLAS 2 payload will be the next mission to fly with
launch scheduled for April 6, 1993 at 1:32 a.m.  EDT. Space
Shuttle Columbia and the STS-55/Spacelab D-2 payload, which
experienced a launch scrub on March 22, has been assigned a new
target launch date of no earlier than April 24.

     The decision for STS-56 to be the next mission flown came
after the main engine team finished analyzing the purge valve
which caused the STS-55 launch scrub.  The team's investigation
concluded that the valve from the number 3 main engine failed to
operate properly because of contamination that had been in the
valve since it was manufactured.  The team also determined that
this condition could exist in other engines.  A series of tests
designed to reveal such a condition have been performed on
Discovery and one suspect valve from one engine is being removed
and replaced.

     "Flying the missions in this order is the most effective
use of all our resources" said Shuttle Director Tom Utsman. "The
early April launch of the ATLAS 2 mission will give scientists
the opportunity to observe changes in the Earth's ozone during
the seasonal transition between spring and summer in the
northern hemisphere.  At the same time, the launch team at
Kennedy will be working to get Columbia back to launch
configuration for launch on April 24.  NASA is very pleased with
the cooperation given by our friends in the German space agency.
They have been involved as all possible options were considered.
Their willingness to let the STS-56 mission have an early April
launch will give the ATLAS folks the chance to collect some very
important data on the Earth's ozone."

     As part of the effort to have Columbia ready at the
earliest possible date, all three main engines are being removed
and will be replaced with ones originally scheduled for use
during the STS-57 mission with Space Shuttle Endeavour .

     The STS-57 mission, which will involve the first flight of
the SPACEHAB commercial payload and the retrieval of the
European Space Agency's EURECA satellite, is now scheduled to
fly in late May. The rest of the Space Shuttle missions planned
for 1993 will stay in their planned order and schedule.

-end-
     Source:NASA Spacelink    Modem:205-895-0028  Internet:192.149.89.61

The planned launch date for STS-56 has now been set for April 6, 05:32 UTC.

STS-56
1 00056U          93 96.29075346  .00055200  00000-0  16200-3 0    56
2 00056  57.0020 177.4323 0011289 286.7156  73.2672 15.91759473    20

Satellite: STS-56
Catalog number: 00056
Epoch time:      93096.29075346   =    ( 6 APR 93   06:58:41.10 UTC)
Element set:     JSC-005
Inclination:       57.0020 deg
RA of node:       177.4323 deg          Space Shuttle Flight STS-56
Eccentricity:     .0011289              Prelaunch Keplerian Elements
Arg of perigee:   286.7156 deg         Launch:   6 APR 93  05:32 UTC
Mean anomaly:      73.2672 deg
Mean motion:   15.91759473 rev/day              G. L. Carman
Decay rate:    5.52000e-04 rev/day~2      NASA Johnson Space Center
Epoch rev:               2

G.L.CARMAN


     Source:NASA Spacelink    Modem:205-895-0028  Internet:192.149.89.61

The STS-56 Press Kit (sans mission logo for now) is available from:

   pragma::public:[nasa]sts-56.ps


19 pages.


- dave

       KENNEDY SPACE CENTER SPACE SHUTTLE STATUS REPORT
                      Friday, April 2, 1993

KSC Contact: Bruce Buckingham
407-867-2468 (fax 867-2692)
 
                             STS-56

Mission: STS-56/ATLAS-2/SSBUV      Orbital altitude: 184 sm
Vehicle: Discovery/OV-103          Inclination: 57 degrees
Location: Launch Pad 39-B          Crew Size: 5
Mission Duration: 8 days/6 hours   KSC Landing: April 14, 7:30am
Launch Date: April 6               Launch Window: 1:32 - 3:57am


IN WORK TODAY:
*  Aft engine compartment closeouts (scheduled to be completed by
   4:00 p.m. Saturday)
*  Orbiter midbody umbilical leak checks
*  External tank purges and inspections
*  Hypergolic quick disconnect closeouts
*  Launch countdown preparations

WORK SCHEDULED:
*  Crew arrives 10:00 p.m. tonight
*  Countdown begins 5:00 a.m. Saturday
*  Removal of main engine protective covers (Saturday)
*  Install aft compartment doors (Saturday)
*  Orbiter aft confidence test (Saturday)

WORK COMPLETED:
*  Leak checks on check valves on main engines complete and good
*  Crew cabin electrical system test
*  Temperature sensor checks on OMS crossfeed line
*  Hydraulic circulation pump tests
*  Ordnance installation
*  Hypergolic fuel tank pressurization



NOTE: The extended weather forecast for launch of Discovery on
April 6 indicates a 50 percent chance of violating launch
constraints due to cloud ceilings below 8000 feet, a chance of
showers and thick clouds. The 24 hour delay predicts a 30 percent
chance of violation, 48 hour delay a 20 percent chance.

 

        KENNEDY SPACE CENTER SPACE SHUTTLE STATUS REPORT
                      Monday, April 5, 1993

KSC Contact: Bruce Buckingham

 
                         STS-56 L-1 DAY

Mission: STS-56/ATLAS-2/SSBUV      Orbital altitude: 184 sm
Vehicle: Discovery/OV-103          Inclination: 57 degrees
Location: Launch Pad 39-B          Crew Size: 5
Mission Duration: 8 days/6 hours   KSC Landing: April 14, 7:30am
Launch Date: April 6               Launch Window: 1:32 - 3:57am

     Operations at launch pad 39-B are running smoothly and
without problem for the launch of Space Shuttle Discovery on
mission STS-56. Launch remains on schedule to occur at the
opening of the window at 1:32 a.m. Tuesday.
     The countdown clock is currently holding at T-11 hours. This
13 hour, 12 minute hold will last until 11:12 a.m. today.
     Rotation of the service structure away from the vehicle was
delayed a few hours earlier this morning as managers waited for
weather to clear and winds at the pad to subside. RSS rotation is
expected to occur before 10:00 a.m. today.
     At this time, late stowage of time critical items and
payloads is underway.
     Later today, the launch team will begin to make a final
purge of the fuel cell lines, mission control in Houston will
configure communications networks, and Discovery's purge system
will be switched from air to gaseous nitrogen.
     The countdown clock will enter the planned one hour hold at
the T-6 hour mark as last minute checks are made prior to loading
the external tank with over 500,000 gallons of liquid hydrogen
and liquid oxygen. Once the pad is cleared of all personnel,
tanking will begin at about 5:12 p.m. today. This operation takes
about  three hours. Following tanking, the ice team will be
deployed to the pad for final assessments of the vehicle.
     All the payloads in the payload bay have been closed out for
flight and require no specific monitoring prior to launch.
     The five members of the flight crew have been divided into
two shifts for around-the-clock operations once in orbit. The
blue team consists of commander Kenneth Cameron, pilot Stephen
Oswald and mission specialist Ellen Ochoa. The red team is
Payload Commander Michael Foale and mission specialist Kenneth
Cockrell.
     The weather forecast for launch tomorrow morning indicates a
20 percent chance of violating launch constraints during the
window opening at 1:32 a.m. The primary concern is a possible
cloud ceiling below 8000 feet and potentially excessive
crosswinds at the Shuttle Landing Facility.
    There is a 20 percent chance of violating tanking constraints
due to lightning within 5 miles of the pad.
     The 24 hour and 48 hour delay predictions show a 20 percent
and a 30 percent chance of violation, respectively.
                            -- more --


          SUMMARY OF STS-56 LAUNCH DAY CREW ACTIVITIES

Monday/Tuesday
8:37 pm        Wake up
9:07 pm        Breakfast/Dinner
9:37 pm        Weather briefing (CDR, PLT, MS2)
9:37 pm        Don flight equipment (MS1, MS3)
9:47 pm        Don flight equipment (CDR, PLT, MS2)
10:17 pm       Depart for launch pad 39-B
10:47 pm       Arrive at white room and begin ingress
12:02 am       Close crew hatch
1:32 am        Launch (April 6, 1993)

 

pragma::public:[nasa]sts-56.nasa_select

- dave

Launch scrub at t-11 seconds due to a valve status being wrong

From: [email protected] (IRENE BROWN)
Subject: Discovery launch aborted
Date: Tue, 6 Apr 93 2:32:49 PDT
Approved: [email protected]

	CAPE CANAVERAL, Fla. (UPI) -- For the second time in as many launch
attempts, a problem with a shuttle main engine halted a launch countdown
Tuesday seconds before the planned liftoff of Discovery on an eight-day
science mission.
	The cause of Tuesday's launch abort, which occurred 11 seconds before
Discovery's planned 2:32 a.m. blastoff, was not immediately known but
engineers suspected faulty main engine instrumentation.
	As a result, computers that detected a valve problem automatically
halted the countdown just five seconds before Discovery's three
hydrogen-fueled main engines were to ignite.
	A similar shutdown occurred during NASA's launch attempt of the
shuttle Columbia on March 22. Columbia's main engines, however, already
had fired and the shuttle was just three seconds away from flight when
the launch was aborted.
	Asked how NASA officials felt about back-to-back failed launch
attempts, Brewster Shaw, deputy shuttle program director, said: ``We
don't come in here to scrub launches.''
	``We'll go fly when the hardware all comes together at T-minus-0,''
he said.
	The problem with Columbia's main engine was traced to a contaminated
valve in a helium purge line, and a similar defect was later detected in
one of Discovery's engines. The faulty valve was replaced prior to
Tuesday's planned launch and is unrelated to the launch abort.
	The valve at issue in Tuesday's abort bleeds gas pockets out of a
liquid propellent line leading to one of the main engines.
	Once the countdown was halted, engineers moved quickly to begin
pumping Discovery's volatile propellants out of its external fuel tank
while commander Kenneth Cameron, 43, and co-pilot Stephen Oswald, 41,
shut down key orbiter equipment.
	Cameron, Oswald, flight engineer Kenneth Cockrell, 42, Ellen Ochoa,
34, and Michael Foale, 36, began to climb out of the orbiter about 45
minutes after the launch abort.
	It was unknown how long Discovery would be grounded, but Shaw said a
launch attempt would not be made before Thursday.
	A lengthy postponement could be costly in terms of science.
Researchers hope to collect atmospheric information over Earth's
northern latitudes during the short-lived winter-spring transition
period now under way.
	Discovery was scheduled for liftoff at 1:32 a.m., but the flight was
delayed an hour to allow gusty winds to subside at the shuttle's
emergency landing site at the Kennedy Space Center and to allow time to
resolve a technical problem with an unrelated main engine valve sensor.
	The primary payload aboard Discovery is the Atmospheric Laboratory
for Applications and Science, a collection of six instruments mounted in
a U-shaped pallet in the orbiter's cargo bay, and a seventh ozone-
monitoring experiment contained in two canisters on the payload bay
walls.
	A variety of medical, science and technology experiments also is
planned.
	Information collected during the Atlas mission also is expected to be
used to calibrate data routinely relayed by three Earth-monitoring
satellites operated by NASA and the National Oceanic and Atmospheric
Administration.

NOTE: Launch of the Shuttle Discovery was aborted this morning at T-11 seconds
by the onboard computers when instrumentation on the liquid hydrogen high point
bleed valve in the main propulsion system indicated off when it should have
indicated on.  Follow-up analysis showed the instrumentation was faulty and
that the valve was in the proper configuration for launch.

     Managers will be meeting later this afternoon to further evaluate the
situation.

     At this time, the launch team is working under the 48-hour scrub
turn-around schedule with the understanding a final decision will be made later
today by the mission management team.  If the 48-hour scrub turn-around
schedule is verified the countdown clock will be recycled to the T-11 hour mark
and paced for a T-0 at 1:29 a.m.  Thursday.

     At this time, there are no plans to rotate the service structure around
the vehicle or service the onboard cryogenic fuels.

     The crew has returned to their quarters in the Operations and Checkout
Building and are essentially following their L-2 day timeline.

IN WORK TODAY:
*  Vehicle safing and securing
*  Liquid hydrogen boiloff
*  Flight crew equipment destow
*  Re-configuring OMS/RCS crossfeed heaters
*  Main engine purging and re-positioning
*  Re-fill water deluge system

WORK SCHEDULED:
*  Change liquid hydrogen system to an inert gaseous purge
*  Open pad for non-hazardous work
*  Begin change-out of time critical mid-deck payloads

WORK COMPLETED:
*  Initial safing and securing of the vehicle
*  Initiated 48-hour scrub turn-around schedule
*  Secured liquid oxygen and liquid hydrogen system and began
   drain back of cryogenic fuels from the external tank




                 STS-56 LAUNCH WEATHER FORECAST

     The weather forecast for launch of Discovery on April 8
indicates a 30 percent chance of violating launch constraints
during the window opening at 1:32 a.m., due to cloud ceilings
below 8000 feet and concerns for crosswinds at the Shuttle
Landing Facility.
     There is a 30 percent chance of violating tanking
constraints due to lightning within 5 miles of the pad. Tanking
is scheduled to begin at 5:12 p.m. Monday.
     The 24 hour and 48 hour delay predictions show a 20 percent
and a 30 percent chance of violation, respectively.


           SUMMARY OF HOLDS AND HOLD TIMES FOR STS-56

T-27 hours --- 4 hour hold ----------- Sat., 9:00 pm - 1:00 am
T-19 hours --- 4 hour hold ----------- Sun., 10:00 am - 2:00 pm
T-11 hours -- 13 hour, 12 min. hold - Sun., 10:00 pm - 11:12 am
T-6 hours ---- 1 hour hold ---------- Mon., 4:12 pm - 5:12 pm
T-3 hours ---- 2 hour hold ---------- Mon., 8:12 pm - 10:12 pm
T-20 minutes - 10 minute hold ------- Tues., 12:52 am - 1:02 am
T-9 minutes -- 10 minute hold ------- Tues., 1:13 am - 1:23 am



          SUMMARY OF STS-56 LAUNCH DAY CREW ACTIVITIES

Monday/Tuesday
8:37 pm        Wake up
9:07 pm        Breakfast/Dinner
9:37 pm        Weather briefing (CDR, PLT, MS2)
9:37 pm        Don flight equipment (MS1, MS3)
9:47 pm        Don flight equipment (CDR, PLT, MS2)
10:17 pm       Depart for launch pad 39-B
10:47 pm       Arrive at white room and begin ingress
12:02 am       Close crew hatch
1:32 am        Launch (April 6, 1993)



                     CREW FOR MISSION STS-56


Commander (CDR) Kenneth Cameron
Pilot (PLT) Stephen Oswald
Payload Commander (MS1) Michael Foale
Mission Specialist (MS2) Kenneth Cockrell
Mission Specialist (MS3) Ellen Ochoa

From: [email protected]
Newsgroups: sci.space.shuttle
Subject: STS-56 abort...
Date: 6 Apr 93 10:24:20 EST
Organization: NASA, Kennedy Space Center

Greetings and Salutations:

I will try to be a little better at a description for this one.

STS-56 abort at T-20 seconds (or thereabouts, maybe 16 seconds per my GLS DD?)
was called today because of the GLS (Ground Launch Sequencer).  It detected
that the MPS (Main Propulsion System) High Point Bleed valve (PV22)  closed
indicator did not come on as expected.

PV22 is a monostable, normally closed, helium pneumatically actuated valve on a
line attached to the LH2 17" manifold.  This 17" manifold is the line that goes
between the ET (External Tank) and the main engines to supply LH2 to the
engines.  The high point bleed line is situated in the Orbiter at the "high
Point" of that manifold.  The LH2 manifold between the ET and the Orbiter looks
like an inverted "U".  One end of this manifold goes down to the bottom of the
LH2 section of the ET (as opposed to the LO2 section at the top of the tank),
the other end goes down towards the engines.  Since LH2 is very cold, just
about any temperature rise will tend to let it gas off.  The high point bleed
allows any gasses / bi-phase liquid that may accumulate at the top of this U to
be siphoned off overboard, where it is sent to the flare stack & burned.  It
only takes a couple of seconds for this valve to be closed before a gas pocket
forms in this section of line, so the valve must be open as close to lighting
the engines as possible so that the engines don't ingest a hydrogen bubble. 
Believe it or not, this still simplifies the operation of the LH2 system with
the engines & loading the tank.  The lines in the aft for the MPS / SSME system
are commonly referred to as "a plumbers nightmare".

During the "terminal count" at about T-20 seconds, the open command is removed.
 Since this is a "monostable" valve, if there is no helium supply or no power
to the solenoid that lets helium to the valve, the valve will close.  GLS then
verified at about 16 seconds (per my last DD) it is closed and everything is
fine.  Today the Open indicator went from ON to OFF (indicating it cycled) but
the Closed indicator never went from OFF to ON (indicating it did indeed close)
thus causing the abort.  A downstream temperature transducer went from cold to
very warm also indicating that the valve closed, but GLS does not check that
temp ducer.  A 48 hour scrub-turnaround has been called contingent on relying
on the temp ducer rather than the Close indicator.  Last I saw the indicator
was not still working.  It would be easy to say the it is a microswitch failure
on the valve, but it could be quite a few things wrong (as always on the
Orbiter) and further troubleshooting will have to be performed in the aft to
figure out exactly what the problem is.

Any problems after T-31 seconds is an abort for the day.  No more holds are
available.

-----------------------------------------------
Ken Hollis  INTERNET: [email protected]
            SPAN/HEPnet: KSCP00::HOLLIS
Dizzyclaimer:
If you believe this is in any way, shape, or form actual official information
or
opinion,then you are probably as confused if not more so than I am...I think...

STS-56 L-1 DAY
Wednesday, April 7, 1993

Mission: STS-56/ATLAS-2/SSBUV      Orbital altitude: 184 sm
Vehicle: Discovery/OV-103          Inclination: 57 degrees
Location: Launch Pad 39-B          Crew Size: 5
Mission Duration: 8 days/6 hours   KSC Landing: April 16, 7:30am
Launch Date: April 8               Launch Window: 1:29 - 3:57am


     The countdown clock for the launch of Space Shuttle Discovery was recycled
yesterday to the T-27 hour mark and the count resumed at 6:29 p.m.  Tuesday for
launch at 1:29 a.m.  Thursday.

     Mission managers are confident Discovery is ready for flight and the
problem that caused the abort of the launch attempt Tuesday morning has been
understood and fixed.  The problem was associated with instrumentation on the
high point bleed valve in the main propulsion system.  Indications were the
valve was in an improper position for launch.  Tests conducted yesterday,
including five cryogenic cycles of the valve, confirmed the valve was working
properly.  It will be checked again this afternoon when fast fill of liquid
hydrogen begins.

     Currently, operations at launch pad 39-B are continuing without problem.
Late stowage of time critical items and mid-deck payloads is underway and
should be concluded by 11:00 a.m.

     All the payloads in the orbiter's payload bay have been closed out for
flight and require no specific monitoring prior to launch.

     Later today, the launch team will begin the final purge of the onboard
fuel cell lines, mission control in Houston will configure communications
networks, and Discovery's purge system will be switched from air to gaseous
nitrogen.

     The countdown clock will enter a planned hold at 9:39 a.m. at the T-11
hour mark and remain there for 90 minutes.  The clock will resume counting at
11:09 a.m. today.  The next hold will be the one hour built in hold at the T-6
hour mark at 4:09 p.m.  At that time, final checks of the main propulsion
system will be made prior to loading the external tank with over 500,000
gallons of liquid hydrogen and liquid oxygen.

     Once the pad is cleared of all personnel, the clock will
again start counting at 5:09 p.m. as tanking begins. This
operation takes about three hours. Following tanking, the ice
team will be deployed to the pad for final assessments of the
vehicle.


     The five members of the flight crew are divided into two shifts for
around-the-clock operations once in orbit.  The blue team consists of commander
Kenneth Cameron, pilot Stephen Oswald and mission specialist Ellen Ochoa. The
red team is Payload Commander Michael Foale and mission specialist Kenneth
Cockrell.

     The weather forecast for launch tomorrow morning indicates a 10 percent
chance of violating launch constraints during the window opening at 1:29 a.m.
The concern is a possible cloud ceiling below 8,000 feet.  There is no chance
of violating tanking constraints.

     The 24 hour and 48 hour delay predictions show a 20 percent
and a 40 percent chance of violation, respectively.



      SUMMARY OF HOLDS AND HOLD TIMES REMAINING FOR STS-56

T-11 hours ---- 1 hour, 40 min. hold - Wed., 9:29 am - 11:09 am
T-6 hours ----- 1 hour hold ---------- Wed., 4:09 pm - 5:09 pm
T-3 hours ----- 2 hour hold ---------- Wed., 8:09 pm - 10:09 pm
T-20 minutes -- 10 minute hold-------- Thurs., 12:52 am - 1:02 am
T-9 minutes --- 10 minute hold ------- Thurs., 1:13 am - 1:23 am




          SUMMARY OF STS-56 LAUNCH DAY CREW ACTIVITIES

Wednesday/Thursday
8:34 pm             Wake up
9:04 pm             Breakfast/Dinner
9:34 pm             Weather briefing (CDR, PLT, MS2)
9:34 pm             Don flight equipment (MS1, MS3)
9:44 pm             Don flight equipment (CDR, PLT, MS2)
10:14 pm            Depart for launch pad 39-B
10:44 pm            Arrive at white room and begin ingress
11:59 pm            Close crew hatch
1:29 am             Launch (April 8, 1993)

    Lift-off was on time.....
    
    ....but I slept through it. :^(
    
    					Godspeed, Discovery!
    
    					--Eric--

6:00 a.m. CDT, April 8, 1993
0/5:31 MET
Spacelab Mission Operations Control
Marshall Space Flight Center
Huntsville, Alabama

For the second time in just over a year, NASA's Atmospheric Laboratory for
Applications and Science (ATLAS) is in orbit, ready to add to our knowledge
about Earth's atmosphere and the Sun's influence upon it and our climate
system.  The ATLAS series is part of NASA's Mission to Planet Earth, a unified
study of the planet and its components, from its deepest interior to its
outermost atmospheric regions.

The Shuttle Discovery roared into orbit at 12:29 a.m.  CDT. Its primary payload
consists of six ATLAS instruments mounted on a Spacelab pallet in its cargo
bay, with a seventh mounted on the side of the bay in two Get-Away-Special
canisters.  All seven instruments were flown last March aboard ATLAS 1, and
they are scheduled to fly again on ATLAS 3 in late 1994.

Mission Specialists Dr. Michael Foale and Dr. Ellen Ochoa completed Spacelab
activation at 4:02 a.m.  CDT, then finished activating the payload at 4:21 a.m.
Experiment teams for each of the ATLAS 2 experiments are stationed at NASA's
Spacelab Mission Operations Control center in Huntsville, Ala., ready to begin
checking out their instruments.  Five nations are represented in the
international group of scientists, underscoring the world-wide importance of
atmospheric research.

"We were pleased to be able to launch on this date and at this time," said
Alternate Mission Scientist Dr. Steve Smith. "A spring mission allows us to
observe the atmosphere in the Northern Hemisphere during the transition between
winter and summer." Factors at work in winter such as cold temperatures and
chemical reactions triggered by polar stratospheric clouds can raise the level
of ozone-depleting chlorine monoxide, creating the potential for dramatic
short-term ozone loss.  Observations of trace gases in spring may help
scientists determine how the ozone level recovers to normal.

The Millimeter-Wave Atmospheric Sounder (MAS) team began activation of their
instrument.  The nighttime launch will allow improved Northern Hemisphere
observations during the ATLAS 2 flight, so the MAS will be able to make
daylight observations in both hemispheres.  This is important because
concentrations of chlorine monoxide in the atmosphere that MAS will observe
vary widely from daylight to dark, and they must be measured in sunlight.

The Atmospheric Trace Molecule Spectroscopy (ATMOS) experiment, mounted on the
opposite side of the Shuttle's cargo bay, will be able to view orbital sunrises
at high latitudes in the Northern Hemisphere. Only during sunrises can the
instrument measure atmospheric gases that are held in reserve during darkness.
These so-called "reservoir gases" release the active gases that participate in
the chemical reactions that determine ozone chemistry when sunlight strikes
them.

The onboard experiment computer initiated the engineering support checkout for
the Atmospheric Trace Molecule Spectroscopy Experiment, and the thermal control
operations for the Measurement of the Solar Spectrum (SOLSPEC) instrument.

During the next shift, the door of the Shuttle Solar Backscatter Ultraviolet
experiment, an investigation to study the amount of solar radiation bouncing
off Earth's atmosphere will open, and an 11-hour period of outgassing will
begin, during which the instrument will be acclimating itself to the
environment of space before its first measurements begin.  Meanwhile, the ATMOS
instrument will begin viewing sunlight through the Earth's atmosphere during
orbital sunrises and sunsets.  ATLAS-2's solar measurement instruments will
begin their observations on the second day of the mission.
 

  I stayed up to watch the launch on the NASA station and it was amazing. 

  I tuned in at about T - 1 hour and change while they were closing the hatch.
The camera in the white room followed the action including white room tear
down. That was followed by about an hour of different views of the shuttle, the
best of which was the close up of the main engines which were boiling off
cryogenic fuel or oxidizer. During the last few minutes you could see them
cycling the rudder and gimbling the engines. 

  The liftoff was beyond words. During the final half minute the view was of
the engines. At about t-8 seconds they were given "go" to light the main
engines. A stream of sparks flooded the area under the engine. I believe that
is to burn off any excess hydrogen. During the day time you can make out the
sparks but at night it has a very dramatic effect. 

  With about 3 seconds to go the main engines lit in a bright orange display of
color. Then they switched to a camera further back just as the SRB's were lit.
About a second after launch the colors were so bright that all you could see
was a bright yellow ball which slowly began climbing up the launch tower. Then
as they pulled away you could see the billowing smoke and steam raining down on
the launch pad back lit by long yellow-orange flames. 

  As they went through the sound barrier you could see the bottom of the main
tank and orange flame pouring out of the SRB's against a jet black background.
That stayed the same right up to the point where they released the SRB's. You
could see them fall away as the 3 main engines moved off leaving them behind. 

  At about 8 minutes into the launch I went out onto my front porch (I live in
the western part of Boston) to see if I could see them go by, but my view to
the south east is blocked by a house and to the east north east I over look
down town Boston so anything small gets lost in the lights of the city. 

  I went back in side and they replayed the launch from each of about 15 TV
cameras, including an airborne camera out over the water. The launch really
lights up the cost and you could see the bay behind the cape. 

  All and all, there is nothing quite like a night time launch,
  George 

My wife suggested that we get up to try and view Discovery as it passed
Massachusetts. We were able to see it, from Westford Mass, for about 10 seconds
or so, intermittently through broken clouds. Although the viewing was poor, it
really has made my day to see a Shuttle orbiter hammering its way up into
space. The exhaust plume was bigger than I expected. I thought it would be
jsut a moving dot, but it was probably the width of a fingertip held at arm's
length. Very distinctive sight.
						-- Tom

Congratulations. Wish I'd thought of it.

All I've viewed havge been scrubs 8^(

re .36:  That's really neat!  Was it low on the horizon, or was it the clouds
that caused it to go out of sight?  About what mission elapsed time did you
see it?  Did you hear any altitude/range calls near when it was visible?

Burns

MISSION CONTROL CENTER
STS-56 Status Report  #2

SPACELINK NOTE:  MCC #1 was issued as an internal document.  This serves as the
first in the series of MCC Status Reports.

Thursday, April 8, 1993, 11 a.m.  CDT

Activation of the Atmospheric Laboratory instruments was the focus of
Discovery's crew in the early hours of the STS-56 mission, today .

The activation was conducted without problems as the crew members turned on the
payload bay equipment in preparation for science data gathering using the
ATLAS-2 instruments.

Shortly after activation, two of Discovery's five-member crew - Mission
Specialists Mike Foale and Ken Cockrell, went to sleep leaving orbiter
operations to Commander Ken Cameron, Pilot Steve Oswald and Mission Specialist
Ellen Ochoa.

Ochoa conducted a checkout of the orbiter's robot arm during the early morning
hours to ensure its health for the SPARTAN-201 satellite deployment on Sunday.
A couple of the steps in the checkout were postponed to allow enough time to
conduct an "extended park" test leaving the arm in one position for a long
period of time.  The two postponed checkout steps will be conducted before
SPARTAN operations get under way.

Much of the remainder of the crew's morning was spent setting up other
experiments, including the amateur radio equipment, the HERCULES precise
location targeting equipment, and the bioreactor designed to help study the
long-term effects of weightlessness on the human immune system.

The bioreactor device has been turning itself off intermittently due to
possible overheating.  Flight controllers are studying a plan to provide a
cooler air flow that might assist in keeping the experiment powered on.

The Red Team of Foale and Cockrell has taken over control of the orbiter and
mission as of about 11:30 this morning when the Blue Team prepared to go to
bed.

Discovery is presently circling the Earth every 90 minutes in a circular orbit
of 160 nautical miles.

--------------------------------------------------------------------------------



MISSION CONTROL STATUS REPORT #3
Thursday, April 8, 1993
6 p.m. CDT

The Red Team of Astronauts Ken Cockrell and Mike Foale onboard the Space
Shuttle Discovery successfully fixed a cooling problem on a middeck lymphocyte
experiment and continued activation of the Atmospheric Laboratory for
Applications and Science instruments in the payload bay.

The in-flight maintenance procedure that put the Human Lymphocyte Locomotion in
Microgravity experiment in operation involved removing the bioreactor hardware
from its middeck locker near the galley, taping it to the crew cabin wall and
placing an "elephant trunk" hose over the bread-box-sized experiment's air
inlet.  The IFM alleviated a suspected cooling air flow problem and allowed the
astronauts to initiate the experiment, also called DSO-322, which looks at cell
orientation and movement that are important to the performance of human immune
system.

Foale activated the Solar Ultraviolet Irradiance Monitor in the payload bay,
which measures on the Sun's ultraviolet radiation.  Cockrell activated two sets
of the experiments belonging to the Commercial MDA ITA Experiments -- both the
Materials Dispersion Apparatus Minilabs and the Bioprocessing Modules,
recording appropriate activation and deactivation times.

Flight controllers in Houston and in Huntsville, Ala., continue to investigate
difficulties in downlinking data from the Atmospheric Trace Molecule
Spectroscopy instrument, but have not yet isolated any specific problem.

Commander Ken Cameron, Pilot Steve Oswald and Mission Specialist Ellen Ochoa
are scheduled to end their sleep shift about 7:30 p.m.  CDT.

Before the Blue Team began its sleep shift, Ochoa conducted a checkout of the
orbiter's robot arm during the early morning hours to ensure its health to
support deployment of the SPARTAN-201 satellite on Sunday and retrieval on
Tuesday. A couple of the steps in the checkout were postponed to allow enough
time to conduct an "extended park" test leaving the arm in one position for a
long period of time.  The two postponed checkout steps will be conducted before
SPARTAN operations.

Discovery continues to circle the Earth every 90 minutes in a circular orbit of
160 nautical miles.
 

RE: <<< Note 842.38 by SKYLAB::FISHER "That's right...you were there for the grovelling" >>>

It was quite low; maybe 10 or fifteen degrees above the horizon. The local
horizon is fairly obscured from where we were; had the horizon been more open
we probably would have first sighted the exhast some seconds sooner. It popped
in and out of clouds four or five times during the ten second or so time span
from first to last sighting. At the time of last sighting it was obscured by
clouds, rather than local terrain features or by doing below the horizon. I'd
say we saw it about eight to ten minutes into the flight.  The exhaust was
in the south-southeast part of the sky as seen from our location. In addition
to being larger in the sky that I expected, it was also pretty bright, like a
near-by jet transport. If the solids had still been attached and burning, I bet
it would have been like a fireball.

We didn't have a radio with us while we were outside. I set the alarm for 1:25,
and we listened (to WBZ Boston) for a launch statement, which WBZ carried live
at 1:29 or so. Given the go, we got up, dressed, and went out. We walked a few
hundred feet to a clearer part of the neighborhood, and waited perhaps two more
minutes until it flew past.
						-- Tom

ATLAS 2 Status Report #2
6:00 p.m. CDT, April 8, 1993
0/17:31 MET
Spacelab Mission Operations Control
Marshall Space Flight Center
Huntsville, Alabama

Six of the seven instruments aboard the second Atmospheric Laboratory for
Applications and Science (ATLAS-2) Spacelab mission have been powered up, and
two have begun taking readings of a variety of gases in the middle atmosphere.
Information from the ATLAS series of mission, along with that gathered by
free-flying satellites, will give scientists increased insight into the complex
chemistry of the middle atmosphere which affects global ozone levels.

This mission's atmospheric studies got underway as the ATLAS 2 experiment
computer activated the Millimeter-Wave Atmospheric Sounder (MAS) and commanded
the spectrometer to scan the atmosphere, looking for traces of water vapor,
ozone and chlorine monoxide.  The limited amount of data received by the MAS
team thus far revealed a pointing control problem, which they are
troubleshooting with the help of other science teams and the crew.

The on-board experiment computer also activated the Atmospheric Trace Molecule
Spectroscopy (ATMOS) instrument to make measurements of the composition of the
troposphere, stratosphere, mesosphere and lower thermosphere, layers of the
Earth's atmosphere ranging from 10 to 150 km (6 to 93 mi).  The composition
profiles of atmospheric gases found in this region will be compared to
measurements from previous missions and with results from atmospheric models in
order to understand more about global, seasonal and long-term changes in the
distribution of 30 to 40 trace gases.

Ground control teams at Spacelab Mission Operations Control in Huntsville,
Ala., worked much of the day to isolate the cause of a problem with the
high-rate data and to rework formats for improved data transmission.  ATMOS is
the only ATLAS-2 experiment requiring high-rate data.  This afternoon, data
management controllers succeeded in receiving some real-time, high-rate data
from the ATMOS experiment.  Throughout the day, ATMOS observations of orbital
sunrises and sunsets have been captured by a new ATMOS experiment recorder,
which was installed on the instrument for the first time during ATLAS 2 for a
test flight.

Mission Specialist Ellen Ochoa activated the Shuttle Solar Backscatter
Ultraviolet (SSBUV) experiment, which will be used to verify the accuracy of
atmospheric ozone and solar ultraviolet irradiance data obtained by instruments
on free-flying National Oceanic and Atmospheric Administration and NASA
satellites.  Its door was opened to expose the instrument to the space
environment, and it will be allowed to "outgas" and then cool until near the
end of the upcoming solar observation period, when SSBUV will take readings
during the last two solar orbits.

The Solar Ultraviolet Irradiance Monitor, the Active Cavity Radiometer and the
Solar Spectrum experiments have been activated and are in the process of being
calibrated.  The Solar Constant experiment will be activated later tonight.
The ATLAS-2 solar observation period will begin shortly after midnight.

--------------------------------------------------------------------------------

MISSION CONTROL CENTER  STS-56 Status Report #4

Friday, April 9, 1993, 4 a.m. CDT


Pilot Steve Oswald late yesterday began initiating maneuvers aboard Discovery
that have continued throughout the night to put the ATLAS-2 atmospheric
instruments in position to observe the very first and last rays of each orbital
sunrise and sunset.

The maneuvers put Discovery in a solar inertial attitude, an orientation that
means the shuttle's position is fixed relative to the Sun rather than to the
Earth. However, when Discovery is on the night side of the Earth, Oswald rolls
the spacecraft so the ATLAS-2 instruments point toward deep space to cool them
after their extended exposure to direct sunlight.

Members of the Blue Team -- Commander Ken Cameron, Pilot Oswald and Mission
Specialist Ellen Ochoa -- have been on duty aboard Discovery during the
morning.  Early in the shift, Ochoa and Oswald completed a successful checkout
of the shuttle's mechanical arm in preparation for operations early Sunday to
deploy the SPARTAN platform and its solar wind-observing instruments.  After
the check, the arm was again put in an extended park position, posed above and
to the left of the shuttle's nose.  The arm will be kept in this position
throughout the flight when it is not being used to avoid having it interfere in
fields of view of the ATLAS-2 instruments.

Cameron reported contacting students at the Royal Grammar School in Surrey,
England, via ham radio of the Shuttle Amateur Radio Experiment as Discovery
flew above that region of Earth. In addition, the Solar Ultraviolet Experiment,
or SUVE, an experiment designed, built and that will be analyzed by students at
the University of Colorado in Boulder, was activated late yesterday.  SUVE
studies how much ultraviolet radiation is absorbed by the upper layer of the
atmosphere and attempts to correlate the amounts of radiation entering the
atmosphere with sunspots, flares and other surface features of the Sun.

Other work onboard during the night included photography using the HERCULES
camera, a camera that prints the location of the area being photographed on the
film when the photo is taken.  In addition to photographing various sites,
Discovery's crew also attempted to transmit several photographs to Mission
Control.

Flight controllers are continuing to analyze and troubleshoot a problem with
the high data rate communications system aboard Discovery. In the meantime, all
high data rate science information from the ATMOS instrument of the ATLAS- 2
array is being recorded onboard.

---------------------------------------------------------------------------------


ATLAS 2  Status Report #03
6:00 a.m. CDT, April 9, 1993
1/5:31 MET
Spacelab Mission Operations Control
Marshall Space Flight Center
Huntsville, Alabama


Experiments to help us understand more about our atmosphere and the sun's
influence upon it continued overnight as the Space Shuttle Discovery orbited
the Earth with the second Atmospheric Laboratory for Applications and Science
(ATLAS 2) payload.

The Atmospheric Trace Molecule Spectroscopy (ATMOS) experiment made global
measurements of the concentration of gases in the upper atmosphere.  ATMOS
measured solar infrared radiation after it passed through the atmosphere during
sunsets and sunrises.  Since different elements absorb solar radiation at
different wavelengths, the patterns of absorption identify which molecules are
present and their amounts.  Scientists will study these trace gases to better
understand the chemistry of the stratosphere.  Teams of scientists and
engineers continued to troubleshoot a problem with data transmission on the Ku
band data system.  This anomaly is preventing the high data rate downlink of
ATMOS data from the Shuttle's High Data Rate Recorder. However, a flight tape
recorder, added as a new component for ATLAS 2, has recorded ATMOS
measurements, storing the data for analysis after the mission.  Furthermore,
data can be down linked at a lower rate, and the instrument itself continues to
function well.

The Millimeter-wave Atmospheric Sounder (MAS) instrument studied the Earth's
middle atmosphere overnight to provide a set of measurements relating to ozone
loss.  MAS measures the strength of millimeter wave emissions from water vapor,
chlorine monoxide and ozone radiating at specific frequencies.  During the
ATLAS series of missions, this instrument scans the atmosphere, providing
information about chemical influences on the ozone layer which shields the
Earth from harmful ultraviolet radiation.  During this observation period, MAS
investigators worked closely with the orbiter team to ensure a stable
environment for the MAS instrument, which is operating in a contingency mode
while it is not able to correctly interpret pointing signals from the Shuttle's
Guidance, Navigation and Control Systems. Members of the science team at
Marshall Space Flight Center in Huntsville, Ala. and in Germany have
temporarily corrected the problem and are currently working to resolve it
through a software modification.  The instrument has been reconfigured and
continues to transmit data through the low-rate channel.

The Shuttle Solar Backscatter Ultraviolet (SSBUV) experiment measured the solar
ultraviolet radiation backscattered from the atmosphere.  Since the ozone layer
absorbs ultraviolet radiation, the amount of ozone present can be determined by
calculating the ratio of radiation "bouncing" back to the amount of ultraviolet
radiation reaching the top of the Earth's atmosphere.  The SSBUV experiment,
housed in two Get-Away-Special canisters on the side of the payload
bay, is used to calibrate the accuracy of ozone data obtained by free-flying
NASA and National Oceanic and Atmospheric Administration satellites.

Four ATLAS 2 instruments are designed to provide information about the sun's
energy output.  Solar energy is essential to life on Earth, and even slight
changes in the amount of that energy can affect our planet.  In order to learn
more about variations in the sun's radiant energy, it is important to measure
its total output during the remainder of this solar cycle.

The Active Cavity Radiometer Irradiance Monitor (ACRIM) measured the total
solar irradiance in wavelengths ranging from ultraviolet through infrared.
Data from this experiment will be compared to those made at the same time by
another ATLAS 2 instrument, the Measurement of the Solar Constant (SOLCON), and
the ACRIM instrument aboard the Upper Atmosphere Research Satellite, launched
in 1991.

SOLCON, pointing directly at the sun, operated during the solar observation
period to measure, with improved accuracy, the total solar energy arriving at
the Earth's atmosphere.  This experiment also will detect any variations in the
energy being emitted by the sun.  During this shift, the instrument made some
unique simultaneous observations with an identical device aboard the European
Retrievable Carrier (EURECA) satellite.  This enabled the ATLAS-2 SOLCON
instrument, remote-commanded from Belgium, to assist in the calibration of the
EURECA SOLCON device, controlled from Germany.

The Solar Spectrum Measurement instrument performed observations to measure
solar energy in the ultraviolet, visible and infrared wavelengths, and
scientists were encouraged by the instrument's performance.  This part of the
solar spectral irradiance is being studied to accurately determine the amounts
of these energies and how they change with time.  Solar energy variations
influence ozone and chemical balance in the upper atmosphere and water vapor
and carbon dioxide absorption at lower altitudes.

Also operating during the solar observation period overnight, the Solar
Ultraviolet Spectral Irradiance Monitor (SUSIM) measured ultraviolet radiation
in the wavelengths that are absorbed by the atmosphere between 20 and 120 km
(10 and 75 mi) high.  Although this radiation is only a small percentage of the
total solar output, it is the main source of energy for the middle atmosphere.

The next 12 hour period will conclude the first set of solar observations.
When the four ATLAS 2 solar instruments have been turned off, ATMOS, MAS and
SSBUV will again examine the Earth's atmosphere.

---------------------------------------------------------------------------------


Mission Control Center   STS-56 Status Report #5

Friday, April 9, 1993, 11 a.m. CDT

  Discovery's crew continued to conduct carefully choreographed manuevers to
assist in pointing the ATLAS instruments at the Sun as it rises and sets on
each horizon.

During the dark portions of each orbit, Pilot Steve Oswald also rotates the
orbiter 360 degrees to keep the instruments pointed toward darkness for cooling
purposes.  Primarily, the Shuttle Solar Backscatter Ultraviolet instrument in
the payload bay tends to get warm and needs to be cooled down between solar
observations.

After the check, the arm was again put in an extended park position, poised
above and to the left of the shuttle's nose.  The arm will be kept in this
position throughout the flight when it is not being used to avoid having it
interfere in fields of view of the ATLAS-2 instruments.

Successful ham radio contacts by Commander Ken Cameron were conducted with the
Unatego Central School District in Otego, New York, the Jarrettsville
Elementary School in Maryland and the Royal Grammar School in Surrey, England.

Flight controllers are continuing to analyze and troubleshoot a problem with
the high data rate communications system aboard Discovery. ATLAS's Atmospheric
Trace Molecule Spectroscopy experiment is the only one that requires the high
data rate transmission capability.  While troubleshooting continues, that data
is being recorded onboard.

Discovery remains in a stable, 160 nautical mile high orbit circling the Earth
every 90 minutes.

ATLAS 2  Status Report #03
6:00 a.m. CDT, April 9, 1993
1/5:31 MET
Spacelab Mission Operations Control
Marshall Space Flight Center
Huntsville, Alabama


Experiments to help us understand more about our atmosphere and the sun's
influence upon it continued overnight as the Space Shuttle Discovery orbited
the Earth with the second Atmospheric Laboratory for Applications and Science
(ATLAS 2) payload.

The Atmospheric Trace Molecule Spectroscopy (ATMOS) experiment made global
measurements of the concentration of gases in the upper atmosphere.  ATMOS
measured solar infrared radiation after it passed through the atmosphere during
sunsets and sunrises.  Since different elements absorb solar radiation at
different wavelengths, the patterns of absorption identify which molecules are
present and their amounts.  Scientists will study these trace gases to better
understand the chemistry of the stratosphere.  Teams of scientists and
engineers continued to troubleshoot a problem with data transmission on the Ku
band data system.  This anomaly is preventing the high data rate downlink of
ATMOS data from the Shuttle's High Data Rate Recorder. However, a flight tape

-------------------------------------------------------------------------------

MISSION CONTROL STATUS REPORT #6
5 p.m. Friday, April 9, 1993

Discovery astronauts continued to focus their attentions on the study of the
Earth's atmosphere with the complement of ATLAS-2 instruments, the Space
Shuttle Backscatter Ultraviolet Experiment and the Solar Ultraviolet
Experiment.

From Discovery's aft flight deck, Mission Specialist Mike Foale provided a
video primer of the process through which chlorofluorcarbons are destroying the
Earth's ozone layer, using molecular models and an inflatable globe.  As part
of NASA's Mission to Planet Earth, the ATLAS-2 mission is providing valuable
data that scientists on the ground will use in an effort to better understand
the chemical reactions affecting the layer of the atmosphere that protects the
Earth from the Sun's ultraviolet radiation.

Foale and crewmate Ken Cockrell also continued to take Earth observation photos
with a variety of cameras, including the HERCULES camera which appends pinpoint
location information onto each electronic photograph it takes.  Cockrell
downlinked three HERCULES electronic still images to the ground, which were
being evaluated by the camera's experts.

The shuttle's robot the arm remained in an extended park position, poised above
 and to the left of the shuttle's nose, following the Blue Team's earlier
 completion of the arm checkout.  The arm will be kept in this position
 throughout the flight when it does not in terfere with the field-of-view of
 the ATLAS-2 instruments.  Mission Specialist Ellen Ochoa will use the arm, on
 Sunday, to deploy the SPARTAN satellite, and then to retrieve it Tuesday.

Flight controllers continued to analyze data interruptions in the high data
rate communications system aboard Discovery. The Atmosp heric Trace Molecule
Spectroscopy experiment is the only one of the instruments that requires the
high data rate transmission capabi lity.  While analysis continues, that data
is being recorded onboard.

Commander Ken Cameron is scheduled to awaken about 7:30 p.m.  CDT, and Pilot
Steve Oswald and Ochoa will end their sleep shifts about 9:30 p.m.

Discovery continues to circle the Earth every 90 minutes in a 160 nautical mile
orbit.

--------------------------------------------------------------------------------

ATLAS-2 STATUS REPORT #4

ATLAS 2 Public Affairs Status Report #4
6:00 p.m. CDT, April 9, 1993
1/17:31 MET
Spacelab Mission Operations Control
Marshall Space Flight Center
Huntsville, Alabama

Solar instruments aboard the the second Atmospheric Laboratory for
Applications and Science (ATLAS-2) completed their first eight
orbits of observations at around noon CDT today, and the mission's
second session of atmospheric observations is in progress.
Scientists need both types of data to fit into the "big picture" of
factors which influence this planet's atmospheric life-support
system, especially its protective ozone layer.  "The sun is the
energy driver of our atmosphere and our climate system," said
Mission Scientist Dr. Tim Miller.  "We cannot measure the
atmosphere and understand all the processes taking place there
without an accurate knowledge of the energy which goes into it."

Science teams for the four solar instruments at Spacelab Mission
Operations Control in Huntsville report their observations went
very smoothly and the quality of the data collected looks good.

The Active Cavity Radiometer Irradiance Monitor (ACRIM), from
NASA's Jet Propulsion Laboratory, and Belgium's Solar Constant
experiment (SOLCON) each made extremely precise, independent
measurements of the total solar irradiance, or total energy from
the sun received by the planet Earth.  This quantity is known to
vary by about 0.1 percent over an 11-year solar cycle.  Computer
models suggest that even small variations in the total solar
irradiance could have significant impacts on climate.  Therefore,
these instruments measure this quantity to a long-term accuracy of
plus or minus 0.1 percent or better.  All SOLCON commands were sent
from their remote control facility in Brussels.

France's Solar Spectrum (SOLSPEC) experiment and the U.S. Naval
Research Laboratory's Solar Ultraviolet Spectral Irradiance Monitor
(SUSIM) concentrated on the sun's output as a function of
wavelength. SOLSPEC measured ultraviolet, visible and infrared
radiation, while SUSIM focused on ultraviolet rays, the form of
solar radiation with the greatest fluctuation and the most impact
on photochemical reactions in the atmosphere.

The Shuttle Solar Backscatter Ultraviolet (SSBUV) instrument, from
NASA's Goddard Space Flight Center, completed a lengthy cooling
period, then made its first observations of the mission during the
last two orbits of the solar period.  Scientists will compare those
measurements with readings of ultraviolet radiation scattered back
from the Earth's atmosphere, which SSBUV is taking during the
remaining atmospheric observation periods of the ATLAS-2 mission.
Ozone absorbs different wavelengths of ultraviolet light at
different altitudes, so comparisons of the incoming ultraviolet
radiation with backscattered radiation gives scientists a highly
accurate map of the total amount of ozone in the atmosphere, as
well as its distribution by altitude.

Atmospheric observations resumed at around 1 p.m., with
remote-sensing operations by the Jet Propulsion Laboratory's
Atmospheric Trace Molecule Spectroscopy (ATMOS) experiment,
Germany's Millimeter-Wave Atmospheric Sounder (MAS) and SSBUV.

Dr. Mike Gunson, principal investigator for ATMOS, reported his
instrument is working extremely well.  Gunson said the engineering
data his team is receiving at Spacelab Mission Operations Control
indicates ATMOS operations are fully nominal, even though there
continues to be a problem preventing high-rate science data from
being downlinked.

As was the case during yesterday's atmospheric observations, all
ATMOS observations are being recorded on a new onboard experiment
recorder and will be retrieved after landing.  The onboard recorder
has a storage capacity for more ATMOS data than was taken during
the entire ATLAS 1 flight.  "The only difference is that we don't
have that nice, warm, fuzzy feeling of seeing our data on the
ground," said Gunson.  Payload controllers hope to come up with a
workaround to get some ATMOS observations from the Shuttle High
Data Rate Recorder downlinked at a lower rate, allowing the ground
team to confirm the quality of their science data.  ATMOS measures
a wider variety of trace gases than any other space instrument,
providing vital information about which atmospheric processes are
becoming more relevant in determining ozone distribution.

The Millimeter-Wave Atmospheric Sounder (MAS) is in the midst of an
extended period of chlorine monoxide observations.  The ground
control team worked around a pointing problem by commanding their
instrument's parabolic antenna to remain stationary, while the
Shuttle itself controls pointing.  Chlorine monoxide, formed mainly
from the breakdown of chlorofluorocarbons (CFC's) in the middle
atmosphere, plays an important part in ozone loss.  Evidence
suggests that great increases in chlorine monoxide concentrations
cause high ozone loss rates during the Antarctic's spring season
and participate in forming the ozone "hole."  Those increases also
may have played a role in low levels of ozone observed this past
winter at high Northern latitudes.  The MAS team is working to
pinpoint the cause of their pointing command problem and hopes to
develop a software patch to correct it later in the mission.

Atmospheric observations will continue throughout the next shift.

MISSION CONTROL CENTER
STS-56 Status Report #7

Saturday, April 10, 1993, 5 a.m. CDT


Discovery's crew and flight controllers spent a quiet night steadily working
through the planned experiments for STS-56 and remaining on the flight's pre-
planned schedule.

Work for the Blue Team -- Commander Ken Cameron, Pilot Steve Oswald and Mission
Specialist Ellen Ochoa -- began early this morning and remains under way.  One
of the first tasks for Cameron and Oswald was to evaluate a rowing machine as a
possible method of exercising aboard the shuttle, while causing little
vibration which might disturb onboard experiments.  Along with the rowing
machine being tested, a stationary bicycle also is being used by the crew
during the flight for exercise to counteract the effects of weightlessness on
the body.

Later, Cameron spoke with students at the Sedhenberg School in Cumbria,
England, by ham radio as part of the Shuttle Amateur Radio Experiment (SAREX).
The students had an opportunity to ask Cameron about a dozen different
questions as Discovery flew overhead.  Later today, more school contacts are
planned for Cameron with students in Portugal and South Africa.

The crew also sent Mission Control seven images taken with the HERCULES camera,
a camera that prints the latitude and longitude of the area being photographed
on the film at the time the photo is taken.  STS-56 is the first flight to
carry a HERCULES camera with the ability to send photographs to the ground, and
the camera's investigators are now analyzing the quality of images received
from Discovery.

Flight controllers are continuing to evaluate difficulties with the ability to
transmit high-rate data from Discovery to the ground for the ATMOS instrument
of the Atmospheric Laboratory for Applications and Science. Although the
information obtained by ATMOS cannot be sent live to the ground, it is being
recorded onboard Discovery for later analysis.  One plan currently in work by
flight controllers may allow a portion of ATMOS information to be sent down at
a slow rate of transmission to provide scientists on the ground the opportunity
to verify that the instrument is making the proper observations.

Other possible methods of increasing the amount of data ATMOS can obtain during
the flight also are being sought by controllers.

No new problems with any of Discovery's equipment were seen overnight and the
spacecraft continues in a 160 nautical mile high orbit.

- end -

--------------------------------------------------------------------------------


ATLAS 2 Public Affairs Status Report #5
6:00 a.m. CDT, April 10, 1993
2/05:31 MET
Spacelab Mission Operations Control
Marshall Space Flight Center
Huntsville, Alabama


The second mission for the Atmospheric Laboratory for Applications
and Science (ATLAS 2) continued overnight as three scientific
instruments gathered data about trace gases in the Earth's
atmosphere and their distribution levels by altitude.

With the cargo bay of Discovery opened toward Earth, the Shuttle
Solar Backscatter Ultraviolet (SSBUV) experiment measured solar
radiation as it scattered back from the atmosphere during the
daylight portions of each orbit.  From the Shuttle's vantage point,
high above the middle atmosphere, this instrument can look down on
the Earth, and measure the amount of ozone present in the
stratosphere.

The SSBUV instrument was developed by the Goddard Space Flight
Center in Maryland, to provide precisely calibrated observations of
ozone to instruments aboard National Oceanic and Atmospheric
Administration satellites.  SSBUV information will help scientists
solve the problem of data accuracy caused by degradation of optical
components of instruments on these free-flying satellites.

The Millimeter-wave Atmospheric Sounder (MAS) scanned the
atmosphere, looking for levels of chlorine monoxide, ozone, and
water vapor in the atmosphere.  MAS studies the chemistry of the
middle atmosphere by measuring the strength of millimeter waves
radiating at the specific frequencies of these molecules.
Principal Investigator Dr. Gerard K. Hartmann of the Max Planck
Institute for Aeronomy, Germany, and his colleagues in the U.S.,
Switzerland and Germany, will use the MAS data to better understand
the distribution of these trace gases in both the Southern and
Northern Hemispheres.

The MAS science teams successfully designed a computer software
"patch" to allow the MAS instrument to correctly interpret
positional signals from the Shuttle's Guidance, Navigation and
Control Systems.  Earlier efforts to compensate for the problem had
been successful, and good data continues to be received via the low
data rate communications channel.

The Atmospheric Trace Molecule Spectroscopy (ATMOS) instrument
viewed the stratosphere during orbital sunsets and sunrises to get
a more detailed picture of the concentrations of trace molecules
there.  ATMOS measured solar infrared radiation after it passed
through the atmosphere, a technique known as occultation limb
sounding.

ATMOS has the ability to measure the distributions of a greater
variety of gases in the stratosphere than has any single
space-based instrument.  Dr. Michael R. Gunson, ATMOS Principal
Investigator from the Jet Propulsion Laboratory in Pasadena,
Calif., and colleagues world-wide, will be analyzing the data from
this ATLAS 2 flight to provide greater understanding of the complex
chemical processes governing the composition of the stratosphere.
Since high data rate downlink capabilities have not yet been
restored, Dr. Gunson's data from these observations will be
retrieved, after landing, from an onboard experiment tape recorder.

Throughout the next 12 hour period, the ATMOS, MAS and SSBUV
instruments will continue to observe the chemical and physical
components of the middle atmosphere.

--------------------------------------------------------------------------------

MISSION CONTROL CENTER
STS-56 Status Report #8

Saturday, April 10, 1993, 12:30 p.m.

Using an alternate telemetry path through Discovery's dish antenna, flight
controllers successfully transferred important science data from the
Atmospheric Trace Spectroscopy experiment through the orbiter's high data rate
recorder to the ground.

Additional tests at higher data rates are planned later today, but expectations
are high that this method will allow investigators to get all of their data for
the mission.

Commander Ken Cameron, Pilot Steve Oswald and Mission Specialist Ellen Ochoa
spent portions of their work day talking to school children in Portugal,
England, South Africa, and England using the on-board ham radio.

Earlier today, Discovery's main experiment computer experienced a problem and
had to be reset.  While that was being done, the experiments in the payload bay
were shut off for a short period of time until the computer could be brought
back on line.

Oswald also worked with the HERCULES camera that identifies and prints latitude
and longitude data of the area being photographed.  Several photos have been
sent down from Discovery using the electronic still camera.

Earth observation became the prime focus of the crew during one particularly
clear overflight of the Caribbean and the Western coastline of South America.
Discovery remains in a stable, 160 nautical mile high orbit circling the Earth
every 90 minutes.

--------------------------------------------------------------------------------

ATLAS 2 Public Affairs Status Report #6
6:00 p.m. CDT, April 10, 1993
2/17:31 MET
Spacelab Mission Operations Control
Marshall Space Flight Center
Huntsville, Alabama


Atmospheric instruments aboard the ATLAS-2 Spacelab continue to use
a variety of remote-sensing techniques to define the chemical
composition of Earth's atmosphere.  The chemistry of the middle
atmosphere is very complex, involving many gases.  Accurate
measurements of a large number of trace molecules are needed to
verify computer models of how that chemistry works, so atmospheric
changes which occur naturally can be distinguished from those that
are induced by human activity.

Mission Specialist Ellen Ochoa and ground controllers quickly
reloaded the experiment computer software after a trap occurred in
the system early this morning.  Experiment operations successfully
resumed within about 45 minutes, with minimal impact on science
gathering.  It is possible one Atmospheric Trace Molecule
Spectroscopy (ATMOS) sunset observation might have been affected,
but this will not be known until the data being recorded onboard is
retrieved after the mission.

ATMOS continued to view the sun's infrared radiation through the
narrow band of Earth's atmosphere during orbital sunrises and
sunsets, making global measurements of the composition of the
troposphere, stratosphere and mesosphere.  Data is still being
recorded on the experiment's dedicated recorder.  A "tiger team" of
specialists from Marshall Space Flight Center, Johnson Space
Center, and Goddard Space Flight Center have developed several
potentially encouraging options for downlinking ATMOS data from the
Spacelab High Data Rate Recorder at lower rates.  Data controllers
and science teams in Huntsville are evaluating the results of tests
of those options.

This morning, Mission Scientist Dr. Tim Miller told the Discovery
crew the Millimeter-Wave Atmospheric Sounder (MAS) is operating at
"full efficiency" since last night's software correction, adding
that the MAS team also was pleased with the quality of the data
collected in a contingency mode prior to the software patch.  The
MAS instrument is similar to a radio receiver.  Its antenna scans
the atmosphere for emissions of important molecules at well-defined
frequencies, in much the same way that a radio dial is tuned to
various stations.  MAS completed an extended period of chlorine
monoxide observations, and it is now switching modes to map water
vapor and ozone in the middle atmosphere.

The Shuttle Solar Backscatter Ultraviolet Experiment (SSBUV) peered
through the atmosphere to the Earth's surface to identify both the
total amount of ozone present and its distribution by altitude.
the SSBUV team has already done preliminary processing of some
ozone science data and are extremely pleased with its quality.
During the current atmospheric observation period, SSBUV has
completed nine concurrent measurements with the its sister
instrument aboard the NOAA-11 spacecraft.  The primary purpose of
SSBUV is to verify the accuracy of data being gathered by
free-flying satellites.

For daylight portions of several orbits, Shuttle video cameras
transmitted pictures of the cloud-covered Earth.  These visual
images will allow the SSBUV science team to verify readings by
their cloud-cover radiometer, which tracks cloud reflectivity
throughout Earth observations.  Ozone absorbs different wavelengths
of ultraviolet light at different altitudes.  The cloud-cover
readings are factored into the SSBUV data to ensure the ozone
wavelengths are not being biased by light reflected off the clouds.

Though the Solar Spectrum (SOLSPEC) experiment is primarily
designed for solar observations, it joined the atmospheric
instruments in viewing the Earth for much of the last 12 hours.
SOLSPEC viewed both ultraviolet and visible light scattered back
from the Earth to make ozone measurements, using a simplified
technique similar to that of SSBUV.  SOLSPEC tested their
Earth-viewing, or "nadir pointing," capability for several orbits
during ATLAS 1, but this mission is the first time it has been put
into extended operation.

Atmospheric observations will continue to be the primary focus of
activity throughout the next shift.  The ATLAS instruments will be
put on temporary standby Sunday morning for the SPARTAN deployment,
after which the mission's second solar pointing period will begin.

--------------------------------------------------------------------------------

MISSION CONTROL STATUS REPORT #9
7 p.m. Saturday, April 10, 1993

Astronauts aboard Discovery reported making contact with the Russian Mir
Space Station this evening, the first such contact made between a shuttle and
Mir using amateur radio equipment.

Mission Specialist Mike Foale reported that the contact was brief, only long
enough to exchange greetings, before the connection was broken.  He speculated
that the loss of contact was due to the Shuttle Amateur Radio Experiment
antenna having been pointed downward at the Earth instead of above at Mir,
which was in an orbit about 50 nautical miles higher than Discovery.

Orbit 3 Flight Director Bob Castle congratulated members of the flight control
team who had contributed to the success of the contact, saying that to his
knowledge it was the first success in after a number of unsuccessful attempts
on previous shuttle flights.

Earlier in the day, using an alternate telemetry path through Discovery's dish
antenna, flight controllers successfully dumped data through the orbiter's high
data rate recorder.

As Foale and Mission Specialst Ken Cameron took care of business aboard
Discovery on the Red Team shift, Commander Ken Cameron, Pilot Steve Oswald and
Mission Specialist Ellen Ochoa got a good night's sleep in preparation for
Sunday's 1 a.m.  CDT deployment of the SPARTAN-201 free- flying platform.
Discovery's robot arm remained in an extended park position over the shuttle's
nose, ready for Ochoa to use it to grapple and deploy the satellite that will
study the Sun's corona and the solar wind for two days before being retrieved
Tuesday.

The Red Team continued Earth observations with the HERCULES camera and fixed
several samples in the Commercial MDA ITA Experiment's Bioprocessing Modules.

Discovery remains in a stable, 160 nautical mile high orbit circling the Earth
every 90 minutes.

MISSION CONTROL CENTER
STS-56 Status Report #10

Sunday, April 11, 1993, 4:30 a.m. CDT

Discovery's crew flawlessly deployed the SPARTAN platform and its array of
sun-watching instruments on time today at 1:11 a.m.  CDT.

SPARTAN will fly free for a little more than 48 hours, pointing the Solar Wind
Generation Experiment's instruments at features of the Sun, before Discovery
retrieves it and tucks it away in the cargo bay at about 2:17 a.m.  CDT
Tuesday. The instruments will study features such as holes and streamers in the
Sun's corona, or outer atmosphere, and their effect on the speed and strength
of the solar wind, a stream of extremely hot gas composed of electrically
charged atoms that constantly floods the solar system.  The solar wind is what
gives comets their tails and creates the Northern Lights when it encounters
Earth's magnetic field and upper atmosphere.  At times, it can be strong enough
to interfere with satellite and radio communications on Earth.

The information gathered by SPARTAN's instruments will be tape recorded and
played back after they are returned to Earth since SPARTAN is totally automatic
and has no communications system.

Discovery is now about 16 miles behind SPARTAN and continuing to separate from
it by about 8 miles per orbit.  It will continue that separation rate for the
next 21 hours before slowing.

After completing the deploy, Discovery's crew did a quick check to see if
interference from electronic devices in the cabin might be responsible for the
difficulties in sending high volume transmissions to the ground from the ATLAS'
ATMOS atmospheric instrument.  However, with the electronic equipment turned
off, high-volume transmissions did not improve.

ATMOS information is still being recorded onboard and some is being transmitted
to the ground via a new transmitting format sent to Discovery that allows it to
be sent in a low-volume mode.  Discovery is now in a 163 by 159 nautical mile
orbit, circling Earth every 90 minutes.


------------------------------------------------------------------------------

ATLAS 2 Public Affairs Status Report #7
6:00 a.m. CDT, April 11, 1993
3/05:31 MET
Spacelab Mission Operations Control
Marshall Space Flight Center
Huntsville, Alabama


Scientific instruments for the second Atmospheric Laboratory for
Applications and Science (ATLAS 2) mission were put on standby for
for several hours last night while crew members released the
Spartan-201 satellite from the cargo bay of the Space Shuttle
Discovery.

Three ATLAS 2 instruments gathered information during the night to
improve our understanding of how the atmosphere responds to
chemical and solar variations.  The Millimeter-wave Atmospheric
Sounder (MAS) experiment measured microwave radiation produced by
water vapor, chlorine monoxide and ozone in the Earth's atmosphere
and, prior to the SPARTAN deployment, spent over seven hours in
improved scan mode.  Scientists made some tests of the instrument's
brightness pointing mode earlier in the shift.  This worked very
well, and they are considering shifting to this data taking scheme
again later in the mission.

Changes in the atmosphere have been observed over the years, but
the causes of those changes are not fully understood.  MAS is
designed to furnish a library of measurement data dealing with
effects of chlorofluorocarbons and related chemicals which release
chlorine into the atmosphere, possibly causing ozone depletion
under some conditions.  Data from this joint German, Swiss and U.S.
experiment will be studied in conjunction with measurements from
the free-flying Upper Atmosphere Research satellite to construct a
more complete picture of the middle atmosphere.

The Shuttle Solar Backscatter Ultraviolet (SSBUV) experiment
provided ozone measurements that will be used to verify the
accuracy of similar instruments aboard free-flying NASA and
National Oceanic and Atmospheric Administration satellites.  Housed
in two Get-Away-Special canisters on the side of the payload bay,
SSBUV measures solar radiation in 12 ultraviolet wavelengths
scattered back from the Earth's atmosphere.  The instrument has
obtained a number of earth view orbits, all of which are of
excellent quality.

ATLAS 2 is the fifth mission for the SSBUV instrument.
Investigators will use pre- and postflight calibration
measurements, along with data from previous flights, to precisely
determine the instrument's characteristics and stability in order
to make accurate measurements of stratospheric ozone for comparison
with other space-based instruments.

The Atmospheric Trace Molecule Spectroscopy (ATMOS) measured solar
infrared radiation passing through the Earth's atmosphere at sunset
and sunrise.  The ATMOS instrument uses an infrared spectrometer to
create spectra which can be read to determine the concentrations of
trace gases present in the area scanned.  This information, coupled
with data from related experiments on balloons, rockets, satellites
and aircraft, will provide a reference source for atmospheric
scientists in the future.

A "tiger team" from Marshall Space Flight Center, Johnson Space
Center and Goddard Space Flight Center developed an option for
allowing some high rate ATMOS data to be captured on the Spacelab
High Data Rate Recorder and downlinked at a slower rate.  This
option was evaluated by the ATLAS science team last night, and a
decision was made to implement the procedure following the SPARTAN
satellite release.  It is expected that this will increase the
ATMOS experiment's overall data return for the mission.

The plan essentially calls for ATMOS sunrise data to continue to be
captured on the instrument's dedicated tape recorder.  Some
selected orbital sunset observations will be stored on the Spacelab
High Data Rate Recorder and will subsequently be downlinked as
tracking and data relay satellite opportunities allow.   Currently
four ATMOS observations have been captured on the Spacelab recorder
and plans are to downlink them during the next solar observing
period.

During the next 12 hours, the Solar Spectrum Measurement and Solar
Ultraviolet Spectral Irradiance Monitor instruments will study
ultraviolet wavelengths of sunlight, including the ultraviolet
region, which is the primary energy source for chemical reactions
in Earth's middle atmosphere.  The Active Cavity Radiometer
Irradiance Monitor and the Measurement of Solar Constant
investigations will make further correlative measurements with the
Upper Atmosphere Research Satellite (UARS) and the European
Retrievable Carrier (EURECA) satellite to refine the value of the
total amount of solar energy reaching the Earth, an important
factor in the study of our climate.

-------------------------------------------------------------------------------

MISSION CONTROL CENTER
STS-56 Status Report #11


Sunday, April 11, 1993, 11 a.m. CDT

Pilot Steve Oswald spent the day carefully maneuvering Discovery away from
the SPARTAN science satellite while keeping the Atmospheric Laboratory for
Applications and Science instruments pointed at the Sun for its scheduled
observations.

SPARTAN will operate away from the orbiter for about 48 hours, pointing its
instruments at the Sun and gathering science data on the solar wind that is
generated by the corona.

The solar wind is what gives comets their tails and creates the Northern Lights
when it encounters Earth's magnetic field and upper atmosphere.  At times, it
can be strong enough to interfere with satellite and radio communications on
Earth.

Discovery's crew will begin a series of small maneuvers during the night to
begin the rendezvous phase with SPARTAN. Plans currently are to retrieve the
free-flying spacecraft and tuck it back into the payload bay shortly after 2
a.m. central Tuesday.

Currently Discovery is trailing SPARTAN by about 55 nautical miles and
separating at about eight nautical miles every hour and a half.

Early this morning, Ellen Ochoa activated the Solar Ultraviolet Experiment. The
small instrument is packaged inside a canister in the rear of the payload bay
and is designed to study the extreme ultraviolet solar radiation as it affects
the Earth's ionosphere.  The experiment was designed, managed and built
entirely by students at the University of Colorado.

Mission Commander Ken Cameron made successful ham radio contacts with the
Lehigh Valley School in Allentown, Pennsylvania and Armand Bayou Elementary in
Houston. He had the added treat of talking with his son who attends the Armand
Bayou school.

Astronauts Ken Cockrell and Mike Foale took over operation of Discovery at
about noon when their three colleagues begain a sleep period.

Discovery is now in a 162 by 159 nautical mile orbit, circling the Earth every
90 minutes.

---------------------------------------------------------------------------------

ATLAS 2 Public Affairs Status Report #8
6:00 p.m. CDT, April 11, 1993
3/17:31 MET
Spacelab Mission Operations Control
Marshall Space Flight Center
Huntsville, Alabama

ATLAS 2 operations are proceeding smoothly on this fourth day of
the STS-56 mission.  Scientists and engineers at Spacelab Mission
Operations Control in Huntsville are pleased with the quality of
information they have been able to review thus far, and they look
forward to more detailed analysis of their data in the weeks and
months ahead.

ATLAS 2 completed six orbits of solar observations at around 2 p.m.
CDT today.  This was the second of four solar periods planned for
the mission.

The Active Cavity Radiometer Irradiance Monitor (ACRIM) and the
Solar Constant (SOLCON) experiment took readings of the total solar
energy coming to Earth.  They made preliminary data comparisons
with each other, as well as with observations by nearly identical
instruments aboard the Upper Atmosphere Research Satellite (UARS)
and the European Retrievable Carrier (EURECA). Science teams said
that the rough comparisons were extremely good, indicating that
instruments measuring total solar irradiance on the satellites had
not experienced significant degradation.

ATLAS instruments take very reliable readings of the atmosphere and
the sun, since they are carefully calibrated against strict
laboratory standards before and after each flight.  Yet these
readings are "snapshots" of only a few days' duration.  Longterm
conditions are tracked by free-flying satellites, whose instruments
may be somewhat degraded by extended exposure to space.  By
comparing the two measurements, scientists can determine the amount
of degradation in free-flying satellite readings.  This allows them
to make accurte corrections, essential to tracking subtle changes
over time in atmospheric conditions and the solar energy which
influences them.

The Solar Spectrum (SOLSPEC) instrument again received excellent
data on the infrared, visible and ultraviolet radiation from the
sun.  The information was sent back to the European Space Agency
facility in Brussels for analysis.  The Naval Research Laboratory's
Solar Ultraviolet Spectral Irradiance Monitor (SUSIM) was
calibrated successfully, then received good real-time data during
the six solar orbits.  The crew regularly interacted with the SUSIM
team to verify that their instrument was centered on the sun.  The
SUSIM instrument aboard the UARS satellite has been decreasing in
sensitivity since UARS was placed in orbit.  This is to be expected
since ultraviolet light, which SUSIM monitors, has a severe impact
on space instruments.  Comparison with ATLAS readings gives
scientists an accurate yardstick for measuring that degradation.

The Shuttle Solar Backscatter Ultraviolet (SSBUV) experiment made
solar irradiance measurements during last two solar orbits and
reports that their instrument is operating "splendidly."  The
Shuttle crew followed the standard procedure of pointing the cargo
bay toward deep space during nighttime portions of solar viewing
orbits, allowing the SSBUV instrument to cool.  Temperature
control, important to successful operations, has been consistent
with pre-flight predictions throughout the mission.  The science
team has used an improved capability for "quick-look" data analysis
during the mission to make rough comparisons of both solar and
ozone data with images taken from the NASA Total Ozone Mapping
Spectrometer aboard Russia's Meteor 3 satellite, as well as
comparisons of ATLAS 2 data with that taken during ATLAS 1.

After a two-hour break to allow an orbiter water dump, ATLAS-2
operations resumed about an hour ago with the cargo bay pointed
toward Earth for atmospheric observations.  Also after the water
dump, SOLCON and SOLSPEC completed planned onboard calibrations to
further ensure the extreme accuracy required for their solar
irradiance measurements.

Data controllers took advantage of the solar viewing period to
downlink all the Atmospheric Trace Molecule Spectroscopy (ATMOS)
data which had been stored on the Spacelab High Data Rate Recorder
during last night's atmospheric observations.  Real-time data from
the solar instruments was transmitted to the ground simultaneously
on another channel, partially confirming the viability of the
workaround approved last night for relaying ATMOS data.  Some
planned television from the Shuttle is being rescheduled so
communications channels can be available for the ATMOS dowlinks.

The High Data Rate Recorder was empty and ready to retrieve more
sunset observations as this afternoon's atmospheric operations
began.  The dedicated ATMOS recorder is about two-thirds full and
will continue to capture observations, giving priority to orbital
sunrises.  ATMOS teams at Spacelab Control and at the Jet
Propulsion Laboratory are evaluating the quality of the downlinked
data they received.  The capacity of the onboard recorder alone,
along with observations already downlinked to Spacelab control,
will allow ATMOS to make as many observations as they did during
the entire ATLAS 1 flight, a very successful mission for the
experiment.

The current atmospheric viewing period will continue until shortly
before midnight Monday.

STS-56 Status Report #12
MISSION CONTROL CENTER

Monday, April 12, 1993, 5 a.m. CDT

This morning Discovery began slowly closing on the SPARTAN platform, deployed
early yesterday, for a retrieval of the satellite and its solar instruments
scheduled for early Tuesday.

Discovery performed a series of three engine firings during the early morning
hours today, the first two to align the shuttle and the third, which dropped
the shuttle to a lower orbit and began its approach back toward SPARTAN.
Discovery obtained a maximum distance of about 171 nautical miles behind
SPARTAN before it began its return to the satellite.  Discovery is now catching
back up to SPARTAN at a rate of about 14 nautical miles per orbit.

Discovery will continue its slow approach back to SPARTAN throughout the day,
with a few small engine firings planned this evening to ensure the shuttle is
aligned with its target and closing on it at the proper rate.  At about 12:14
a.m.  Tuesday, an engine firing will be performed that will begin Discovery's
close operations with SPARTAN, culminating in a grasp of the platform with the
mechanical arm at bout 2:17 a.m.

The information gathered by SPARTAN's solar instruments is being recorded
onboard the satellite and will be analyzed by scientists after Discovery lands.
Discovery is currently in a 161 by 156 nautical mile high orbit.

---------------------------------------------------------------------------------

ATLAS 2 Status Report #09
6:00 a.m. CDT, April 12, 1993
4/05:31 MET
Spacelab Mission Operations Control
Marshall Space Flight Center
Huntsville, Alabama

The second mission of the Atmospheric Laboratory for Applications
and Science (ATLAS 2) is providing an opportunity for scientists
from around the world to gather data about our planet and its
atmosphere.  Instruments on board Space Shuttle Discovery operated
throughout the night, sending back information about the conditions
of the Earth's protective blanket.

Investigators for the Shuttle Solar Backscatter Ultraviolet (SSBUV)
experiment have been compiling a precisely calibrated database of
global stratospheric ozone measurements.  SSBUV, which compares
solar ultraviolet radiation with the amount of sunlight scattered
off the Earth's surface, records the amount of global cloud
coverage in order to determine if the backscatter is caused by
clouds or by specific molecules present in the atmosphere.

A primary objective of SSBUV during the ATLAS series of missions is
to provide highly accurate ozone measurements that will be used to
verify data being obtained by free-flying satellites.  SSBUV
readings will help scientists solve the problem of data accuracy
caused by calibration drifts in ozone-sensing instruments that are
exposed to the environment of space for long periods of time.

The Atmospheric Trace Molecule Spectroscopy (ATMOS) continued to
study the atmosphere last night.  Scientists want to learn more
about the components of the middle atmosphere, how they interact,
and how they change over time.  Models of stratospheric chemistry
are used to predict the future evolution of this atmospheric
region, and ATMOS data will help in the evaluation of those models.

A portion of ATMOS data, earlier recorded onto the Spacelab High
Data Rate Recorder and then downlinked using a newly developed
procedure, was sent to the Jet Propulsion Laboratory for analysis.
A team of scientists for the ATMOS experiment has completed their
evaluation of that data and found it to be of good quality.  The
method of transmitting data at one-sixteenth the rate it is
acquired will continue for the rest of the mission to provide
additional data to that recorded on the on-board dedicated
recorder.

The Millimeter-wave Atmospheric Sounder (MAS) measured the
atmosphere's thermal radiation in the 61 to 204 gigahertz frequency
range overnight.  MAS uses a parabolic antenna to gather
millimeter-wave radiation and directs that data to the Shuttle's
onboard electronics storage facility where it is downlinked via the
tracking and data relay satellite system.

        The information provided by these MAS measurements and by
correlative measurements with the Upper Atmosphere Research
Satellite (UARS) helps scientists understand more about the Earth's
middle atmosphere.  In particular, MAS measures the ozone and water
vapor profiles in the stratosphere and mesosphere and performs
global measurements of chlorine monoxide.  Since chlorine monoxide
is a key substance involved in the  destruction of ozone,
scientists are very interested in finding out how much of this
chemical is present in the atmosphere.

MAS, ATMOS and SSBUV will continue their observations of the
Earth's atmosphere during the next 12 hours.
 

STS-56
1 22621U 93 23  A 93101.42729449 0.00057240  00000-0  17184-3 0   112
2 22621  57.0073 164.1203 0006381 283.1092  76.9272 15.91824663   522

Satellite: STS-56
Catalog number: 22621
Epoch time:      93101.42729449         (11 APR 93   10:15:18.24 UTC)
Element set:     GSFC-011a
Inclination:       57.0073 deg
RA of node:       164.1203 deg          Space Shuttle Flight STS-56
Eccentricity:    0.0006381                  Keplerian Elements
Arg of perigee:   283.1092 deg
Mean anomaly:      76.9272 deg
Mean motion:   15.91824663 rev/day      Semi-major Axis: 6675.3091 Km
Decay rate:       0.57E-03 rev/day*2    Apogee  Alt:        301.18 Km
Epoch rev:              52              Perigee Alt:        292.66 Km


NOTE - This element set is based on NORAD element set # 011.
       The spacecraft has been propagated to the next ascending
       node, and the orbit number has been adjusted to bring it
       into agreement with the NASA numbering convention.

R.A. Parise, Goddard Space Flight Center

G.L.CARMAN



STS-56
                   FLIGHT DAY 2 STATE VECTOR (ACTUAL)
                         ON ORBIT OPERATIONS
                 (Posted 04/09/93 by Bruce Williamson)

The following vector for the flight of STS-56 is provided by NASA
Johnson Space Center Flight Design and Dynamics Division for use in
ground track plotting programs.  The vector is valid for flight
day two.  The vector represents the trajectory of Discovery after
the OMS-2 maneuver.  Questions regarding these postings may be
addressed to Don Pearson, Mail Code DM4, L. B. J. Space Center,
Houston, Texas 77058, Telephone (713) 483-8052.


Lift off Time : 1993/098/05:28:59.950
Lift off Date : 04/08/93

Vector Time (GMT) : 099/13:30:00.00
Vector Time (MET) : 001/08:01:00.05
Orbit Count : 22
Weight : 224876.0 LBS
Drag Coefficient : 2.00
Drag Area : 2750.0 SQ FT

     M50 Elements                           Keplerian Elements
-----------------------                 --------------------------
X    =     4453511.8  FT                A          = 3599.8507 NM
Y    =   -12175603.3  FT                E          = 0.000537
Z    =    17629159.4  FT                I  (M50)   =  57.01746 DEG
Xdot =  24651.987451  FT/S              Wp (M50)   = 318.68275 DEG
Ydot =    430.344756  FT/S              RAAN (M50) = 172.03355 DEG
Zdot =  -5921.325652  FT/S            / N (True)   = 147.49768 DEG
                           Anomalies  \ M (Mean)   = 147.46460 DEG

                                        Ha         = 160.544   NM
                                        Hp         = 157.192   NM

Mean of 1950 (M50)   : Inertial, right-handed Cartesian system whose
Coordinate System      origin is the center of the earth.  The epoch is the
                       beginning of the Besselian year 1950.
                       X axis: Mean vernal equinox of epoch
                       Z axis: Earth's mean rotational axis of epoch
                       Y axis: Completes right-hand system
A:    Semi-major axis
E:    Eccentricity                         N:    True anomaly
I:    Inclination                          M:    Mean anomaly
Wp:   Argument of perigee                  Ha:   Height of apogee
RAAN: Right ascension of ascending node    Hp:   Height of perigee
POSTED BY JBWMSON AT VMSPFHOU ON VMSPFHOU.VMBOARDS:PAONEWS

STS-56 Status Report #13
MISSION CONTROL CENTER

Monday, April 12, 1993, 12 noon CDT

Discovery continued to close on the SPARTAN satellite as the crew conducted
attitude maneuvers designed to put the two spacecraft about 35 feet apart at
the time of its retrieval scheduled for shortly after 2 a.m. central tomorrow.

The orbiter currently is trailing SPARTAN by about 130 statute miles and is
closing in at a rate of 15 miles per orbit.

SPARTAN is a self-contained, free-flying platform that measures the solar wind
and the Sun's corona while deployed away from Discovery.

In between those maneuvers, the Blue Team of crew members, Ken Cameron, Steve
Oswald and Ellen Ochoa made several contacts with schools around the country
using the on-board ham radio equipment.

The school contacts today included the Bellingham Public Schools in Washington
and Parkway Middle School in La Mesa, California.

An excited Cameron radioed down that he could see the flight controllers in
Mission Control using the fast scan television feature of the Shuttle Amateur
Radio Experiment equipment as Discovery flew over Houston.

In its spare time, the crew has been evaluating for the first time a new
on-orbit printer that is designed to eventually replace the older methods of
sending printed data and images to Space Shuttle crews.  Called the thermal
impulse printer system, or TIPS, this commercial off-the-shelf unit cost one
tenth of a newly developed system.

Discovery's systems continue to work well allowing the crew to devote its full
attention to the many experiments on going aboard the spacecraft.

---------------------------------------------------------------------------------

ATLAS 2 Public Affairs Status Report #10
6:00 p.m. CDT, April 12, 1993
4/17:31 MET
Spacelab Mission Operations Control
Marshall Space Flight Center
Huntsville, Alabama

"We have passed the halfway mark in the mission now, and the
science teams at Spacelab Mission Operations Control are very
pleased with the data they are getting," said Teresa Vanhooser,
mission manager for NASA's second Atmospheric Laboratory for
Applications and Science (ATLAS 2).  "We are looking forward to
sending them off with a lot of data about the Earth's atmosphere
and the sun to begin their post-mission analyses."

ATLAS 2 has completed about 70 orbits of observations.  Fourteen of
those orbits were devoted to two solar pointing periods, with the
rest focusing on the atmosphere.  Currently, the Shuttle
Discovery's cargo bay is pointed toward Earth for the flight's
third period of atmospheric observations.  All the ATLAS 2
instruments continue to operate well.

The Millimeter-Wave Atmospheric Sounder (MAS), a cooperative effort
of Germany, Switzerland and the United States, looks through the
atmosphere over the side of the Shuttle cargo bay to detect
microwave emissions of key components that affect global ozone
levels.  For most of the current 19-orbit atmospheric viewing
period, the MAS radio antenna has been scanning the atmosphere for
levels of ozone and water vapor.  Water vapor plays a central role
in ozone photochemistry because it is the source of active hydrogen
compounds that dominate ozone photochemical loss above 30 miles (50
km).  It is also a primary tracer of motion in the middle
atmosphere.  Therefore, MAS water vapor measurements provide
important information about the distribution of ozone.

MAS Principal Investigator Dr. Gerd Hartmann, from the Max Plank
Institute for Aeronomy in Germany, reports his instrument will take
more data during this flight than it did during ATLAS 1.
Improvements in the instrument should provide resolution twice as
sharp as that of observations collected during last year's flight.
In addition, improved mathematical models are giving the science
team better real-time data on chlorine monoxide, ozone and water
vapor than on the last mission.  The MAS team also was quite
pleased with preliminary analysis of a unique microwave scan of the
moon they performed earlier, saying they "got exactly what they
expected."  It was essentially a calibration exercise to measure
the scanning patten of their antenna in space against an object of
known brightness.  However, it also was the first time a scan has
been made of the moon at the MAS operating frequencies.

The Shuttle Solar Backscatter Ultraviolet (SSBUV) team has used its
improved capability since the last ATLAS flight to preview their
ozone measurements in near-real time.  A small amount of ozone data
has already been reviewed by the SSBUV staff at Goddard Space
Flight Center.  Principal Investigator Ernest Hilsenrath said rough
analysis indicates the ozone level is about what they would expect
it to be at this time of year.  However, he stressed that ozone
trends must be tracked on a long-term basis.  While Shuttle SBUV
flights provide important short-term observations, their primary
value is to verify the accuracy of ozone-monitoring instruments
aboard free-flying satellites.  "The best global ozone measurements
are being made by the National Oceanic and Atmospheric
Administration's NOAA-11 satellite, and that is our primary target
for concurrent measurements," said Hilsenrath.  Thus far, the
flight paths of NOAA 11 and the Shuttle Discovery have allowed at
least 11 orbits of comparisons.

In an experiment to test their new capability for ground control of
their spectrometer gratings, the SSBUV team took readings of sulfur
dioxide over Asia and the Eastern United States during the last 24
hours.  They worked closely with a Marshall Space Flight Center
team which tracks global weather patterns to determine when cloud
cover over target areas would allow sulfur dioxide readings.

The Atmospheric Trace Molecule Spectroscopy (ATMOS) team took data
both on their dedicated flight recorder and via low-rate downlinks
from the Spacelab High Data Rate Recorder.  Late this afternoon,
the ATMOS recorder reached its capacity, and plans were made to
downlink data from as many of the remaining orbital sunrises and
sunsets Tracking and Data Relay Satellite coverage will permit.
Priority will be given to sunrises, since those observations over
the Northern Hemisphere should reveal important information about
factors influencing suspected ozone depletion in that region.
However, sunsets will be downlinked as well, as these measurements
are important for verifying similar instruments aboard the Upper
Atmosphere Research Satellite.

The Solar Spectrum (SOLSPEC) experiment continued to do double duty
as an atmospheric instrument, taking readings of the distribution
of ozone by altitude.  The other three solar instruments are on
standby, awaiting four orbits of solar observations which will
begin Tuesday morning after the SPARTAN retrieval.

STS-56
1 22621U 93 23  A 93102.43207146 0.00059046  00000-0  16177-3 0   149
2 22621  57.0024 159.4708 0006016 323.5261  36.5406 15.93561138   682

Satellite: STS-56
Catalog number: 22621
Epoch time:      93102.43207146         (12 APR 93   10:22:10.98 UTC)
Element set:     GSFC-014
Inclination:       57.0024 deg
RA of node:       159.4708 deg          Space Shuttle Flight STS-56
Eccentricity:    0.0006016                  Keplerian Elements
Arg of perigee:   323.5261 deg
Mean anomaly:      36.5406 deg
Mean motion:   15.93561138 rev/day      Semi-major Axis: 6670.4589 Km
Decay rate:       0.59E-03 rev/day*2    Apogee  Alt:        296.08 Km
Epoch rev:              68              Perigee Alt:        288.06 Km


NOTE - This element set is based on NORAD element set # 014.
       The spacecraft has been propagated to the next ascending
       node, and the orbit number has been adjusted to bring it
       into agreement with the NASA numbering convention.

R.A. Parise, Goddard Space Flight Center

G.L.CARMAN



STS-56 Flight Day 5 vector

                               STS-56
                   FLIGHT DAY 5 STATE VECTOR (ACTUAL)
                         ON ORBIT OPERATIONS
                 (Posted 04/12/93 by Bruce Williamson)

The following vector for the flight of STS-56 is provided by NASA
Johnson Space Center Flight Design and Dynamics Division for use in
ground track plotting programs.  The vector is valid for flight
day five.  The vector represents the trajectory of Discovery after
the NC2 maneuver.  The next maneuver will be at approximately an MET
of 4 days 20 hours.  This maneuver may change the phasing slightly, so
allow a few seconds for early or late viewing.  Questions regarding
these postings may be addressed to Don Pearson, Mail Code DM4, L. B. J.
Space Center, Houston, Texas 77058, Telephone (713) 483-8052.


Lift off Time : 1993/098/05:28:59.950
Lift off Date : 04/08/93

Vector Time (GMT) : 102/19:58:59.950
Vector Time (MET) : 004/14:30:00.000
Orbit Count : 74
Weight : 219555.4 LBS
Drag Coefficient : 2.00
Drag Area : 5000.0 SQ FT

     M50 Elements                           Keplerian Elements
-----------------------                 --------------------------
X    =    12168888.4  FT                A          = 3602.3248 NM
Y    =   -13651453.8  FT                E          = 0.0011207
Z    =    12025490.1  FT                I  (M50)   =  57.09816 DEG
Xdot =  19368.102555  FT/S              Wp (M50)   =  50.89312 DEG
Ydot =   3049.918649  FT/S              RAAN (M50) = 156.89166 DEG
Zdot = -16085.058009  FT/S            / N (True)   =  88.23357 DEG
                           Anomalies  \ M (Mean)   =  88.10521 DEG

                                        Ha         = 160.88820 NM
                                        Hp         = 155.30357 NM

Mean of 1950 (M50)   : Inertial, right-handed Cartesian system whose
Coordinate System      origin is the center of the earth.  The epoch
                       is the beginning of the Besselian year 1950.
                       X axis: Mean vernal equinox of epoch
                       Z axis: Earth's mean rotational axis of epoch
                       Y axis: Completes right-hand system
A:    Semi-major axis
E:    Eccentricity                         N:    True anomaly
I:    Inclination                          M:    Mean anomaly
Wp:   Argument of perigee                  Ha:   Height of apogee
RAAN: Right ascension of ascending node    Hp:   Height of perigee

        KENNEDY SPACE CENTER SPACE SHUTTLE STATUS REPORT
                     Monday, April 12, 1993

KSC Contact: Bruce Buckingham

 
                            STS-56

Mission: STS-56/ATLAS-2/SSBUV      Orbital altitude: 184 miles
Vehicle: Discovery/OV-103          Inclination: 57 degrees
Mission Duration: 8 days/6 hours   Crew size: 5
KSC Landing Date/Time: April 16/approximately 7:27 a.m.


NOTE:  The Shuttle Discovery remains in orbit following launch on
April 8 at 1:29 a.m. Landing is scheduled for KSC on Friday,
April 16 at 7:27 a.m.

 

STS-56 Status Report #14
MISSION CONTROL CENTER

Tuesday, April 13, 1993, 5:30 a.m. CDT

Discovery's crew sailed through the retrieval of a science satellite this
morning that they had dropped off early Sunday.

After Commander Ken Cameron had eased Discovery up to the Spartan satellite,
Mission Specialist Ellen Ochoa slipped the shuttle's mechanical arm over a
special fixture on the science platform and locked on at 2:20 a.m.  CDT. Ochoa
then lowered the satellite into its latches in the cargo bay and locked them in
place at 3:02 a.m.  CDT.

Spartan spent two days flying free of Discovery, pointing its scientific
instruments at the sun to probe the nature of the solar wind and the sun's
corona.  The information gathered by the instruments was tape recorded onboard
Spartan and will be analyzed by scientists after Discovery brings it back to
Earth. All activities involved with Spartan's deployment and retrieval went
exactly as scheduled with no problems encountered, in fact, using less
propellant than had been predicted preflight.

Members of the blue shift are now at work on Discovery -- Cameron, Ochoa and
Pilot Steve Oswald. Discovery has been powered down to its normal
electricity-conserving mode for this flight, and much of the rest of today will
be spent pointing the atmospheric insturments of the ATLAS-2 array at sunrises
and sunsets so they may continue ozone-related research.

Discovery is now in a 162 by 157 nautical mile high orbit, circling Earth every
90 minutes and 31 seconds.

---------------------------------------------------------------------------------

ATLAS 2 Public Affairs Status Report #11
6:00 a.m. CDT, April 13, 1993
5/05:31 MET
Spacelab Mission Operations Control
Marshall Space Flight Center
Huntsville, Alabama


As the fifth night of the second Atmospheric Laboratory for
Applications and Science (ATLAS 2) mission got under way, science
operations were temporarily put on hold, while the Space Shuttle
Discovery crew members retrieved the Spartan-201 satellite, and
then resumed after the satellite grapple concluded.

The Atmospheric Trace Molecule Spectroscopy (ATMOS) experiment
measured the chemical and physical composition of the middle
atmosphere.  Since ATMOS first flew on Spacelab 3 in 1985,
scientists have identified over 30 different gases that are present
in the atmosphere and their location by altitude, including several
chlorofluorocarbons, nitrogen-oxygen compounds, ozone, carbon
monoxide, carbon dioxide, water and methane.

The ATMOS instrument viewed the stratosphere at orbital sunrise and
sunset, gathering information in the infrared portion of the
electromagnetic spectrum.  Since trace gas molecules absorb solar
radiation at different wavelengths, ATMOS determines which
wavelengths are being absorbed, giving scientists a more detailed
picture of the molecular makeup of the atmosphere.  ATMOS data from
ATLAS 2 will be compared to information gathered during other
missions to note worldwide, seasonal and long-term atmospheric
changes.  ATMOS data will be compared with infrared measurements
obtained by the Upper Atmosphere Research Satellite (UARS).

The Millimeter-wave Atmospheric Sounder (MAS) instrument, a
multi-national ATLAS 2 investigation, measured the amounts of water
vapor, ozone and chlorine monoxide (a major culprit in ozone
destruction), as well as temperature, in the middle atmosphere.
The ozone layer absorbs ultraviolet light from the sun, protecting
Earth from this harsh radiation and providing a heat source in the
middle atmosphere.

The MAS instrument uses a parabolic antenna to receive extremely
faint signals from our atmosphere.  This permits scientists such as
Principal Investigator Dr. Gerd K. Hartmann of the Max Plank
Institute for Aeronomy in Germany to infer trace gas concentrations
from the emitted radiation.

The Shuttle Solar Backscatter Ultraviolet (SSBUV) experiment
continued to make calibration measurements for NASA and NOAA
free-flying ozone instruments, part of the National Plan for
Stratospheric Monitoring.  The SSBUV instrument makes its ozone
measurements by comparing the amount of solar radiation reaching
the top of the Earth's atmosphere to the amount being scattered
back from the atmosphere.  This information gives scientists a
measure of the amount of ozone present in a given area.  In
addition, the device continued to operate successfully in its new
experimental mode as it acquired its third set of sulfur dioxide
measurements in the troposphere (lower atmosphere), this time over
eastern Asia.

The Solar Spectrum (SOLSPEC) experiment, designed primarily for
solar observations, demonstrated its versatility by spending much
of the last 12 hours viewing the Earth, looking at ultraviolet and
visible light scattering back from the top of the atmosphere.
SOLSPEC's Earth-viewing, or nadir pointing, capability uses a
technique similar to that of SSBUV to determine the amount of ozone
in the middle atmosphere.

The instrument had also completed some very good coincident
measurements with the Solar Spectrum (SOSP) device, SOLSPEC's twin
counterpart, aboard the European Retrievable Carrier (EURECA)
satellite, especially during the second solar viewing period.  The
scenarios for these comparative observations, and also for those
made by the ATLAS-2 Measurement of the Solar Constant (SOLCON)
experiment and the EURECA Solar Variation (SOVA) device, were
prepared by the European Space Agency's European Space Observation
Center (ESOC) in Germany.

During the next 12 hours, the four solar science instruments for
ATLAS 2 will begin their third period of solar observations.  The
Active Cavity Radiometer Irradiance Monitor, from the Jet
Propulsion Laboratory, and Belgium's SOLCON experiment will measure
the total solar energy received by the Earth.  The SOLSPEC
experiment will concentrate on the sun's radiant output in
ultraviolet, visible and infrared wavelengths while the U.S. Naval
Research Laboratory's Solar Ultraviolet Spectral Irradiance Monitor
examines solar output in the ultraviolet wavelengths.

---------------------------------------------------------------------------------

STS-56 Status Report #15
MISSION CONTROL CENTER

Tuesday, April 13, 1993, 11 a.m. CDT


With the SPARTAN satellite safely back in the payload bay, Discovery's crew
turned its attention back to the ATLAS-2 complement of instruments.

STS-56 Pilot Steve Oswald continued to conduct carefully choreographed
manuevers of the orbiter using the small thruster rockets to assist in pointing
the various experiments at the Sun above the payload bay and as it rises and
sets on each horizon.

During the dark portions of each orbit the spacecraft is rotated one full turn
to keep the instruments pointed toward darkness for cooling purposes.

Crew members also conducted several ham radio contacts with schools in Otego,
New York and in Montana.

Mission Specialists Ken Cockrell and Mike Foale are scheduled to wake up at
about one this afternoon to relieve Oswald, Commander Ken Cameron and Mission
Specialist Ellen Ochoa currently overseeing all orbiter and payload activities.

The long-range weather report from the Spacefllight Meteorology Group at the
Johnson Space Center shows the possibility of rain and thunderstorms in the
vicinity of the Kennedy Space Center at landing time Friday. Saturday's weather
is forecast to improve.

Discovery is currently in a 160 by 157 orbit, circling the Earth every 90
minutes.

---------------------------------------------------------------------------------

STS-56 Status Report #16
MISSION CONTROL CENTER

Tuesday, April 13, 1993, 6 p.m. CDT

Discovery's astronauts continued to take high resolution photographs of the
Earth and worked to restore some experiment support equipment to operations
since retrieving the SPARTAN satellite early this morning.

A laptop computer used by the HERCULES experiment to identify and append
precise geographic location to Earth observations photographs was replaced and
Ken Cockrell made some programming changes that will allow another to help
store the information, allowing the crew to make as much use of the HERCULES
system as possible.

Mike Foale inspected the connections among the computer, antenna, and receiver
that receive and store precise positioning cues from a Global Positioning
System satellite.  After the flight, scientists may be able to use that
information to verify the exact location of the orbiter when ATLAS-2
instruments recorded their readings.  The developmental system appears now to
be in working order.

The long-range weather report from the Spaceflight Meteorology Group at the
Johnson Space Center shows the possibility of rain and thunderstorms in the
vicinity of the Kennedy Space Center at landing time Friday. Saturday's weather
is forecast to improve.

Discovery is currently in a 161 by 157 orbit, circling the Earth every 90
minutes.

--------------------------------------------------------------------------------

ATLAS 2 Public Affairs Status Report #12
6:00 p.m. CDT, April 13, 1993
5/17:31 MET
Spacelab Mission Operations Control
Marshall Space Flight Center
Huntsville, Alabama

The ATLAS 2 solar instruments completed four orbits of observations
at around 1 p.m. CDT.  This was the third of four periods planned
during ATLAS 2 when the Shuttle's cargo bay will be pointed to the
sun.  By accumulating data during multiple observation periods,
scientists have more points of comparison to arrive at extremely
precise measurements of the sun's total energy output and how it is
broken down by wavelength.  Multiple solar periods also allow them
to study short-term solar variations.  All the solar instruments
again collected very high quality data.

Two University of Colorado students participated in science
planning meetings in Huntsville during the last three solar
observation periods.  The students represented a Colorado Space
Grant Consortium project, the Solar Ultraviolet Experiment (SUVE),
housed in a Get-Away-Special canister in the Shuttle cargo bay.
Although not part of the ATLAS 2 payload, SUVE is making
observations concurrently with the ATLAS solar instruments.  SUVE's
study of extreme ultraviolet solar radiation will complement both
ATLAS and SPARTAN measurements.  The experiment was designed,
managed and built at the University of Colorado in Boulder.  The
Space Grant Consortium program is funded by NASA to educate
students in the science and engineering aspects of exploring and
working in space.

After the solar period ended, the Shuttle crew maneuvered
Discovery's cargo bay to point toward Earth for the mission's
fourth period of atmospheric observations.  For the first three
orbits, the Shuttle has traveled with its nose into the flight path
as it did during the previous atmospheric viewing periods, rather
than tail-first as had been planned.  This change allowed an
increased data flow to the ground, making it possible to dump three
additional Atmospheric Trace Molecule Spectroscopy (ATMOS)
observations from the Spacelab High Data Rate Recorder.

ATMOS Principal Investigator Dr. Mike Gunson gave high praise to
the data management team at Spacelab Mission Operations Control for
their efforts to retrieve a maximum amount of high-rate ATMOS
data.  "They explored every possible way to cram every available
recorder with ATMOS observations," said Gunson.  The data team has
been scheduling dumps of ATMOS data from the Spacelab recorder as
Tracking and Data Relay Satellite coverage allows.  Because the
data is coming down at a rate sixteen times slower than that at
which it was acquired, the scheduling is a fairly complicated
process.  However, the team expects to get the majority of ATMOS
observations dumped from the Spacelab recorder by the end of the
mission.  ATMOS has reduced the length of observations from four
minutes to two minutes to allow more sunrises and sunsets to be
recorded.  The shortened observations will only reach as high as
the the top of the mesosphere.  However, because the stratosphere
(the atmospheric layer beneath the mesosphere) is of primary
interest to ATMOS, this change results in relatively little
scientific loss.

The ATMOS experiment team also was pleased to find their onboard
recorder is not full, as they suspected at the end of yesterday's
atmospheric period.  Observations will continue to be captured on
the onboard recorder until it has indeed reached capacity.  This
morning, Principal Investigator Gunson estimated there may be room
for 10 to 15 more observations on the recorder.  ATMOS ground
monitors indicate when the recorder is on or off, but not how much
of the tape has been used.

On the fourth atmospheric orbit, beginning at around 6 p.m., the
Shuttle will turn with its tail to the flight path.   This
reorientation will allow the Millimeter-Wave Atmospheric Sounder
(MAS), positioned on the left side of the cargo bay, to take
readings of the Northern Hemisphere polar region as the
stratosphere makes the critical transition from winter.  The MAS
team gave up three of 23 scheduled North-viewing orbits to allow
the extra ATMOS downlinks, in what Mission Scientist Dr. Tim Miller
termed an example of "scientific altruism."  MAS looked toward the
South during the three earlier atmospheric sessions.  The
instrument only pointed toward the South for a small portion of its
ATLAS 1 observations.

The MAS team has decided to forego some calibrations planned for
the remainder of the flight, since a calibration mirror proved
difficult to move out of their antenna's field of view after an
early-morning calibration.  The change will complicate post-flight
calibration somewhat, but it is not expected to have a significant
impact on the accuracy of their data.

Science teams and payload controllers at Marshall are considering
the best ways to use any additional experiment time, should it
become available due to a weather-related landing delay.

The current, 26-orbit atmospheric period will continue until early
Thursday morning.


--------------------------------------------------------------------------------

STS-56 Status Report #17
MISSION CONTROL CENTER

Wednesday, April 14, 1993, 5:30 a.m. CDT


Discovery's crew performed a standard pre-landing checkout of their spacecraft
and then talked with reporters at the Kennedy Space Center during an early
morning press conference.

Commander Ken Cameron and Pilot Steve Oswald went through a normal hour and a
half checkout of the equipment Discovery will use for its return home to the
Kennedy Space Center on Friday. The flight control systems checkout found
Discovery's systems in excellent condition with no problems that would affect
the return to Earth.

At about 4:09 a.m.  CDT, Discovery's crew talked with members of the press at
Kennedy. During the 20-minute session, crew members discussed their views of
Earth, their sighting and contact with the Russian Mir Space Station, their
impressions of increased cooperation with Russia in space, and their
atmospheric work and other experiments aboard Discovery.

Earlier in the morning, Cameron and the rest of the crew received a television
transmisssion of Mission Control by a ham radio experiment on the shuttle.  It
was the second such transmission the crew reported having seen.  As it took
place, flight controllers watched the crew's reaction by standard television
sent from the spacecraft.

Discovery's crew will speak with interviewers and school children at Channel
One television at about 10:14 a.m. central today and with Chicago's Museum of
Science and Industry by WGN television at 11:54 a.m. central.

Discovery remains in a 160 by 156 nautical mile orbit, circling Earth once each
90 minutes.

STS-56
1 22621U 93 23  A 93104.25176571 0.00045467  00000-0  13024-3 0   216
2 22621  57.0049 151.0369 0003961 279.5591  80.5039 15.92828848   978

Satellite: STS-56
Catalog number: 22621
Epoch time:      93104.25176571         (14 APR 93   06:02:32.56 UTC)
Element set:     GSFC-021
Inclination:       57.0049 deg
RA of node:       151.0369 deg          Space Shuttle Flight STS-56
Eccentricity:    0.0003961                  Keplerian Elements
Arg of perigee:   279.5591 deg
Mean anomaly:      80.5039 deg
Mean motion:   15.92828848 rev/day      Semi-major Axis: 6672.5032 Km
Decay rate:       0.45E-03 rev/day*2    Apogee  Alt:        296.76 Km
Epoch rev:              97              Perigee Alt:        291.47 Km


NOTE - This element set is based on NORAD element set # 021.
       The spacecraft has been propagated to the next ascending
       node, and the orbit number has been adjusted to bring it
       into agreement with the NASA numbering convention.

R.A. Parise, Goddard Space Flight Center

G.L.CARMAN


STS-56 Flight Day 6 Vector

                               STS-56
                   FLIGHT DAY 6 STATE VECTOR (ACTUAL)
                         ON ORBIT OPERATIONS
                 (Posted 04/13/93 by Bruce Williamson)

The following vector for the flight of STS-56 is provided by NASA
Johnson Space Center Flight Design and Dynamics Division for use in
ground track plotting programs.  The vector is valid for flight
day six.  The vector represents the trajectory of Discovery after
completion of the SPARTAN rendezvous.  Questions regarding these
postings may be addressed to Don Pearson, Mail Code DM4, L. B. J.
Space Center, Houston, Texas 77058, Telephone (713) 483-8052.


Lift off Time : 1993/098/05:28:59.950
Lift off Date : 04/08/93

Vector Time (GMT) : 103/16:58:59.950
Vector Time (MET) : 005/11:30:00.000
Orbit Count : 88
Weight : 221270.0 LBS
Drag Coefficient : 2.00
Drag Area : 5000.0 SQ FT

     M50 Elements                           Keplerian Elements
-----------------------                 --------------------------
X    =     4769886.8  FT                A          = 3600.7239 NM
Y    =   -14104573.4  FT                E          = 0.0006550
Z    =    16034817.8  FT                I  (M50)   =  57.10113 DEG
Xdot =  22767.280310  FT/S              Wp (M50)   =  16.17316 DEG
Ydot =  -4129.428495  FT/S              RAAN (M50) = 152.84509 DEG
Zdot = -10382.843003  FT/S            / N (True)   = 103.04561 DEG
                           Anomalies  \ M (Mean)   = 102.97248 DEG

                                        Ha         = 160.39550 NM
                                        Hp         = 156.61930 NM

Mean of 1950 (M50)   : Inertial, right-handed Cartesian system whose
Coordinate System      origin is the center of the earth.  The epoch
                       is the beginning of the Besselian year 1950.
                       X axis: Mean vernal equinox of epoch
                       Z axis: Earth's mean rotational axis of epoch
                       Y axis: Completes right-hand system
A:    Semi-major axis
E:    Eccentricity                         N:    True anomaly
I:    Inclination                          M:    Mean anomaly
Wp:   Argument of perigee                  Ha:   Height of apogee
RAAN: Right ascension of ascending node    Hp:   Height of perigee

MISSION CONTROL CENTER
STS-56 Status Report #18

Wednesday, April 14, 1993,  2 p.m. CDT

Science data gathering in support of the ATLAS instruments in Discovery's
payload bay continued throughout the day, while crew members took part in
several in-flight special events.

Several successful ham radio contacts were made today with the Franklin
Institute in Philadelphia, Pennsylvania, and Wilson Junior High School in El
Centro, California. Additional contacts are planned throughout tonight.

One container of the rodent experiment automatically switched from night to day
at one point.  Commander Ken Cameron manually activated the light.  The
experiment now is operating normally.

Operations with the HERCULES precise targeting camera equipment also continued
throughout the day in parallel with ATLAS observations.

Mission Specialist Ellen Ochoa took time out to discuss the flight with school
children in California and Mississippi during an interview with Channel 1, a
daily newscast for junior and senior high school students.  In a second
interview, Ochoa talked with students at Chicago's Museum of Science and
Technology.

Discovery currently is circling the Earth every 90 minutes at an altitude of
160 nautical miles.

--------------------------------------------------------------------------------

ATLAS 2 Public Affairs Status Report #13
6:00 a.m. CDT, April 14, 1993
6/05:31 MET
Spacelab Mission Operations Control
Marshall Space Flight Center
Huntsville, Alabama


During its sixth night in orbit, the second Atmospheric Laboratory
for Applications and Science (ATLAS 2) payload gathered data about
the relationship between the Earth and sun.  Scientists from the
U.S., Belgium, Germany, France, The Netherlands and Switzerland are
participating in this Spacelab mission, an integral part of NASA's
Mission to Planet Earth.

While atmospheric instruments were taking advantage of their fourth
observation period, Mission Specialist Michael Foale performed an
in-flight maintenance procedure that temporarily corrected a
problem with the on-board Global Positioning System (GPS).  The
GPS, designed to indicate an object's position in space, is being
flown and evaluated for the first time on a Spacelab mission.
After landing, scientists will look at the information from GPS to
help confirm the orbiter's position during their data-collection
periods.

The Atmospheric Trace Molecule Spectroscopy (ATMOS) instrument
continued to observe orbital sunsets and sunrises to identify and
measure molecules and their vertical distribution in the
atmosphere, and the device acquired good spectral data on key types
of these molecules (i.e. chlorine nitrate) that it was intended to
measure as part of its science objectives.  During the night, this
instrument also viewed the sun with no atmosphere.  This procedure
provides a solar reference for calibrating the ATMOS equipment.

Once the ATMOS dedicated recorder becomes full, the observation
periods will be shortened from four minutes to two minutes,
allowing the instrument to view the stratosphere (the primary
target for this investigation), the mesosphere, but not the
thermosphere.  Once the recorder is filled to capacity, the data
collected during these two-minute observations will later be
selectively captured on the Spacelab High Data Rate Recorder.  The
ATMOS science team, working from the Spacelab Mission Operations
Control center in Huntsville, Ala., closely monitored the remaining
storage capacity of the Spacelab recorder to ensure the maximum
number of atmospheric measurements would be available for analysis
after landing.

Overnight, the Millimeter-wave Atmospheric Sounder (MAS), a joint
investigation for Germany, Switzerland and the United States,
continued to operate with its Hot Target calibration mirror locked
in the "out" position.  This allowed data acquisition but will make
post-flight analysis somewhat more complicated.  However, data
quality appears to be as good as that obtained in nominal mode, and
the device measured the amounts of chlorine monoxide in the
atmosphere during the daylight portions of the orbits.  During the
dark, or shadowed, portion of the orbits, this instrument scanned
the atmosphere, measuring molecules that were present at different
altitudes, using what is known as a stepped-pointing mode.

Two other instruments of the ATLAS 2 payload operated overnight,
helping scientists to measure the amount of solar radiation that
bounces back from the top of the Earth's atmosphere.

The Shuttle Solar Backscatter Ultraviolet (SSBUV) experiment
measured ultraviolet radiation as part of an investigation into the
amount of ozone present in our atmosphere.  During the fourth run
of an experimental SSBUV procedure, sulfur dioxide readings were
made as the orbiter passed over industrialized areas of Japan.
SSBUV Mission Manager, Mr. Don Williams, reported that the amount
of data collected so far for ATLAS 2 has surpassed the volume of
data that was collected during ATLAS 1 in 1992.

The Solar Spectrum Measurement (SOLSPEC) instrument, which measures
solar radiation in the ultraviolet, visible and near-infrared
wavelengths in conjunction with its sister instrument aboard the
European Retrievable Carrier (EURECA) satellite, viewed the Earth
during this atmospheric observation period.  Although primarily a
solar instrument, SOLSPEC took advantage of the Earth-viewing
position of the orbiter to record ultraviolet and visible light as
it scattered back from the atmosphere.  This data will be combined
with information from SOLSPEC's solar observations to determine
concentrations of trace gases in the atmosphere.

The next 12 hour period will be dedicated to continued atmospheric
observations by the ATMOS, MAS, SSBUV and SOLSPEC instruments.

---------------------------------------------------------------------------------

ATLAS 2 Public Affairs Status Report #14
6:00 p.m. CDT, April 14, 1993
6/17:31 MET
Spacelab Mission Operations Control
Marshall Space Flight Center
Huntsville, Alabama

The ATLAS 2 Spacelab is in the ninteenth orbit of its fourth atmospheric
observation period, the longest of the mission.  This afternoon, Mission
Scientist Dr. Tim Miller announced that each of the three atmospheric
instruments -- the Millimeter Wave Atmospheric Sounder (MAS), the Atmospheric
Trace Molecule Spectroscospy (ATMOS) experiment, and the Shuttle Solar
Ultraviolet Backscatter (SSBUV) instrument -- have already accumulated more
data than they did during the entire ATLAS 1 flight last year.  He told the
crew, "The mission has more than lived up to our expectations."

The Shuttle Discovery is oriented with its tail into the path of flight for
most of this Earth-viewing period, rather than nose-first as it had been flying
previously.  This reorientation allows the Millimeter-Wave Atmospheric Sounder
to look toward both hemispheres during the course of the mission, and make
observations over around 94 percent of the globe, rather than the 84 percent
covered by Discovery's high-inclination orbit alone.  The maneuver is enabling
the MAS to make important readings of chlorine monoxide relevant to the study
of ozone loss in the stratosphere.  A major goal of ATLAS 2 is to make detailed
measurements of the northern stratosphere, so scientists can better understand
the processes and more reliably predict phenomena such as ozone depletion.

This winter, scientists announced record low ozone observations over Canada and
Northern Europe. While these values are not nearly as low as those for the
Antarctic ozone hole in the Southern Hemisphere spring, ATLAS 2 scientists
believe there is reason for concern.  In addition, the Upper Atmosphere
Research Satellite observed high levels of chlorine monoxide and cold
temperatures for a large part of the past Northern Hemisphere winter.  MAS is
using an improved pointing mode to take chlorine monoxide measurements during
daylight portions of orbits, then a scan mode for water vapor and ozone
measurements during night passes.  Because chlorine monoxide is broken down
from chlorine compounds by ultraviolet light, there is much less of it present
in the dark.

The ATMOS experiment is viewing sunrises and sunsets through the narrow band of
Earth's atmosphere, measuring the trace gases which are a result of the
chemistry of the stratosphere and mesosphere.  The ATMOS onboard recorder is
nearing capacity, but observations will be downlinked from the Spacelab High
Data Rate Recorder through the remainder of the mission.

The Shuttle Solar Ultraviolet Backscattter (SSBUV) experiment is continuing its
measurements of global concentrations of ozone in its Earth-viewing
configuration.  For two orbits today, the SSBUV team concentrated on the
wavelengths in which the next generation of NASA's Total Ozone Mapping
Spectrometers (TOMS) will operate.  This was the first time a space-based
instrument has checked out the new TOMS frequencies, planned to provide
improved long-term readings of ozone distribution.  Throughout the mission, the
SSBUV team has reported "superb quality" in both real-time and recorded data,
as well as excellent performance by their instrument.

All the careful measurements from the ATLAS series of missions, as well as
those made by free-flying satellites, contribute to the atmospheric portion of
NASA's Mission to Planet Earth. "The most important application of this mission
is to understand the effects of human activity on the atmosphere and separate
them from the effects of natural consequences such as variations in the sun's
energy," Mission Specialist Ellen Ochoa told students this morning in a
televised interview from the Shuttle. "The more we know about that, the more we
as people on Earth will be able to respond to changes in the atmosphere and
change the way we do things on Earth."

During the day, the crew took various photographs and made videos of the Earth
for the three atmospheric instruments to use in post-flight data analysis.

ATMOS and SSBUV are on standby during an orbiter water dump.  They will rejoin
MAS just after 6:30 p.m.  CDT for about 11 more hours of atmospheric
observations.  The mission management team at Marshall continues to evaluate
options for an extension of science activities, should the STS-56 landing
tomorrow be waved off because of poor weather at Kennedy Space Center.

Article 3062 of clari.tw.space:
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Subject: Lost pliers found in shuttle booster rocket
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References: <[email protected]> <[email protected]> <[email protected]>
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	CAPE CANAVERAL, Fla. (UPI) - One of the reuseable solid rocket
boosters that helped propel shuttle Discovery into orbit last week
carried a technician's lost pliers, officials said Wednesday.
	The 8-inch-long cutting tool caused no damage, but NASA managers
planned to step up safety rules to make sure similar accidents do not
happen again.
	``During the routine post-flight inspection of the solid rocket
boosters, we found a set of diagonal cutting pliers,'' said NASA
spokeswoman Lisa Malone. ``We did find this tool posed no threat to the
safe operation of the launch, however it is causing us some concern.''
	``This is a serious matter,'' she added.
	The pliers, which had fallen between the booster's outer coating and
one of the four posts that pin it to the shuttle's launch platform, were
discovered only after the booster was recovered from the Atlantic Ocean
and returned to Kennedy Space Center for refurbishment and reuse.
	The tool fell to the floor of a hangar Saturday as workers washed the
rocket before disassembling it. An investigation into the incident was
under way.
	Techncians are supposed to keep tools tethered to their wrists when
working on flight equipment, and a formal report should be filed when
any tool turns out missing.
	``It had quite a ride,'' shuttle Launch Director Robert Sieck told
the Orlando Sentinel. Sieck noted that missing tools were a rare
occurrence.
	``We were proud of our record,'' he said.

MISSION CONTROL CENTER
STS-56 Status Report  #19

Thursday, April 15, 1993, 5 a.m. CDT

Discovery's crew continues to work thourgh a variety of experiments onboard,
while stowing a few away in anticipation of tomorrow's return home.

Discovery remains scheduled for a 6:33 a.m.  CDT touchdown Friday at the
Kennedy Space Center. The weather forecast at present is favorable for landing,
although flight controllers are keeping a close watch on the speed with which a
frontal system is approaching Florida.

Early this morning, Discovery's crew wrapped up their work with the Hercules
camera, a camera that records the location of its subject on the film at the
time a photo is taken.  The camera's location information was accurate as seen
in a host of very clear photos that were transmitted to the ground by special
equipment aboard Discovery for this flight.

Also, Mission Specialist Ellen Ochoa powered down Discovery's mechanical arm
and latched it in place along the left edge of the cargo bay for the trip home.
Today, the atmospheric instruments in Discovery's payload bay will be pointed
to catch the first and last rays of orbital sunrises and sunsets so they may
continue gathering information on the ozone and chemistry of the upper
atmosphere.  Secondary experiments inside the cabin will be concluded and put
away throughout the day as well.

Discovery is in excellent mechanical shape in a 161 by 157 nautical mile orbit.

--------------------------------------------------------------------------------

ATLAS 2 Public Affairs Status Report #15
6:00 a.m. CDT, April 15, 1993
7/05:31 MET
Spacelab Mission Operations Control
Marshall Space Flight Center
Huntsville, Alabama


Science teams at the Spacelab Mission Operations Control center in Huntsville,
Ala., monitored the activities of four instruments for the second Atmospheric
Laboratory for Applications and Science (ATLAS 2) mission last night.  While
solar-viewing instruments "rested" in the cargo bay of the Space Shuttle
Discovery, atmospheric observations were conducted for the fourth time during
this mission.

The Atmospheric Trace Molecule Spectroscopy (ATMOS) scientists monitored
feedback from their instrument's dedicated tape recorder during the night and
received indications that there is still some storage space on the 44-gigabyte,
high-density tape.  ATMOS data concerning different trace gases in the middle
atmosphere is being captured on both the dedicated tape recorder and the
Spacelab's High Data Rate Recorder.

The Millimeter-wave Atmospheric Sounder (MAS) instrument, which has been
compared to a specialized radio receiver, continued to measure the strength of
millimeter waves radiating from water vapor, chlorine monoxide and ozone in the
middle atmosphere over northern latitudes.  The scientists unlocked the
device's hot target calibration mirror for this shift's last orbit in order to
obtain one more calibration in the standard mode of operation.

Mission Manager for the Shuttle Solar Ultraviolet Backscatter (SSBUV)
experiment, Mr. Don Williams, described ATLAS 2 as being, "an extremely wealthy
mission in relationship to the amount of ozone data that SSBUV has been able to
receive." SSBUV measures the amount of ozone in a "column" of the atmosphere,
as well as the way ozone is distributed by altitude.  The total ozone values
measured by the SSBUV instrument so far are agreeing with expected values for
the amount of ozone in the atmosphere.

The Solar Spectrum Measurement (SOLSPEC) experiment took advantage of the cargo
bay-to-Earth position of the orbiter to observe global ozone levels on the
sunlit side of the orbit.  SOLSPEC data will help scientists understand more
about how the changes in the sun's energy affect our atmosphere.

During the next 12 hours, the ATLAS 2 solar-viewing instruments will be
operational.  The Solar Constant (SOLCON) experiment and the Active Cavity
Radiometer Irradiance Monitor (ACRIM) will measure the total amount of energy
emitted by the sun.  SOLSPEC and the Solar Ultraviolet Spectral Irradiance
Monitor (SUSIM) will measure absolute values of solar radiation.

Mission Specialist Michael Foale performed a second in-flight maintenance
procedure to repair a cable that connects the Global Positioning System's
on-board electronic receiver to a laptop computer.  After the procedure proved
unsuccessful, the equipment was stowed for post-flight examination.  This
device provides only complementary non-critical information, so the science
objectives of the ATLAS-2 experiments will not be affected.

Managers at Kennedy Space Flight Center, Johnson Space Center and Marshall
Space Flight Center are currently discussing options for additional science
collection in the event of a weather-related landing delay.

--------------------------------------------------------------------------------

MISSION CONTROL CENTER
STS-56 Status Report #20


Thursday, April 15, 1993, 2 p.m. CDT


As Discovery's sixteenth mission draws to a close, flight controllers in
Houston and Huntsville looked at options for gaining additional science, if
possible, on an extension should tomorrow's landing be postponed.

Many discussions are on going relative to prioritizing activities and reviewing
the electricity available from the orbiter to support such experiment work.

Decisions will be made late tonight and early tomorrow morning based on the
updated weather conditions as the landing opportunities approach.  The current
forecast calls for a chance of thunderstorms in the KSC area at the time of
landing.  In the meantime, landing remains scheduled for a 6:33 a.m.  CDT
Friday at the Kennedy Space Center with a backup opportunity one orbit later at
8:06 a.m.

The rest of the day will involve deactivating the STS-56 ATLAS experiments and
disconnecting the electricity stream from the orbiter to the payloads.  The
crew will stow equipment taken out during the flight and prepare the cabin for
the return home.

After the Entry Team takes over in Mission Control late tonight, Commander Ken
Cameron, Pilot Steve Oswald and Mission Specialist Ken Cockrell will test all
of the small thruster jets in the nose and tail of the orbiter that are
required for the entry phase of the mission.  The moveable surfaces on the
wings and tail were tested yesterday and are ready to support the atmospheric
portion of the flight.

The fifty-fourth Space Shuttle mission continues to go smoothly as Discovery
circles the Earth every ninety minutes at an altitude of 160 nautical miles.

-------------------------------------------------------------------------------

ATLAS 2 Public Affairs Status Report #16
6:00 p.m. CDT, April 15, 1993
7/17:31 MET
Spacelab Mission Operations Control
Marshall Space Flight Center
Huntsville, Alabama

The Discovery crew maneuvered the orbiter's cargo bay to to face the sun this
morning for the last of four ATLAS 2 solar observation periods.  All four solar
experiments -- the Active Cavity Radiometer Irradiance Monitor (ACRIM), the
Solar Constant (SOLCON) and Solar Spectrum (SOLSPEC) experiments, and the Solar
Ultraviolet Spectral Irradiance Monitor (SUSIM) -- added six orbits of
observations to the excellent data they acquired during previous solar periods.
The Shuttle Solar Backscatter Ultraviolet (SSBUV) operated in its solar-viewing
mode during the last two sun orbits.  Solar observations are a vital part of
this atmospheric mission, because energy coming down from the sun drives the
Earth's climate system and the photochemistry of ozone in the stratosphere.

Co-Investigator Roger Helizon, of NASA's Jet Propulsion Laboratory, is
especially pleased with comparative measurements his team has made with the
ATLAS 2 SOLCON experiment and with similar instruments aboard the Upper
Atmosphere Research Satellite (UARS) and the European Retrievable Carrier
(EURECA). "ATLAS 2 is the first time we have been able to retrieve our data
during the mission, and thus far rough comparisons of the four instruments have
been very close indeed." SOLCON Principal Investigator Dr. Dominique
Crommelynck agreed, saying, "The coincidence is amazing."

The solar constant experiments, designed to take measurements to an accuracy of
one-tenth of one percent, are part of a long-term plan during which scientists
hope to collect 100 years of data on solar variations.  The total energy output
of the sun varies only slightly, but variations of just one-half percent over a
time scale of decades are thought to be capable of creating major climate
changes.  Observations of the sun made from space, above the distortions of the
atmosphere, can be much more precise than ground-based readings.  The first
observations with this level of accuracy were made by NASA's Solar Maximum
Mission Satellite in the 1980s.

The crew placed the Shuttle in a special attitude during the fifth solar orbit
to calibrate the SUSIM experiment.  Then, on the last sun-viewing orbit, they
executed a complex maneuver called a "criss-cross scan" to allow the other
solar instruments and SSBUV to pinpoint the exact center of the sun.  A
standard criss-cross scan, during which the orbiter panned the instruments
across the disc of the sun vertically and horizontally, was completed during
the first solar orbit of the mission.  Today's maneuver added two diagonal
scans to enhance the precision of the calibration.  Scientists monitoring their
instruments at Spacelab Mission Operations Control declared the calibration to
be extremely successful.  Instrument teams will use the calibration to ensure
exact match-ups of their readings during post-flight comparisons.

The six-orbit solar session ended at about 2:30 p.m., and the crew reoriented
the Shuttle for a few more orbits of atmospheric studies for SSBUV and the
Atmospheric Trace Molecule Spectroscopy (ATMOS) experiment.  As expected, the
Shuttle's Remote Manipulator System arm, which was stowed in accordance with
flight rules 24-hours prior to nominal landing time, blocks the view of the
Millimeter Wave Atmospheric Sounder (MAS).  Therefore, the MAS instrument has
ceased operations for the remainder of the mission.

Currently, crew members are scheduled to deactivate the payload at about 9:30
p.m.  CDT. Science teams and payload controllers at Marshall are still awaiting
word as to whether the Shuttle landing will be delayed due to weather.  ATLAS
instruments might have an opportunity for bonus observations, the length and
nature of which will depend upon when a decision is made to postpone landing.

"After the mission, scientists will start the hard and painful process of
translating their raw data into geophysical parameters reflecting the amounts
of ozone, the strength of solar ultraviolet radiation and the total energy from
the sun," said NASA Headquarters Program Scientist Dr. Jack Kaye. "Only then
will they be able to 'do science' with the data to learn more about the sun and
the atmosphere." Kaye added that another important ATLAS 2 objective will begin
then as well -- comparing measurements with those of sister instruments flying
on the Upper Atmosphere Research Satellite, Total Ozone Mapping Spectrometers
aboard NASA's Nimbus 7 and Russia's Meteor 3 satellites, and National Oceanic
and Atmospheric Administration's Solar Backscatter Ultraviolet (SBUV/2)
instruments on NOAA 9 and NOAA 11.  The data ultimately will be deposited in
Earth Observing System Data Information System archives at NASA's Goddard Space
Flight Center, where it will be available to atmospheric scientists around the
world.

--------------------------------------------------------------------------------

ATLAS 2 Public Affairs Status Report #17
6:00 a.m. CDT, April 16, 1993
8/05:31 MET
Spacelab Mission Operations Control
Marshall Space Flight Center
Huntsville, Alabama


Instruments aboard the ATLAS-2 payload have additional
opportunities to make solar and atmospheric measurements, due to a
weather-related landing delay.

Atmospheric and solar scientists stationed at the Spacelab Mission
Operations Control center in Huntsville, Ala., monitored their
instruments during deactivation procedures shortly after 10:30 p.m.
CDT, as the second Atmospheric Laboratory for Applications and
Science mission prepared for completion.  Then, at around 4:15 a.m.
CDT, STS-56 was waved off from landing on Friday.

The Spacelab pallet systems will be reactivated at about 9:00 a.m.
CDT, and the Active Cavity Radiometer Irradiance Monitor (ACRIM),
the Solar Spectrum Measurement (SOLSPEC) instrument, the
Measurement of the Solar Constant (SOLCON) experiment, and the
Shuttle Solar Backscatter Ultraviolet (SSBUV) experiment will
benefit from two additional sun observation orbits beyond the
already acquired nominal mission solar measurements.  After the
solar orbits, SSBUV and the Atmospheric Trace Molecule Spectroscopy
(ATMOS) instrument  are scheduled to make additional atmospheric
measurements during the following six orbits prior to deactivation
for a landing attempt on Saturday morning.

------------------------------------------------------------------------------


STS-56 Status Report #21
MISSION CONTROL CENTER


Friday, April 16, 1993, 5:30 a.m. CDT


Discovery's landing has been postponed one day because of bad weather at the
Kennedy Space Center landing site.  Weather conditions are expected to improve
for a landing tomorrow morning at KSC at approximately 6:40 a.m. central time.
Two alternate opportunities for landing at Edwards AFB in California also look
favorable tomorrow.

The blue team, commander Ken Cameron, pilot Steve Oswald, and mission
specialist Ellen Ochoa, are powering on Shuttle systems and the Spacelab's
atmospheric research equipment for another day of science data taking in orbit.
About 7 p.m., the red team, mission specialists Mike Foale and Ken Cockrell,
will begin powering down and stowing equipment for the return home tomorrow.
 

STS-56
1 22621U 93 23  A 93105.94620954 0.00044106  00000-0  12690-3 0   264
2 22621  57.0056 143.1899 0003284 299.6828  60.3923 15.92765567  1247

Satellite: STS-56
Catalog number: 22621
Epoch time:      93105.94620954         (15 APR 93   22:42:32.51 UTC)
Element set:     GSFC-026
Inclination:       57.0056 deg
RA of node:       143.1899 deg          Space Shuttle Flight STS-56
Eccentricity:    0.0003284                  Keplerian Elements
Arg of perigee:   299.6828 deg
Mean anomaly:      60.3923 deg
Mean motion:   15.92765567 rev/day      Semi-major Axis: 6672.6799 Km
Decay rate:       0.44E-03 rev/day*2    Apogee  Alt:        296.48 Km
Epoch rev:             124              Perigee Alt:        292.10 Km


NOTE - This element set is based on NORAD element set # 026.
       The spacecraft has been propagated to the next ascending
       node, and the orbit number has been adjusted to bring it
       into agreement with the NASA numbering convention.

R.A. Parise, Goddard Space Flight Center

G.L.CARMAN


STS-56 FLIGHT DAY 7 STATE VECTOR (ACTUAL)
ON ORBIT OPERATIONS
(Posted 04/14/93 by Bruce Williamson)

The following vector for the flight of STS-56 is provided by NASA Johnson
Space Center Flight Design and Dynamics Division for use in ground track
plotting programs.  The vector is valid for flight day seven.  The vector
represents the trajectory of Discovery during the coasting phase of the
flight, and should be reasonably valid for the remainder of the flight.
Additional vectors will be posted, if necessary.

Lift off Time : 1993/098/05:28:59.950
Lift off Date : 04/08/93

Vector Time (GMT) : 104/21:28:59.950
Vector Time (MET) : 006/16:00:00.000
Orbit Count : 107
Weight : 220522.0 LBS
Drag Coefficient : 2.00
Drag Area : 2000.0 SQ FT

     M50 Elements                           Keplerian Elements
-----------------------                 --------------------------
X    =    -6074447.0  FT                A          = 3598.6745 NM
Y    =   -10211393.3  FT                E          = 0.0004418
Z    =    18366861.8  FT                I  (M50)   =  57.11517 DEG
Xdot =  21487.398065  FT/S              Wp (M50)   = 292.64218 DEG
Ydot = -13467.827958  FT/S              RAAN (M50) = 147.37176 DEG
Zdot =   -376.268945  FT/S            / N (True)   = 158.37943 DEG
                           Anomalies  \ M (Mean)   = 158.36077 DEG

                                        Ha         = 160.27061 NM
                                        Hp         = 156.22608 NM

Mean of 1950 (M50)   : Inertial, right-handed Cartesian system whose
Coordinate System      origin is the center of the earth.  The epoch
                       is the beginning of the Besselian year 1950.
                       X axis: Mean vernal equinox of epoch
                       Z axis: Earth's mean rotational axis of epoch
                       Y axis: Completes right-hand system
A:    Semi-major axis
E:    Eccentricity                         N:    True anomaly
I:    Inclination                          M:    Mean anomaly
Wp:   Argument of perigee                  Ha:   Height of apogee
RAAN: Right ascension of ascending node    Hp:   Height of perigee
 

    Didn't the shuttle ever come down ... (-;
    Suddenly no more news in the conference ?

  I saw it on the news. It landed at the Cape over the weekend. I believe
they were delayed one day due to weather at the landing site so they fired
up their experiments and got in an extra day of research.

  George

        KENNEDY SPACE CENTER SPACE SHUTTLE STATUS REPORT
                    Wednesday, April 21, 1993

KSC Contact: Bruce Buckingham

 
                                STS-56

Up Mission: STS-51/ACTS-TOS/ORFEUS-SPAS
Down Mission: STS-56/ATLAS-2/SSBUV
Vehicle: Discovery/OV-103
Location: OPF bay 3


IN WORK TODAY:
*  Post flight engine inspections
*  Orbiter hydraulic operations
*  Access to aft engine compartment
*  Flight control frequency response tests
*  Activate orbital maneuvering system purges

WORK SCHEDULED:
*  Open payload bay doors (Thursday)
*  Payload bay door latch and functional tests (Thursday)
*  Remove forward reaction and control system access panels
   (Thursday)
*  Remove main engine carrier panels and heat shields (Thursday)
*  Remove SUVE payload (Friday)
*  Remove Atlas and Spartan payloads (Monday)

WORK COMPLETED:
*  Roll to OPF following landing at KSC on Saturday April 17
*  Installation of payload bay door strongback
*  Forward and aft thruster inspections
*  Clean-up in OPF following minor hypergolic oxidizer spill
*  Install main engine locks

Brian Dunbar
Headquarters, Washington, D.C.          June 23, 1993

Jim Doyle
Jet Propulsion Laboratory, Pasadena, Calif.


RELEASE:  93-118

        Important ozone data was saved by a new tape recorder during an April
Space Shuttle mission.

        Despite transmitting problems, the on-board data recovery system
captured 103 orbital sunrises and sunsets observed by the Atmospheric Trace
Molecule Spectroscopy (ATMOS) instrument.  ATMOS, part of the second
Atmospheric Laboratory for Applications and Science (ATLAS 2), measures up to
40 gases that affect global ozone levels.  The ATLAS 2 mission's orbital path
allowed ATMOS to measure the gases over high northern latitudes during the
early spring, when the atmosphere is changing from winter to summer circulation
patterns.  These circulation patterns affect the weather conditions that can
lead to ozone depletion.

        The ATLAS series, which began in 1992, is part of NASA's Mission to
Planet Earth, which uses the unique global perspective available from space to
study how the environment changes.  The ATLAS instruments observe the chemical
makeup of the atmosphere and the energy output of the Sun, two of the key
factors in the creation and depletion of ozone.

        ATMOS has flown aboard the Shuttle two other times but the April
flight, designated STS-56, was an engineering test flight for the ATMOS
recorder subsystem.


        During the flight, the Shuttle's telemetry system, which would have
transmitted ATMOS data to the ground during flight, ran into problems.
ATMOS/Spacelab controllers and the Space Shuttle flight team developed a plan
that allowed the Spacelab's high data rate recorder to record some data on the
orbiter data system and transmit it at a reduced rate.  Unfortunately the data
included some errors, project officials said, rendering most of this data
useless.

        The ATMOS team was able to rely on its recorder subsystem, a separate,
dedicated data recording system that uses a tape recorder manufactured by
Schlumberger Industries, a French company.  The recorder saved the atmospheric
observations, said ATMOS Assistant Project Manager Greg Goodson. In early June,
the data tape was played back for the first time at NASA's Jet Propulsion
Laboratory, Pasadena, Calif.; scientists found the data's quality to be
excellent.

        The new recorder subsystem, which has a 44-gigabyte (353 billion bits)
storage capacity, recorded more than half of the scheduled ATMOS observations
-- nearly 6-1/2 hours of data.  Results of the data analysis, which is already
underway, are expected to be published within the next year, Goodson said.  The
results will present a better understanding of the gases that damage the ozone
layer.
 

Michael Braukus
Headquarters, Washington, D.C.                    October 8, 1993

Jane Hutchison
Ames Research Center, Mountain View, Calif.


RELEASE:  93-181

     Unexpected results from a recent Space Shuttle experiment on rats some day
may lead to the discovery of the genes that direct bone cells to produce more
bone.

     Last April's third Physiological and Anatomical Rodent Experiment (PARE-3)
studied changes in the activity of bone- forming cells after 9 days of space
flight.  It also investigated whether these changes were reversed within 3 days
of return to Earth.

     "We were totally surprised by some of the data from this flight
experiment," said Dr. Emily Morey-Holton of NASA's Ames Research Center,
Mountain View, Calif.

     Although she cautioned that much research remains to be done, Morey-Holton
said the findings may accelerate the development of drugs to stimulate the
production of new bone.  Such medications could be important not only for
astronauts on long-duration space missions but also for people on Earth
suffering from bone-weakening disorders.

     At the end of the mission Morey-Holton and co-investigators Drs. Kim
Westerlind and Russell Turner of the Mayo Clinic, Rochester, Minn., found a
decrease in the production of certain chemical messages necessary for bone
formation.  This was followed within 24 hours by a dramatic increase in
production of these chemicals.  Levels again decreased within 72 hours after
landing.

     The 40 percent decrease in chemical messages was seen in cells on the
outer surface of the lower leg bones (cortical bone).  These messages direct
bone-forming cells to produce proteins that are part of the process that
results in formation of new bone.  The investigators had expected this decrease
since space flight is known to slow the rate of bone growth.


     "The big surprise was an unexpected 300 percent increase in these proteins
within 24 hours after return to Earth," Morey- Holton said. "The response to
reloading must have occurred almost immediately," she said.  Walking or
movement against the force of gravity is known as a load.

     Morey-Holton said re-exposure to Earth's gravity may have caused the cells
to overcompensate for the slowed bone growth during space flight.

     "This suggests that the best time to learn about the initial steps in bone
formation may be within 24 hours after space flight," Morey-Holton said. "The
increase is probably large enough to allow scientists to establish a time
course of events during the 24-hour period," she said.

     "It may be possible to tease out the genes involved in initiating cortical
bone formation.  If you know what the actual trigger is, you should be able to
use that particular message to actually stimulate bone formation," she said.
This, in turn, could lead to development of drug therapy.

     Because rats with unloaded hind limbs on Earth "showed virtually identical
responses to the flight animals" on PARE-3, much additional research can be
done in laboratories on the ground, she said. "This should accelerate the
research, because it eliminates the years of waiting often necessary for a
flight opportunity on the Space Shuttle."