PUBLIC AFFAIRS CONTACTS

For Information on the Space Shuttle

Ed Campion  Policy/Management
202/358-1778
  Headquarters, Wash., D.C.

James Hartsfield    Mission
Operations/Astronauts  713/483-5111
  Johnson Space Center, Houston

Bruce Buckingham  Launch Processing  407/867-2468
  Kennedy Space Center, Fla.  KSC Landing Information

June Malone  External Tank/SRBs/SSMEs  205/544-0034
  Marshall Space Flight
  Center, Huntsville, Ala.

Don Haley  DFRC Landing Information  805/258-3448
  Dryden Flight Research Center,
  Edwards, Calif.

For Information on NASA-Sponsored STS-68 Experiments

Brian Dunbar  SRL-2  202/358-1547
  Headquarters, Wash., D.C.

Mike Braukus  BRIC, CHROMEX  202/358-1979
  Headquarters, Wash., D.C.

Debra Rahn  International Cooperation  202/358-1639
  Headquarters, Wash., D.C.

Charles Redmond  CPCG  202/358-1757
  Headquarters, Wash., D.C.

Tammy Jones  GAS Experiments  301/286-5566
  Goddard Space Flight Center,
  Greenbelt, Md.

For Information on DOD-Sponsored STS-68 Experiments

Dave Hess   CREAM, MAST  713/483-3498
  Johnson Space Center, Houston


CONTENTS

GENERAL BACKGROUND
General Release  3
Media Services Information  6
Quick-Look Facts  7
Shuttle Abort Modes  9
Summary Timeline  10
Payload and Vehicle Weights  11
Orbital Events Summary  11
Crew Responsibilities  12

CARGO BAY PAYLOADS & ACTIVITIES
Space Radar Laboratory-2 (SRL-2)  13
Get Away Special (GAS) Experiments  27

IN-CABIN PAYLOADS
Commercial Protein Crystal Growth (CPCG)  31
Biological Research in Canisters (BRIC)  32
Chromosomes and Plant Cell Division in Space Experiment
(CHROMEX)  32
Cosmic Radiation Effects and Activation Monitor (CREAM)  33
Military Applications of Ship Tracks (MAST)  33

STS-68 CREW BIOGRAPHIES
Michael Baker, Commander (CDR)  34
Terrence Wilcutt, Pilot (PLT)  34
Thomas Jones, Payload Commander (MS4)  34
Steven Smith, Mission Specialist 1 (MS1)  35
Daniel Bursch, Mission Specialist 2 (MS2)  35
Jeff Wisoff, Mission Specialist 3 (MS3)  36

SPACE SHUTTLE PROGRAM INFORMATION
BRIC-01 graphic  37
G-541 graphic  38
N.C. A&T University graphic  39
Upcoming Shuttle Flights  40
Previous Shuttle Missions  41






RELEASE:  94-114


SPACE RADAR LABORATORY MAKES SECOND FLIGHT

        In August 1994, scientists around the world will again be
provided a unique vantage point for studying how the Earth's
global environment is changing when Endeavour begins the STS-
68 Space Shuttle mission.  During the 10 day mission, the
Space Radar Laboratory (SRL) payload in Endeavour's cargo bay
will make its second flight.  The SRL payload, which first
flew during STS-59 in April 1994, will again give scientists
highly detailed information that will help them distinguish
between human-induced environmental changes and other natural
forms of change.  NASA will distribute the data to the
international scientific community so that this essential
research is available worldwide to assist people in making
informed decisions about protecting the environment.

        Leading the STS-68 crew will be Mission Commander Michael
A. Baker, who will be making his third flight.  Pilot for the
mission is Terrence W. Wilcutt, who is making his first
flight.  The four mission specialists aboard Endeavour are
Thomas D. Jones, the Payload Commander, who will be making
his second flight; Steven L. Smith who will be making his
first flight; Daniel W. Bursch, who will be making his second
flight; and Peter J.K. Wisoff, who will be making his second
flight.

        Launch of Endeavour currently is scheduled for no earlier
than August 18, 1994, at 6:54 a.m. EDT.  The planned mission
duration is 10 days, 4 hours, 40 minutes.  With an on-time
launch on August 18, Endeavour's landing would take place at
11:34 a.m. EDT on August 28 at the Kennedy Space Center's
Shuttle Landing Facility.

        The SRL payload is comprised of the Spaceborne Imaging
Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR), and
the Measurement of Air Pollution from Satellite (MAPS).  The
German Space Agency (DARA) and the Italian Space Agency (ASI)
are providing the X-SAR instrument.

        The imaging radar of the SIR-C/X-SAR instruments has the
ability to make measurements over virtually any region at any
time, regardless of weather or sunlight conditions.  The
radar waves can penetrate clouds, and under certain
conditions, also can "see" through vegetation, ice and
extremely dry sand.  In many cases, radar is the only way
scientists can explore inaccessible regions of the Earth's
surface.

        The SIR-C/X-SAR radar data provide information about how
many of Earth's complex systemsQthose processes that control
the movement of land, water, air and lifeQwork together to
make this a livable planet.  The science team particularly
wants to study the amount of vegetation coverage, the extent
of snow packs, wetlands areas, geologic features such as rock
types and their distribution, volcanic activity, ocean wave
heights and wind speed.  STS-68 will fly over the same sites
that STS-59 observed so that scientists will be able to study
seasonal changes that may have occurred in those areas
between the missions.

        An international team of 49 science investigators and
three associates will conduct the SIR-C/X-SAR experiments.
Thirteen nations are represented:  Australia, Austria,
Brazil, Canada, China, the United Kingdom, France, Germany,
Italy, Japan, Mexico, Saudi Arabia and the United States.

        The MAPS experiment will measure the global distribution
of carbon monoxide in the troposphere, or lower atmosphere.
Measurements of carbon monoxide, an important element in
several chemical cycles, provide scientists with indications
of how well the atmosphere can cleanse itself of "greenhouse
gases," chemicals that can increase the atmosphere's
temperature.

        STS-68 will see the continuation of NASA's Get Away
Special (GAS) experiments program.  The project gives a
person or organization a chance to perform experiments in
space on a Shuttle mission.  Two universities, North Carolina
A&T State University and University of Alabama in Huntsville,
and the Swedish Space Corp., Soina, Sweden, will have small
self-contained payloads flying during the STS-68  mission.
Other GAS hardware in Endeavour's payload bay will carry
500,000 commemorative stamps for the U.S. Postal Service in
recognition of the 25th anniversary of the Apollo 11 Moon
landing.

        Other payloads aboard Endeavour include the Biological
Research in Canister (BRIC) which will fly for the first
time, and the Military Applications of Ship Tracks (MAST)
which will be making its second flight.  BRIC experiments,
sponsored by NASA's Office of Life and Microgravity Sciences
and Applications, are designed to examine the effects of
microgravity on a wide range of physiological processes in
higher order plants and arthropod animals (e.g., insects,
spiders, centipedes, crustaceans).  MAST is an experiment
sponsored by the Office of Naval Research (ONR) and is part
of a five-year research program developed by ONR to examine
the effects of ships on the marine environment.

        The Commercial Protein Crystal Growth (CPCG) experiment,
the Chromosome and Plant Cell Division in Space Experiment
(CHROMEX) and the Cosmic Radiation Effects and Activation
Monitor (CREAM) experiment also will be carried aboard
Endeavour.

        Shuttle Mission STS-68 will be the 7th flight of Endeavour
and the 64th flight of the Space Shuttle System.


- end -

MEDIA SERVICES INFORMATION


NASA Television Transmission

        NASA Television is available through Spacenet-2,
Transponder 5, located at 69 degrees west longitude with
horizontal polarization.  Frequency is 3880.0 MHz, audio is
6.8 MHz.

        The schedule for television transmissions from the Shuttle
and for mission briefings will be available during the
mission at Kennedy Space Center, Fla; Marshall Space Flight
Center, Huntsville, Ala.; Dryden Flight Research Center,
Edwards, Calif.; Johnson Space Center, Houston, and NASA
Headquarters, Washington, D.C.  The television schedule will
be updated to reflect changes dictated by mission operations.

        Television schedules also may be obtained by calling
COMSTOR 713/483-5817.  COMSTOR is a computer data base
service requiring the use of a telephone modem.  A voice
report of the television schedule is updated daily at noon
Eastern time.

Status Reports

        Status reports on countdown and mission progress, on-orbit
activities and landing operations will be produced by the
appropriate NASA newscenter.

Briefings

        A mission briefing schedule will be issued prior to
launch.  During the mission, status briefings by a flight
director or mission operations representative and when
appropriate, representatives from the payload team, will
occur at least once per day.  The updated NASA Television
schedule will indicate when mission briefings are planned.



STS-68 Quick Look

Launch Date/Site:       August 18, 1994/KSC Pad 39A
Launch Time:            6:54 a.m. EDT
Orbiter:                        Endeavour (OV-105) - 7th Flight
Orbit/Inclination:      120 nautical miles/57 degrees
Mission Duration:       10 days, 4 hours, 40 minutes
Landing Time/Date:      11:34 a.m. EDT Aug. 28, 1994
Primary Landing Site:   Kennedy Space Center, Fla.
Abort Landing Sites:    Return to Launch Site - KSC, Fla.
                                        TransAtlantic Abort landing -
Zaragoza, Spain;
                                        Moron, Spain; Ben Guerir, Morocco
                                        Abort Once Around - White Sands Space
Harbor,                                           N.M.

STS-68 Crew:            Michael Baker, Commander (CDR)
                                        Terrence Wilcutt, Pilot (PLT)
                                        Thomas Jones, Payload Commander (MS4)
                                        Steven Smith, Mission Specialist 1
(MS1)
                                        Daniel Bursch, Mission Specialist 2
(MS2)
                                        Jeff Wisoff, Mission Specialist 3
(MS3)

                                        Red shift: Baker, Wilcutt, Wisoff
                                        Blue shift: Bursch, Jones, Smith


Cargo Bay Payloads:     Space Radar Laboratory-2 (SRL-2)
                                        Get Away Special canisters (GAS cans)

Middeck Payloads:       Commercial Protein Crystal Growth (CPCG)
                                        Biological Research in Canisters
(BRIC)
                                        Cosmic Radiation Effects and
Activation Monitor                                        (CREAM)
                                        Military Applications of Ship Tracks
(MAST)


Detailed Test Objectives/Detailed Supplementary
Objectives:

        DTO 251:        Entry Aerodynamic Control Surfaces Test
        DTO 254:        Subsonic Aerodynamics Verification
Objectives
        DTO 301D:       Ascent Structural Capability Evaluation
        DTO 305D:       Ascent Compartment Venting Evaluation
        DTO 306D:       Descent Compartment Venting Evaluation
        DTO 307D:       Entry Structural Capability Evaluation
        DTO 312:        External Tank Thermal Protection System
Performance
        DTO 414:        Auxiliary Power Unit Shutdown Test
        DTO 521:        Orbiter Drag Chute System Test
        DTO 656:        PGSC Single Event Upset Monitoring
        DTO 664:        Cabin Temperature Survey
        DTO 700-8:      Global Positioning System Flight Test
        DTO 805:        Crosswind Landing Performance
        DSO 317:        Shuttle Humidity Condensate
Collection/Evaluation
        DSO 326:        Window Impact Observations
        DSO 484:        Assessment of Circadian Shifting in
Astronauts by Bright                              Light
        DSO 487:        Immunological Assessment of Crewmembers
        DSO 491:        Characterization of Microbial Transfer
Among
                                  Crewmembers During Spaceflight
        DSO 603B:       Orthostatic Function During Entry, Landing
and Egress
        DSO 604:        Visual-Vestibular Integration as a Function
of Adaptation
        DSO 605:        Postural Equilibrium Control During
Landing/Egress
        DSO 614:        The Effect of Prolonged Spaceflight on Head
and Gaze                                Stability During Locomotion
        DSO 621:        In-Flight Use of Florinef to Improve
Orthostatic                                       Intolerance
Postflight
        DSO 624:        Pre and Postflight Measurement of
Cardiorespiratory                               Responses to
Submaximal Exercise
        DSO 626:        Cardiovascular and Cerebrovascular
Responses to Standing                             Before and After
Spaceflight
        DSO 901:        Documentary Television
        DSO 902:        Documentary Motion Picture Photography
        DSO 903:        Documentary Still Photography



SPACE SHUTTLE ABORT MODES

        Space Shuttle launch abort philosophy aims toward safe and
intact recovery of the flight crew, Orbiter and its payload.
Abort modes include:

        * Abort-To-Orbit (ATO) -- Partial loss of main engine
thrust late enough to permit reaching a minimal 105-nautical
mile orbit with orbital maneuvering system engines.

        * Abort-Once-Around (AOA) -- Earlier main engine
shutdown with the capability to allow one orbit around before
landing at White Sands Space Harbor, N.M.

        * TransAtlantic Abort Landing (TAL) -- Loss of one or
more main engines midway through powered flight would force a
landing at either Zaragoza, Spain; Moron, Spain; or Ben
Guerir, Morocco.

        * Return-To-Launch-Site (RTLS) -- Early shutdown of
one or more engines, and without enough energy to reach
Zaragoza, would result in a pitch around and thrust back
toward KSC until within gliding distance of the Shuttle
Landing Facility.

        STS-68 contingency landing sites are the Kennedy Space
Center, White Sands, Zaragoza, Moron and Ben Guerir.





STS-68 Summary Timeline


Flight Day One
Ascent
OMS-2 burn (120 n.m. x 120 n.m.)
SRL-2 activation/operations

Blue Flight Days Two-Seven
SRL-2 operations
   - SIR-C/X-SAR Radar Imaging
   - MAPS Carbon Monoxide Survey

Red Flight Days Two-Seven
SRL-2 operations
   - SIR-C/X-SAR Radar Imaging
   - MAPS Carbon Monoxide Survey

Blue Flight Day Eight
SRL-2 operations
   - SSIR-C/X-SAR Interferometry
   - MAPS Carbon Monoxide Survey

Red Flight Day Eight
SRL-2 operations
   - SIR-C/X-SAR Interferometry
   - MAPS Carbon Monoxide Survey

Blue Flight Day Nine W RESPONSIBILITIES

TASK/PAYLOAD            PRIMARY         BACKUPS/OTHERS

Shift CDR                               Baker (red)     Bursch (blue)

Payload CDR                     Jones
SRL-2                           Wisoff (red)    Jones (blue)
GAS Cans                                Baker (red)     Smith (blue)

Secondary Payloads:

CPCG                            Smith           Wilcutt
CHROMEX                         Smith           Wilcutt
CREAM                           Wilcutt                 Bursch
BRIC                                    Baker           Wilcutt
MAST                            Bursch          Baker

Detailed Supplementary/Test Objectives:

Medical DSOs                    Bursch          Baker
DTO 251                         Wilcutt                 Baker
DTO 312                         Jones           Smith
DTO 326                         Wilcutt                 Baker
DTO 414                         Wilcutt                 Bursch
DTO 521                         Baker           Wilcutt
DTO 656                         Wisoff          Jones
DTO 664                         Smith           Wisoff
DTO 700-8                       Bursch          Jones
DTO 805                         Baker           Wilcutt

Other:

Photography/TV                  Wisoff          Smith
In-Flight Maintenance           Wisoff          Smith
EVA                                     Wisoff (EV1)    Smith (EV2),
Wilcutt (IV)
Earth Observations              Wisoff          Wilcutt
Geography                               Smith           Wilcutt
Oceanography                    Bursch          Baker
Meteorology                     Smith           Bursch
Medical                         Bursch          Baker


SPACE RADAR LABORATORY-2 (SRL-2)

SIR-C/X-SAR

Mission Objectives

        As part of NASA's Mission to Planet Earth, SIR-C/X-SAR is
studying how our global environment is changing.  From the
unique vantage point of space, the radar system will observe,
monitor and assess large-scale environmental processes.  The
spaceborne data, complemented by aircraft and ground studies,
will give scientists highly detailed information that will
help them distinguish natural environmental changes from
those that are the result of human activity.  NASA will
distribute the Mission to Planet Earth data to the
international scientific community so that this essential
research is available worldwide to people who are trying to
make informed decisions about protecting the environment.

        SIR-C/X-SAR is also a part of the continuing efforts by
DARA, the German Space Agency, and ASI, the Italian Space
Agency, in the field of Earth observations.

Why Radar?

        The unique feature of imaging radar is its ability to
collect data over virtually any region at any time,
regardless of weather or sunlight conditions.  Some radar
waves can penetrate clouds, and under certain conditions, can
also see through vegetation, dry snow and extremely dry sand.
In many cases, radar is the only way scientists can explore
inaccessible regions of Earth's surface.

        Radar is a lowercase acronym for "radio detection and
ranging."  A synthetic aperture radar transmits pulses of
microwave energy toward Earth and measures the strength and
time-delay of the energy that is scattered back to the
antenna.  In the case of SIR-C/X-SAR, the motion of the
Shuttle creates, or synthesizes, an antenna opening, or
aperture, that is much longer than the actual antenna
hardware.  A longer antenna produces images of finer
resolution.

        Conditions on the Earth's surface influence how much radar
energy is reflected back to the antenna.  An area with a
variety of surface types, such as hills, trees and large
rocks, will generally reflect more energy back to the radar
than a less complex area such as a desert.  The resulting
radar image of the varied terrain will be brighter overall
and have higher contrasts than the image of the simpler area.
The three frequencies of SIR-C/X-SAR will enable scientists
to view three different scales of features in the images.


Results of STS-59

        Flying aboard STS-59 in April 1994, SIR-C collected 65
hours of data during the 10-day mission, roughly
corresponding to 26 million square miles (66 million square
kilometers).  All data were stored onboard the Shuttle using
a new generation of high density, digital, rotary head tape
recorders.  The data filled 166 digital tape cartridges
(similar to VCR tape cassettes).  X-SAR data filled 25 of
those tapes.

        The mission returned 47 terabits of data (47 x 1012 bits).
Stated another way, each of the radars generates 45 million
bits of data per second.  When all the radars are operating,
they produce 225 million bits of data per second, the
equivalent of 45 simultaneously operating television
stations.  Using JPL's digital SAR processor and German-
Italian X-SAR processors, the ground team processed the raw
data into images.

        High-priority SIR-C data were downlinked, processed, and
released to the science team via the Internet within 24 hours
of collection.  The payload operations team processed the
SIR-C data in survey mode and displayed it during the mission
on NASA Television.

Science

        The STS-59 mission achieved 100 percent of the SIR-C/X-SAR
science objectives.  The SRL-1 team completed 850 data takes,
97% of those planned.  The team acquired 99% of the
"supersite" opportunities over highest priority targets.  The
94 hours of radar imagery were obtained over 44 countries,
covering 43.75 million square miles (70 million square
kilometers).  In addition to taking high-resolution data at
all of the planned sites, the science team was able to adjust
the mission timeline and observe events as they were
happening on the ground.  SIR-C/X-SAR took data of the severe
flooding that inundated the mid-western United States and
Thringen, Germany, as well as three different views of
tropical Cyclone Odille as it formed in the Pacific Ocean.
Scientists also acquired a series of radar images over Canada
documenting the annual spring thaw of snow, ice and soil.

        Scientists use SIR-C/X-SAR data to study how our global
environment is changing.  The SIR-C/X-SAR radar data provides
information about how many of Earth's complex systemsQthose
processes that control the movement of land, water, air and
lifeQwork together to make this a livable planet.  The
science team particularly wants to study the amount of
vegetation coverage, the extent of snow packs, wetlands
areas, geologic features such as rock types and their
distribution, volcanic activity, ocean wave heights and wind
speed.  STS-68 will fly over the same sites that STS-59
observed so that scientists will be able to study seasonal
changes that may have occurred in those areas between the
missions.

        Data will be taken over more than 400 sites on Earth.
Nineteen of the sites are "supersites," the highest priority
targets and the focal point for many of the scientific
investigators.  There are 15 backup supersites.  If problems
should occur during the flight that would drastically reduce
the team's ability to collect data, the supersite data will
take precedence over other data acquisition.

        During STS-59 the scientists who were working in the
Payload Operations Control Center in Houston were in daily
communication with the researchers who were part of the
"ground truth" teams.  The ground teams at several of the
supersites made simultaneous measurements of vegetation, soil
moisture, sea state, snow and weather during the mission.
Aircraft and ships also collected data to ensure an accurate
interpretation of the radar data taken from space.  In
addition, the astronauts recorded their personal observations
of weather and environmental conditions in coordination with
SIR-C/X-SAR operations.

Supersites

        The supersites represent different environments within
each scientific discipline.  They are areas where intensive
field work will occur before, during and after the flight.

Ecology

Supersites:  Manaus, Brazil; Raco, Mich.; Duke Forest, N.C.

        Ecologists study life on Earth and how different species
of animals and plants interact with one another and their
local environment.  SIR-C/X-SAR ecology investigations focus
on mapping wetlands, deforestation and flooding under forest
canopies over the tropical forests of the Amazon basin in
South America and over the temperate forests of North America
and Central Europe.  Scientists also are studying wetlands
and are using the data to validate computer models to
determine the type and density of vegetation and to study
seasonal thaws.  The science team will use the images to
study land use, including the volume, types and extent of
vegetation and the effects of fires, floods and clear-
cutting.

        Using early-release data, science team members have
already generated both tree classification and vegetation
biomass maps of the Raco, Michigan site and a freeze/thaw map
over the Prince Albert, Saskatchewan backup supersite.  A map
of flooding near Manaus, Brazil also has been produced as a
step toward improving models and our understanding of
flooding and wetlands under dense forest canopies.

        SIR-C/X-SAR's three radar frequencies interact with the
vegetation in different ways, providing views of different
parts of the forest.  The shortest wavelength (X-band),
reflects from the leaves of trees.  C-band microwaves reflect
from twigs and branches, and L-band wavelengths reflect from
the trunks of trees.  These data give scientists a clearer
picture of the conditions on the ground.

        The science team will study seasonal changes in the forest
by comparing data from the two SIR-C/X-SAR flights.  For
example, data from two previous imaging radar missions showed
a decrease in forests along the Mississippi River between
1978 and 1981.  Deforestation threatens both temperate and
tropical forests around the world.  SIR-C/X-SAR data and
ground data will be used to understand the impact of the loss
of forests on local populations of plants and animals.  By
studying the short-term and long-term changes in forests,
scientists can determine what effects changing environmental
conditions and land uses have on the forests and, in turn, on
global climate change.

Hydrology

Supersites:  Chickasha, Oklahoma; Otztal, Austria; Bebedouro,
Brazil; Montespertoli, Italy

        SIR-C/X-SAR hydrology investigations are focused on
Brazil, Austria, Italy and Oklahoma, where the radar data
will be used to determine soil moisture patterns.  These
studies will help scientists develop ways to estimate soil
moisture and evaporation rates over large areas, which could
ultimately be incorporated into computer models to help
predict a region's water cycle.

        Another significant part of hydrology centers on snow
cover.  Using data from STS-59, investigators generated a
snow and ice classification map over the Oetztal, Austria,
supersite and a snow-wetness map of the Mammoth Mountain,
Calif., backup supersite.  Spring snow melt often determines
the annual runoff cycle and the resulting water supply,
ground water and reservoir replenishment rates.  For many
areas, long-term or ground-based snow cover data do not
exist, and radar data is the only efficient way to collect
this information.

        SIR-C/X-SAR acquired snow cover data over Mammoth Lakes,
Calif., the Austrian Alps and northwest China.  The shorter
wavelength X-band data are useful in determining snow type,
while the longer wavelengths of L-band and C-band help
estimate snow thickness.  These data might help communities
determine how much water will be available for human and
agriculture use.  In August, this investigation's emphasis
will shift to the Patagonian district in southern Chile,
which contains the largest glaciers and ice fields in South
America.

Oceanography

Supersites:  The Gulf Stream (mid-Atlantic region);  eastern
North Atlantic Ocean; Southern Ocean

        Oceanographers study how waves move through the ocean and
how the air and sea interact.  The ocean is a reservoir for
heat and energy, and the air-sea interaction moves this heat
and energy around the globe regulating the Earth's climate.
The Gulf Stream off the eastern coast of North America is a
major ocean current that transports heat from the equator
toward the poles.

        The relatively low altitude of the Shuttle is particularly
advantageous for oceanography investigations since the SIR-
C/X-SAR radars are more sensitive to ocean features than
satellites in higher orbits.  Oceanographers are using data
from SIR-C/X-SAR to study surface and internal waves and the
interactions of waves and current.  In addition, an
associated experiment provided by the Applied Physics
Laboratory of the Johns Hopkins University, Baltimore, Md.,
collected extensive information on wave energy over the
Southern Ocean.  These data will help scientists study how
the ocean moderates Earth's climate.

Geology

Supersites:  Galapagos Islands; Sahara Desert; Death Valley,
Calif.; Andes Mountains, Chile

        Geologists study the present surface of the Earth.  By
observing older rocks they can determine how an area came to
be and what it may have looked like in the past.  Scientists
are using SIR-C/X-SAR data to map geologic structures and
variations in rock types over large areas, as well as areas
of volcanic activity and erosion.

        The longer L-band radar wavelength is particularly useful
for looking beneath surfaces.  SIR-C/X-SAR obtained
penetration data of the Sahara desert that show stream
channels and a larger river valley beneath an extensive sand
sheet.  On the ground and in photographs, this big valley and
the channels in it are entirely covered by windblown sand.
SIR-A observed some of these channels in 1981.  Scientists
hypothesize that an ancient westward-flowing river carved the
large valley, tens of millions of years before the Nile River
existed.  The Nile flows north about 200 miles (300
kilometers) east of the area observed by the radar.

        The existence of hidden river channels indicates that
portions of the Sahara have undergone significant climate
change and have evolved from an area of flowing streams to
what is now an arid desert.  SIR-C/X-SAR also is  studying
other geologic features that record past climate changes.

        In areas of Death Valley, Calif., western China and the
Patagonia region of the southern Andes, the radar imaged
alluvial fans.  Alluvial fans are gravel deposits that erode
and wash down from the mountains.  They are found throughout
the semi-arid deserts of the world in areas where there is a
significant amount of tectonic activity and erosion.  The
gravel builds up at the base of the mountains during periods
of overall wetter climate.  The radar is sensitive to these
rocky and rough surfaces, allowing scientists to study an
area's climatic and geologic history and the relative age of
surfaces.  As an area ages, it is exposed to weathering.
This changes its roughness characteristics.  Studying past
climate changes will give scientists a base from which to
monitor and predict future climate changes.

        During STS-59, SIR-C/X-SAR acquired radar images of
several volcanoes, including Mount Pinatubo in the
Philippines and the volcanoes of the Galapagos Islands.
These radar images are helping scientists identify the
different types of lava flows and their ages and assess
environmental risks posed by the volcanoes.  A key objective
of STS-68 will be to obtain a second image of Mount Pinatubo
during the summer monsoon season, when new mudflows are
likely to occur, and to evaluate whatever short-term changes
may have taken place.

Calibration

Supersites:  Flevoland, The Netherlands; Kerang, Australia;
Oberpfaffenhofen, Germany; Western Pacific Ocean

        The ground teams placed calibration devices, called corner
reflectors, and transponders  in southern Germany, the
Netherlands, Australia and Death Valley, Calif., to measure
the amount of radar energy obtained on the ground during the
flight.  The teams are investigators hope to generate digital
elevation models (topography) of the Earth's surface.  Once
topography is determined, a third interferometric pass can be
used to determine what, if any, topographic change has
occurred in the intervening time between radar passes.

        The focus of these experiments is to improve our
understanding of natural hazards such as  flooding,
subsidence, mudflows, earthquakes and volcanic eruptions.
For example, the topography of mountain glaciers is important
because it directly reflects ice-flow dynamics and is closely
linked to global climate and sea level change.  Monitoring
mountain glaciers on a global, long-term basis could give
scientists important information on the rate of global
warming.  In addition, the use of topographic data may help
reduce the risk of natural disasters by monitoring volcanoes,
flooding and earthquake-prone faults.

Spaceborne Imaging Radar C/X-Band Synthetic Aperture
Radar
(SIR-C/X-SAR)

        SIR-C/X-SAR is a sophisticated set of radars that fills
nearly all of Endeavour's cargo bay.  SIR-C, built by the Jet
Propulsion Laboratory (JPL) Pasadena, Calif., and the Ball
Communications Systems Division, is a two-frequency radar
including L-band (9-inch, or 23-cm, wavelength) and C-band
(2.4-inch, or 6-cm wavelength).  SIR-C is the first
spaceborne radar with the ability to transmit and receive
horizontally and vertically polarized waves at both
frequencies.  The multi-frequency, multi-polarization
capability creates a new and more powerful tool for studying
the world.  A good way to understand this is to think of
visual images:  Just as color pictures have more information
about a subject than black and white pictures, multi-
frequency, multi-polarization radar images contain more
information about the surface than single frequency, single
polarization radar images.

        The SIR-C antenna is the most massive piece of flight
hardware ever built at JPL.  Its mass is 16,100 pounds (7,300
kg) and it measures 39.4 feet by 13.1 feet (12 meters by 4
meters).  The instrument comprises several subsystems:  the
antenna array, the transmitter, the receivers, the data-
handling subsystem and the ground processor.  The antenna
consists of three leaves, and each is divided into four
subpanels.

        Hundreds of small transmitters embedded in the surface of
the antenna form the radar beam.  By adjusting the energy
from these transmitters, the payload operations team can
point the beam electronically, without moving the antenna.
This feature, combined with the roll and yaw maneuvers of the
Shuttle, will allow the team to acquire images from 15-to 55-
degree angles of incidence.

        Advances in radar technology will allow SIR-C to acquire
simultaneous images at L-band and C-band frequencies at
multiple polarizations.  Polarization describes how the radar
wave travels in space.  For example, for HH-polarized data,
the antenna transmits energy in the horizontal plane and
receives the backscattered radiation in the horizontal plane.
For HV polarization, the wave is transmitted horizontally,
but is received in the vertical plane.  The interaction
between the transmitted waves and the Earth's surface
determines the polarization of the waves received by the
antenna.

        Multi-polarization data contain more specific information
about surface conditions than single polarization data.
Multi-polarization data are particularly useful to scientists
studying vegetation because the data allow them to see
different types of crops and to measure the volume of trees
contained under the canopy of a forest.  SIR-C can acquire
data with HH, VV, HV, and VH polarizations.

        X-SAR was built by the Dornier and Alenia Spazio companies
for the German Space Agency, Deutsche Agentur fuer
Raumfahrtangelegenheiten (DARA), and the Italian Space
Agency, Agenzia Spaziale Italiana (ASI), with the Deutsche
Forschungsanstalt fr Luft- und Raumfarht (DLR) as a major
partner.  It is a single-polarization radar operating at X-
band (1-inch, or 3-centimeter wavelength).

        X-SAR uses a finely tuned slotted waveguide antenna to
produce a pencil-thin beam of energy.  The X-SAR antenna
rests on a supporting structure that is tilted mechanically
to align the X-band beam with the L-band and C-band beams.
X-SAR will provide VV polarization images.

        The payload team can operate SIR-C and X-SAR independently
or together.  When combined into a three-frequency, multi-
polarization instrument, SIR-C/X-SAR becomes the most
powerful civilian radar ever flown in space.  The width of
the ground swath varies from 9 to 56 miles (15 to 90
kilometers), depending on the orientation of the antenna
beams.  The resolution of the radars varies from 33 to 656
feet (10 to 200 meters).

Previous Radar Missions

        Since the late 1970s a variety of NASA satellite missions
have used imaging radar to study Earth and our planetary
neighbors.  Perhaps the most familiar example of NASA's
success using imaging radar is the Magellan mission to Venus.
Magellan's radar pierced the dense clouds covering Venus to
map the entire surface of the planet, revealing a world
hidden to humans until the late 20th century.

        SIR-C is the latest in a series of Earth observing imaging
radar missions that began in June 1978 with the launch of
Seasat SAR and continued with SIR-A in November 1981 and with
SIR-B in October 1984.  Both the SIR-A and SIR-B sensors
built upon the Seasat SAR, and all three could transmit and
receive horizontally polarized radiation at L-band frequency.

        The major difference between the Seasat and SIR-A sensors
was the orientation of the radar's antenna with respect to
Earth's surface.  Microwave radiation transmitted by Seasat
struck the surface at a fixed angle of approximately 23
degrees from the local zenith direction.  SIR-A viewed the
surface at a fixed 40-degree angle.

        SIR-B improved upon both those missions because its
antenna could be mechanically tilted.  This allowed SIR-B to
obtain multiple radar images of a given target at different
angles during successive Shuttle orbits.

        The X-SAR antenna is a follow-on to Germany's Microwave
Remote
Sensing Experiment (MRSE), which flew aboard the first
Shuttle Spacelab mission in 1983.

        These early missions had a tremendous impact on the
international remote sensing community when SIR-A discovered
ancient river beds hidden beneath the sands of the Sahara,
and SIR-B data led explorers to the Lost City of Ubar in
Oman.

Data Acquisition Plans for STS-68

        Portions of the SIR-C/X-SAR data will be downlinked to the
ground in near-real time through NASA's Tracking and Data
Relay Satellite System (TDRSS).  However, only one channel of
data can be downlinked or played back at a time.  This is not
a problem for X-SAR since it only has one channel of data.
SIR-C has up to four channels of data, and each channel must
be played back separately.  The payload teams will process
the data in images using digital SAR processors in Pasadena,
Calif., Oberpfaffenhofen, Germany, and Matera, Italy.

        Historically, processing SAR data has required a great
deal of computer time on special-purpose computer systems.
SIR-C/X-SAR scientists will benefit, however, from rapid
advances in computer technology that make it possible to
process the images with a standard parallel supercomputer.
Yet even with these advances, it will still take five months
to produce survey images from the large volume of data
acquired.  Detailed processing will take another nine months.
Italy, Germany and the United States will exchange data to
meet the needs of the science investigators.

        NASA, DARA and ASI will attempt to release some radar
images to the press during the Shuttle flight.  JPL will
process SIR-C images and send them over the Internet to the
Johnson Space Center, where the image will be released on
NASA Television.  JPL also will release hard-copy prints
simultaneously to the wire services.  In Germany, DLR will
process X-SAR imagery.  In addition, X-SAR "quick look" data
will be available for release over NASA Television.

Science Team

        An international team of 49 science investigators and
three associates will conduct the SIR-C/X-SAR experiments,
representing 13 nations:  Australia, Austria, Brazil, Canada,
China, England, France, Germany, Italy, Japan, Mexico, Saudi
Arabia and the United States.

        Dr. Diane Evans of JPL is the U.S. project scientist.  Dr.
Herwig Ottl of DLR is the German project scientist and Prof.
Mario Calamia of the University of Florence is the Italian
project scientist.  Dr. Miriam Baltuck of NASA's Office of
Mission to Planet Earth is the program scientist.

Management

        JPL manages the SIR-C mission for NASA's Office of Mission
to Planet Earth, Washington, D.C.  Michael Sander is the JPL
project manager.  X-SAR is managed by the Joint Project
Office (JPO) located near Bonn, Germany.  Rolf Werninghaus of
DARA is the project manager and Dr. Paolo Ammendola of ASI is
the deputy project manager.  James McGuire of the Office of
Life and Microgravity Sciences and Applications, Washington,
D.C., is the SRL program manager.  Richard Monson of the
Office of Mission to Planet Earth is the SIR-C program
manager.


MEASUREMENT OF AIR POLLUTION FROM SATELLITES (MAPS)

        The MAPS experiment measures the global distribution of
carbon monoxideQan important indicator of the atmosphere's
ability to cleanse itself of greenhouse gases and pollutantsQ
in the lower atmosphere (2 to 10 miles above the surface).
Covering the Earth between 57 degrees North latitude and 57
degrees South latitude, the MAPS measurements provide the
only near-global database of lower-atmosphere carbon monoxide
values available to scientists.

        Preliminary results from the April 1994 MAPS flight aboard
STS-59 showed low carbon monoxide concentrations in the
Southern Hemisphere (very clean air) with a gradual increase,
moving northward, in carbon monoxide levels.  The highest
levels of carbon monoxide were present north of the 40 degree
latitude band in the Northern Hemisphere.  The MAPS
measurements will be correlated with ground- and aircraft-
based carbon monoxide measurements, astronaut observations
and photography, and meteorological data analyses and
satellite images.

        MAPS' unique measurements of carbon monoxide, a gas
produced by the burning of gasoline and other carbon-based
fuels, provide scientists with indications of how well the
atmosphere can cleanse itself of these pollutants. How far
pollutants such as carbon monoxide are transported from their
source regions and the size of the source regions are two
other invaluable pieces of information provided by the MAPS
measurements.

        Because MAPS is being flown twice this year, scientists
will be able to examine seasonal differences in the
distribution of carbon monoxide.  This will be especially
valuable to scientists studying the transportation of
industrial pollutants in the Northern Hemisphere and biomass
burning in the tropics and Southern Hemisphere.

        The STS-68 flight will occur during the Southern
Hemisphere's dry season (June-October), when the maximum
amount of biomass burning, such as clearing forests for
agriculture uses, occurs.  The dry season carbon monoxide
levels from this flight will be compared to data from the wet
season (April 1994) flight.  The MAPS measurements also will
be compared to data from previous dry-season MAPS flights
(November 1981 and October 1984).

Why do we measure carbon monoxide?

        World-wide increases in human technological and
agricultural activity are causing increasing amounts of
carbon monoxide to be released into the atmosphere.  Carbon
monoxide, a colorless and odorless gas, is produced by the
burning of carbon-based fuels and by the burning of forests
and grasslands.

        Once released into the atmosphere, carbon monoxide can be
transported over long distances, eventually converting to
carbon dioxide by reacting with a chemical called the
hydroxyl radical (chemical symbol:  OH).  The OH radical is a
key participant in the destruction and removal of greenhouse
gases such as methane.  Methane also is important in the
chemical cycle of stratospheric ozone.

        As the amount of carbon monoxide in the atmosphere
increases, its reactions with the OH radical increase
accordingly.  These reactions may leave less OH available to
break down and remove greenhouse gases, chemicals that can
trap heat near the Earth's surface, increasing atmospheric
temperatures.  Therefore, increases in carbon monoxide levels
may cause subsequent decreases in OH levels, which can have
long-term consequences on stratospheric ozone and the levels
of various greenhouse gases, potentially influencing the
Earth's climate.

Data Collection and Processing

        The primary goal of the MAPS experiment is to measure the
distribution of carbon monoxide in the atmosphere between the
altitudes of 2 to 10 miles (4 to 15 kilometers).  The MAPS
measurements will be stored on a tape recorder aboard the
instrument and also will be transmitted to the ground in
real-time through the Space Shuttle telemetry system.  The
real-time data transmissions will be processed at the Payload
Operations Control Center to produce "quick look" maps of the
measured carbon monoxide distribution.  The "quick look"
maps, along with real-time observations by the astronaut
crew, will be used to determine areas of special interest,
such as large areas of  biomass burning.

        An infrared camera attached to the MAPS instrument will
take pictures of each region of the Earth being measured
during the first half of the flight. The astronaut crew also
will keep watch for any signs of industrial pollution (smoke
stacks, gas flares from oil fields, etc.) and for smoke and
fires caused by biomass burning.  Real-time observations by
the astronaut crew and the analysis of astronaut and MAPS
instrument photographs, will play a crucial role in
understanding the measurements from the MAPS experiment.

        Following the flight, the data recorded aboard the
instrument and the data transmitted to the ground in real-
time will be merged, then processed using more sophisticated
techniques than the preliminary ("quick look") MAPS data.  In
addition, the MAPS measurements will be correlated with a
global network of intercalibrated ground- and aircraft-based
measurements. To ensure the accuracy of the ground and
aircraft measurements, all the ground sites will be using the
same four gas cylinders to calibrate their instruments.  This
ensures that all the ground sites have the same calibration
standard (that they are 'intercalibrated') and allows for the
intercomparison of carbon monoxide data measured by dozens of
different instruments around the world.

        The 25 ground sites include locations in the United
States, South Africa, Russia, Germany, Bermuda, Ireland, Hong
Kong, Australia, and New Zealand. The aircraft underflights
of the MAPS instrument include the NASA DC-8, and aircraft
from INPE, Brazil; CSIRO, Australia; the University of
Maryland; and the National Oceanic and Atmospheric
Administration in Boulder, Colo.

Results From Previous Flights

        MAPS, the first Space Shuttle science payload, has flown
three times:  in November 1981 (STS-2), October 1984 (STS-
41G) and April 1994 (STS-59).  The 1981 flight proved
surprising because the greatest concentrations of
tropospheric carbon monoxide were found in the Earth's
tropical regions rather than in the industrialized Northern
Hemisphere as had been expected.  The 1981 flight also showed
that carbon monoxide concentrations vary greatly from region
to region.

        The October 1984 flight confirmed the November 1981
finding that the burning of forests in South America and
grasslands in Africa is a significant source of global
tropospheric carbon monoxide during the Southern Hemisphere
spring (dry season).

        Preliminary results from the April 1994 flight show low
carbon monoxide concentrats a day.
The information is available via DOS, MAC, and UNIX
platforms.  This information will be updated weekly prior to
the SRL-2 launch with updates during the mission as time
allows.

        The information can be accessed through NCSA Mosaic (an
Internet information browser and World Wide Web client).  For
information on obtaining Mosaic software or help using it
please send electronic mail to:

        mosaic@ncsa.uiuc.edu

        For those who already have Mosaic, to access the Mosaic
MAPS home page directly, click on the File button in the
header at the top of the Mosaic home page; click on Open;
type in URL to open: http://stormy.larc.nasa.gov/press.html;
click on Open.

        For more information on the MAPS home page please contact:

        Scott Nolf: s.r.nolf@larc.nasa.gov

The MAPS Instrument

        The MAPS flight hardware consists of an optical box, an
electronics box, a tape recorder and a camera, all mounted to
a single baseplate.  This assembly is mounted to a Multi-
Purpose Experiment Support Structure near the forward end of
the cargo bay.  The instrument is about 36 inches long, 30
inches wide, and 23 inches high.  It weighs 203 pounds and
consumes about 125 watts of electrical power.

        The Program Manager is Louis Caudill, and Dr. Robert J.
McNeal is the Program Scientist, both at NASA Headquarters,
Washington,D.C.  The MAPS Principal Investigator is Dr. Henry
G. Reichle, Jr., and the Project Manager is John Fedors, both
at NASA Langley Research Center in Hampton, Va.


GET AWAY SPECIALS

        Two universities and a foreign country have small self-
contained payloads flying on this mission.  These customers
are taking advantage of NASA's unique Get Away Special (GAS)
program.  GAS, managed by the Goddard Space Flight Center
(GSFC), Greenbelt, Md., provides an opportunity for anyone in
the world to access space.

        The GAS program presents an excellent educational tool for
students.  Individuals and organizations are able to send
scientific research and development experiments into space
aboard the Space Shuttle.   So far, more than a hundred GAS
payloads have flown on the Shuttle.  Customers flying
payloads on this mission include:  G-316, North Carolina A&T
University; G-503, University of Alabama in Huntsville; G-
541, Swedish Space Corp.  Following is a brief description of
each.

G-316
Customer:  North Carolina A&T State University,
Greensboro, NC
Customer:  Dr. Stuart Ahrens
NASA Technical Manager:  Charlie Knapp

        This payload contains two experiments designed to take
advantage of the microgravity environment of the orbiting
Shuttle.  The first is a biology experiment that will study
the effects of microgravity on the survival, mating and
development of the milkweed bug.  The second is a chemistry
experiment that will use the microgravity environment to
improve the growth quality and size of a crystal of rochelle
salt.

        The entire payload weighs 100 pounds (45.36 kilograms) and
fits in an airtight cylindrical canister which is mounted out
in the payload bay of the orbiter.  The payload is entirely
self-contained and automated except for two relays that are
controlled from the orbiter by the crew.  Approximately half
of the payload weight is due to batteries needed to control
the experiments and keep the payload warm.

        The payload was conceived, designed and fabricated
entirely by students in the university's Student Space
Shuttle Program (SSSP).  The SSSP owes its beginning to the
late North Carolina A&T graduate and astronaut, Dr. Ronald E.
McNair.  More than 100 students representing 12 different
majors have participated in the SSSP.  The SSSP has received
support in excess of $500,000 from more than 25 outside
organizations, including Fortune 500 corporations.  This
support has been in the form of funds, consultation and
payload parts.

        In addition to the primary goal of conceiving, designing
and fabricating the payload, the SSSP has a number of
secondary goals that are very important.  These secondary
goals are:  to enhance the classroom experience by placing
students in a real world project; to develop in students a
strong sense of professionalism about their work; to have
students interface with the high technology of the Space
Shuttle; and to motivate students to pursue Dr. McNair's
dream.

        When G-316 is launched aboard Endeavour in August, a
number of tributes to Dr. McNair also will be on board.
Attached to the outside of the payload's canister will be a
large emblem in the university's colors.  Included in the
emblem will be the university's name and mascot and the
inscription "Dr. Ron McNair, 1950-1986."  Also in the
orbiter's cabin will be two special 8x10 color photos, one of
the Challenger crew anl
structure (silicon dioxide) will be performed that will
provide information about changes in cell metabolism.  The
results will be compared against ground experiments operating
simultaneously to determine the cause of any observed
changes.

        Experiment #2:  The Concrete Curing In Microgravity
(ConCIM) experiment is designed to give scientists and
engineers valuable data about the feasibility of mixing and
curing concrete in a microgravity environment.  This data
would be extremely valuable for future moon base
applications.   The concrete, cured for at least seven days
in microgravity, will develop most of its ultimate chemical
and physical properties.  Once the experiment has been
recovered, testing and material analysis will be performed to
determine the chemical composition, the pore structure and
strength of the space concrete.  Test results will be
compared to data obtained from a ground-based control sample
of concrete, mixed and cured under similar conditions to
determine the effect of the gravitational differences.

        Experiment #3:  The Root Growth In Space (RGIS)
experiment will study effects of microgravity on the early
stages of germination of several seed types.  The specific
effects to be examined include production of gases during
germination and the development and distribution of chemicals
and hormones as they are affected by gravity.

        Experiment #4:  The Microgravity Corrosion Experiment
(COMET) is designed to examine the effects of microgravity on
the mutation and growth of pitting in metals.  Pitting is an
extremely localized corrosion phenomenon which initiates on
exposed surfaces and results in holes in the metal.  It is
one of the most destructive and insidious forms of corrosion
and usually occurs in metal systems that exhibit a passive
layer.  Its effects are particularly vicious because it is a
localized and intense form of corrosion, and failures often
occur with extreme suddenness.  Also, unlike many types of
corrosion, pitting is difficult to predict.

        COMET will attempt to induce pitting in a stainless steel
samplTechnical Manager:  Barbara Milner

        The purpose of this experiment is to study the breakdown
of a planar solid/liquid interface during crystal growth.  A
sample of Germanium treated with Gallium will be processed
during the flight.

        The experiment is performed in a gradient furnace.  In
this furnace, which was developed for the previous G-330
flight, the growth rate can be controlled along the length of
the crystal.  The furnace is designed with electro-dynamic
control of the temperature with a gradient moving along the
sample.

        First the sample is heated up, melted and a controlled
temperature gradient of 20 degrees Celsius is established.
It is important to keep a short part of the sample solid
because this part acts as a monocrystal seed.  Subsequently
the absolute temperature is decreased but the temperature
gradient is maintained.  The rate of the solidification front
is kept constant at approximately 1 mm/sec.  The dopant (an
impurity added to a pure substance to produce a deliberate
change) concentration alonements and a            cooler
        *  Sample cooling system, low pressure internal cooling
system
        *  Mechanical structure
        *  Microprocessor-based system for control of the
experiment, data                  handling and housekeeping
        *  Accelerometers
        *  Energy system, sealed lead batteries (1375 Wh)

Other GAS hardware

        GAS hardware also is being used by the U.S. Postal Service
to fly 500,000 commemorative stamps in recognition of the
25th anniversary of the Apollo 11 Moon Landing.  The stamp
that is being flown is a $9.95 Express Mail stamp.  Artwork
for the stamp was created by the father and son team of Paul
and Chris Calle, experienced stamp designers and participants
in the NASA Art Program.

        The new stamp shows two astronauts on the moon's surface
with the Apollo landing module.  The Express Mail stamp will
be sold individually and in panes of 20 stamps.

SECONDARY PAYLOADS


COMMERCIAL PROTEIN CRYSTAL GROWTH (CPCG)

        The Commercial Protein Crystal Growth (CPCG) experiment
has sever surrounding the syringe tip contains a
reservoir with a highly concentrated solution of
precipitating agent.  The crystallization process is driven
by the difference in the vapor pressures of the hanging drop
and the reservoir solution.  Water vapor is transported from
the hanging droplet of protein/precipitant solution to the
reservoir solution of precipitating agent.  Protein
crystallization is initiated when the protein/precipitant
concentrations within the hanging drop are altered by this
vapor transport.  When a unique protein/precipitant
concentration for a particular sample is obtained in each of
the growth chambers, crystallization occurs.

Biological Research in Canisters P BRIC-01

        STS-68 will fly the first in a new series of life sciences
experiments titled, "Biological Research in Canisters
(BRIC)."  BRIC experiments, sponsored by NASA's Office of
Life and Microgravity Sciences and Applications, are designed
to examine the effects of microgravity on a wide range of
physiological processes in higher order plants and arthropod
animals (e.g., insects, spiders, centipedes, crustaceans).
BRIC hardware consists of a small, self-contained, two-
chambered aluminum container that requires no power.  The
first BRIC experiment (BRIC-01) will fly gypsy moth eggs to
determine how microgravity affects the developing moth's
diapause cycle.  The diapause cycle is the period of time
when the moth is in a dormant state and undergoing
development.  Previous spaceflights of gypsy moths have
indicated that microgravity may shorten the diapause cycle
which leads to the emergence of sterile gypsy moth larvae.
Since the gypsy moth is among the most damaging insect pests
of hardwood trees in the eastern United States, extensive
ground-based research has been conducted to modify the gypsy
moth's life cycle to create sterile moths.  Results from
NASA's BRIC-01 experiment could greatly enhance these
research efforts.  The investigator for this experiment, Dr.
Dora K. Hayes, is a scientist with the U.S. Department of
Agriculture in Beltsville, Md., in the Livestock Insects
Laboratory.

CHROMEX-05

        STS-68 marks the fifth flight in the series of CHROMEX
experiments designed to examine the effects of microgravity
on a wide range of physiological processes in plants.
CHROMEX experiments are flown in the Plant Growth Unit (PGU),
an automated system that provides lighting, limited
temperature control, and nutrients to support plant growth in
the Shuttle middeck.  Previous CHROMEX experiments (CHROMEX-
03 and 04)  indicate that plants grown in space may not
produce seed embryos.  The primary objective of CHROMEX-05 is
to determine if plants grown in space are infertile due to
microgravity or some other environmental factor.   For this
experiment, 13-day old Mouse-ear Cress (Arabidopsis thaliana)
seedlings will be grown in space and will be compared to
plants grown under similar conditions on the Earth.  Results
from this experiment will advance the field of space biology
and will benefit the development of planned plant-based life
support systems for future long duration space crews.
Results may also benefit ther the
direction of the DoD's Space Test Program.


MILITARY APPLICATIONS OF SHIP TRACKS (MAST)

        The Office of Naval Research (ONR) is sponsoring the
Military Applications of Ship Tracks (MAST) experiment on
STS-68.  MAST, which flew for the first time on STS-65 in
July 1994, is part of a five-year research program developed
by ONR to examine the effects of ships on the marine
environment.  The Naval Postgraduate School, Monterey,
Calif., will conduct the experiment at the Johnson Space
Center during the mission.  The objective of MAST is to
determine how pollutants generated by ships modify the
reflective properties of clouds.  Ship tracks are observed in
satellite imagery as long, narrow, curvilinear cloud features
that have greater brightness than the surrounding clouds.
The STS-68 crew will photograph ship tracks using handheld
cameras.  These high-resolution photographs will provide
insight into the processes of ship track production on a
global scale.  MAST will help in understanding the effects of
man-made aerosols on clouds and the resulting impact on the
climate system.  MAST is a Department of Defense payload and
is being flown under the direction of the DoD Space Test
Program.


STS-68 CREW BIOGRAPHIES

        Michael (Mike) A. Baker, 40, Capt., USN, will be
Commander (CDR) of STS-68.  Selected as an astronaut in 1985,
Baker considers Lemoore, Calif., his hometown and will be
making his third Shuttle flight.

        Baker graduated from Lemoore Union High School in 1971 and
received a bachelor's degree in aerospace engineering from
the University of Texas in 1975.

        Baker's first Shuttle flight was as pilot aboard Atlantis'
STS-43 mission in August 1991, a mission that deployed the
fifth NASA Tracking and Data Relay Satellite.  His second
flight was as pilot of STS-52 in October 1992, a mission that
deployed the Italian Laser Geodynamic Satellite and operated
the first United States Microgravity Payload.

        Baker has logged more than 450 hours in space and more
than 4,300 hours of flying time in 50 different types of
aircraft.

        nd received a doctorate
in planetary science from the University of Arizona in Tucson
in 1988.


        Jones served as an Air Force officer for six years, flying
strategic bombers at Carswell AFB, Texas, and accumulating
more than 2,000 hours of jet experience.  He resigned his
commission in 1983 and began work on his doctorate as a
graduate research assistant.  Following graduation in 1988,
he served as a program management engineer in the CIA's
Office of Development and Engineering.  In 1990, he joined
Science Applications International Corp., as a senior
scientist, working on advanced program planning for the Solar
System Exploration Division at NASA Headquarters, Washington,
D.C.

        Jones' first flight was as a mission specialist on STS-59
in April 1994, the first flight of the Space Radar Lab.  He
has logged more than 269 hours in space.

        Steven (Steve) L. Smith, 35, will be Mission
Specialist 1 (MS1). Selected as an astronaut in 1992, he
considers San Jose, Calif., his hometown and will be making
his first space flight.

        Smith graduated from Leland High School in San Jose in
1977; received a bachelor's degree in electrical engineering
from Stanford University in 1981; received a master's degree
in electrical engineering in 1982 from Stanford; and received
a master's degree in business administration in 1987 from
Stanford.

        Smith worked for IBM in the Large Scale Integration
Technology Group in San Jose from 1982-1985, working on the
development of electron beam chemical and lithographic
processes for semiconductors.  After a leave to pursue
graduate studies, Smith returned to IBM's Hardware and
Systems Management Group in Santa Clara, Calif., as a product
manager for voice and telephony products.

        Smith joined NASA in 1989, serving in the Payload
Operations Branch, Mission Operations Directorate, at the
Johnson Space Center.  He supported STS-37, STS-48, and STS-
49 as a Payload Officer in Mission Control before his
selection as an astronaut.

        Daniel (Dan) W. Bursch, 37, CDR., USN, will be Missioning the
development of new vacuum
ultraviolet and high intensity laser sources and the medical
application of lasers to the reconstruction of damaged
nerves.

        His recent work includes collaboration with researchers at
Rice University on developing new techniques for growing and
evaluating semiconductor materials using lasers.

        Wisoff's first flight was as a mission specialist on STS-
57, a mission that retrieved the European Retrievable Carrier
satellite and was the first flight of Spacehab.  He has
logged more than 239 hours in space.