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IML-1: The First International Microgravity Laboratory

     For seven days in early 1992, NASA's Spacelab will transform
the Space Shuttle Discovery into an international, orbiting
laboratory.  Discovery's crew of seven, representing three
different countries, will explore the effects of weightlessness on
both materials and certain life functions.  While some experiments
will be carried out in the Shuttle crew cabin, most will take place
in the shirtsleeve environment of Spacelab, a fully-equipped
research laboratory carried within the orbiter's cargo bay.

     The first in a series of International Microgravity Laboratory
missions, IML-1 is a NASA Office of Space Science and Applications
mission operation and a cooperative venture of space agencies
around the world.  It is managed by and controlled from NASA's
Marshall Space Flight Center in Huntsville, Ala.  More than 220
scientists from 14 nations (including the U.S.) have contributed to
the experiments for the IML-1 flight aboard Shuttle mission STS-42.


     The near weightlessness, or "microgravity," of low-Earth orbit
makes it a unique environment for science.  Gravity is an
influential factor in the way life develops and how materials
interact on Earth.  The IML-1 science crew will delve into the
fundamentals or materials processing, measuring subtle interactions
that would be masked by gravity's pull on Earth.  They will grow
crystals of interest to researchers in advanced electronics and
medicine.  They will test the adaptation to microgravity of their
own bodies, as well as that of life forms ranging from tiny cells
to plants and insects.  The physical changes astronauts experience
in space, such as the space adaptation syndrome and bone and muscle
deterioration, will be closely examined.  Lessons learned will be
important to planning future long-term missions aboard Space
Station Freedom and exploration of the moon and Mars.

     Discoveries gained through the IML-1 mission will not only aid
future space exploration; they hold potential for improving life on
Earth as well.  As space experiments increase our knowledge about
biological processes such as bone cell production and inner ear
sensitivity to gravity, we can apply what we learn to medical
problems at home.  Insights into the influence of gravity and other
physical phenomena on producing improved materials will be useful
on Earth.  Also, in some cases higher quality protein crystals can
be grown in space than on the ground, assisting scientists in the
definition of the structures of these proteins -- many of which are
basic components of life and a few of which may be keys to
producing more effective treatments for disease.


An International Mission

     IML-1 equipment has been provided by NASA, the European Space
Agency (ESA), the Canadian Space Agency (CSA), the French National
Center for Space Studies (CNES), the German Space Agency (DARA),
and the National Space Development Agency of Japan (NASDA).  The
experiments were developed by scientists from those agencies and
from other institutions around the world.  Together, principal
investigators (experiments science team leaders) for each of the
experiments form the IML-1 Investigator Working Group which guides
science planning for the mission.

     The international cooperation of missions such as IML-1 is a
mutually beneficial arrangement.  NASA provides mission management
and some experiments, prepares the payload, and furnishes Shuttle
transportation to and from orbit.  Other space agencies provide
additional hardware of particupar interest to U.S. scientists that
both international and American scientists use.  In addition to
reducing costs for the individual agencies, this cooperation allows
scientists from all over the world to share experiment results.


The Laboratory

     In view of their international nature, it is appropriate that
the IML flights are Spacelab missions.  The European Space Agency
provided Spacelab to NASA in 1981 as its contribution to the Space
Shuttle program.  Spacelab equipment, which operates within the
Shuttle's cargo bay throughout a mission, consists of several
components which can be assembled into different configurations to
meet needs of specific missions.  A fully-equipped pressurized
laboratory module allows scientists to work much as they would in
Earth-bound labs, while open platforms, called pallets, are
available for mounting experiments requiring direct exposure to
space.  The IML-1 mission uses the module only, which is connected
to the orbiter's crew cabin by a pressurized tunnel.

     Spacelab control equipment and experiment facilities are
stowed in racks lining the sides of the module.  For the IML-1
mission, the center aisle of the laboratory will also be occupied
by experiment equipment.  One important advantage of Spacelab is
that all hardware is returned to Earth, allowing it to be used
again.  The four previous Spacelab module missions have produced an
impressive international inventory of hardware  equipment.  Some 60
percent of the IML-1 experiments flew aboard previous Spacelabs.

     During Spacelab missions, controllers and experiment
scientists direct science activities from the Spacelab Mission
Operations Control facility in Huntsville, Ala.  They have a direct
voice communication link with the orbiting Spacelab crew, and
on-board video cameras make it possible for them to view crew and
experiment activities.  Scientists and controllers on the ground
can receive information from Spacelab experiments and send commands
via computer links.  With this ready communications access,
scientists on the ground and scientists in orbit can work together
sharing information about experiments, monitoring data, solving
problems and revising experiment plans to take advantage of
unexpected research opportunities.


The IML-1 Crew

     The STS-42 IML-1 flight has a seven-member crew.  Air Force
Colonel Ronald J. Grabe, a NASA astronaut since 1980 and veteran of
two previous Shuttle missions, serves as commander.  The orbiter
crew, which will support scientific research in addition to
operating the Shuttle, includes on their first Shuttle flight Pilot
Stephen S. Oswald and Mission Specialist William R. Readdy, both
aerospace engineers and former test pilots.

     Science investigations in orbit will be conducted primarily by
the Spacelab payload crew, composed of two mission specialists and
two payload specialists.  Mission specialists are NASA astronauts
with expertise in medicine, science or engineering.  Payload
specialists are not career NASA astronauts, but rather scientists
nominated by the Investigator Working Group to participate in a
Shuttle mission.  The two mission specialist members of the payload
crew are: Dr. Norman E. Thagard, a medical doctor, electrical
engineer, and former naval aviator; and Marine Lieutenant Colonel
David C. Hilmers, an electrical engineer.  Both have flown on three
previous Shuttle missions.

     Payload specialists are: Dr. Roberta L. Bondar, a medical
doctor who has been a member of the Canadian Astronaut Program
since 1983; and Dr. Ulf D. Merbold, a German physicist representing
the European Space Agency and head of his country's astronaut
office.  Merbold flew on the first Spacelab mission (Spacelab 1,
1983) as a payload specialist.  Alternate payload specialists, who
serve as backup for the payload specialists, are Dr. Roger K.
Crouch, chief scientist in NASA's Microgravity Science and
Applications Division; and Dr. Kenneth E. Money, a Canadian
scientist who has done extensive research in vestibular function
and motion sickness.  During the mission, they will perform a key
role in the Spacelab control center as communicators between the
scientists on the ground and the crew in orbit.


The IML-1 Mission

     Many IML experiments require a very smooth ride through space
so their delicate operations will not be disturbed.  Therefore,
when the Shuttle Discovery achieves its 160-nautical-mile orbit, it
will be placed into a "gravity-gradient" attitude with its tail
pointed toward Earth.  This allows its position to be maintained
primarily by natural forces and reduces the need for frequent
orbiter thruster firings which could disturb sensitive experiments.

     Because of the great number of experiments planned for the
mission, the crew will work around the clock in two 12-hour
shifts.  The first hours of the mission will be especially busy.
The payload crew will begin the mission by setting up equipment and
turning on experiment facilities.  Because the Spacelab module is
placed in the Shuttle's cargo bay weeks before launch, critical
biological and materials samples, which degrade quickly, will be
loaded into crew-cabin lockers a few hours before liftoff.  Orbiter
and payload crew members will transfer these samples to experiment
facilities in the laboratory before science operations are begun.

     During the first days of the mission, the payload crew will
activate critical biological and materials experiments and set up
those involving plants, cells and crystals.  Much of the crew time
throughout the mission will be devoted to experiments which measure
how their own bodies adapt to living in space.  Throughout the
mission, crystal growth and fluid physics research will be
conducted, and experiments will be carried out.  Experiments also
will continue with plants, cells and other biological specimens.
The crew will check investigations periodically, make adjustments
needed to enhance results and, when necessary, replace specimens or
preserve them for ground-based analysis.  The payload crew aboard
Spacelab will use both voice and video links to consult with the
scientists on the ground during critical operations and to modify
experiments as required.

     The last days will be spent completing investigations.   The
crew will repeat some experiments performed earlier in the mission
to measure how their bodies have adapted to space over the course
of the flight.  On the final day, they will turn off the equipment,
store samples and specimens, and prepare the laboratory for
landing.

     Complete analysis of all the data acquired during the mission
may take from a few months to several years.  Results will be
shared with the worldwide scientific community through normal
publication channels.


The IML-1 Experiments

     Life science and materials science are logical partners for
Spacelab missions.  Materials processing facilities draw an
extensive amount of the power available for experiments, but they
demand comparatively little crew time.  On the other hand, life
science experiments -- particularly those where the crew serve as
test subjects as well as scientists -- are time-intensive but do
not require a great deal of power.

Life Science

     Many of the IML-1 life science experiments will study the
impact of weightlessness on certain elements of human function,
using the crew as experiment subjects.  Others will concentrate on
the effects of gravity and radiation on the development of
biological samples -- from spores and plants to bacteria and fruit
flies.  Before we can send astronauts on long space journeys or
establish outposts on other worlds, we must know more about the
effects of space on all forms of life.

     NASA's Microgravity Vestibular Investigations place a crew
member in a rotating and oscillating chair, located in the center
aisle of the laboratory, to test optic and inner ear responses to
head and body movements in weightlessness.  On Earth, the brain
perceives movement by comparing what a person sees and hears with
signals from the gravity- and motion-detecting vestibular organs of
the inner ear.  These vestibular signals are altered in space, so
astronauts often experience unusual motion sensations or even
experience nausea similar to motion sickness until they adjust to
the new environment.  Crew members will be subjected to different
frequencies and directions of rotation in the test chair, while eye
motions are recorded with a tiny video camera mounted in a special
helmet.  These types of data will be taken at the beginning, in the
middle, and near the end of the flight, allowing scientists to
track changes over time.

     Effects of weightlessness on the human body will also be
evaluated with five Space Physiology Experiments, provided by
Canada.  The most extensive of these focuses on the vestibular
system, while others study cardiovascular deconditioning, the back
pain often experienced by astronauts, crew member energy
expenditure, and eye movement resulting from motion stimulation of
the inner ear.  Crew member test subjects will ride in a mini-sled
attached to a track on the Spacelab floor.  A sixth experiment,
investigating the physics of phase partitioning (separation of two
materials), a process which may be used to separate biological
materials, is also included in this group.

     The Mental Workload and Performance Evaluation, a NASA
experiment, has a very practical purpose: determining the most
comfortable positions and efficient equipment for doing "desk work"
in space.  Crew members will perform various tasks requiring
interaction with a computer workstation.  The facility includes an
adjustable surface for planning sessions and record keeping, as
well as a portable computer with a keyboard, joystick, and
trackball.  Crew reports on the most efficient positions and
equipment will influence the design of workstations for future
missions.

     NASA's Gravitational Plant Physiology Experiments will study
the response of plants to two forces: gravity and light.  Normally
on Earth, the roots of a plant grow downward -- even if the plant
is turned on its side -- and its stem grows upward and bends toward
the light.  In the low gravity of space, it is possible to study
the effects of light and gravity separately.  To evaluate the
influence of gravity on plants, payload crew members will place oat
seedlings in one centrifuge for germination, then in another that
exposes them to various levels of gravity parallel to the soil
surface.  They will be illuminated only by infrared light (to which
the plants do not respond).  Plant responses to light in the
absence of the complicating force of gravity will be studied by
exposing wheat seedlings in microgravity to varying durations of
blue light (to which plants are most sensitive).  Responses in both
experiments will be recorded on videotape for later study.

Biorack, a European Space Agency facility which was flown on
Spacelab D-1 in 1985, hosts 17 international experiments --  three
of them from the U.S. They will study the effects of both
microgravity and space radiation on plants, tissues, cells,
bacteria, fruit flies, frog eggs, and other biological samples.
Crew members will conduct experiments on duplicate sets of up to
150 pre-packaged samples, placing one of each sample in a rack
exposed to weightlessness and putting its twin in a centrifuge
which spins to approximate Earth's gravity.  Meanwhile, scientists
on Earth will conduct the same experiments in true gravity.
Samples will be compared after the mission for variations in
development.  Duplicate specimens grown in different environments
will help scientists determine whether changes were caused by the
trauma of launch, microgravity, radiation or a combination of
these.

     Radiation, like microgravity, is a factor of the space
environment whose impact on people and plants is little
understood.  Most harmful radiation never reaches Earth, because it
is filtered out by the atmosphere.  However, it is a long-term
hazard in space.  In addition to Biorack, two other IML experiments
will measure the effects of radiation.  Germany's Biostack package,
which alternates sheets of plastic radiation detectors with layers
of bacteria, fungus spores, thale cress seeds and shrimp eggs, will
be placed in various parts of the Shuttle.  After the mission,
scientists can track paths of radiation particles and determine if
they altered the samples.  Japan's Radiation Monitoring Container
Device, which also layers radiation detectors and biological
samples, is enclosed on all sides by gauges which measure radiation
dosages.  It will be mounted on the end cone of Spacelab, which has
somewhat lower radiation protection than other areas in the module.

Materials Science

     IML-1 materials science experiments primarily concentrate on
various methods of crystal growth, along with the study of fluid
behavior in microgravity.  Pure, nearly perfect crystals are needed
in computers, lasers, and other optical and electrical devices.
Crystals grown on Earth are often flawed, since they are pulled
downward by gravity during their formation or distorted by their
containers.  In microgravity, crystals are free to develop without
distortion.

     Two facilities will be used to grow mercury iodide crystals,
used as X-ray and gamma-ray detectors.  These crystals are so
fragile they can be deformed under their own weight when grown on
Earth.  Both the Vapor Crystal Growth System, provided by NASA, and
France's Mercury Iodide Crystal Growth experiment use vapor
transport to form crystals.  Various temperatures and pressures are
used to determine conditions which produce the best crystal growth
results.  Both experiments have flown on previous Spacelab
missions.

     Japan's Organic Crystal Growth Facility will grow organic
superconductor crystals from solution.  Researchers are interested
in these materials because, in spite of their organic nature, they
can -- at extremely low temperatures -- transfer electric current
with no resistance, just like a metal superconductor.
Superconductors are key components of computers, communications
satellites, and other electrical devices.

     NASA's Fluids Experiment System will allow scientists, using
sophisticated optics, to monitor the flow of fluids during
crystallization.  A laser system will make three-dimensional
holograms of samples, and a video camera will record images of
fluid flows.  Triglycine sulfate crystals, valuable as
room-temperature infrared detectors, will be grown in the
facility.  Also conducted in the facility will be an experiment
which uses a metal-modeling salt to study how alloys solidify.  Of
particular interest to industry, it will improve our understanding
of methods used to produce high performance alloys for jet engines,
nuclear power plant turbines, and future spacecraft.

     Two different facilities for growing protein crystals --
large, complex molecules that are essential to all life -- will fly
aboard IML-1.  Germany's Cryostat will grow protein crystals in two
thermostat chambers: one in a room-temperature stabilizer mode and
the other in a freezer mode which varies from below freezing to
room temperature during an experiment.  NASA's Protein Crystal
Growth experiment is the only IML-1 materials science facility not
located in the Spacelab module.  Rather, it is mounted in place of
two Shuttle middeck lockers and operated by the orbiter crew.
During previous Shuttle missions, this experiment produced several
crystals of better quality than any grown on Earth.  Scientists may
use their analyses of protein crystals to develop more effective
disease-fighting drugs.

     ESA's Critical Point Facility is designed for the optical
study of transparent fluids.  Scientists will use it to observe
fluids at their "critical point," where a precise combination of
temperature and pressure makes the vapor and liquid states
indistinguishable.  Such observations are hampered on Earth, since
as soon as vapor begins to liquefy, forming droplets, gravity pulls
the drops down.  IML-1 will be this facility's first Shuttle
flight, so results gained during this mission will offer unique new
insights on fundamental questions about the basic laws of physics.
Many different materials behave in a very similar manner near their
critical points.  Thus, observations of experiment samples in the
facility may be related universally to various physical problems
regarding phase changes in both liquids and solids.

     In addition to the experiment facilities, the IML-1 payload
includes the Space Acceleration Measurement System, which measures
and records disturbances in the Spacelab caused by crew motion,
experiment and Spacelab operations, and orbiter thruster firings.
Also on board will be the IMAX camera, a 70-millimeter large-format
movie camera for filming mission activities.


IML-1 Management

     The IML program is sponsored by NASA's Office of Space Science
and Applications in Washington, D.C.  Mission management and
science mission control is the responsibility of the Marshall Space
Flight Center in Huntsville, Ala.  The Spacelab module and
experiment racks are processed at the Kennedy Space Center in
Florida, which is also responsible for launching the lab aboard the
Space Shuttle.  Shuttle orbiter control during the mission is
furnished by Johnson Space Center in Houston, Texas.  Goddard Space
Flight Center in Greenbelt, Md., provides communications links
between the Shuttle and ground controllers via a network of
satellites and relay stations.  Goddard also records experiment
data.

Program Manager
     Mr. R. Wayne Richie
     NASA Headquarters
     Office of Space Science and Applications

Program Scientist
     Dr. Ronald J. White
     NASA Headquarters
     Office of Space Science and Applications

Mission Manager
     Mr. Robert O. McBrayer
     Marshall Space Flight Center
     Payload Projects Office

Assistant Mission Manager
     Mr. John L. Frazier
     Marshall Space Flight Center
     Payload Projects Office

Mission Scientist
     Dr. Robert S. Snyder
     Marshall Space Flight Center
     Space Science Laboratory

Assistant Mission Scientist
     Ms. Teresa Y. Miller
     Marshall Space Flight Center
     Space Science Laboratory


IML-1 Quick Facts

Flight Number:           STS-42
Orbiter:                 Discovery
Altitude:                160 nautical miles (296 kilometers)
Orbital Path:            Circular
Inclination:             57 degrees
Mission Duration:        7 days
Payload Operations:      Around the clock; two 12-hour shifts

Crew Assignments:

Blue Team:
Commander Ron Grabe, New York, N.Y.
Pilot Steve Oswald, considers Bellingham, Wash., to be hometown
Mission Specialist Norm Thagard, considers Jacksonville, Fla., to
be hometown
Payload Specialist Roberta Bondar, Sault Ste. Marie, Ontario, Canada

Red Team:
Mission Specialist Bill Readdy, considers McLean, Va., to be hometown
Mission Specialist Dave Hilmers, considers DeWitt, Iowa, to be hometown
Payload Specialist Ulf Merbold, Greiz, Germany

Spacelab Configuration:
Long module, 23 feet (7.0 meters) in length and 14 feet (4.27
meters) in diameter

Equipment Racks:
More than 30 feet (9.14 meters) of racks line the Spacelab module,
with four 40-inch (1.01-meter) wide double racks and four 19-inch
(0.48-meter) wide single racks dedicated to science experiments.
Others are occupied by the Spacelab computer control center, a work
bench and support equipment.

Participating Agencies:

     National Aeronautics and Space Administration (NASA)
     European Space Agency (ESA)
     Canadian Space Agency (CSA)
     French National Center for Space Studies (CNES)
     German Space Agency (DARA)
     National Space Development Agency of Japan (NASDA)