NATIONAL AERONAUTICS AND SPACE ADMINISTRATION

                    SPACE SHUTTLE MISSION

                       STS-46 PRESS KIT

                          JULY 1992

PUBLIC AFFAIRS CONTACTS

NASA Headquarters

Office of Space Flight/Office of Space Systems Development
Mark Hess/Jim Cast/Ed Campion
(Phone:  202/453-8536)

Office of Space Science
Paula Cleggett-Haleim/Mike Braukus/Brian Dunbar
(Phone:  202/453-1547)

Office of Commercial Programs
Barbara Selby
(Phone:  703/557-5609)

Office of Aeronautics and Space Technology
Drucella Andersen/Les Dorr
(Phone:  202/453-2754)

Office of Safety & Mission Quality/Office of Space
Communications
Dwayne Brown
(Phone:  202/453-8596)

Ames Research Center              Langley Research Center
Jane Hutchison                    Jean Drummond Clough
(Phone:  415/604-4968)            (Phone:  804/864-6122)

Dryden Flight Research Facility   Lewis Research Center
Nancy Lovato                      Mary Ann Peto
(Phone:  805/258-3448)            (Phone:  216/433-2899)

Goddard Space Flight Center       Marshall Space Flight Center
Dolores Beasley                   Mike Simmons
(Phone:  301/286-2806)            (Phone:  205/544-6537)

Jet Propulsion Laboratory         Stennis Space Center
James Wilson                      Myron Webb
(Phone:  818/354-5011)            (Phone:  601/688-3341)

Johnson Space Center              Wallops Flight Center
James Hartsfield                  Keith Koehler
(Phone:  713/483-5111)            (Phone:  804/824-1579)

Kennedy Space Center
Lisa Malone
(Phone:  407/867-2468)

CONTENTS

General Release                                      1

Media Services Information                           2

Quick-Look-Facts                                     3

Summary of Major Activities                          4

Payload and Vehicle Weights                          5

Trajectory Sequence of Events                        7

Space Shuttle Abort Modes                            8

Prelaunch Processing                                 9

Tethered Satellite System (TSS-1)                   10

European Retrievable Carrier (EURECA)               31

Evaluation of Oxygen Interaction with Materials
(EOIM)/Two Phase Mounting Plate Experiment (TEMP)   45

Consortium for Materials Development
in Space (Complex Autonomous Payload)               47

Limited Duration Space Environment
Candidate Materials Exposure (LDCE)                 48

Pituitary Growth Hormone Cell Function (PHCF)       50

IMAX Cargo Bay Camera (ICBC)                        50

Air Force Maui Optical Station (AMOS)               53

Ultraviolet Plume Imager (UVPI)                     53

STS-46 Crew Biographies                             53

Mission Management for STS-46                       56

Previous Shuttle Flights                            58

Upcoming Space Shuttle Flights                      59

Release:  92-95

49th SHUTTLE FLIGHT TO DEPLOY TETHERED SATELLITE SYSTEM

     Shuttle mission STS-46 will be highlighted by the
deployment of the Tethered Satellite System-1 (TSS-1), an
Italian space agency-developed satellite, from the Shuttle
cargo bay while attached to a 12.5-mile-long cable for 31 hours
to explore the dynamics and electricity-generating capacity of
such a system.  Also, the European Retrievable Carrier (EURECA)
platform will be placed into orbit from Atlantis to expose
several experiments to weightlessness for about 9 months before
being retrieved by a Shuttle in late April 1993.

     In addition to EURECA and TSS-1, Atlantis also will carry
the Evaluation of Oxygen Interaction with Materials III and
Thermal Energy Management (EOIM and TEMP 2A) experiments in the
cargo bay.  EOIM will explore the interaction of various
materials with the atomic oxygen present in low-Earth orbit,
and the TEMP 2A experiment will test a new cooling method that
may be used in future spacecraft.

     An IMAX camera also will be in the payload bay to film
various aspects of the mission for later IMAX productions, and
the Consortium for Material Development in Space Complex
Autonomous Payload and Limited Duration Space Environment
Candidate Materials Exposure experiments will explore materials
processing methods in weightlessness.

     Atlantis will be commanded by USAF Col. Loren Shriver,
making his third Shuttle flight.  Marine Corps Major Andy Allen
will serve as Pilot, making his first flight.  Mission
specialists will include Claude Nicollier, a European Space
Agency astronaut making his first Shuttle flight; Marsha Ivins,
making her second Shuttle flight; Jeff Hoffman, making his
third space flight; and Franklin Chang-Diaz, making his third
space flight.  Franco Malerba from the Italian Space Agency
will be a payload specialist aboard Atlantis .

     Currently planned for a mid-July launch, STS-46, Atlantis'
12th flight, is scheduled to last 6 days, 22 hours and 11
minutes, with a planned Kennedy Space Center, Fla., landing.

                             -end-

MEDIA SERVICES INFORMATION

NASA Select Television Transmission

	NASA Select television is available on Satcom F-2R,
Transponder 13, located at 72 degrees west longitude; frequency
3960.0 MHz, audio 6.8 MHz.

	The schedule for television transmissions from the
orbiter and for the mission briefings will be available during
the mission at Kennedy Space Center, Fla; Marshall Space Flight
Center, Huntsville; Ames-Dryden Flight Research Facility,
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 update 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 news center.

Briefings

	A mission press briefing schedule will be issued prior to
launch.  During the mission, change-of-shift briefings by the
off-going flight director and the science team will occur at
least once per day.  The updated NASA Select television
schedule will indicate when mission briefings are planned.

STS-46 QUICK LOOK

Launch Date/Site:       July 21, 1992 - Kennedy Space Center,
                        Fla., Pad 39B
Launch Window:          9:48 a.m. - 12:18 p.m. EDT
Orbiter:                Atlantis (OV-104)
Orbit:                  230 n.m. x 230 n.m. (EURECA deploy)
                        160 n.m. x 160 n.m. (TSS operations)
                        128 n.m. x 128 n.m. (EOIM operations)
Landing Date/Time:      7:57 a.m. EDT July 28, 1992
Primary Landing Site:   Kennedy Space Center, Fla.
Abort Landing Sites:    Return to Launch Site - Kennedy Space
                        Center, Fla.
                        Transoceanic Abort Landing - Banjul, The Gambia
                        Alternates - Ben Guerir, Morocco; Moron, Spain
                        Abort Once Around - Edwards Air Force Base, Calif.
Crew:                   Loren Shriver, Commander
                        Andy Allen, Pilot
                        Claude Nicollier, Mission Specialist 1
                        Marsha Ivins, Mission Specialist 2
                        Jeff Hoffman, Mission Specialist 3
                        Franklin Chang-Diaz, Mission Specialist 4
                        Franco Malerba, Payload Specialist 1
Operational shifts:     Red team -- Ivins, Hoffman, Chang-Diaz
                        Blue team -- Nicollier, Allen, Malerba
Cargo Bay Payloads:     TSS-1 (Tethered Satellite System-1)
                        EURECA-1L (European Retrievable Carrier-1L)
                        EOIM-III/TEMP 2A (Evaluation of Oxygen Integration with
			Materials/Thermal Management Processes)
                        CONCAP II (Consortium for Materials Development in
			Space Complex Autonomous Payload)
                        CONCAP III
                        ICBC (IMAX Cargo Bay Camera)
                        LDCE (Limited Duration Space Environment Candidate
			Materials Exposure)

Middeck Payloads:       AMOS (Air Force Maui Optical Site)
                        PHCF (Pituitary Growth Hormone Cell Function)
                        UVPI (Ultraviolet Plume Instrument)

STS-46 SUMMARY OF MAJOR ACTIVITIES

Blue Team Flight Day One:  Red Team Flight Day One
                           Launch
                           Orbit insertion (230 x 230 n.m.)
                           TSS activation
                           RMS checkout
                           TSS deployer checkout
                           EOIM/TEMP-2A activation

Blue Flight Day Two:       Red Flight Day Two:
EURECA deploy              TEMP-2A operations
EURECA stationkeeping      Tether Optical Phenomenon (TOP) checkout

Blue Flight Day Three:     Red Flight Day Three:
TOP checkout               TSS checkout/in-bay operations
Supply water dump nozzle DTO
TEMP-2A operations
OMS-3 burn
OMS-4 burn (160 x 160 n.m.)

Blue Flight Day Four:         Red Flight Day Four:
TSS in-bay operations         TSS deploy
                              TEMP-2A operations

Blue Flight Day Five:         Red Flight Day Five:
TSS on station 1 (12.5 miles) TSS retrieval to 1.5 miles
                              TSS final retrieval
                              TSS dock

Blue Flight Day Six:          Red Flight Day Six:
TSS safing                    EOIM/TEMP-2A operations
TSS in-bay operations
OMS-5 burn
OMS-6 burn (128 x 128 nm)

Blue Flight Day Seven:        Red Flight Day Seven:
TSS science deactivation      EOIM/TEMP-2A operations
EOIM/TEMP-2A operations       Flight Control Systems checkout
                              Reaction Control System hot-fire

Blue Flight Day Eight:        Red Flight Day Eight:
                              Cabin stow
                              Deorbit preparations
                              Entry and landing

STS-46 VEHICLE AND PAYLOAD WEIGHTS
                                            Pounds

Orbiter (Atlantis) empty, and 3 SSMEs      151,377

Tethered Satellite -- pallet,
 support equipment                          10,567

Tethered Satellite -- satellite, tether      1,476

European Retrievable Carrier                 9,901

EURECA Support Equipment                       414

Evaluation of Oxygen Interaction
with Materials                               2,485

CONCAP-II                                      590

CONCAP-III                                     368

LDCE                                         1,125

PHDF                                            69

Detailed Supplementary Objectives               56

Detailed Test Objectives                        42

Total Vehicle at SRB Ignition             4,522,270

Orbiter Landing Weight                      208,721

STS-46 Cargo Configuration

STS-46 TRAJECTORY SEQUENCE OF EVENTS

       	                		 RELATIVE
EVENT  	        		MET      VELOCITY  MACH       ALTITUDE
		            (d:h:m:s)    (fps)                (ft)

Launch 			    00/00:00:00

Begin Roll Maneuver	    00/00:00:10     189     .16           797

End Roll Maneuver	    00/00:00:15     325     .29         2,260

SSME Throttle Down to 80%   00/00:00:26     620     .55         6,937

SSME Throttle Down to 67%   00/00:00:53   1,236    1.20        28,748

SSME Throttle Up to 104%    00/00:01:02   1,481    1.52        37,307

Maximum Dynamic Press.      00/00:01:04   1,548    1.61        41,635
(Max Q)

SRB Separation              00/00:02:04   4,221    4.04       152,519

Main Engine Cutoff (MECO)   00/00:08:29  24,625   22.74       364,351

Zero Thrust                 00/00:08:35  24,624     N/A       363,730

ET Separation               00/00:08:48

OMS-2 Burn                  00/00:41:24

Landing                     06/22:11:00

Apogee, Perigee at MECO:          226 x 32 nautical miles
Apogee, Perigee post-OMS 2:       230 x 230 nautical miles

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
either Edwards Air Force Base, Calif., White Sands Space
Harbor, N.M, or the Shuttle Landing Facility (SLF) at the
Kennedy Space Center, Fla.

     * Trans-Atlantic Abort Landing (TAL) -- Loss of one or
more main engines midway through powered flight would force a
landing at either Banjul, The Gambia; Ben Guerir, Morroco; or
Moron, Spain.

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

     STS-46 contingency landing sites are Edwards Air Force
Base, the Kennedy Space Center, White Sands Space Harbor,
Banjul, Ben Guerir and Moron.

STS-46 PRE-LAUNCH PROCESSING

     KSC's processing team began readying the orbiter Atlantis
for its 12th flight into space following its STS-45 flight
which ended with a landing at KSC on April 2.  Atlantis was in
the Orbiter Processing Facility from April 2 to June 4,
undergoing post-flight inspections and pre-flight testing and
inspections.  While in the OPF, technicians installed the three
main engines.  Engine 2024 is in the No. 1 position, engine
2012 is in the No. 2 position and engine 2028 is in the No. 3
position.

     The remote manipulator system was installed on Apr. 28.
Members of the STS-46 flight crew participated in the Crew
Equipment Interface Test on May 16.

     Atlantis was towed from the Orbiter Processing Facility
(OPF) on June 4 to the Vehicle Assembly Building where it was
mated to its external tank and solid rocket boosters on the
same day.  Rollout to Launch Pad 39-B occurred on June 11,
1992.  On June 15-16, the Terminal Countdown Demonstration Test
with the STS-46 flight crew was conducted.

     The Tethered Satellite System (TSS) was processed for
flight in the Operations and Checkout Building high bay and the
EURECA payload was processed at the commercial Astrotech
facility in Titusville, Fla.  The two primary payloads were
installed in the payload canister at the Vertical Processing
Facility before they were transferred to the launch pad.

     Payload installation into Atlantis' payload bay was
scheduled for late June. Several interface verification tests
were scheduled between the orbiter and the payload elements.  A
standard 43-hour launch countdown is scheduled to begin 3 days
prior to launch.  During the countdown, the orbiter's fuel cell
storage tanks will be loaded with fuel and oxidizer and all
orbiter systems will be prepared for flight.

     About 9 hours before launch, the external tank will be
filled with its flight load of a half million gallons of liquid
oxygen and liquid hydrogen propellants.  About 2 and one-half
hours before liftoff, the flight crew will begin taking their
assigned seats in the crew cabin.

     Atlantis's end-of-mission landing is planned at Kennedy
Space Center. Several hours after landing, the vehicle will be
towed to the Vehicle Assembly Building for a few weeks until an
OPF bay becomes available. Atlantis will be taken out of flight
status for several months for a planned modification period.
Atlantis' systems will be inspected and improved to bring the
orbiter up to par with the rest of the Shuttle fleet.

     Atlantis's next flight, STS-57, is planned next year with
the first flight of the Spacehab payload and the retrieval of
the EURECA payload deployed on the STS-46 mission.

TETHERED  SATELLITE  SYSTEM (TSS-1)

     An exciting new capability for probing the space
environment and conducting experiments will be demonstrated for
the first time when the NASA/Italian Space Agency Tethered
Satellite System (TSS-1) is deployed during the STS-46 Space
Shuttle flight.  The reusable Tethered Satellite System is made
up of a satellite attached to the Shuttle orbiter by a super
strong cord which will be reeled into space from the Shuttle's
cargo bay.  When the satellite on its cord, or tether, is
deployed to about 12 miles above the orbiter, TSS-1 will be the
longest structure ever flown in space.

     Operating the tethered system is a bit like trolling for
fish in a lake or the ocean.  But the potential "catch" is
valuable data that may yield scientific insights from the vast
sea of space.  For the TSS-1 mission, the tether -- which looks
like a 12-mile-long white bootlace -- will have electrically-
conducting metal strands in its core.  The conducting tether
will generate electrical currents at a high voltage by the same
basic principle as a standard electrical generator -- by
converting mechanical energy (the Shuttle's more than 17,000-
mile-an-hour orbital motion) into electrical energy by passing
a conductor through a magnetic field (the Earth's magnetic
field lines).

     TSS-1 scientific instruments, mounted in the Shuttle cargo
bay, the middeck and on the satellite, will allow scientists to
examine the electrodynamics of the conducting tether system, as
well as clarify their understanding of physical processes in
the ionized plasma of the near-Earth space environment.

     Once the investigations are concluded, it is planned to
reel the satellite back into the cargo bay and stow it until
after the Shuttle lands.

     The TSS-1 mission will be the first step toward several
potential future uses for tethers in space now being evaluated
by scientists and engineers.  One possible application is using
long conducting tethers to generate electrical power for Space
Station Freedom or other orbiting bodies.  Conversely, by
expending electrical power to reverse the current flow into a
tether, the system can be placed in an "electric motor" mode to
generate thrust for orbit maintenance.  Tethers also may be
used to raise or lower spacecraft orbits.  This could be
achieved by releasing a tethered body from a primary
spacecraft, thereby transferring momentum (and imparting
motion) to the spacecraft.  Another potential application is
the creation of artificial gravity by rotating two or more
masses on a tether, much like a set of bolas.

     Downward deployment (toward Earth) could place a satellite
in regions of the atmosphere that have been difficult to study
because they lie above the range of high-altitude balloons and
below the minimum altitude of free-flying satellites.
Deploying a tethered satellite downward from the Shuttle also

could make possible aerodynamic and wind tunnel type testing in
the region 50 to 75 nautical miles above the Earth.

Mission  Objectives

     Space-based tethers have been studied theoretically since
early in this century.  More recently, the projected
performance of such systems has been modeled extensively on
computers.  In 1984, the growing interest in tethered system
experiments resulted in the signing of an agreement between
NASA and the Italian Space Agency (Agenzia Spaziale Italiana -
ASI) to jointly pursue the definition and development of a
Tethered Satellite System to fly aboard the Space Shuttle.
Scientific investigations (including hardware experiments) were
selected in 1985 in response to a joint NASA/ASI announcement
of opportunity.

     The TSS-1 mission will be the first time such a large,
electrodynamic tethered system has ever been flown.  In many
respects, the mission is like the first test flight of a new
airplane:  the lessons learned will improve both scientific
theory and operations for future tether missions.

     The primary objectives of the first tethered satellite
mission are to evaluate the capability to safely deploy,
control and retrieve a tethered satellite, to validate
predictions of the dynamic forces at work in a tethered
satellite system and to conduct exploratory electrodynamic
science investigations and demonstrate the capability of the
system to serve as a facility for research in geophysical and
space physics.

     Since the dynamics of the Tethered Satellite System are
complex and only can be tested fully in orbit, it is impossible
to predict before the mission exactly how the system will
perform in the space environment.  Though tether system
dynamics have been extensively tested and simulated, it could
be that actual dynamics will differ somewhat from predictions.
The complexity of a widely separated, multi-component system
and the forces created by the flow of current through the
system are other variables that will affect the system's
performance.

Responsibilities

     Responsibility for Tethered Satellite System activities
within NASA is divided between the Marshall Space Flight
Center, Huntsville, Ala., and the Johnson Space Center,
Houston.  Marshall has the development and integration
responsibility.  Marshall also is responsible for developing
and executing the TSS-1 science mission, and science teams for
each of the 12 experiments work under that center's direction.
During the mission, Johnson will be responsible for the
operation of the TSS-1 payload.  This includes deployment and
retrieval of the satellite by the crew as well as controlling
the satellite's motion in orbit and monitoring the state of the
Spacelab pallet, the deployer and the satellite.  Marshall will
furnish real-time engineering support for the TSS-1 system
components and tether dynamics.  ASI is furnishing satellite
engineering and management support.  All remote commanding of
science instruments aboard the satellite and
deployer will be executed by a Marshall payload operations
control cadre stationed at Johnson for the mission.

Tethered  Satellite  System  Hardware

     The Tethered Satellite System has five major components:
the deployer system, the tether, the satellite, the carriers on
which the system is mounted and the science instruments.  Under
the 1984 memorandum of understanding, the Italian Space Agency
agreed to provide the satellite and NASA agreed to furnish the
deployer system and tether.  The carriers are specially adapted
Spacelab equipment, and the science instruments were developed
by various universities, government agencies and companies in
the United States and Italy.

Carriers

     TSS-1 hardware rides on two carriers in the Shuttle cargo
bay.  The deployer is mounted on a Spacelab Enhanced
Multiplexer-Demultiplexer pallet, a general-purpose
unpressurized platform equipped to provide structural support
to the deployer, as well as temperature control, power
distribution and command and data transmission capabilities.
The second carrier is the Mission Peculiar Equipment Support
Structure, an inverted A-frame truss located immediately aft of
the enhanced pallet.  The support structure, also Spacelab-
provided, holds science support equipment and two of the TSS-1
science experiments.

Deployer

     The deployer system includes the structure supporting the
satellite, the deployment boom, which initially lifts the
satellite away from the orbiter, the tether reel, a system that
distributes power to the satellite before deployment and a data
acquisition and control assembly.

     Cables woven through the structure provide power and data
links to the satellite until it is readied for release.  When
the cables are disconnected after checkout, the satellite
operates on its internal battery power.  If the safety of the
orbiter becomes a concern, the tether can be cut and the
satellite released or the satellite and boom jettisoned.

     The boom, with the satellite resting atop it, is housed in
a canister in the lower section of the satellite support
structure.  As deployment begins, the boom will unfold and
extend slowly out of the turning canister, like a bolt

Tether cutaway

being forced upward by a rotating nut.  As the upward part of
the canister rotates, horizontal cross members (fiberglass
battens similar to those that give strength to sails) are
unfolded from their bent-in-half positions to hold the vertical
members (longerons) erect.  Additional strength is provided by
diagonal tension cables.  The process is reversed for
retrieval.  When it is fully extended, the 40-foot boom
resembles a short broadcasting tower.

     The tether reel mechanism regulates the tether's length,
tension and rate of deployment -- critical factors for tether
control.  Designed to hold up to 68 miles of tether, the reel
is 3.3 feet in diameter and 3.9 feet long.  The reel is
equipped with a "level-wind" mechanism to assure uniform
winding on the reel, a brake assembly for control of the tether
and a drive motor.  The mechanism is capable of letting out the
tether at up to about 10 miles per hour.  However, for the TSS-
1 mission, the tether will be released at a much slower rate,
about 2.5 miles per hour.

Tether

     The tether's length and electrical properties affect all
aspects of tethered operations.  For the TSS-1 mission, the
tether will be reeled out to an altitude about 12 miles above
the Shuttle, making the TSS-1/orbiter combination 100 times
longer than any previous spacecraft.  It will create a large
current system in the ionosphere, similar to natural currents
in the Earth's polar regions associated with the aurora
borealis.  When the tether's current is pulsed by electron
accelerators, it becomes the longest and lowest frequency
antenna ever placed in orbit.  Also, for the first time,
scientists can measure the level of charge or electric
potential acquired by a spacecraft as a result of its motion
through the Earth's magnetic field lines.  All these
capabilities are directly related to the structure of the
bootlace-thick tether, a conducting cord designed to anchor a
satellite miles above the orbiter.

     The TSS-1 tether is 13.6 miles long.  When deployed, it is
expected to develop a 5,000-volt electrical potential and carry
a maximum current of 1 ampere.  At its center is the conductor,
a 10-strand copper bundle wrapped around a Nomex (nylon fiber)
core.  The wire is insulated with a layer of Teflon, then
strength is provided with a layer of braided Kevlar -- a tough,
light synthetic fiber also used for making bulletproof vests.
An outer braid of Nomex protects the tether from atomic oxygen.
The cable is about 0.1 inch in diameter.

Satellite

     Developed by the Italian Space Agency, the spherical
satellite is a little more than 5 feet in diameter and is
latched atop the deployer's satellite support structure.  The
six latches are released when boom extension is initiated.
After the satellite is extended some 40 feet above the orbiter
atop the boom, tether unreeling will begin.

     The satellite is divided into two hemispheres.  The
payload module (the upper half of the sphere opposite the
tether) houses satellite-based science instruments.  Support
systems for power distribution, data handling, telemetry and
navigational equipment are housed in the service module or
lower half.  Eight aluminum-alloy panels, covered with
electrically conductive paint, developed at the Marshall Space
Flight Center, form the outer skin of the satellite.  Doors in
the panels provide access for servicing batteries; windows for
sun, Earth and charged-particle sensors; and connectors for
cables from the deployer.

     A fixed boom for mounting science instruments extends some
39 inches from the equator of the satellite sphere.  A short
mast opposite the boom carries an S-band antenna for sending
data and receiving commands.  For the TSS-1 mission, the
satellite is outfitted with two additional instrument-mounting
booms on opposite sides of the sphere.  The booms may be
extended up to 8 feet from the body of the satellite, allowing
instruments to sample the surrounding environment, then be
pulled back inside before the satellite is reeled back to the
Shuttle.

     Motion of the tethered satellite is controlled by its
auxiliary propulsion module, in conjunction with the deployer's
tether reel and motor.  The module also initiates, maintains
and controls satellite spin at up to 0.7 revolution per minute
on command from the Shuttle.  One set of thrusters near the
tether attachment can provide extra tension on the tether,
another can be used to reduce or eliminate pendulum-type
motions in the satellite, and a third will be used to spin and
de-spin the satellite.  A pressurized tank containing gaseous
nitrogen for the thrusters is located in the center of the
sphere.

TSS Spacecraft

TETHERED SATELLITE SYSTEM-1 FLIGHT OPERATIONS

     The responsibility for flying the tethered satellite,
controlling the stability of the satellite, tether and
Atlantis, lies with the flight controllers in the Mission
Control Center at the Johnson Space Center, Houston.

     The primary flight control positions contributing to the
flight of the Tethered Satellite System (TSS) are the Guidance
and Procedures (GPO) area and the Payloads area.  GPO officers
will oversee the dynamic phases of deployment and retrieval of
the satellite and are responsible for determining the correct
course of action to manage any tether dynamics.  To compute
corrective actions, the GPO officers will combine data from
their workstations with inputs from several investigative
teams.

     The Payloads area will oversee control of the satellite
systems, the operation of the tether deployer and all other TSS
systems.  Payloads also serves as the liaison between Mission
Control Center and the science investigators, sending all real-
time commands for science operations to the satellite.
Atlantis' crew will control the deployer reel and the satellite
thrusters from onboard the spacecraft.

Deploy Operations

     The satellite will be deployed from Atlantis when the
cargo bay is facing away from Earth, with the tail slanted
upward and nose pitched down.  A 39-foot long boom, with the
satellite at its end, is raised out of the cargo bay to provide
clearance between the satellite and Shuttle during deploy and
retrieval operations.  The orientation of the payload bay will
result in the tethered satellite initially deployed upward but
at an angle of about 40 degrees behind Atlantis' path.

     Using the tether reel's electric motors to unwind the
tether, an electric motor at the end of the boom to pull the
tether off of the reel and a thruster on the satellite that
pushes the satellite away from Atlantis, the satellite will be
moved away from the Shuttle. The deploy will begin extremely
slowly, with the satellite, after 1 hour has elapsed since the
tether was first unwound, moving away from Atlantis at about
one-half mile per hour. The initial movement of the satellite
away from the boom will be at less than two-hundredths of 1
mile per hour.  The speed of deploy will continue to increase,
peaking after 1 and a half hours from the initial movement to
almost 4 miles per hour.

     At this point, when the satellite is slightly less than 1
mile from Atlantis, the rate of deployment will begin slowing
briefly, a maneuver that is planned to reduce the 40-degree
angle to 5 degrees and put the satellite in the same plane
almost directly overhead of Atlantis by the time that about 3
miles of tether has been unwound.

     When the satellite is 3.7 miles from Atlantis, 2 and one-
half hours after the start of deployment, a one-quarter of a
revolution-per-minute spin will be imparted to it via its
attitude control system thrusters.  The slight spin is needed
for science operations with the satellite.

     After this, the speed of deployment will again be
increased gradually, climbing to a peak separation from
Atlantis of almost 5 mph about 4 hours into the deployment when
the satellite is about 9 miles distant.  From this point, the
speed with which the tether is fed out will gradually decrease
through the rest of the procedure, coming to a stop almost 5
and half hours after the initial movement, when the satellite
is almost 12.5 miles from Atlantis.  Just prior to the
satellite arriving on station at 12.5 miles distant, the
quarter-revolution spin will be stopped briefly to measure
tether dynamics and then, a seven-tenths of a revolution-per-
minute spin will be imparted to it.  At full deploy, the
tension on the tether or the pull from the satellite is
predicted to be equivalent to about 10 pounds of force.

     The tether, in total, is 13.7 miles long, allowing an
extra 1.2 miles of spare tether that is not planned to be
unwound during the mission.

Dynamics Functional Objectives

     During the deploy of TSS, several tests will be conducted
to explore control and dynamics of a tethered satellite.
Models of deployment have shown that the longer the tether
becomes, the more stable the system becomes.  The dynamics and
control tests to be conducted during deploy also will aid in
preparing for retrieval of the satellite and serve to verify
the ability to control the satellite during that operation.
During retrieval, it is expected that the stability of the
system will decrease as the tether is shortened, just opposite
the way stability increased as the tether was lengthened during
deploy.

     The dynamics tests involve maintaining a constant tension
on the tether and correcting any of several possible
disturbances to it.  Possible disturbances include:  a bobbing
motion, also called a plumb bob, where the satellite bounces
slightly on the tether causing it to alternately slacken and
tighten; a vibration of the tether, called a libration,
resulting in a clock-pendulum type movement of tether and
satellite; a pendulous motion of the satellite or a rolling and
pitching action by the satellite at the end of the tether; and
a lateral string mode disturbance, a motion where the satellite
and Shuttle are stable, but the tether is moving back and forth
in a "skip rope" motion.  All of these disturbances may occur
naturally and are not unexpected.  However, some disturbances
will be induced intentionally.

     The first test objectives will be performed before the
satellite reaches 200 yards from Atlantis and will involve
small firings of Atlantis' steering jets to test the
disturbances these may impart to the tether and satellite.  The
crew will test three different methods of damping the libration
(clock  pendulum) motion expected to be created in the tether
and the pendulous (rolling and pitching) motion expected in the
satellite.  First, using visual contact with the satellite, to
manually stabilize it from onboard the Shuttle by remotely
firing TSS's attitude thrusters.  Second, using the telemetry
information from the satellite to manually fire the satellite's
attitude thrusters.  Third, using an automatic attitude control
system for the satellite via the Shuttle's flight control
computers to automatically fire the TSS thrusters and stabilize
the system.

     Another test will be performed when the satellite is about
2.5 miles from Atlantis.  Atlantis' autopilot will be adjusted
to allow the Shuttle to wobble by as much as 10 degrees in any
direction before steering jets automatically fire to maintain
Atlantis' orientation.  The 10-degree deadband will be used to
judge any disturbances that may be imparted to the satellite if
a looser attitude control is maintained by Atlantis.  The
standard deadband, or degree of wobble, set in Shuttle
autopilot for the tethered satellite operations is 2 degrees of
wobble.  Tests using the wider deadband will allow the crew and
flight controllers to measure the amount of motion the
satellite and tether impart to Atlantis.

     When the satellite is fully deployed and on station at
12.5 miles, Atlantis will perform jet firings to judge
disturbances imparted to the tether and satellite at that
distance.

     Dampening of the various motions expected to occur in the
tether and satellite will be accomplished while at 12.5 miles
using electrical current flow through the tether.  During
retrieval, test objectives will be met using a combination of
the Shuttle's steering jets, a built-in dampening system at the
end of the deploy boom and the satellite's steering jets.

Retrieval Operations

     Satellite retrieval will occur more slowly than
deployment.  The rate of tether retrieval, the closing rate
between Atlantis and the satellite, will build after 5 hours
since first movement to a peak rate of about 3 miles per hour.
At that point, when the satellite is about 4 and a half miles
from Atlantis, the rate of retrieval will gradually decrease,
coming to a halt 10 hours after start of retrieval operations
when the satellite is 1.5 miles from Atlantis.

     The satellite will remain at 1.5 miles from Atlantis for
about 5 hours of science operations before the final retrieval
begins.  Final retrieval of the satellite is expected to take
about 2 hours.  A peak rate of closing between Atlantis and the
satellite of about 1.5 miles per hour will be attained just
after the final retrieval begins, and the closing rate will
decrease gradually through the remainder of the operation.  The
closing rate at the time the satellite is docked to the cradle
at the end of the deployer boom is planned to be less than one-
tenth of 1 mile per hour.

TSS-1 SCIENCE OPERATIONS

     Speeding through the magnetized ionospheric plasma at
almost 5 miles per second, a 12-mile-long conducting tethered
system should create a variety of very interesting plasma-
electrodynamic phenomena.  These are expected to provide unique
experimental capabilities, including the ability to collect an
electrical charge and drive a large current system within the
ionosphere; generate high voltages (on the order of 5
kilovolts) across the tether at full deployment; control the
satellite's electrical potential and its plasma sheath (the
layer of charged particles created around the satellite); and
generate low-frequency electrostatic and electromagnetic waves.
It is believed that these capabilities can be used to conduct
controlled experimental studies of phenomena and processes that
occur naturally in plasmas throughout the solar system,
including Earth's magnetosphere.

     A necessary first step toward these studies -- and the
primary science goal of the TSS-1 mission -- is to characterize
the electrodynamic behavior of the satellite-tether-orbiter
system.  Of particular interest is the interaction of the
system with the charged particles and electric and magnetic
fields in the ionosphere.

     A circuit must be closed to produce an electrical current.
For example, in a simple circuit involving a battery and a
light bulb, current travels down one wire from the battery to
the bulb, through the bulb and back to the battery via another
wire completing the circuit.  Only when the the circuit is
complete will the bulb illuminate.  The conductive outer skin
of the satellite collects free electrons from the space plasma,
and the induced voltage causes the electrons to flow down the
conductive tether to the Shuttle.  Then, they will be ejected
back into space with electron guns.

     Scientists expect the electrons to travel along magnetic
field lines in the ionosphere to complete the loop.  TSS-1
investigators will use a series of interdependent experiments
conducted with the electron guns and tether current-control
hardware, along with a set of diagnostic instruments, to assess
the nature of the external current loop within the ionosphere
and the processes by which current closure occurs at the
satellite and the orbiter.

Science Operations

     The TSS-1 mission is comprised of 11 scientific
investigations selected jointly by NASA and the Italian Space
Agency.  In addition, the U.S. Air Force's Phillips Laboratory,
by agreement, is providing an experimental investigation.
Seven investigations provide equipment that either stimulates
or monitors the tether system and its environment.  Two
investigations will use ground-based instruments to measure
electromagnetic emissions from the Tethered Satellite System as
it passes overhead, and three investigations were selected to
provide theoretical support in the areas of dynamics and
electrodynamics.

     Most of the TSS-1 experiments require measurements of
essentially the same set of physical parameters, with
instrumentation from each investigation providing different
parts of the total set.  While some instruments measure
magnetic fields, others record particle energies and densities,
and still others map electric fields.  A complete set of data
on plasma and field conditions is required to provide an
accurate understanding of the space environment and its
interaction with the tether system.  TSS-1 science
investigations, therefore, are interdependent.  They must share
information and operations to achieve their objectives.  In
fact, these investigations may be considered to be different
parts of a single complex experiment.

     The TSS-1 principal and associate investigators and their
support teams will be located in a special Science Operations
Center at the Mission Control Center in Houston.  During the
tethered satellite portion of the STS-46 flight, all 12 team
leaders will be positioned at a conference table in the
operations center.  Science data will be available to the
entire group, giving them an integrated "picture" of conditions
observed by all the instruments.  Together, they will assess
performance of the experiment objectives.  Commands to change
any instrument mode that affects the overall data set must be
approved by the group, because such a change could impact the
overall science return from the mission.  Requests for
adjustments will be relayed by the mission scientist, the
group's leader, to the science operations director for
implementation.

     The primary scientific data will be taken during the
approximately 10.5-hour phase (called "on-station 1") when the
satellite is extended to the maximum distance above the
Shuttle. Secondary science measurements will be taken prior to
and during deployment, during "on-station 1," and as the
satellite is reeled back to the orbiter.  However, during the
latter phase, satellite recovery has a higher priority than
continued science data gathering.

     Science activities during the TSS-1 mission will be
directed by the science principal investigator team and
implemented by a payload cadre made up primarily of Marshall
Space Flight Center employees and their contractors.  Science
support teams for each of the 12 experiments will monitor the
science hardware status.  From the Science Operations Center at
Mission Control, the principal investigator team will be able
to evaluate the quality of data obtained, replan science
activities as needed and direct adjustments to the instruments.
The cadre will be led by a science operations director, who
will work closely with the mission scientist, the mission
manager and Mission Control's payloads officer to coordinate
science activities.

     During the mission, most activities not carried out by the
crew will be controlled by command sequences, or timeline
files, written prior to the mission and stored in an onboard
computer.  For maximum flexibility, however, during all TSS
phases, modifications to these timeline files may be uplinked,
or commands may be sent in real-time from the Science
Operations Center to the on-board instruments.

SCIENCE  INVESTIGATIONS

TSS Deployer Core Equipment and Satellite Core Equipment (DCORE/SCORE)

Principal Investigator:

Dr. Carlo Bonifazi
Italian Space Agency, Rome, Italy

     The Tethered Satellite System Core Equipment controls the
electrical current flowing between the satellite and the
orbiter.  It also makes a number of basic electrical and
physical measurements of the system.

     Mounted on the aft support structure in the Shuttle cargo
bay, the Deployer Core Equipment features an electron
accelerator with two electron beam emitters that can each eject
up to 500 milli-amperes (one-half amp) of current from the
system.  A master switch, power distribution and electronic
control unit, and command and data interfaces also are included
in the deployer core package.  A voltmeter measures tether
potential with respect to the orbiter structure, and a vacuum
gauge measures ambient gas pressure to prevent operations if
pressure conditions might cause electrical arcing.

     Core equipment located on the satellite itself includes an
accelerometer to measure satellite movements and an ammeter to
measure tether current collected on the skin of the TSS-1
satellite.

Research on Orbital Plasma Electrodynamics (ROPE)

Principal Investigator:

Dr. Nobie Stone
NASA Marshall Space Flight Center, Huntsville, Ala.

     This experiment studies behavior of ambient charged
particles in the ionosphere and ionized neutral particles
around the satellite under a variety of conditions.
Comparisons of readings from its instruments should allow
scientists to determine where the particles come from that make
up the tether current as well as the distribution and flow of
charged particles in the space immediately surrounding the
satellite.

     The Differential Ion Flux Probe, mounted on the end of the
satellite's fixed boom, measures the energy, temperature,
density and direction of ambient ions that flow around the satellite
as well as neutral particles that have been ionized in its plasma
sheath and accelerated outward by the sheath's electric field.

     The Soft Particle Energy Spectrometer is actually five
electrostatic analyzers -- three mounted at different locations
on the surface of the satellite itself, and the other two
mounted with the Differential Ion Flux Probe on the boom.
Taken together, measurements from the two boom-mounted sensors
can be used to determine the electrical potential of the sheath
of ionized plasma surrounding the satellite.  The three
satellite-mounted sensors will measure geometric distribution
of the current to the satellite's surface.

Research on Electrodynamic Tether Effects (RETE)

Principal Investigator:

Dr. Marino Dobrowolny
Italian National Research Council, Rome, Italy

     This experiment measures the electrical potential in the
plasma sheath around the satellite and identifies waves excited
by the satellite and tether system.  The instruments are
located in two canisters at the end of the satellite's
extendible booms.  As the satellite spins, the booms are
extended, and the sensors sweep the plasma around the entire
circumference of the spacecraft.  To produce a profile of the
plasma sheath, measurements of direct-current potential and
electron currents are made both while the boom is fully
extended and as it is being extended or retracted.  The same
measurements, taken at a fixed distance from the spinning
satellite, produce a map of the angular structure of the
sheath.

Magnetic Field Experiment for TSS Missions (TEMAG)

Principal Investigator:

Prof. Franco Mariani
Second University of Rome, Italy

     The primary goal of this investigation is to map the
levels and fluctuations in magnetic fields around the
satellite.  Two magnetometers -- very accurate devices for
measuring such fields -- are located on the fixed boom of the
satellite, one at its end and the other at its midpoint.
Comparing measurements from the two magnetometers allows real-
time estimates to be made of unwanted disturbances to the
magnetic fields produced by the presence of satellite
batteries, power systems, gyros, motors, relays and other
magnetic material.  After the mission, the variable effects of
switching satellite subsystems on and off, of thruster firings
and of other operations that introduce magnetic disturbances
will be modeled on the ground, so these satellite effects can
be subtracted from measurements of the ambient magnetic fields
in space.

Shuttle Electrodynamic Tether System (SETS)

Principal Investigator:

Dr. Peter Banks
University of Michigan, Ann Arbor

     This investigation studies the ability of the tethered
satellite to collect electrons by determining current and
voltage of the tethered system and measuring the resistance to
current flow in the tether itself.  It also explores how tether
current can be controlled by the emission of electrons at the
orbiter end of the system and characterizes the charge the
orbiter acquires as the tether system produces power,
broadcasts low-frequency radio waves and creates instabilities
in the surrounding plasma.

     The hardware is located on the support structure in the
orbiter cargo bay.  In addition to three instruments to
characterize the orbiter's charge, the experiment includes a
fast-pulse electron accelerator used to help neutralize the
orbiter's charge.  It is located close to the core electron gun
and aligned so beams from both are parallel.  The fast-pulse
accelerator acts as a current modulator, emitting electron
beams in recognizable patterns to stimulate wave activity over
a wide range of frequencies.  The beams can be pulsed with
on/off times on the order of 100 nanoseconds.

Shuttle Potential and Return Electron Experiment (SPREE)

Associate Investigators:

Dr. Dave Hardy and Capt. Marilyn Oberhardt
Dept. of the Air Force, Phillips Laboratory, Bedford, Mass.

     Also located on the support structure, this experiment
will measure populations of charged particles around the
orbiter.  Measurements will be made prior to deployment to
assess ambient space conditions as well as during active TSS-1
operations.  The measurements will determine the level of
orbiter charging with respect to the ambient space plasma,
characterize the particles returning to the orbiter as a result
of TSS-1 electron beam ejections and investigate local wave-
particle interactions produced by TSS-1 operations.  Such
information is important in determining how the Tethered
Satellite System current is generated, and how it is affected
by return currents to the orbiter.  The experiment uses two
sets of two nested electrostatic analyzers each, which rotate
at approximately 1 revolution per minute, sampling the
electrons and ions in and around the Shuttle's cargo bay.

Tether Optical Phenomena Experiment (TOP)

Associate Investigator:

Dr. Stephen Mende
Lockheed, Palo Alto Research Laboratory, Palo Alto, Calif.

     This experiment uses a hand-held, low-light-level TV
camera system operated by the crew, to provide visual data to
allow scientists to answer a variety of questions about tether
dynamics and optical effects generated by TSS-1.  The imaging
system will operate in four configurations:  filtered,
interferometer, spectrographic and filtered with a telephoto
lens.  In particular, the experiment will image the high
voltage plasma sheath surrounding the satellite when it is
reeled back toward the orbiter near the end of the retrieval
stage of the mission.

Investigation of Electromagnetic Emissions for Electrodynamic
Tether (EMET)

Principal Investigator:

Dr. Robert Estes
Smithsonian Astrophysical Observatory, Cambridge, Mass.

Observations at the Earth's Surface of Electromagnetic Emission
by TSS (OESEE)

Principal Investigator:

Dr. Giorgio Tacconi, University of Genoa, Italy

     The main goal of these experiments is to determine how
well the Tethered Satellite System can broadcast from space.
Ground-based radio transmissions, especially below 15
kilohertz, are inefficient since most of the power supplied to
the antenna -- large portions of which are buried -- is
absorbed by the ground.  Since the Tethered Satellite System
operates in the ionosphere, it should radiate waves more
efficiently.  Magnetometers at several locations in a chain of
worldwide geomagnetic observatories and extremely low-fequency
receivers at the Arecibo Radio Telescope facility, Puerto Rico,
and other sites around the world, will try to measure the
emissions produced and track direction of the waves when
electron accelerators pulse tether current over specific land
reference points.  An Italian ocean surface and ocean bottom
observational facility also provides remote measurements for
TSS-1 emissions.

The Investigation and Measurement of Dynamic Noise in the TSS
(IMDN)

Principal Investigator:

Dr. Gordon Gullahorn
Smithsonian Astrophysical Observatory, Cambridge, Mass.

Theoretical and Experimental Investigation of TSS Dynamics (TEID)

Principal Investigator:

Prof. Silvio Bergamaschi
Institute of Applied Mechanics, Padua University, Padua, Italy

     These two investigations will analyze data from a variety
of instruments to examine Tethered Satellite System dynamics or
oscillations over a wide range of frequencies.  Primary
instruments will be accelerometers and gyros on board the
satellite, but tether tension and length measurements and
magnetic field measurements also will be used.  The dynamics
will be observed in real-time at the Science Operations Center
and later, subjected to detailed post-flight analysis.  Basic
theoretical models and simulations of tether movement will be
verified, extended or corrected as required.  Then they can be
used confidently in the design of future systems.

Theory and Modeling in Support of Tethered Satellite
Applications (TMST)

Principal Investigator:

Dr. Adam Drobot
Science Applications International Corp., McLean, Va.

     This investigation provides theoretical electro-dynamic
support for the mission.  Numerical models were developed of
anticipated current and voltage characteristics, plasma sheaths
around the satellite and the orbiter and of the system's
response to the operation of the electron accelerators.  These
models tell investigators monitoring the experiments from the
ground what patterns they should expect to see in the data.

THE TSS-1 TEAM

     Within NASA, the Tethered Satellite System program is
directed by the Office of Space Flight and the Office of Space
Science and Applications.  The Space Systems Projects Office at
the Marshall Space Flight Center, Huntsville, Ala., has
responsibility for project management and overall systems
engineering.  Experiment hardware systems were designed and
developed by the U.S. and Italy.  Responsibility for
integration of all hardware, including experiment systems, is
assigned to the project manager at the Marshall center.  The
Kennedy Space Center, Florida, is responsible for launch-
processing and launch of the TSS-1 payload.  The Johnson Space
Center, Houston, has responsibility for TSS-1/STS integration
and mission operations.

     R.J. Howard of the Office of Space Science and
Applications, NASA Headquarters, Washington, D.C., is the TSS-1
Science Payload Program Manager.  The TSS Program Manager is
Tom Stuart of the Office of Space Flight, NASA Headquarters.
Billy Nunley is NASA Project Manager and TSS-1 Mission Manager
at the Marshall Space Flight Center.  Dr. Nobie Stone, also of
Marshall, is the NASA TSS-1 Mission Scientist, the TSS Project
Scientist and Co-chairman of the Investigator Working Group.

     For the Italian Space Agency, Dr. Gianfranco Manarini is
Program Manager for TSS-1, while the Program Scientist is Dr.
F. Mariani.  Dr. Marino Dobrowolny is the Project Scientist for
the Italian Space Agency, and Co-chairman of the investigator
group.  Dr. Maurizio Candidi is the Mission Scientist for the
Italian Space Agency.

     Martin Marietta, Denver, Colo., developed the tether and
control system deployer for NASA.  Alenia in Turin, Italy,
developed the satellite for the Italian Space Agency.

TSS-1 SCIENCE INVESTIGATIONS

            Title                  Institution (Nation)

Research on Electrodynamic
CNR or Italian National
Tether Effects Research Council     (Italy)

Research on Orbital Plasma          NASA/MSFC (U.S.)
Electrodynamics

Shuttle Electrodynamic Tether Sys   University of
                                    Michigan (U.S.)

Magnetic Field Experiments          Second University of Rome
for TSS Missions                    (Italy)

Theoretical & Experimental          Univ. of Padua (Italy)
Investigation of TSS Dynamics

Theory & Modeling in Support        SAIC (U.S.)
of Tethered Satellite

Investigation of Electromagnetic    Smithsonian Astrophysical
Emissions for Electrodynamic        Observatory (U.S.)
Tether

Investigation and Measurement of    Smithsonian Astrophysical
Dynamic Noise in TSS                Observatory (U.S.)

Observation on Earth's Surface of   Univ. of Genoa (Italy)
Electromagnetic Emissions by TSS

Deployer Core Equipment and Satellite  ASI (Italy)
Core Equipment

Tether Optical Phenomena Experiment Lockheed (U.S.)

Shuttle Potential & Return          Dept. of the Air Force
Electron Experiment                 Phillips Laboratory (U.S.)

EUROPEAN RETRIEVABLE CARRIER (EURECA)

     The European Space Agency's (ESA) EURECA will be launched
by the Space Shuttle and deployed at an altitude of 425 km.  It
will ascend, using its own propulsion, to its operational orbit
of 515 km.  After 6 to 9 months in orbit, it will descend to
the lower orbit where it will be retrieved by another orbiter
and brought back to Earth.  It will refurbished and equipped
for the next mission.

     The first mission (EURECA-1) primarily will be devoted to
research in the fields of material and life sciences and
radiobiology, all of which require a controlled microgravity
environment.  The selected microgravity experiments will be
carried out in seven facilities.  The remaining payload
comprises space science and technology.

     During the first mission, EURECA's residual carrier
accelerations will not exceed 10-5g.  The platform's altitude
and orbit control system makes use of magnetic torquers
augmented by cold gas thrusters to keep disturbance levels
below 0.3 Nm during the operational phase.

Physical characteristics

o  Launch mass                                  4491 kg
o  Electrical power solar array                 5000w
o  Continuous power to EURECA experiments       1000w
o  Launch configuration               dia: 4.5m, length: 2.54m
o  Volume                                       40.3m
o  Solar array extended                         20m x 3.5

User friendly

     Considerable efforts have been made during the design and
development phases to ensure that EURECA is a "user friendly"
system.  As is the case for Spacelab, EURECA has standardized
structural attachments, power and data

EURECA-1L

interfaces.  Unlike Spacelab, however, EURECA has a
decentralized payload control concept.  Most of the onboard
facilities have their own data handling device so that
investigators can control the internal operations of their
equipment directly.  This approach provides more flexibility as
well as economical advantages.

Operations

     EURECA is directly attached to the Shuttle cargo bay by
means of a three-point latching system.  The spacecraft has
been designed with a minimum length and a close-to-optimum
length-to-mass ratio, thus helping to keep down launch and
retrieval costs.

     All EURECA operations will be controlled by ESA's Space
Operations Centre (ESOC) in Darmstadt, Germany.  During the
deployment and retrieval operations, ESOC will function as a
Remote Payload Operations Control Centre to NASA's Mission
Control Center, Houston, and the orbiter will be used as a
relay station for all the commands.  In case of unexpected
communication gaps during this period, the orbiter crew has a
back-up command capability for essential functions.

     Throughout the operational phase, ESOC will control EURECA
through two ground stations at Maspalomas and Korrou.  EURECA
will be in contact with its ground stations for a relatively
short period each day.  When it is out of contact, or
"invisible", its systems operate with a high degree of
autonomy, performing failure detection, isolation and recovery
activities to safeguard ongoing experimental processes.

     An experimental advanced data relay system, the Inter-
orbit Communication package, is included in the first payload.
This package will communicate with the European Olympus
Communication Satellite to demonstrate the possible
improvements for future communications with data relay
satellites.  As such a system will significantly enhance
realtime data coverage, it is planned for use on subsequent
EURECA missions to provide an operational service via future
European data relay satellites.

EURECA Retrievable Carrier

Structure

     The EURECA structure is made of high strength carbon-fibre
struts and titanium nadal points joined together to form a
framework of cubic elements.  This provides relatively low
thermal distortions, allows high alignment accuracy and simple
analytical verification, and is easy to assemble and maintain.
Larger assemblies are attached to the nadal points.
Instruments weighing less than 100 kg are assembled on standard
equipment support panels similar to those on a Spacelab pallet.

Thermal Control

     Thermal control for EURECA combines active and passive
heat transfer and radiation systems.  Active transfer, required
for payload facilities which generated more heat, is achieve by
means of a freon cooling loop which dissipates the thermal load
through two radiators into space.  The passive system makes use
of multilayer insulation blankets combined with electrical
heaters.  During nominal operations, the thermal control
subsystem rejects a maximum heat load of about 2300 w.

Electrical Power

     The electrical power subsystem generates, stores,
conditions and distributes power to all the spacecraft
subsystems and to the payload.  The deployable and retracable
solar arrays, with a combined raw power output of some 5000 w
together with four 40 amp-hour (Ah) nickel-cadmium batteries,
provide the payload with a continuous power of 1000 w,
nominally at 28 volts, with peak power capabilities of up to
1500 w for several minutes.  While EURECA is in the cargo bay,
electric power is provided by the Shuttle to ensure that
mission critical equipment is maintained within its temperature
limits.

 Attitude and Orbit Control

     A modular attitude and orbit control subsystem (AOCS) is
used for attitude determination and spacecraft orientation and
stabilization during all flight operations and orbit control
manoeuvres.  The AOCS has been designed for maximum autonomy.
It will ensure that all mission requirements are met even in
case of severe on-board failures, including non-availability of
the on-board data handling subsystem for up to 48 hours.

     An orbit transfer assembly, consisting of two redundant
sets of four thrusters, is used to boost EURECA to its
operation attitude at 515 km and to return it to its retrieval
orbit at about 300 km.  The amount of onboard propellant
hydrazine is sufficient for the spacecraft to fly different
mission profiles depending on its nominal mission duration
which may be anywhere between 6 and 9 months.

     EURECA is three-axis stabilized by means of a magnetic
torque assembly together with a nitrogen reaction control
assembly (RCA).  This specific combination of actuators was
selected because its' control accelerations are well below the
microgravity constraints of the spacecraft.  The RCA cold gas
system can be used during deployment and retrieval operations
without creating any hazards for the Shuttle.

Communications and Data Handling

     EURECA remote control and autonomous operations are
carried out by means of the data handling subsystem (DHS)
supported by the telemetry and telecommand subsystems which
provide the link to and from the ground segment.  Through the
DHS, instructions are stored and executed, telemetry data is
stored and transmitted, and the spacecraft and its payload are
controlled when EURECA is no longer "visible" from the ground
station.

EURECA SCIENCE

Solution Growth Facility (SGF)

Principal Investigator:

J.C. Legros
Universite Libre de Bruxelles, Brussels, Belgium

     The Solution Growth Facility (SGF) is a multi-user
facility dedicated to the growth of monocrystals from solution,
consisting of a set of four reactors and their associated
control system.

     Three of the reactors will be used for the solution growth
of crystals.  These reactors have a central buffer chamber
containing solvent and two reservoirs containing reactant
solutions.  The reservoirs are connected to the buffer chamber
by valves which allow the solutions to diffuse into the solvent
and hence, to crystallize.

     The fourth reactor is divided into twenty individual
sample tubes which contain different samples of binary organic
mixtures and aqueous electrolyte solutions.  This reactor is
devoted to the measurement of the Soret coefficient, that is,
the ratio of thermal to isothermal diffusion coefficient.

     The SGF has been developed under ESA contract by Laben and
their subcontractors Contraves and Terma.

Protein Crystallization Facility (PCF)

Principal Investigator:

W. Littke
Chemisches Laboratorium, Universitat Freiburg, Freiburg,
Germany

     The Protein Crystallization Facility (PCF) is a multi-user
solution growth facility for protein crystallization in space.
The object of the experiments is the growth of single, defect-
free protein crystals of high purity and of a size sufficient
to determine their molecular structure by x-ray diffraction.
This typically requires crystal sizes in the order of a few
tenths of a millimeter.

     The PCF contains twelve reactor vessels, one for each
experiment.  Each reactor, which is provided with an
individually controlled temperature environment, has four
chambers -- one containing the protein, one containing a buffer
solution and two filled with salt solutions.  When the reactors
have reached their operating temperatures, one of the salt
solution chambers, the protein chamber and the buffer solution
chamber are opened.  Salt molecules diffuse into the buffer
chamber causing the protein solution to crystalize.  At the end
of the mission the second salt solution chamber is activated to
increase the salt concentration.  This stabilizes the crystals
and prevents them from dissolving when individual temperature
control for the experiments ceases and the reactors are
maintained at a common storage temperature.

     One particular feature of the PCF is that the
crystallization process can be observed from the ground by
means of a video system.

     The PCF has been developed under ESA contract by MBB
Deutsche Aerospace and their subcontractors Officine Galileo
and Reusser.

Exobiology And Radiation Assembly (ERA)

Principal Investigator:

H. Bucker
Institut fur Flugmedizin Abt. Biophysik, DLR, Cologne, Germany

     The Exobiology and Radiation Assembly (ERA) is a multi-
user life science facility for experiments on the biological
effects of space radiation.  Our knowledge of the interaction
of cosmic ray particles with biological matter, the synergism
of space vacuum and solar UV, and the spectral effectiveness of
solar UV on viability should be improved as a result of
experiments carried out in the ERA.

     The ERA consists of deployable and fixed experiment trays
and a number of cylindrical stacks, known as Biostacks,
containing biological objects such as spores, seeds or eggs
alternated with radiation and track detectors.  An electronic
service module also is included in the facility.  The
deployable trays carry biological specimens which are exposed
to the different components of the space radiation environment
for predetermined periods of time.  The duration of exposure is
controlled by means of shutters and the type of radiation is
selected by the use of optical bandpass filters.

The ERA has been developed under ESA contract by Sira Ltd..

Multi-Furnace Assembly (MFA)

Principal Investigator:

A. Passerone
Ist. di Chimica Fisica Applicata dei Materiali, National
Research Council (CNR), Genova, Italy

     The Multi-Furnace Assembly (MFA) is a multi-user facility
dedicated to material science experiments.  It is a modular
facility with a set of common system interfaces which
incorporates twelve furnaces of three different types, giving
temperatures of up to 1400xC.  Some of the furnaces are
provided by the investigators on the basis of design
recommendations made by ESA.  The remainder are derived from
furnaces flown on other missions, including some from sounding
rocket flights.  These are being used on EURECA after the
necessary modifications and additional qualification.  The
experiments are performed sequentially with only one furnace
operating at any one time.

     The MFA has been developed under ESA contract by Deutsche
Aerospace, ERNO Raumfahrttechnik and their subcontractors SAAB,
Aeritalia, INTA and Bell Telephone.

Automatic Mirror Furnace (AMF)

Principal Investigator:

K.W. Benz
Kristallographisches Institut, Universitat Freiburg, Freiburg,
Germany

     The Automatic Mirror Furnace (AMF) is an optical radiation
furnace designed for the growth of single, uniform crystals
from the liquid or vapor phases, using the traveling heater or
Bridgman methods.

     The principal component of the furnace is an ellipsoidal
mirror.  The experimental material is placed at the lower ring
focus of the mirror and heated by radiation from a 300 w
halogen lamp positioned at the upper focus.  Temperatures of up
to 1200xC can be achieved, depending on the requirements of
individual samples.  Seven lamps are available and up to 23
samples can be processed in the furnace.

     As the crystal grows, the sample holder is withdrawn from
the mirror assembly at crystallization speed, typically 2
mm/day, to keep the growth site aligned with the furnace focus.
The sample also is rotated while in the furnace.

     The AMF is the first of a new generation of crystal growth
facilities equipped with sample and lamp exchange mechanisms.
Fully automatic operations can be conducted in space during
long microgravity missions on free flying carriers.  During a 6
month mission, about 20 different crystal growth experiments
can be performed.

     The AMF has been developed under ESA contract by Dornier
Deutsche Aerospace and their subcontractors Laben, ORS and SEP.

Surface Forces Adhesion Instrument (SFA)

Principal Investigator:

G. Poletti
Universita di Milano, Milan, Italy

     The Surface Forces Adhesion instrument (SFA) has been
designed to study the dependence of surface forces and
interface energies on physical and chemical-physical parameters
such as surface topography, surface cleanliness, temperature
and the deformation properties of the contacting bodies.  The
SFA experiment aims at refining current understanding of
adhesion-related phenomena, such as friction and wear, cold
welding techniques in a microgravity environment and solid body
positioning by means of adhesion.

     Very high vacuum dynamic measurements must be performed in
microgravity conditions because of the extreme difficulty
experienced on Earth in controlling the physical parameters
involved.  As a typical example, the interface energy of a
metallic sphere of 1 g mass contacting a pane target would be
of the order of 10-3 erg. corresponding to a potential
gravitational energy related to a displacement of 10-5 mm.  In
the same experiment performed on the EURECA platform, in a 10
to 100,000 times lower gravity environment, this energy
corresponds to a displacement of 1 mm, thus considerably
improving measurements and reducing error margins.

     The SFA instrument has been funded by the Scientific
Committee of the Italian Space Agency (ASI) and developed by
the University of Milan and their subcontractors
Centrotechnica, Control Systems and Rial.

High Precision Thermostat Instrument (HPT)

Principal Investigator:

G. Findenegg
Ruhr Universitat Bochum, Bochum, Germany

     Basic physics phenomena around the critical point of
fluids are not, as yet, fully understood.  Measurements in a
microgravity environment, made during the German mission D-1,
seem to be at variance with the expected results.  Further
investigations of critical phenomena under microgravity
conditions are of very high scientific value.

     The High Precision Thermostat (HPT) is an instrument
designed for long term experiments requiring microgravity
conditions and high precision temperature measurement and
control.  Typical experiments are "caloric", "critical point"
or "phase transition" experiments, such as the "Adsorption"
experiment designed for the EURECA mission.

     This experiment will study the adsorption of Sulphur
Hexafluoride (SF6), close to its critical point (Tc=45.55xC,
pc=0.737 g/cm3) on graphitised carbon.  A new volumetric
technique will be used for the measurements of the adsorption
coefficient at various temperatures along the critical isochore
starting from the reference temperature in the one-phase region
(60x) and approaching the critical temperature.  The results
will be compared with 1g measurements and theoretical
predictions.

     The HPT has been developed under DLR contract by Deutsche
Aerospace ERNO Raumfahrttechnik and their subcontractor Kayser-
Threde GmbH.

Solar Constant And Variability Instrument (SOVA)

Principal Investigator:

D. Crommelynck
IRMB, Brussels, Belgium

     The Solar Constant and Variability Instrument (SOVA) is
designed to investigate the solar constant, its variability and
its spectral distribution, and measure:

  o  fluctuations of the total and spectral solar irradiance
within periods of a few minutes up to several hours and with a
resolution of 10-6 to determine the pressure and gravity modes
of the solar oscillations which carry information on the
internal structure of the sun;

  o  short term variations of the total and spectral solar
irradiance within time scales ranging from hours to few months
and with a resolution of 10-5 for the study of energy
redistribution in the solar convection zone.  These variations
appear to be associated with solar activities (sun spots);

  o  long term variations of the solar luminosity in the time
scale of years (solar cycles) by measuring the absolute solar
irradiance with an accuracy of better than 0.1 percent and by
comparing it with previous and future measurements on board
Spacelab and other space vehicles.  This is of importance for
the understanding of solar cycles and is a basic reference for
climatic research.

     The SOVA instrument has been developed by the Institut
Royal Meteorologique de Belgique of Brussels, by the
Physikalisch-Meteorologishces Observatorium World Radiation
Center (PMOD/WRC) Davos and by the Space Science Department
(SSD) of the European Space Agency (ESA-ESTEC), Noordwijk.

Solar Spectrum Instrument (SOSP)

Principal Investigator:

G. Thuillier
Service d'Aeronomie du CNRS, Verrieres le Buisson, France

     The Solar Spectrum Instrument (SOSP) has been designed for
the study of solar physics and the solar-terrestrial
relationship in aeronomy and climatology.  It measures the
absolute solar irradiance and its variations in the spectral
range from 170 to 3200 nm, with an expected accuracy of 1
percent in the visible and infrared ranges and 5 percent in the
ultraviolet range.

     Changes in the solar irradiance mainly relate to the
short-term solar variations that have been observed since 1981
by the Solar Maximum spacecraft, the variations related to the
27-day solar rotation period and the long-term variations
related to the 11-year sun cycles.  While the short term
variations can be measured during one single EURECA flight
mission, two or three missions are needed to assess the long
term variations.

     SOSP has been developed by the Service d'Aeronomie of the
Centre National de Recherche Scientifique (CNRS), the Institut
d'Aeronomie Spatiale de Belgique (IASB), the Landassternwarte
Koenigstuhl and the Hamburger Sternwarte.

Occultation Radiometer Instrument (ORA)

Principal Investigator:

E. Arijs
Belgisch Instituut voor Ruimte Aeronomie (BIRA), Brussels,
Belgium

     The Occultation Radiometer instrument (ORA) is designed to
measure aerosols and trace gas densities in the Earth's
mesosphere and stratosphere.  The attenuation of the various
spectral components of the solar radiation as it passes through
the Earth's atmosphere enables vertical abundance profiles for
ozone, nitrogen dioxide, water vapor, carbon dioxide and
background and volcanic aerosols to be determined for altitudes
between 20 and 100 km.

     The ORA instrument has been developed by the Institut
d'Aeronomie Spatiale, and the Clarendon Laboratory of the
University of Oxford.

Wide Angle Telescope (WATCH)

Principal Investigator:

N. Lund
Danish Space Research Institute, Lyngby, Denmark

     The Wide Angle Telescope (WATCH) is designed to detect
celestial gamma and x-ray sources with photon energies in the
range 5 to 200 keV and determine the position of the source.

     The major objective of WATCH is the detection and
localization of gamma-ray bursts and hard x-ray transients.
Persistent x-ray sources also can be observed.

     Cosmic gamma-ray bursts are one of the most extreme
examples of the variability of the appearance of the x-ray sky.
They rise and decay within seconds, but during their life they
outshine the combined flux from all other sources of celestial
x- and gamma rays by factors of up to a thousand.

     Less conspicuous, but more predictable are the x-ray novae
which flare regularly, typically with intervals of a few years.
In the extragalactic sky, the "active galactic nuclei" show
apparently are random fluctuations in their x-ray luminosity
over periods of days or weeks.

     WATCH will detect and locate these events.  The data from
the experiment can be used to provide light curves and energy
for the sources.  The data also may be searched for
regularities in the time variations related to orbital movement
or rotation or for spectral features that yield information
about the source.  Additionally, other, more powerful sky
observation instruments can be alerted to the presence of
objects that WATCH has detected as being in an unusual state of
activity.

WATCH has been developed by the Danish Space Research
Institute.

Timeband Capture Cell Experiment (TICCE)

Principal Investigator:

J.A.M. McDonnell
Unit for Space Science, Physics Laboratory
University of Kent, Great Britain

     The Timeband Capture Cell Experiment (TICCE) is an
instrument designed for the study of the microparticle
population in near-Earth space -- typically Earth debris,
meteoroids and cometary dust.  The TICCE will capture micron
dimensioned particles with velocities in excess of 3 km/s and
store the debris for retrieval and post-mission analysis.

     Particles detected by the instrument pass through a front
foil and into a debris collection substrate positioned 100 nm
behind the foil.  Each perforation in the foil will have a
corresponding debris site on the substrate.  The foil will be
moved in 50 discrete steps during the six month mission, and
the phase shift between the debris site and the perforation
will enable the arrival timeband of the particle to be
determined.  Between 200 and 300 particles are expected to
impact the instrument during the mission.  Ambiguities in the
correlation of foil perforations and debris sites will probably
occur for only a few of the impacts.

     Elemental analysis of the impact sites will be performed,
using dispersive x-ray techniques, once the instrument has
returned to Earth.

     TICCE has been developed by the University of Kent.  Its
structural support has been sponsored by ESA and subcontracted
to SABCA under a Deutsche Aerospace ERNO Raumfahrttechnik
contract.

Radio Frequency Ionization Thruster Assembly (RITA)

Principal Investigator:

H. Bassner
MBB Deutsche Aerospace, Munich, Germany

     The Radio Frequency Ionization Thruster Assembly (RITA) is
designed to evaluate the use of electric propulsion in space
and to gain operational experience before endorsing its use for
advanced spacecraft technologies.

     The space missions now being planned - which are both more
complex and of longer duration - call for increased amounts of
propellant for their propulsion systems which, in turn, leads
to an increase in the overall spacecraft mass to the detriment
of the scientific or applications payload.  Considerable
savings can be made in this respect by the use of ion
propulsion systems, wherein a gas is ionized and the positive
ions are them accelerated by an electric field.  In order to
avoid spacecraft charging, the resulting ion beam is then
neutralized by an electron emitting device, the neutralizer.
The exhaust velocities obtained in this way are about an order
of magnitude higher than those of chemical propulsion systems.

     RITA has been developed under ESA and BMFT
 contract by Deutsche Aerospace ERNO Raumfahrttechnik.

Inter-Orbit Communication (IOC)

R. Tribes
CNES Project Manager, CNES-IOC
Toulouse, France

N. Neale
ESA Project Manager, ESTEC-CD
Noordwijk, The Netherlands

     The Inter-Orbit Communication (IOC) instrument is a
technological experiment designed to provide a pre-operational
inflight test and demonstration of the main functions, services
and equipment typical of those required for a data relay
system, namely:

o  bi-directional, end-to-end data transmission between the
user spacecraft and a dedicated ground station via a relay
satellite in the 20/30 GHz frequency band;

o  tracking of a data relay satellite;

o  tracking of a user spacecraft;

o  ranging services for orbit determination of a user
spacecraft via a relay satellite.

     In this case, the EURECA platform is the user spacecraft
and the ESA communications satellite Olympus the relay
satellite.  One of the Olympus steerable spot beam antennas
will be pointed towards the IOC on EURECA and the other towards
the IOC ground station.  The IOC instrument is provided with a
mobile directional antenna to track Olympus.

     The IOC has been developed under ESA contract by CNES and
their subcontractors Alocatel Espace, Marconi Space Systems,
Laben, Matra Espace, Sener, Alcatel Bel, AEG-Telefunken, ETCA,
TEX, MDS and COMDEV.

Advanced Solar Gallium Arsenide Array (ASGA)

Principal Investigator:

C. Flores
CISE SPA, Segrate, Italy

     The Advanced Solar Gallium Arsenide Array (ASGA) will
provide valuable information on the performance of gallium
arsenide (GaAs) solar arrays and on the effects of the low
Earth orbit environment on their components.  These solar
cells, already being used in a trial form to power the Soviet
MIR space station, are expected to form the backbone of the
next generation of compact, high power-to-weight ratio European
solar energy generators.

     The most significant environmental hazards encountered
arise from isotropic proton bombardment in the South Atlantic
Anomaly, high frequency thermal cycling fatigue of solar cell
interconnections and the recently discovered atomic oxygen
erosion of solar array materials.  Although a certain amount of
knowledge may be gained from laboratory experiments, the
crucial confirmation of the fidelity of the GaAs solar array
designs awaits the results of flight experiments.

     The project has been sponsored by the Italian Space Agency
(ASI) and developed by CISE with its subcontractor, Carlo
Gavazzi Space.  The planar solar module has been assembled by
FIAR.  The miniature Cassegranian concentrator components have
been developed in collaboration with the Royal Aircraft
Establishments and Pilkington Space Technology.

     EURECA has been developed under ESA contract by Deutsche
Aerospace, ERNO Raumfahrttechnik, (Germany), and their
subcontractors Sener, (England), AIT, (Italy), SABCA,
(Belgium), AEG, (Germany), Fokker, (The Netherlands), Matra,
(France), Deutsche Aerospace, ERNO Raumfahrttechnik, (Germany),
SNIA-BPD, (Italy), BTM, (Belgium), and Laben, (Italy).

F. Schwan - Industrial Project Manager
Deutsche Aerospace, ERNO Raumfahrttechnik, Bremen, Germany

W. Nellessen - ESA Project Manager
ESTEC MR, Noordwijk, The Netherlands

EVALUATION OF OXYGEN INTERACTION WITH MATERIALS/TWO PHASE
MOUNTING PLATE EXPERIMENT (EOIM-III/TEMP 2A-3)

EOIM

     The Evaluation of Atomic Oxygen Interactions with
Materials (EOIM) payload will obtain accurate reaction rate
measurements of the interaction of space station materials with
atomic oxygen.  It also will measure the local Space Shuttle
environment, ambient atmosphere and interactions between the
two.  This will improve the understanding of the effect of the
Shuttle environment on Shuttle and payload operations and will
update current models of atmospheric composition.  EOIM also
will assess the effects of environmental and material
parameters on reaction rates.

     To make these measurements, EOIM will use an ion-neutral
mass spectrometer to obtain aeronomy measurements and to study
atom-surface interaction products.  The package also provides a
mass spectrometer rotating carousel system containing RmodeledS
polymers for mechanistic studies.  EOIM also will study the
effects of mechanical stress on erosion rates of advanced
composites and the effects of temperature on reaction rates of
disk specimens and thin films.  Energy accommodations on
surfaces and surface-atom emission characteristics concerning
surface recession will be measured using passive
scatterometers.  The payload also will assess solar ultraviolet
radiation reaction rates.

     The environment monitor package will be activated pre-
launch, while the remainder of the payload will be activated
after payload bay door opening.  Experiment measurements will
be made throughout the flight, and the package will be powered
down during de-orbit preparations.

TEMP

     The Two Phase Mounting Plate Experiment (TEMP 2A-3) has
two-phase mounting plates, an ammonia reservoir, mechanical
pumps, a flowmeter, radiator and valves, and avionics
subsystems.  The TEMP is a two-phase thermal control system
that utilizes vaporization to transport large amounts of heat
over large distances.  The technology being tested by TEMP is
needed to meet the increased thermal control requirements of
space station.  The TEMP experiment will be the first
demonstration of a mechanically pumped two-phase ammonia
thermal control system in microgravity.  It also will evaluate
a propulsion-type fluid management reservoir in a two-phase
ammonia system, measure pressure drops in a two-phase fluid
line, evaluate the performance of a two-phase cold plate design
and measure heat transfer coefficients in a two-phase boiler
experiment.  EOIM-III/TEMP 2A-3 are integrated together on a
MPESS payload carrier in the payload bay.

EOIM 111/TEMP 2A

CONSORTIUM FOR MATERIALS DEVELOPMENT IN SPACE COMPLEX
AUTONOMOUS PAYLOAD (CONCAP)

     The Consortium for Materials Development in Space Complex
Autonomous Payload (CONCAP) is sponsored by NASA's Office of
Commercial Programs (OCP).  On STS-46, two CONCAP payloads
(CONCAP-II and -III) will be flown in 5-foot cylindrical GAS
(Get Away Special) canisters.

     CONCAP-II is designed to study the changes that materials
undergo in low-Earth orbit.  This payload involves two types of
experiments to study the surface reactions resulting from
exposing materials to the atomic oxygen flow experienced by the
Space Shuttle in orbit.  The atomic oxygen flux level also will
be measured and recorded.  The first experiment will expose
different types of high temperature superconducting thin films
to the 5 electron volt atomic oxygen flux to achieve improved
properties.  Additional novel aspects of this experiment are
that a subset of the materials samples will be heated to 320
degrees Celsius (the highest temperature used in space), and
that the material resistance change of 24 samples will be
measured on-orbit.

     For the second CONCAP-II experiment, the surface of
different passive materials will be exposed (at ambient and
elevated temperatures) to hyperthermal oxygen flow.  This
experiment will enable enhanced prediction of materials
degradation on spacecraft and solar power systems.  In
addition, this experiment will test oxidation-resistant
coatings and the production of surfaces for commercial use,
development of new materials based on energetic molecular beam
processing and development of an accurate data base on
materials reaction rates in orbit.

     CONCAP-III is designed to measure and record absolute
accelerations (microgravity levels) in one experiment and to
electroplate pure nickel metal and record the conditions
(temperature, voltage and current) during this process in
another experiment.  Items inside the orbiter experience
changes in acceleration when various forces are applied to the
orbiter, including thruster firing, crew motion and for STS-46,
tethered satellite operations.  By measuring absolute
accelerations, CONCAP-III can compare the measured force that
the orbiter undergoes during satellite operations with
theoretical calculations.  Also, during accelerations
measurements, CONCAP-III can gather accurate acceleration data
during the electroplating experiments.

     The second CONCAP-III experiment is an electroplating
experiment using pure nickel metal.  This experiment will
obtain samples for analysis as part of a study of microgravity
effects on electroplating.  Materials electroplated in low
gravity tend to have different structures than materials
electroplated on Earth.  Electroplating will be performed
before and during the tethered satellite deployment to study
the differences that occur for different levels of
accelerations.

     The CONCAP-II and -III experiments are managed and
developed by the Consortium for Materials Development in Space,
a NASA Center for the Commercial Development of Space at the
University of Alabama in Huntsville (UAH).  Payload integration
and flight hardware management is handled by NASA's Goddard
Space Flight Center, Greenbelt, Md.

     Dr. John C. Gregory and Jan A. Bijvoet of UAH are
Principal investigator and payload manager, respectively, for
CONCAP-II.  For CONCAP-III, principal investigator for the
acceleration experiment is Bijvoet, principal investigator for
the electrodeposition (electroplating) is Dr. Clyde Riley, also
of UAH, and payload manager is George W. Maybee of McDonnell
Douglas Space Systems Co., Huntsville, Ala.

LIMITED DURATION SPACE ENVIRONMENT CANDIDATE MATERIALS EXPOSURE
(LDCE)

     The first of the Limited Duration Space Environment
Candidate Materials Exposure (LDCE) payload series is sponsored
by NASA's Office of Commercial Programs (OCP).  The LDCE
project on STS-46 represents an opportunity to evaluate
candidate space structure materials in low-Earth orbit.

     The objective of the project is to provide engineering and
scientific information to those involved in materials selection
and development for space systems and structures.  By exposing
such materials to representative space environments, an
analytical model of the performance of these materials in a
space environment can be obtained.

     The LDCE payload consists of three separate experiments,
LDCE-1, -2 and -3, which will examine the reaction of 356
candidate materials to at least 40 hours exposure in low-Earth
orbit.  LDCE-1 and -2 will be housed in GAS (Get Away Special)
canisters with motorized door assemblies.  LDCE-3 will be
located on the top of the GAS canister used for CONCAP-III.
Each experiment has a 19.65-inch diameter support disc with a
15.34-inch diameter section which contains the candidate
materials.  The support disc for LDCE-3 will be continually
exposed during the mission, whereas LDCE-1 and -2 will be
exposed only when the GAS canisters' doors are opened by a crew
member.  Other than opening and closing the doors, LDCE payload
operations are completely passive.  The doors will be open once
the Shuttle achieves orbit and will be closed periodically
during Shuttle operations, such as water dumps, jet firings and
changes in attitude.

     Two primary commercial goals of the flight project are to
identify environmentally-stable structural materials to support
continued humanization and commercialization of the space
frontier and to establish a technology base to service growing
interest in space materials environmental stability.

LDCE

     The LDCE payload is managed and developed by the Center
for Materials on Space Structures, a NASA Center for the
Commercial Development of Space at Case Western Reserve
University (CWRU) in Cleveland.  Dr. John F. Wallace, Director
of Space Flight Programs at CWRU, is lead Investigator.  Dawn
Davis, also of CWRU, is program manager.

PITUITARY GROWTH HORMONE CELL FUNCTION (PHCF)

Principal Investigator:

Dr. W.C. Hymer
The Pennsylvania State University, University Park, Pa.

	The Pituitary Growth Hormone Cell Function (PHCF)
experiment is a middeck-locker rodent cell culture experiment.
It continues the study of the influence of microgravity on
growth hormone secreted by cells isolated from the brain's
anterior pituitary gland.

	PHCF is designed to study whether the growth hormone-
producing cells of the pituitary gland have an internal gravity
sensor responsible for the decreased hormone release observed
following space flight.  This hormone plays an important role
in muscle metabolism and immune-cell function as well as in the
growth of children.  Growth hormone production decreases with
age.  The decline is thought to play an important role in the
aging process.

	The decreased production of biologically active growth
hormone seen during space flight could be a factor in the loss
of muscle and bone strength and the decreased immune response
observed in astronauts following space flight.  If the two are
linked, PHCF might identify mechanisms for providing
countermeasures for astronauts on long space missions.  It also
may lead to increased understanding of the processes underlying
human muscle degeneration as people age on Earth.

	The PHCF experiment uses cultures of living rat pituitary
cells.  These preparations will be placed in 165 culture vials
carried on the Shuttle's middeck in an incubator.  After the
flight, the cells will be cultured and their growth hormone
output assayed.

IMAX CARGO BAY CAMERA (ICBC)

     The IMAX Cargo Bay Camera (ICBC) is aboard STS-46 as part
of NASA's continuing collaboration with the Smithsonian
Institution in the production of films using the IMAX system.
This system, developed by IMAX Corp., Toronto, Canada, uses
specially-designed 70 mm film cameras and projectors to produce
very high definition motion picture images which, accompanied
by six channel high fidelity sound, are displayed on screens up
to ten times the size used in conventional motion picture
theaters.

PHCF

ICBC

"The Dream is Alive" and "Blue Planet," earlier products of
this collaboration, have been enjoyed by millions of people
around the world.  On this flight, the camera will be used
primarily to cover the EURECA and Tether Satellite operations,
plus Earth scenes as circumstances permit.  The footage will be
used in a new film dealing with our use of space to gain new
knowledge of the universe and the future of mankind in space.
Production of these films is sponsored by the Lockheed
Corporation.

AIR FORCE MAUI OPTICAL SYSTEM (AMOS)

     The Air Force Maui Optical System (AMOS) is an electrical-
optical facility located on the Hawaiian island of Maui.  The
facility tracks the orbiter as it flies over the area and
records signatures from thruster firings, water dumps or the
phenomena of shuttle glow, a well-documented glowing effect
around the shuttle caused by the interaction of atomic oxygen
with the spacecraft.

     The information obtained is used to calibrate the infrared
and optical sensors at the facility.  No hardware onboard the
shuttle is needed for the system.

ULTRAVIOLET PLUME EXPERIMENT

     The Ultraviolet Plume Experiment (UVPI) is an instrument
on the Low-Power Atmospheric Compensation Experiment (LACE)
satellite launched by the Strategic Defense Initiative
Organization in February 1990.  LACE is in a 43-degree
inclination orbit of 290 n.m.  Imagery of Columbia's engine
firings or attitude control system firings will be taken on a
non-interference basis by the UVPI whenever an opportunity is
available during the STS-46 mission.

STS-46 CREW BIOGRAPHIES

     Loren J. Shriver, 47, Col., USAF, will serve as commander
of STS-46.  Selected as an astronaut in January 1978, Shriver
considers Paton, Iowa, his hometown and will be making his
third space flight.

     Shriver graduated from Paton Consolidated High School,
received a bachelor's in aeronautical engineering from the Air
Force Academy and received a master's in aeronautical
engineering from Purdue University.

     Shriver was pilot of STS-51C in January 1985, a Department
of Defense-dedicated shuttle flight.  He next flew as commander
of STS-31 in April 1990, the mission that deployed the Hubble
Space Telescope.  Shriver has logged more than 194 hours in
space.

     Andrew M. Allen, 36, Major, USMC, will serve as pilot.
Selected as an astronaut in June 1987, Allen was born in
Philadephia, Pa., and will be making his first space flight.

     Allen graduated from Archbishop Wood High School in
Warminster, Pa., in 1973 and received a bachelor's in
mechanical engineering from Villanova University in 1977.

     Allen was commissioned in the Marine Corps in 1977.
Following flight school, he was assigned to fly the F-4 Phantom
at the Marine Corps Air Station in Beaufort, S.C.  He graduated
from the Navy Test Pilot School in 1987 and was a test pilot
under instruction at the time of his selection by NASA.  He has
logged more than 3,000 flying hours in more than 30 different
types of aircraft.

     Claude Nicollier, 47, will be Mission Specialist 1 (MS1).
Under an agreement between the European Space Agency and NASA,
he was selected as an astronaut in 1980.  Nicollier was born in
Vevey, Switzerland, and will be making his first space flight.

     Nicollier graduated from Gymnase de Lausanne, Lausanne,
Switzerland, received a bachelor's in physics from the
University of Lausanne and received a master's in astrophysics
from the University of Geneva.

     In 1976, he accepted a fellowship at ESA's Space Science
Dept., working as a research scientist in various airborne
infrared astronomy programs.  In 1978, he was selected by ESA
as one of three payload specialist candidates for the Spacelab-
1 shuttle mission, training at NASA for 2 years as an
alternate.  In 1980, he began mission specialist training.
Nicollier graduated from the Empire Test Pilot School, Boscombe
Down, England, in 1988, and holds a commission as Captain in
the Swiss Air Force.  He has logged more than 4,300 hours
flying time, 2,700 in jet aircraft.

      Marsha S. Ivins, 41, will be Mission Specialist 2 (MS2).
Selected as an astronaut in 1984, Ivins was born in Baltimore,
Md., and will be making her second space flight.

     Ivins graduated from Nether Providence High School,
Wallingford, Pa., and received a bachelor's in aerospace
engineering from the University of Colorado.

     Ivins joined NASA shortly after graduation and was
employed at the Johnson Space Center as an engineer in the Crew
Station Design Branch until 1980.  she was assigned as a flight
simulation engineer aboard the Shuttle Training Aircraft and
served as co-pilot of the NASA administrative aircraft.

     She first flew on STS-32 in January 1990, a mission that
retrieved the Long Duration Exposure Facility (LDEF).  She has
logged more than 261 hours in space.

     Jeffrey A. Hoffman, 47, will be Mission Specialist 3 (MS3)
and serve as Payload Commander.  Selected as an astronaut in
January 1978, Hoffman considers Scarsdale, N.Y., his hometown
and will be making his third space flight.

     Hoffman graduated from Scarsdale High School, received a
bachelor's in astronomy from Amherst College, received a
doctorate in astrophysics from Harvard University and received
a master's in materials science from Rice University.

     Hoffman first flew on STS-51D in April 1985, a mission
during which he performed a spacewalk in an attempt to rescue a
malfunctioning satellite.  He next flew on STS-35 in December
1990, a mission carrying the ASTRO-1 astronomy laboratory.

     Franklin R. Chang-Diaz will be Mission Specialist 4 (MS4).
Selected as an astronaut in May 1980, Chang-Diaz was born in
San Jose, Costa Rica, and will be making his third space
flight.

     Chang-Diaz graduated from Colegio De La Salle in San Jose
and from Hartford High School, Hartford, Ct.; received a
bachelor's in mechanical engineering from the University of
Connecticut and received a doctorate in applied physics from
the Massachusetts Institute of Technology.

     Chang-Diaz first flew on STS-61C in January 1986, a
mission that deployed the SATCOM KU satellite.  He next flew on
STS-34 in October 1989, the mission that deployed the Galileo
spacecraft to explore Jupiter.  Chang-Diaz has logged more than
265 hours in space.

     Franco Malerba, 46, will serve as Payload Specialist 1
(PS1).  An Italian Space Agency payload specialist candidate,
Malerba was born in Genova, Italy, and will be making his first
space flight.

     Malerba graduated from Maturita classica in 1965, received
a bachelor's degree in electrical engineering from the
University of Genova in 1970 and received a doctorate in
physics from the University of Genova in 1974.

     From 1978-1980, he was a staff member of the ESA Space
Science Dept., working on the development and testing of an
experiment in space plasma physics carried aboard the first
shuttle Spacelab flight.  From 1980-1989, he has held various
technical and management positions with Digital Equipment Corp.
in Europe, most recently as senior telecommunications
consultant at the European Technical Center in France.  Malerba
is a founding member of the Italian Space Society.

MISSION MANAGEMENT FOR STS-46

NASA HEADQUARTERS, WASHINGTON, D.C.

Office of Space Flight
Jeremiah W. Pearson III - Associate Administrator
Brian O'Connor - Deputy Associate Administrator
Tom Utsman - Director, Space Shuttle

Office of Space Science
Dr. Lennard A. Fisk - Associate Administrator, Office of Space Science
	and Applications
Alphonso V. Diaz - Deputy Associate Administrator, Office of Space Science
	and Applications
George Withbroe - Director, Space Physics Division
R.J. Howard - TSS-1 Science Payload Program Manager

Office of Commercial Programs
John G. Mannix  - Assistant Administrator
Richard H. Ott - Director, Commercial Development Division
Garland C. Misener - Chief, Flight Requirements and Accommodations
Ana M. Villamil - Program Manager, Centers for the Commercial Development
	of Space Office of Safety and Mission Quality
Col. Federick Gregory - Associate Administrator
Dr. Charles Pellerin, Jr. - Deputy Associate Administrator
Richard Perry - Director, Programs Assurance

KENNEDY SPACE CENTER, FLA.

Robert L. Crippen - Director
James A. "Gene" Thomas - Deputy Director
Jay F. Honeycutt - Director, Shuttle Management and Operations
Robert B. Sieck - Launch Director
Conrad G. Nagel - Atlantis Flow Director
J. Robert Lang - Director, Vehicle Engineering
Al J. Parrish - Director of Safety Reliability and Quality Assurance
John T. Conway - Director, Payload Management and Operations
P. Thomas Breakfield - Director, Shuttle Payload Operations
Joanne H. Morgan - Director, Payload Project Management
Robert W. Webster - STS-46 Payload Processing Manager

MARSHALL SPACE FLIGHT CENTER, HUNTSVILLE, ALA.

Thomas J. Lee - Director
Dr. J. Wayne Littles - Deputy Director
Harry G. Craft - Manager, Payload Projects Office
Billy Nunley - TSS-1 Mission Manager
Dr. Nobie Stone - TSS-1 Mission Scientist
Alexander A. McCool - Manager, Shuttle Projects Office
Dr. George McDonough - Director, Science and Engineering
James H. Ehl - Director, Safety and Mission Assurance
Otto Goetz - Manager, Space Shuttle Main Engine Project
Victor Keith Henson - Manager, Redesigned Solid Rocket Motor Project
Cary H. Rutland - Manager, Solid Rocket Booster Project
Gerald C. Ladner - Manager, External Tank Project

JOHNSON SPACE CENTER, HOUSTON, TEX.

Paul J. Weitz - Director (Acting)
Paul J. Weitz - Deputy Director
Daniel Germany - Manager, Orbiter and GFE Projects
Donald R. Puddy - Director, Flight Crew Operations
Eugene F. Krantz - Director, Mission Operations
Henry O. Pohl - Director, Engineering
Charles S. Harlan - Director, Safety, Reliability and Quality Assurance

STENNIS SPACE CENTER, BAY ST. LOUIS, MISS.

Roy S. Estess - Director
Gerald Smith - Deputy Director
J. Harry Guin - Director, Propulsion Test Operations

AMES-DRYDEN FLIGHT RESEARCH FACILITY, EDWARDS, CALIF.

Kenneth J. Szalai - Director
T. G. Ayers - Deputy Director
James R. Phelps - Chief, Space Support Office

AMES RESEARCH CENTER, MOUNTAIN VIEW, CALIF.

Dr. Dale L. Compton		Director
Victor L. Peterson		Deputy Director
Dr. Steven A. Hawley		Associate Director
Dr. Joseph C. Sharp		Director, Space Research