"6_2_2_43_2_22.TXT" (105330 bytes) was created on 02-04-93

STS-55 PRESS KIT


                       STS-55 PRESS KIT

                       FEBRUARY 3, 1993


PUBLIC AFFAIRS CONTACTS


NASA Headquarters, Washington, D.C.

Office of Space Flight/Office of Space Systems Development
Mark Hess/Jim Cast/Ed Campion


Office of Space Science and Applications
Paula Cleggett-Haleim/Mike Braukus/Brian Dunbar


Office of Policy Coordination & International Relations
Debra Rahn


Office of Space Communications/Office of Safety & Mission Quality
Dwayne Brown


Dryden Flight Research Facility, Edwards, Calif.
Nancy Lovato


Goddard Space Flight Center, Greenbelt, Md.
Dolores Beasley


Marshall Space Flight Center, Huntsville, Ala.
June Malone


Johnson Space Center, Houston
James Hartsfield


Kennedy Space Center, Fla.
George Diller


Stennis Space Center, Miss.
Myron Webb


CONTENTS

GENERAL BACKGROUND

     General Release                  03
     Media Services Information.      07
     DLR Newsroom Operations          08
     Quick-Look Facts                 09
     Payload and Vehicle Weights      10
     STS-55 Orbital Events Summary     10
     Summary Timeline                  11
     Space Shuttle Abort Modes.        12

PAYLOADS & ACTIVITIES

Spacelab-D2                          13
Spacelab-D2 Payloads/Experiments     15
Material Sciences Laboratory/Experiments      17
Optics Laboratory/Experiments                 23
Baroreflex Experiment                         24
Robotics Experiment                           25
Anthrorack/Experiments                        26
Biolabor/Experiments                          33
Cosmic Radiation/Experiments                  37
Material Science Autonomous Payload/Experiments   38
Atomic Oxygen Exposure Tray                       39
Galactic Ultrawide-Angle Schmidt System Camera    39
Modular Optoelectronic Multispectral Stereo Scanner    40
Crew Telesupport Experiment                            40
Shuttle Amateur Radio Experiment (SAREX)               40


CREW BIOGRAPHIES & MISSION MANAGEMENT

STS-55 Crew Biographies                    43
Mission Management for STS-55               46

STS-55 General Release
Second German Spacelab Mission is SPACE Shuttle's 54th Flight

Release:  93-20                          February 1993

        The 54th flight of the Space Shuttle will be devoted 
primarily to Germany for conducting a wide range of experiments in 
the microgravity environment of space flight.

        Columbia, the flagship of the Shuttle fleet, will make its 
14th voyage into Earth orbit carrying a crew of seven, including 
two German payload specialists.  STS-55's primary payload is 
Spacelab D2, for the second Shuttle mission dedicated to Germany.  
Spacelab D1 was flown in 1985.  Spacelab is a self-contained, 
space-based research laboratory carried inside the Shuttle's 60-
foot-long cargo bay. 

        The seven member crew is a mix of veterans and first-time 
space travelers.  Commander Steve Nagel and mission specialist 
Jerry Ross will both be making their 4th trip into orbit.  STS-55 
will mark Pilot Tom Henricks' second flight.  Mission specialist 
Charles Precourt and Bernard Harris will be making their first 
space flights, as will the two German payload specialists Ulrich 
Walter and Hans Schlegel.

        Mission management resides in the German Aerospace Research 
Establishment (DLR), the scientific program responsibility in the 
German Space Agency (DARA).  Payload control and operation during 
the mission are handled by DLR's Space Operation Control Center 
(GSOC) at Oberpfaffenhofen near Munich, Germany.

        Columbia is scheduled to be launched from the Kennedy Space 
Center (KSC), Fla., in late February.  The mission is planned for 
9 days with a landing at KSC.

        Some 90 experiments are planned during the mission.  The 7-
member crew will be divided into two teams, red and blue, so that 
science operations can be carried out around the clock. 

        Most of the experiments have been provided by the German 
Space Agency and the European Space Agency (ESA).  Japan has 
provided a number of experiments, and NASA is furnishing 3 
experiments for this mission.  

        In addition to developing the concept of Spacelab itself, 
ESA will fly a total of 21 experiments. and participate in 11 
experiments.  Five are contained in the Advanced Fluid Physics 
Module and 19 are placed in the unique equipment facility, called 
Anthrorack, for human physiological research in microgravity.  Six 
other experiments are in the field of materials synthesis and two 
flight experiments are for the future Columbus Attached 
Pressurized Module, which will form part of the international 
Space Station Freedom.  

        NASA also is flying its "ham" radio experiment, SAREX, which 
will enable Nagel and Ross to talk to schools and amateur radio 
enthusiasts on the ground.  Both German payload specialists are 
licensed ham radio operators as well and will be operating their 
own ham system called SAFEX.

        One payload that had been manifested on STS-55, BREMSAT, was 
removed prior to launch and will be reflown later this year.  The 
payload was to have been deployed into space from a getaway 
special canister (GAS) to detect micrometeorites in near-Earth 
orbit and to measure cosmic dust.  NASA mangers delayed the flight 
of the BREMSAT because problems with another GAS-deployed payload 
flown on STS-53 have not been satisfactorily resolved. 

        Most of the Spacelab D2 experiments will explore the 
behavior of humans, other living organisms and materials when the 
force of gravity is essentially removed.  

        "Our scientific methods, like our everyday behavior, are 
governed by a natural condition - the effect of gravity," said 
DLR's Spacelab D2 Project Manager Dr. Hauke Dodeck.  "Objects fall 
down, lighter materials float or are carried upwards, heavier ones 
sink to the bottom. 

        "What happens to these processes when there is no 
gravitational force, in other words:  no sedimentation, no thermal 
convection, no hydrostatic pressure?  What new mixtures, 
structures and forms are possible?" he posed. "Concrete answers to 
such questions can be given only by space research."

        D2 experiments will be carried out in 6 major scientific 
disciplines:  materials sciences, biological sciences, technology, 
Earth observations, atmospheric physics and astronomy.  Most of 
the experiments are contained in racks, about the size of a side-
by-side refrigerator, inside the Spacelab module.  A special 
fixture, called the Unique Support Structure, has been placed in 
Columbia's cargo bay.  Astronomy, Earth-observing instruments and 
materials which require direct exposure to space are mounted to 
this structure.

        In the materials sciences field, among the experiments to be 
performed are those involved in growing semiconductor materials.  
For this mission, the material will be gallium arsenide - a 
semiconductor of great importance for electronic applications.  
The objective is to produce crystals of high quality and large 
size.  It is expected that the results will contribute to the 
improvement of terrestrial crystal growth methods.

        The Material Sciences Laboratory will be the site for 
experiments on alloys and for experiments which use the 
microgravity environment to produce single-crystal bodies of a 
shape similar to a turbine blade.  

        "If the tests produce the hoped-for results," said Dodeck, 
"turbine blades can be developed which are strongly resistant to 
heat and stress, thereby improving the performance and lifetime of 
aircraft engines."  

        An experimental facility called the Holographical Optical 
Laboratory (HOLOP) will use holography to gain insight into 
processes of heat and mass transfer and of cooling in transparent 
materials which are of great interest for reserarch into 
metallurgy and casting. 

        "HOLOP will transmit video pictures of experiments to the 
ground while they are being performed," Dodeck explained.  
"Scientists on Earth can not only watch what happens, but also may 
intervene in the test sequence, thus demonstrating a concept 
called telescience."  The telescience experiment will be carried 
out from DLR's Microgravity Life Support Center (MUSC) at Cologne-
Porz.

        Other experiments will focus on protein crystal growth and 
biology.  One experiment will use electrical impulses in an 
attempt to fuse cells to create hybrids.  The results will advance 
both basic and applied research. 

        An experiment called the Statolith Experiment will study the 
development of balance-sensing organs in tadpoles of the South 
American clawed frog and larvae of a type of colored perch.  An 
understanding of how those sensors develop, when not influenced by 
gravity, could lead to new insights into the causes of space 
sickness.

        "D2 will use the human body as a test subject," said Dodeck.  
"A special medical research facility on this flight, called 
Anthrorack, is the most advanced of its type which has flown in 
space."  

        Some 20 different experiments will be performed in the 
facility, ranging from investigations on body organs and their 
controlling mechanisms, control of heart and blood circulation, to 
the functions of the lungs.  In addition, a multitude of 
physiological processes will be observed. 

        A robotic technology experiment, called ROTEX, will gather 
basic experience on how a robot can operate in microgravity.  A 
robot arm with 6 joints will perform a variety of tasks, including 
building a small tower of cubes and retrieving a small object 
floating in space.  The robot can be operated from onboard or by 
scientists on the ground.  Both modes will be tested.

        Investigations on the effects of radiation upon organisms 
also will be studied.  Astronauts will wear radiation detectors.  
Other detectors will be placed near biological experiments as 
control indicators.  The results will contribute to the assessment 
of the biological effects of specific cosmic radiation, which will 
help reduce the health risks for future missions.

        Part of the ongoing preparations for the assembly and 
operation of Space Station Freedom, over 200 samples of different 
materials will be placed on the support structure in the payload 
bay to gather data on interaction with atomic oxygen.  The goal is 
to examine how different materials - polymers, compounds and 
organic films - stand up to atomic oxygen which is of keen 
interest to builders of the orbiting outpost which will be in 
space at least 3 decades.

        Another instrument mounted outside, called MOMS, will obtain 
data to enable topographical maps to be produced by automatic data 
evaluation processes for the first time.  A spherical mirror 
camera, GAUSS, which also is fixed to the payload bay structure, 
will take pictures in six spectral bands of all parts of the Milky 
Way, thereby extending the knowledge of the galaxy.  

                    -end of general release-

STS-55 MEDIA SERVICES INFORMATION

NASA Select Television Transmissions

        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 Shuttle 
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 available daily at noon EST.

Status Reports

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

Briefings

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

D2 NewsRoom Operations
 
        A D2 mission news center will be established at DLR's 
Operations Control Center/German Space Operations Center (GSOC) at 
Oberpfaffenhofen, where mission science operations will be 
controlled.  Media work space and facilities will be available on 
a limited basis and will be allocated on a daily first-come, 
first-served basis.

        News media planning to cover the mission from the D2 news 
center should contact DLR's Public Affairs Office, Linder Hohe, 
5000 Koln-Porz, by writing or sending a request via fax at (02203) 
601-3249.
 
Operating Hours

        The D2 news center will be open from 9 a.m. untill 6 p.m. 
local time.  Media which plan mission related reports early in the 
morning will have access to the news center and will be provided 
with pertinent information.  Media will have access to mission 
timing and tracking displays.

Staffing

        The D2 news center will be staffed by DLR public affairs 
officers, by public affairs officers representing the German Space 
Agency, the European Space agency, the German space industry, NASA 
and other experts.  An interview desk in the news center will 
arrange and schedule interviews with mission participants.
 
Briefings, Status Reports And Press Releases

        D2 status briefings will originate from the D2 news center 
at 12:30 p.m. local time, daily throughout the mission.  Status 
reports and press releases in German will be issued once daily at 
1 p.m. local time.  English translations will be provided soon 
after release.

Mission Television

        Coverage emanating from GSOC will include television from 
Spacelab and Space Shuttle and its payload bay and from the 
Payload Control Rooms in Oberpfaffenhofen and special programming. 
Special programming includes video highlights as well as comments 
and interviews by mission participants. 

        The "All-TV" program will originate from GSOC and will be 
distributed by Deutsche Bundespost/Telekom.  "All-TV" is available 
on DFS Kopernikus 2, Transponder A2, located at 28.5 degrees, best 
downlink fequency 11.525 GHz.  The transmission is scheduled from 
11 a.m. to 5 p.m. 

STS-55 Quick Look


Launch Date/Site:     Feb. 25, 1993/Kennedy Space Center, Fla. 
                       Pad 39A

Launch Time:           10:20 a.m. EST

Orbiter:               Columbia (OV-102) - 14th Flight

Orbit/Inclination:       160 nautical miles/28.45 degrees

Mission Duration:        8 days, 22 hours, 2 minutes

Landing Time/Date:        8:25 a.m. EST/March 6, 1993

Primary Landing Site:     Kennedy Space Center, Fla.

Abort Landing Sites: 
Return to Launch Site    Kennedy Space Center, Fla.
TransAtlantic Abort      Banjul, The Gambia
                          Ben Guerir, Morroco
                          Moron, Spain
Abort Once Around         Edwards AFB, Calif.
                          Kennedy Space Center, Fla.
                          White Sands, N.M.

Crew:                     Steve Nagel, Commander (CDR)
                          Tom Henricks, Pilot (PLT)
                          Jerry Ross, Mission Specialist 1 (MS1)
                          Charles Precourt, Mission 
                          Specialist 2 (MS2)
                          Bernard Harris, Jr.,
                          Mission Specialist 3 (MS3)
                          Ulrich Walter, Payload 
                          Specialist 1 (PS1)
                          Hans W. Schlegel, Payload
                          Specialist 2 (PS2)

Blue Team:                Nagel, Henricks, Ross, Walter
Red Team:                 Precourt, Harris, Schlegel

Cargo Bay Payloads:       Spacelab D2
                          Reaction Kinetic in Glass Melts GAS

In-Cabin Payloads:        Shuttle Amateur Radio Experiment-II



STS-55 Orbital Events Summary

Event       Elapsed Time     Velocity         Orbit (n.m.)
                                                Change

Launch      00/00:00:00       N/A                N/A
OMS-2       00/00:42:00      220.9 fps       160 x 162 
Deorbit     08/21:05:00      TBD                N/A
Landing     08/22:05:00      N/A                N/A


STS-55 Vehicle and Payload Weights

Vehicle/Payload                              Pounds

Orbiter (Columbia) empty and 3 SSMEs         181,034

Spacelab D-2                                 25,025

RKGM                                           200

RKGM GAS Support Equipment                     190

SAREX-II                                       24

Total Vehicle at SRB Ignition              4,518,724

Orbiter Landing Weight                      227,494



STS-55 Summary Timeline

Flight Day One                          Flight Day Seven
Launch                                  Spacelab-D2 operations
OMS-2
Spacelab-D2 activation                   Flight Day Eight
                                         Spacelab-D2 operations
Flight Day Two
Spacelab-D2 operations                   Flight Day Nine
SAREX-II set-up                          Spacelab-D2 operations
                                          Reaction Control System
                                          hot-fire
Flight Day Three                          Flight Control Systems 
checkout
Spacelab-D2 operations                     Medical DSOs

                                           Flight Day Ten
Flight Day Four                            SAREX deactivation
Spacelab-D2 operations                     Spacelab-D2 
                                           deactivation
                                           Cabin stow
Flight Day Five                             Deorbit burn
Spacelab-D2 operations                      Entry
                                            Landing
Flight Day Six
Spacelab-D2 operations



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 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 Banjul, would result 
in a pitch around and thrust back toward KSC until within gliding 
distance of the Shuttle Landing Facility.


     STS-55 contingency landing sites are Edwards Air Force Base, 
the Kennedy Space Center, White Sands Space Harbor, Benjul, Ben 
Guerir and Moron.


SPACELAB D2

Overview
 
        The Spacelab D2 mission is the second under German mission 
management and responsibility.  The D1 mission was conducted in 
November 1985 with German and European astronauts on board.  

        Besides continuing research areas and scientific experiments 
from D1, the D2 mission will be multi-disciplinary covering the 
fields of materials and life sciences mainly dedicated to micro-g 
research and also to technology, automation, robotics and Earth 
and space observations.  Both the D1 and D2 missions are the only 
two Spacelab missions with payload operations control from foreign 
countries.
 
        Mission management resides in the German Research Aerospace 
Establishment (DLR) and program management in the German Space 
Agency (DARA).  Tasks performed by DLR are training of astronauts, 
flight planning and flight operations and payload control and 
operations.  Some 16 experiments are furnished by DLR, covering 
the fields of material sciences, life sciences, robotics (ROTEX) 
and earth observation (MOMS-02).  DASA/ERNO Raumfahrttechnik is 
responsible for payload integration, including preparation, 
corresponding tests and mission support.
 
        The experimental program of the D2 mission is oriented 
towards the goals of the space utilization program of the Federal 
Republic of Germany and also of the microgravity program of ESA.  
D2 includes some 90 experiments ranging from investigations of the 
dynamics of the solidification boundary to the electrofusion of 
cells.  Numerous universities, research institutes and industrial 
concerns in Germany and other countries, contribute to the 
scientific experimental program. 

        The cooperation with NASA goes beyond the provision of the 
Shuttle/Spacelab System.  The experiment Baroreflex and two 
further investigations are supported by the U.S. agency.  
Furthermore ESA, CNES (France) and MITI (Japan) are taking part in 
the mission.
 
        To guarantee that the D2 mission goes successfully, the 
payload specialists and the flight operations crew have been 
prepared for their tasks under "real" conditions.  The cooperation 
between the astronauts in space and the experts on Earth has been 
practiced within the framework of these "integrated simulations", 
as they are known. 

        For this purpose, the astronauts were "on board" the DLR 
Spacelab simulator in Cologne-Porz, while the ground teams were in 
the DLR Space Operation Control Center in Oberpfaffenhofen.  
"Shuttle" and "ground" worked round-the-clock in two 12-hour 
shifts.  Voice communication was by radio, as during the real 
flight.
 
        DLR's Control Center at Oberpfaffenhofen offers scientific 
spaceflight a modern ground system that allows control of all the 
experiments.  During the D1 mission, some still had to be 
monitored from Houston because the data transmission capacity was 
insufficient at that time.  However, it has been expanded 
considerably since then, and the data transmitted via satellite 
are now received by ground stations on the premises of the DLR and 
then forwarded to the computer installations in the Control 
Center. 

        Once the data have been edited and stored, they are 
distributed to the computers of the experimenters in the user 
control rooms in real-time mode.  The main data stream is 
forwarded to the processing system of the Control Center.  It is 
there that telemetry and telecommand data processing, mission 
planning and timeline compilation are handled, as well as 
distribution of the roughly 10,000 parameters to the workstations 
in the control and user rooms. 

Payload Operations
 
        The task "payload operations" covers all activities for 
operation of the payload, i.e. the experiments on board and the 
support from ground control during the preparation and execution 
of the D2 mission.  A large variety of activities are included:
 
        The responsibility to operate the payload lies within the 
German Aerospace Research Establishment (DLR).  This means that 
the D2 mission will be executed from two different agencies, NASA 
and DLR, and from two different countries, the United States and 
Germany.  The Mission Control Center (MCC) in Houston and the 
German Space Operations Center (GS0C) at Oberpfaffenhofen near 
Munich are supporting the mission in close cooperation. 

        In GSOC is located the mission operation support team which 
includes all the experimenters/investigators and their technical 
industrial support.  The cadre team directs the entire payload and 
is split into several subteams responsible for real time mission 
execution, replanning efforts and communication (data, voice, TV).  
In case of anomalies, experimenters and cadre team together to 
work out a solution that the astronauts in orbit will execute.  
The astronauts in orbit will work in two shifts around the clock, 
so GSOC and MCC are staffed for 24 hours a day during the 9-day 
mission.
 
        Three voice loops, data channels and TV channels are 
available between the orbiter/spacelab and the two control 
centers.  For communication between the two control centers, 19 
voice loops, data lines, TV-lines and fax lines will be used via 
different satellite systems.
 

Payloads/Experiments
SPACELAB D2 Material Sciences Laboratory/Experiments

Material Sciences Experiment Double Rack for Experiment Modules 
and Apparatus (MEDEA)
 
        MEDEA is located in rack 3 of the Spacelab module and 
accommodates three different experiment furnace facilities.  These 
furnaces are the Elliptical Mirror Furnace (ELLI), the Gradient 
Furnace (GFQ) and the High Precision Thermostat (HPT).

        The Elliptical Mirror Furnace is used for long-term 
crystallization experiments performed in microgravity.  Crystal 
growth is established by moving the sample along the main axis of 
the furnace traversing the focus.  The Gradient Furnace studies 
material processing in microgravity by direct solidification 
methods using metallic crystals grown at high temperatures.  The 
High Precision Thermostat investigates critical phenomena of 
metals under precisely controlled temperature conditions.

Experiments

        *FLOATING-ZONE-GROWTH OF GAAS
 
        GaAs is the most important material for high-speed 
electronic circuits, especially optoelectronic devices.  Under 1g, 
only crystals of a few mm in diameter can be grown due to the 
unfavorable ratio of density to surface tension.  In the D2 
experiment, a crystal of 20mm diameter will be crystallized, 
allowing a quantitative evaluation of the expected reduction of 
the structural defects in comparison with CZ- or Bridgman-grown 
material.  
 
        *FLOATING ZONE CRYSTAL GROWTH OF GALLIUM-DOPED GERMANIUM
 
        In-situ Seebeck measurements will be used to control non- 
stationary thermocapillary-driven flows during floating zone 
crystal growth of gallium doped germanium.  With the first sample, 
the influence of growth parameters will be investigated through 
several runs.  The results will be used to optimize the processing 
parameters for the second sample.  Quantitative post- flight 
analysis of convective effects will be made through extensive 
measurements of micro- and macro-segregations.   

        *Hysteresis of the specific heat CV during heating and 
         cooling through the critical point
 
        During the D2 mission, CV will be measured while heating and 
cooling the test substance SF6 through the critical state to 
investigate relaxational effects.  These are considered to be the 
dominant mechanism for the surprising results of the CV-
measurements during the D1 mission.  A new spherical cell, housed 
in the slightly refurbished High Precision Thermostat, is heated 
and cooled only by radiation from the surrounding shell.  CV is 
determined by the temperature difference between the cell and the 
shell.  Additionally, the temperature field in the fluid is 
measured by several thermistors to help answer the open question 
of the temperature equilibration at the critical point.  On line 
data processing during the mission provides the possibility of 
changing the experiment timeline if necessary.

        *Diffusion of Nickel in liquid Copper-Aluminum
         and copper-Gold Alloys

        The diffusion of nickel in liquid Cu-Al and Cu-Au alloys 
will be observed at 1150 1/2 C under minimized influences of 
convection.  The aim of this work is to determine the diffusion 
coefficient of nickel with respect to the concentration of the 
solute atoms Al and Au.  The concentration of the solute atoms is 
ranging from 0 to 5.5 at percent.

        *Directional Solidification of Ge/GaAS Eutectic composites

        The eutectic melt in Ge-GaAs solidifies into the layered 
structures having varied composition of the sub-micron thickness.  
The microstructures thus formed are compared in the light of the 
effects of gravity during unidirectional solidification.

        *Cellular-Dendritic Solidification with Quenching of
         aluminium-Lithium Alloys

        Critical microgravity experiments in the cellular and 
dendritic regimes will be carried out on aluminium-lithium alloys.  
Quenching at the end of the experiments will retain the tip radius 
and the microsegregation.  Reliable data for 3D-solification with 
pure diffusion in the liquid phase thus will be obtained, which 
will be used to test the theories of pattern formation and 
selection, especially of the primary spacing.  The comparison with 
1-g samples will enable the effects of convection to be evidenced.
 
        *Directional Solidification of a Cu-Mn alloy
 
        Three experiment runs of directional solidification of a Cu-
Mn alloy under low gravity will be used to investigate the 
transition from diffusive to diffusive-convective transport within 
the melt in front of a planar moving solidification interface.  
The thermosolutal instable system also will be used to study the 
onset of convection with increasing instability produced by the 
solidification parameters and to analyze the impact of g-gitters 
on the transport mechanisms and the concentration of the 
solidified crystal.  Microanalysis of the concentration of the 
solid will be done afterwards on metallographic cross sections and 
the determined variations will be corellated to the different 
variations of the experiment parameters.


        *THERMOCONVECTION AT DENDRITIC-EUTECTIC SOLIDIFICATION 
         OF AN AL-SI ALLOY
 
        Following the D1 experiments with an Al-Si alloy, the 
influence of the silicon content and the crystallization 
parameters on the dendrite morphology and eutectic microstructure 
is investigated utilizing a close eutectic aluminium-silicon 
alloy.

        *GROWTH OF GaAs FROM GALLIUM SOLUTIONS
 
        The aim of this experiment is to improve the crystal quality 
by investigating the following objectives under reduced gravity as 
well as under Earth conditions:
 
        - dopant inhomogeneities on the macro and micro scale
 
        - crystal perfection with respect to low defect density and 
the distribution of defects
 
        - crystal perfection with respect to stoichiometry and 
residual impurity concentration
 
        - studies of the influence of different transport phenomena 
in the solution
 
        - studies of growth kinetics and mechanisms of dopant 
incorporation

Werkstofflabor (WL) Material Sciences Laboratory 

        Located in rack 8, this facility consists of five furnaces, 
a fluid physics module and a crystal growth module.  The 
experiments study several areas of metal processing, crystal 
growth for electronics applications, fluid boundary surfaces and 
transport phenomena.

Facilities

Isothermal Heating Facility (IHF) is a high temperature furnace 
used to process metal samples that investigate a variety of 
topics.

Heater Facility, Turbine Blade Facility (HFT) is designed for 
processing special metallic alloys.  The samples as processed and 
solidified under microgravity conditions and cast into the shape 
of turbine blades.

Gradient Heating Facility (GHF) provides the necessary heating and 
cooling for experiments investigating crystal growth, melting 
solidification and eutetics.

Advanced Fluid Physics Module (AFPM) is a multipurpose facility 
designed to enable investigations on the behavior of fluids in a 
microgravity environment.  AFPM is an improved version of units 
flown on Spacelab 1 in 1983 and D1 in 1985.
High Temperature Thermostat (HTT and HTS), which consists of two 
identical furnaces, were developed to study diffusion processes in 
liquid metals under microgravity conditions.

Cryostat (CRY) attempts to grow high-quality crystals of 
biochemical macromolecules by diffusion of protein into 
corresponding saline solutions.

Experiments

        *OSIRIS:  OXIDE DISPERSION STRENGTHENED SINGLE CRYSTALLINE 
          ALLOYS IMPROVED BY RESOLIDIFICATION IN SPACE
 
        The experiment shall prove that, with an extensive 
elimination of the terrestrial gravity field, a single crystalline 
material can be produced with a finely distributed particle 
inclusion.  The intended matrix material is a nickel- based alloy, 
which is to be solidified with a dispersion of yttrium oxide 
particles.  Due to the application-oriented objectives of the 
project, turbine blade-shaped sample will be processed.  For the 
remelting of shaped material, a ceramic mold skin will be applied.   
        An important role plays the computer-assisted simulation of 
the ground and flight experiments.  The time-dependent 
crystallization parameters in the system furnace/sample are 
evaluated 3-dimensionally. 

        *Impurity Transport and Diffusion in InSb Melt under 
         MicroGravity Environment

        Impurity diffusion experiment for compound semiconductor, 
InSb, melt will use the Isothermal Heating Facility (IHF) in the 
D2 mission.  Impurity transport and diffusion behavior in the 
micro-g environment will be studied using the diffusion couple 
method where Zn, Ga, As, Se and Te are to be selected as the 
impurity species.  The diameter effects and the temperature 
dependency on diffusion will be seen in addition to the function 
of plug structure located at the diffusion couple edges, which is 
aimed to compensate the material volume change upon solid-liquid 
phase transformation.

        *Cellular-Dendritic Solidification At Low Rate Of 
         Aluminium-Lithium Alloys
 
        Under diffusive conditions, the deep cell-dendrite 
transition will be investigated by solidifying three aluminium-
lithium alloys in the GHF.  In nondimensional form, the data 
points for the primary spacing will be used to construct a 3D-
representation.  The microsegregation and macrosegregation of 
lithium will be analyzed.  Also to be studied is the organization 
(defects, disorder) of the cellular and dendritic bidimensional 
arrays.  The influence of convection will be deduced from a 
comparison with 1g samples.

        *Directional Solidification of the LiF - LIBaF3 - Eutectic
 
        The lamellar eutectic system LiF - LiBaF3 shall be 
directionally solidified in a gradient furnace.  The influence of 
the growth parameters gravity, melt composition, growth velocity 
and temperature gradient on the eutectic microstructure will be 
examined.

        *Separation behavior of monotectic alloys

        By directional melting of  sandwich-like samples of Al-Si-Bi 
alloys in which Bi-droplets are dispersed, the transport 
mechanisms of droplets in Al-melts will be investigated.  The 
sandwich-like samples consist of periodically arranged cylinders 
of an Al-Si alloy.  Ahead of the melting front there exists a 
temperature gradient which leads to a motion of the droplets 
within the Al-Si matrix melt.  The droplets are free to move in as 
much as the melting front moves in a controlled manner through the 
sample.  The droplet free zones will lead to a strong reduction of 
possible scattering and coagulation events of droplets of 
different sizes.  

        Therefore, at the end of an experiment there will be enough 
droplets located within the molten zone.  From the spatial 
arrangement of the droplets and a comparison with computer 
simulations of the whole process, conclusions shall be drawn 
concerning the transport of Bi droplets in a temperature gradient.  
The investigations are relevant for the improvement of terrestrial 
industrial casting processes currently being under investigation.

        *Liquid Columns' Resonances
 
        This experiment will measure the resonance curves of liquid 
columns between coaxial circular disks and to test the 
corresponding theoretical models.  The experiment will be 
performed in the Advanced Fluid Physics Module (AFPM).  The 
supporting circular disks are vibrated with varying frequency.  
The response of the liquid column is observed by position and 
pressure sensors.  

        It is intended to investigate two liquids differing in 
viscosity and surface tension and to use several liquid volumes 
and surface shapes.  The resonance frequencies first are roughly 
determined by applying a frequency ramp and subsequently may be 
checked more accurately by frequency variation from hand.  The 
interest in liquid columns has been stimulated by the numerous 
applications to crystal growth by the floating zone or travelling-
heater techniques.

        *Stability of long liquid Columns
 
        The aim is to measure the outer shape deformation of long 
liquid bridges under microgravity when subjected to mechanical 
disturbances, namely change of geometry, rotation and vibration.  
This configuration has, aside of its own relevance in fluid 
mechanics and interface science, a well-known application in 
materials processing, particularly in the floating zone technique 
of crystal growth in the semiconductor industry.  

        As a spin-off of this research, this configuration has 
proved to be a unique accelerometer at very low frequencies.  The 
aim is at gathering experimental data to validate several 
theoretical predictions on equilibrium shapes, stability limits 
and dynamics of stable and unstable bridges, to provide further 
guidance to more realistic and complex modeling.

        *Higher modes and their Instabilities of oscillating 
         Marangoni Convection in a large cylindrical liquid 
         column 

        The various types of liquid motion (convection) due to 
inhomogeneities of the interfacial tension in a free liquid 
surface are called Marangoni effects.  The proposed experiment 
deals with investigations of higher oscillating modes of the 
Marangoni convection and their transitions into non-periodic 
states (turbulent convections) in a large liquid column as a 
function of the aspect ratio (height diameter) of the column and 
of the Marangoni numbers.  This experiment will make use of the 
Advanced Fluid Physics Module.

        *MARANGONI-BENARD INSTABILITY

        The Marangoni-Benard instability will be studied in the 
steady state to measure the critical Marangoni number and to 
observe the inverse bifurcation behavior. The transient behavior 
will be studied to observe the effect of a nondistribution.  
Finally, by heating in the opposite direction, transverse 
capillary-gravity waves will be observed .

        *ONSET OF OSCILLATORY MARANGONI FLOWS

        The investigators intend to perform a systematic study of a 
series of cylindrical floating zones characterized by different 
values of the aspect ratio of disk diameter to determine the 
influence of sample geometry on oscillations onset and to 
determine the critical conditions and obtain a better 
understanding of the flow organization during oscillatory 
conditions.

        *Marangoni Convection in a Rectangular Cavity

        There are various types of liquid motion (convection) due to 
inhomogeneities of the interfacial tension in free liquid surfaces 
which are called Marangoni effects.  The experiment investigates 
one of the Marangoni effects, namely thermocappillary convection 
driven by temperature gradients applied parallel to the free 
liquid-gas surface.  The experiment investigates the pure 
thermocappillary effect under microgravity to reduce the 
complexity of the highly non-linear coupled hydrodynamic system on 
Earth.

        *Stationary Interdiffusion in a Non-Isothermal Molten 
         Salt Mixture

        A new interdiffusion experiment on a molten salt mixture 
will be performed as the necessary continuation of the preceding 
D1 experiment.  It is shown that the stationary state which was 
far from being obtained in D1, due to a smaller than predicted 
interdiffusion coefficient, should then be attained during a 24-
hour duration experiment.  In addition, the investigators intend 
to evidence a variation of the interdiffusion coefficient with the 
mixture composition.
 
        *TRANSPORT KINETICS AND STRUCTURE OF METALLIC MELTS:
 
        Diffusion processes in melts are more or less disturbed 
under 1-g by convections which contribute to the atomic mixing 
process in a similar but irregular way.  It is the goal of the D2 
experiments to determine the temperature dependence of the 
diffusion coefficients for materials which are as much as possible 
different from Tin.  Furthermore, there are different aspects to 
use the experimental opportunities of the D2 flight:  continue 
self-diffusion experiments on other materials; continue inter-
diffusion experiments with complex formation; determine inter-
diffusion coefficients for the "Compound Project Monotectic 
Alloys" and complete measurements in the system started in D1.
        *Nucleation and Phase selection during Solidification of 
         undercooled Alloys

        Metallic melts of various alloys, embedded in a liquid 
matrix of boron-trioxide, will be cooled below their 
solidification temperature in their liquid state.  Since under 
microgravity conditions, sedimentation is reduced by orders of 
magnitude, a contact of sample with crucible is avoided leading to 
the elimination of heterogeneous nucleation by wall contact.  It 
is the goal of this experiment to determine the degree of 
undercooling for different alloy compositions by measuring the 
recalescence temperature and comparing with nucleation theory.  In 
addition, the influence of undercooling on the grain size and 
phase selection will be investigated. 

        *Heating and remelting of an allotropic Fe-c-Si alloy in a 
         ceramic skin and the effect of the volume change on the 
         mold's stability 
 
        The skin technology is to be tested with allotropic and non-
allotropic materials for its suitability for remelting processes.  
For this purpose a melting sample with sections of Fe-C-Si alloys 
with different compositions will be remelted in a zirconia mold 
and solidified directionally.  The interpretation will concentrate 
on the skin behavior, the crystallization of the graphite and the 
distribution of the elements in the transition zone.
 
        *IMMISCIBLE LIQUID METAL SYSTEMS
 
        NUCIM is an experiment investigating the behavior of two 
liquid immiscible metals in contact with different ceramic 
materials.  In particular the Cu-Pb system with two different 
compositions will be investigated in contact with vitreous carbon, 
boron nitride and sapphire.

        *Convective Effects On The Growth Of Gainsb Crystals

        This experiment will check the effects of convection on the 
chemical segregation of the components of highly concentrated 
terrary semiconductors.  The purpose is to obtain homogeneous 
crystals, which is not possible on Earth.

        *Vapor growth of Inp-Crystal with Halogen Transport in a 
         closed Ampoule
 
        It is well known that the mass transport phenomena are 
strongly affected by gravity.  In the D2 mission, vapor growth of 
InP epitaxial layer with halogen transport in a closed ampoule is 
proposed to study the relation between the gravity and epitaxial 
layer quality.

        *Solution Growth of GAAS Crystals Under Microgravity
 
        The solution growth experiment of GaAs crystals under 
microgravity planned aboard the D2 mission involves a technique 
that avoids the surface-tension-induced convection which destroys 
diffusion-controlled crystal growth, even under microgravity.  

        *Crystallization of Nucleic Acids and Nucleic Acid-Protein 
         Complexes
 
        The main purpose of this research project is to study the 
structure of ribosomal 5S RNAs, their protein complexes and the 
structure of the elongation factor EF-TU complex.  The ribosomal 
5S RNAs and their binding proteins are essential for the function 
of ribosomes, and their complexes also are considered to be good 
model systems for the study of RNA-protein complexes.  The 
elongation factor EF-TU is required for protein synthesis.  Since 
this protein forms in addition specific complexes with GTP and 
GDP, it also has been considered as a model system for the 
important class of regulatory G-proteins.  

        The objective is to explore all possibilities to crystallize 
these important biological molecules and their complexes to 
determine their three dimensional structure by x-ray analysis.  
The purpose of this project is to determine the influence of 
microgravity on the crystallization of these molecules during the 
D2 Spacelab mission. 

        *Crystallization of Ribosomal Particles
 
        The main goal of our project is to elucidate the model of 
the ribosome. The investigators are pursuing single crystal X-ray 
crystallographic studies and support them with information 
obtained from neutron diffraction and three-dimensional image 
reconstruction from electron-micrographs. The investigators 
believe that at microgravity more isotropic crystals can be grown. 


SPACELAB D2 OPTICS LABORATORY/EXPERIMENTS

Holographic Optics Laboratory (HOLOP)

        The Holographic Optics Laboratory (HOLOP) is a multi-user 
experiment facility where fluid physics experiments are conducted 
under microgravity conditions.  Located in rack 11, the aim of 
HOLOP is to investigate phenomena such as transient heat transfer, 
mass transfer, surface convections and particle motion in gatical 
transparent media through holographic methods.  One of the four 
experiments is a test subject for studying the application of 
"telescience" techniques for preparation of utilization of space 
station missions.

        *MARANGONI CONVECTION IN A RECTANGULAR CAVITY
 
        There are various types of liquid motion (convection) due to 
inhomogeneities of the interfacial tension in free liquid surfaces 
which are called Marangoni effects.  The MARCO experiment 
investigates one of the Marangoni effects, namely thermocapillary 
convection driven by temperature gradients applied parallel to the 
free liquid-gas surface.  MARCO investigates the pure 
thermocapillary effect under microgravity to reduce the complexity 
of the highly non-linear coupled hydrodynamic system on Earth.  
 
        *Interferometric Determination of the Differential 
         Interdiffusion Coefficient of Binary Molten Salts
 
        Interdiffusion coefficients are transport data that are 
difficult to measure.  Under microgravity conditions, it is 
possible to exclude convection and to obtain exact reference 
values for the diffusion coefficients.  The initial concentration 
step profile is generated with a flowing junction cell and the 
diffusion process is observed by means of holographic real time 
interferometry.  The chosen system is Potassium Nitrate/Silver 
Nitrate at eutectic composition.  The diffusion coefficient is 
going to be determined in dependence on temperature.

        *Idile:  Measurements of Diffusion Coefficients
         In Aqueous Solution

        IDILE is an experiment dedicated to measurements of 
diffusion coefficients through interferometric holography 
observation of refractive index changes due to evolution of 
concentration profiles as a function of time.

        *NUGRO:  Phase Separation in Liquid Mixtures with 
         Miscability Gap
 
        Phase separation of a demixing binary liquid mixture under 
1-g conditions is observed by holographic image recording.  A 
pressure jump technique is applied to induce the phase transition.

        Radiation Detector (RD) is a set of four experiments in 
which different types of material and biological probes are 
exposed to different environmental conditions.  The scientific 
products will be brought back for analyses to learn and develop 
techniques for radiation protection in space. 


Baroreflex (BA )

        The Baroreflex (BA) experiment is located in rack 12.  This 
experiment will investigate the theory that lightheadedness and a 
reduction in blood pressures in astronauts upon standing after 
landing may arise because the normal reflex system regulating 
blood pressure behaves differently after having adapted to a 
microgravity environment. 

        In particular, the ability of the body's blood pressure 
sensors to control heart rate (the baroreceptor reflex) will be 
measured to see if the predicted impairment does indeed occur.  
Space-based measurements of the baroreflex will be compared to 
ground-based measurements to see if microgravity affects the 
reflex.

        The tendency of a person to faint because of inadequate 
blood flow to the brain is called orthostatic hypotension.  When 
standing on Earth, gravity tends to pull blood toward the feet and 
the baroflex acts to increase heart rate and blood pressure in the 
blood vessels, maintaining normal blood flow to the head.  
However, in microgravity the body does not have to make such 
cardiovascular adjustments to compensate for changes in body 
position. 

        In space, blood shifts naturally toward the head rather than 
the feet and the baroflex is not utilized during postural changes.  
Therefore, impairment or desensitization of normal baroreflex 
control of blood pressure may occur. 

        The purpose of this experiment is to determine if there are 
changes in the baroreflex in microgravity and if so, how they 
contribute to postflight orthostatic hypotension.  Although 
orthostatic hypotension disappears within a few days after flight, 
it is very important to understand the causes of this condition 
which affects the health and safety of the astronauts, including 
the ability to land the Shuttle at the end of the mission.

        The experiment uses the Baroreflex cuff, a silicone rubber 
cuff which seals around the neck when pressure is applied.  The 
pressure system is controlled by a microprocessor.  The crew 
member wears a rubber neck chamber and electrocardiograph (ECG) 
electrodes.  Pulses of pressure and suction, which mimic natural 
blood pressure, are applied through the neck chamber and 
transmitted through the neck to baroreceptors.  The heart rate 
change provoked by each pressure pulse is measured from the ECG.  
Heart rate changes will be measured before, during and after the 
spaceflight.


MICROGRAVITY MEASUREMENT ASSEMBLY (MMA)

        The Microgravity Measurement Assembly (MMA) is the core 
acceleration measurement system of D2.  It consists of 6 tri-axial 
accelerometers, four of which are permanently mounted in 
experiment racks.  Two packages can be placed at any suitable 
location within the Spacelab module.

        *RESIDUAL ACCELERATION IN SPACELAB D2

        The majority of investigations performed on D2 is intended 
to make use of the state of weightlessness which is virtually 
simulated in a freely drifting spacecraft.  Deviations of the 
spacecraft's dynamic state from ideal free fall conditions result 
in residual gravity-like accelerations.  Despite orders of 
magnitude below 1-g, this microgravity condition can seriously 
affect the results of experiments.  A detailed knowledge of the 
residual acceleration history, therefore, is mandatory for a 
thorough experiment analysis. 

        For the reason, Spacelab D2 is equipped with various 
measurement systems to detect the spatial and temporarily 
variation of the acceleration vector.  There is, however, a lack 
of measurement data in the low-frequency range due to general 
sensor bias problems.  Acceleration data in this regime will be 
estimated on the basis of a dynamic atmospheric model and the 
attitude data of the orbiter.

        *Transfer Function Experiment
 
        The proposed Transfer Function Experiment will cover the 
empirical and systematic investigation of the disturbance 
transmissibility characteristics and the transfer functions of the 
spacecraft structure under weightlessness.  The microgravity 
transfer function describes the transmissibility behavior of a 
flexible spacecraft structure.  It describes how a flexible 
structure will respond with vibrations/accelerations when excited 
at another location of the structure by a disturbance source.  It 
will be extended by an impulse hammer enabling the measurement of 
inflight structural transfer functions.  

        The results of this experiment will substantiate and improve 
understanding of the on-orbit dynamic behavior of microgravity 
spacecraft structures.  The evaluation of on-orbit transfer 
function measurements and comparison with on-ground test data and 
analytical predictions will improve the microgravity dynamics 
database and will directly support the preparation of further 
Spacelab missions and subsequent orbital microgravity spacecraft 
such as Eureca and Columbus.

Robotics Experiment (rotex)

        ROTEX is a robotic arm that operates within an enclosed 
workcell in rack 6 of the Spacelab module and uses teleoperation 
from both an on-board work station located in rack 4 and the 
ground.  This precise robotic arm uses teleprogramming and 
artificial intelligence to look at the design, verification and 
operation of advanced autonomous systems for use in future 
applications.
 
        ROTEX is comprised of:

        *A robot arm with six joints which can reach in all 
directions to grasp objects

        *Two torque sensors located of the back of the gripper to 
ensure that the robot arm does not become overloaded

        *A gripping assembly containing laser distance-measuring 
devices, tactile sensors and stereo television cameras 
which give a direct view of the object

        *Two fixed video cameras that provide stereo pictures of 
the whole assembly.
 
        For future spaceflight, it wiii be necessary to reduce the 
operational costs of space systems.  In this context, the 
application of robotic systems will play a key role.  The 
technology-transfer or spin-off back to terrestrial applications 
is expected to be larger than in many other areas and important in 
terms of political economics.  Manipulators and robots will be 
used for assisting in and carrying out different tasks in space 
laboratories ("internal" use) and in free space ("external use"), 
in particular:

        - exchange of orbit-replaceable units (ORU)
        - handling of experiments and manufacturing processes
        - assistance in rendezvous/docking
        - repair
        - supply and maintenance of free-flying 
          platforms or geostationary satellites
        - refuelling and "garbage collection"
        - assembly of structures

        The performance of diverse tasks by space manipulators 
requires a hierarchically and modularly structured automation 
concept tuneable to the special operational case, which in 
addition allows human interference on different levels of 
supervisory and decision control.  This in term yields the 
requirements for the hardware and software concepts to be 
realized, covering the range from telemanipulation up to a 
completely autonomous operation.  Independent of the different 
tasks and application scenarios, development of space robot 
technology tends to focus on the following topics:

        - intelligent, sensor-controlled, light-weight manipulators
        - modular gripper and tool systems for high versatility
        - improved man-machine interfaces for teleoperation and
          supervisory control ("telerobotics" and "telescience")
         concepts
        - stepwise increase of planning and decision autonomy by 
         knowledge-based technology,
        - cooperation and coordination of multi-arm and 
         multi-robot system.

Anthrorack (AR)

        The payload element "Anthrorack," developed for ESA, is 
designed to investigate human physiology under microgravity 
conditions.  AR will provide a set of common user stimulation and 
measurement instruments, supported by centralized services 
including power supply, control and data handling.  The AR is 
composed of the following service elements:
 

        - Blood Sample Collection Kit
        - Urine Monitoring System
        - High Speed Centrifuge
        - Respiratory Monitoring System
        - Ergometer
        - Peripheral Blood Measurement System
        - Manual Blood Pressure Measurement System
        - Limb Volume Measurement Device
        - Electrode Contact Impedance Meter
        - Ultrasound Monitoring System
 
        AR components essentially are accommodated in a double rack.  
The ergometer is mounted to the experiment section of the lab's 
main floor.

        *CARDIOVASCULAR REGULATION AT MICROGRAVITY
 
        The mechanisms involved in the cardiovascular adaptation to 
microgravity will be examined during inflight studies of the 
responses to acute redistribution of body fluids.  Intravenous 
saline loading is superimposed on the microgravity-induced fluid 
shifts.  Supplementary pre- and post-flight procedures include 
quantitation of changes in myocardial and skeletal muscle mass by 
magnetic resonance imaging and characterization of adrenergic 
function by in-vivo and in-vitro experiments.  
 
        *THE CENTRAL VENOUS PRESSURE DURING MICROGRAVITY
 
        The central venous pressure (CVP) is theorized to increase 
during weightlessness because of a central blood volume shift.  
Although CVP is an important physiological parameter, it never has 
been registered in humans during the launch conditions or long 
term weightlessness.  Significant "microgravity" adaptation may 
occur while the astronauts are waiting on the launch pad in supine 
seated launched position.  The aim of this experiment is to 
measure the CVP in two crewmembers during the supine seated 
position on the launch pad, the microgravity onset and the early 
adaptation through an arm vein.  
 
        *LEG FLUID DISTRIBUTION AT REST AND UNDER LBNP

                Human adaptation to microgravity is a complex process 
involving multiple organ systems.  Among these, the function and 
control of health and vessels are changed due to the lack of 
gravitational stress.  First, body fluids shift towards the upper 
part of the body.  Next, the body becomes dehydrated due to 
increased excretion and possibly, decreased fluid intake.  As a 
result, the autonomic response patterns may be altered.  
Dehydration and disuse lead to volume reduction, especially in the 
lower limbs.  Textural changes of the skin, musculature and 
vessels are anticipated to occur.

        *DETERMINATION OF SEGMENTAL FLUID CONTENT AND 
         PERFUSION

        In weightlessness, the lack of hydrostatic pressure induces 
a large cephalad fluid shift that in turn causes a reduction in 
total body fluid.  The hypothesis is that this results in a new 
body fluid distribution pattern.  Different body segments are 
affected to different degrees.  Additionally, reduced peripheral 
demands due to muscular underloading and a change in the activity 
pattern of the cardiovascular autonomic control system contribute 
to induce a process of cardiovascular adaptation.
 
        *LEFT VENTRICULAR FUNCTION AT REST AND UNDER 
         STIMULATION
 
        This experiment intends to get insight into the mechanisms 
underlying cardiovascular adaptation to weightlessness.  The 
experiment emphasizes the role played by the heart in the process 
of adaptation to weightlessness and readaptation to Earth's 
gravity.

        *Peripheral and Central Hemodynamic Adaptation To 
         Microgravity during Rest Exercise And Lower Body 
         Negative Pressure in Humans

        This experiment will investigate the cardiovascular reflexes 
during weightlessness in man by applying standard stimuli to the 
body and record the induced changes.  Cardiovascular parameters to 
be measured include Echo Cardiograph (ECG), cardiac output 
(rebreathing method), arterial blood pressures during rest and 
during isometric exercise (sustained handgrip exercise) and 
dynamic exercise (bicycle exercise on a specially constructed 
mechanically breaked ergometer).  

        However, during this experiment the subcutaneous blood flow 
on the forearm will be studied.  This way it will be possible to 
calculate the changes in both total periperal resistance as well 
as forearm vascular resistance as an expression of cardiovascular 
regulation.  The experiments will be performed preflight and 
inflight.

        *Tonometry - Intraocular Pressure In Microgravity
 
        Microgravity leads to an increase in intraocular pressure 
due to a fluid shift from the lower to the upper part of the body.  
Up to now little was known about the peak values and the 
adaptation process.  The greatest alteration in intraocular 
pressure is expected during the early phase after launch.  Because 
the astronauts are fastened in during this phase, measurements 
have not been performed.  To solve this problem and to save crew 
time, a tonometer was developed which enables self tonometry.  
Initial measurements during so-called "parabolic flights" could 
demonstrate the practical use of the new equipment under 
micrgogravity conditions without any problem.
 

        *THE CENTRAL VENOUS PRESSURE DURING MICROGRAVITY
 
        The central venous pressure (CVP) is theorized to increase 
during weightlessness because of a central blood volume shift.  
Although CVP is an important physiological parameter, it never has 
been registered in humans during the launch conditions or long 
term weightlessness.  Significant microgravity adaptation may 
occur while the astronauts are waiting on the launch pad in supine 
seated launch position.  The purpose of this experiment is to 
measure the CVP in two crew members during the supine seated 
position on the launch pad, the microgravity onset and the early 
adaptation to weightlessness by means of a thin catheter 
introduced through an arm vein.

        *Tissue thickness and tissue compliance along body axis 
         under micro-g conditions

        A new method will be introduced to quantify fluid shifts 
within superficial tissues along the body axis of a human subject.  
Furthermore, the distensibility of these tissues will be measured.  
The methods will be applied under micro-g conditions, to answer 
basic questions of the salt-water balance of humans under extreme 
conditions.
 
        *CHANGES IN THE RATE OF WHOLE-BODY NITROGEN TURNOVER, 
         PROTEIN SYNTHESIS AND PROTEIN BREAKDOWN UNDER 
         CONDITIONS OF MICROGRAVITY

        Under conditions of microgravity, there is a fluid shift 
away from the peripheral muscles of the lower limbs towards the 
viscera of the gut and splanchnic regions of the body.  This is 
accompanied by a negative fluid and nitrogen balance, the latter 
of which results in a reduction of muscle tone, muscle fatigue and 
muscle atrophy.  The purpose of the present study is to measure 
the rates of whole-body nitrogen turnover (flux), protein 
synthesis and protein breakdown in 3 astronauts before, during and 
after the D2 mission to identify the mechanism(s) responsible for 
the negative nitrogen balance.

        *Regulation of volume homeostasis in reduced gravity 
         Possible involvement of atrial natriuretic factor 
         urodilatin and cyclic GMP
 
        The objective of this investigation is to study the 
involvement of hormonal systems in the readaptation of humans to 
weightlessness.  In detail, possible alterations in the plasma 
levels and urinary excretion rates of atrial natriuretic factor, 
of urodilatin and of cyclic GMP will be studied.  These factors 
are important hormones and parameters regulating volume 
homeostasis which is known to be markedly altered in 
weightlessness.  Thus, the current investigation is aimed at 
gaining a better understanding of volume homeostasis under 
microgravity conditions.

        *EFFECTS OF MICROGRAVITY ON GLUCOSE TOLERANCE
 
        Based on results from simulation experiments on the ground, 
it is hypothesized that an abnormal glucose/insulin relation and 
an impaired glucose tolerance occurs in spaceflight.  The 
metabolic imbalance may increase with progressive exposure.  It is 
anticipated that the results of the study in space will have 
significance for both the assessment of metabolic responses to 
weightlessness and for clinical medicine on Earth.
        *The Influence of Microgravity on Endocrine and Renal 
         Elements of Volume Homeostasis 
 
        It is hypothesized that the renal excretion of electrolytes 
and water in humans increase upon entering the microgravity 
environment and that a new state of adaptation is reached in 
regard to volume homeostatic mechanisms.  Therefore, the purpose 
is to investigate the lack of hydrostaticendocrine and renal 
elements of volume homeostasis in human test subjects.

        *Effects of Spaceflight on Pituitary-Gonad-adrenal 
         Function in the Human
 
        Spaceflight conditions are very strong, stressful stimuli 
and are expected to have some impact on individual working 
capacity.  A very important topic, on the other hand, is the 
circadian rhythmicity of hormonal secretion.  Such regular rhythms 
might be disrupted by incorrect time shift schedules.  The aim of 
this study is to check blood, urine and saliva to detect any signs 
of adrenal/reproductive glands disturbance occurring in 
microgravity to better design working/resting rhythms during next 
flights.  It is in fact of enormous relevance to human species 
survival and to subject's space work motivation that the hormonal 
milieu, somehow responsible for subject's well-being and working 
capacity as well as for reproductive and sexual equilibrium, keep 
within normal ranges in microgravity conditions.

        *ADAPTATION TO MICRO-G AND READAPTATION TO TERRESTRIAL 
         CONDITIONS
 
        In this experiment, the observation of the Renin-
Angiotensin- Aidosterone System, which is one of the main factors 
in the regulation of salt-balance and blood pressure, will be 
made.
 
        *Pulmonary Stratification and Compartment Analysi with 
         Reference to Microgravity
 
        The in-orbit elimination of the gravity vector provides an 
unique opportunity to study the effect of gravity on the 
distribution of ventilation in the human lung.  The primary 
scientific objective of this experiment is to test, whether entry 
into orbit will alleviate the inhomogeneity in the distribution of 
the ventilation-volume ratio, as measured by a multiple breath gas 
wash-in/wash-out test.


        *PULMONARY PERFUSION AND VENTILATION IN MICROGRAVITY 
         REST AND EXERCISE
 
        Gravity is considered to be the most important factor 
influencing the distribution of both ventilation and blood 
perfusion in the lung.  According to current hypotheses, both 
these processes take place mainly in the lower part of the lungs.  
However, the degree of unevenness is different between ventilation 
and perfusion, so that upper parts (with respect to the G vector) 
are relatively over-ventilated with respect to perfusion and lower 
parts are relatively over perfused with respect to ventilation.  

        The concept described has a major impact on present 
scientific and clinical understanding of the pulmonary function.  
The concept, however, is hypothetical and remains to be proven by 
direct experimental evidence.  The proposed experiments include 
methods and procedures for such studies.

        *Ventilation Distribution in Microgravity

        Under normal gravity conditions on Earth, the lower part of 
the lung ventilates almost twice as much as the upper part of the 
lung.  The major scientific objective of this experiment, carried 
out in the Anthrorack facility, is to understand the role of 
gravity in determining the pattern of ventilation in the lungs and 
the components involved in ventilation. 

        This will be accomplished by studying the influence of 
microgravity on lung ventilation, lung blood flow, capillary 
volume, the lung's liquid content and changes in the breathing 
pattern. 

        In a parabolic aircraft flight, an experiment was conducted 
to look at some of these changes.  Data from this experiment 
showed a much more even pattern of ventilation in the lung than 
expected when in microgravity.  It also was observed that the lung 
volume decreases significantly and the pattern of breathing is 
changed. 

        The flight of this experiment aboard the Spacelab D2 mission 
will help to define the effects of microgravity on the lung.  This 
experiment will use experiment specific equipment called the 
"Respitrace."

        *Effects of microgravity on the dynamics of gas exchange, 
         ventilation and heart rate in submaximal dynamic 
         exercise 

        Before, during and after the D2 mission, pseudo-randomized 
power changes between 20 w and 80 w of cycle ergometer exercise 
will be applied as stimulus to study the kinetics of oxygen 
consumption, C02-output, ventilation, blood pressure and heart 
rate.  A major intention is to find out whether the determination 
of C02 kinetics qualifies as a method for monitoring endurance 
performance during space flight.


        *Cardiovascular Regulation IN Microgravity

        The objective of this experiment is to study the 
cardiovascular effects of microgravity on subjects at rest and 
during exercise.  

        This study, performed in the Anthrorack facility, will study 
the multiple mechanisms believed to be responsible for rapid and 
effective adaptation to microgravity as well as the cardiovascular 
dysfunction that is observed on return to Earth.  An additional 
objective is to validate 24-hour, 5-degree head-down bedrest as a 
model for studies of acute cardiovascular response to 
weightlessness.  

        This experiment uses specific equipment called the Doppler 
flow device along with the Blood Pressure Measurement System.

        Based on current evidence, upon entering microgravity, 
astronauts experience a dramatic fluid shift from the lower into 
the upper part of the body.  This occurs primarily because of the 
loss of all hydrostatic gradients; the compressive force of the 
muscles and blood vessels in the legs and dependent abdominal 
areas is therefore unopposed by gravity and propels fluid 
headward.  As a result of this fluid shift, central blood volume 
and cardiac pressures increase, simulating an expansion of the 
intravascular volume and setting in motion a cascade of volume-
regulating mechanisms. 

        The end result of this process is a reduction of fluids in 
the lower part of the body and a loss of the excess fluid in the 
upper part of the body that had shifted headward.  Significant net 
losses of body fluid therefore are experienced by crewmembers in 
space during the first few days in microgravity and in the ensuing 
week or so, other elements of the cardiovascular system change to 
accomodate the loss of fluid and gravity stimulus. 

        The objectives of this experiment are to study the multiple 
mechanisms believed to be responsible for the adverse responses in 
astronauts upon landing, including hypovolemia, altered 
neurohumoral control mechanism and structural changes affecting 
the cardiovascular system and to examine interactions between 
these mechanisms.  Understanding these processes suggest methods 
for countering their unwanted effects.

        Two different in-flight procedures will be performed:  rapid 
intravenous saline loading and lower body negative pressure.  Both 
procedures are based on collaboration among several groups of D2 
investigators and both will produce detailed data on 
cardiovascular and neurohumoral responses.

Biolabor (BB)

        The Biolabor will be used to perform research in 
electrofusion of cells, cell cultivation, botany experiments and 
zoological experiments.  The Biolabor facility is a life sciences 
and biotechnology research device developed by Germany (MBB/Erno) 
for use in the Shuttle/Spacelab.  Biolabor consists of a cell 
electrofusion workbench equipped with a microscope, a cell 
electrofusion control unit, two cell cultivation incubators, a 41 
C cooler and two middeck-mounted cooling boxes.  

        The workbench can accommodate a series of experiment-
specific test chambers, including chambers to support 
electrofusion of different protoplasts of plant species and 
chambers for electrofusion of mammal cells.  The workbench 
microscope allows observation of the test chambers by the crew and 
the experimenter via downlinked video.  Biolabor experiments 
include:

        *Development of vestibulocular reflexes in amphibia and 
         fishes with microgravity experience
 
        This experiment will examine whether the functional 
development of the vestibular system of lower vertebrates is 
affected by a short lasting stay under micro-g conditions during 
very early periods of life.  Vestibulocular reflexes are a useful 
tool to determine efficiency changes of the developing vestibular 
system.  After the spaceflight, the extent of these reflexes will 
be determined for each of the very delicate animals throughout its 
life until metamorphosis.  For this purpose, a closed living 
system will be constructed which also allows the recording of the 
reflexes without changing the environment.

        *Comparative investigations of microgravity effects on 
         structural development and function of the gravity 
         perceiving organ of two water living vertebrates 

        This contribution is a survey of the DLR-part of the space 
experiment "The Observation of Gravity and Neuronal Plasticit" or 
STATEX II.  The main points are the morphological differentiation 
of the vestibular organs and their subunits in weightlessness and 
an analysis of the loop swimming behavior following gravity 
variations.  For the first time, the development of two different 
aquatic vertebrates, exposed to identical experimental conditions 
in space, can be compared.

        *Structure- and Function-related Neuronal Plasticity of 
         the CNS of Aquatic Vertebrates during Early 
         ontogenetic Development under Microgravity-
         Conditions
 
        On the basis of behavioral studies, the influence of about 9 
days of near weightlessness during early ontogenetic development 
of larvae of a type of colored perch fish and tadpoles of the 
South American clawed frog will be investigated by means of light 
and electronmicroscopical techniques and biochemical analyses 
especially with regard to the differentiation of gravity-related 
integration centers in the central nervous system.

        *Immunoelectron microscopic investigation of cerebellar 
         development at microgravity 
 
        By means of immunoelectron microscopical the influence of 
weightlessness on structural and functional parameters of the 
cerebellum of cichlid fish and clawed toad larvae will be 
investigated using poly- and monoclonal antibodies against 
specific cell adhesion molecules.

        *GRAVISENSITIVITY OF CRESS ROOTS
 
        Gravity sensing systems in plants are characterized by three 
intracellular components:

        - sedimenting particles functioning as statoliths
        - the ground cytoplasm as surrounding medium and
        - membranes (probably inner membranes) functioning as signal 
          transducers.
 
        The experiment gravisensing will determine threshold value, 
the minimum dose for cress roots cultivated on a 1g centrifuge and 
under reduced gravity, respectively, using a threshold value 
centrifuge.  In a second approach, the fine structural 
characteristic of the gravity perceiving cells (statocytes) is 
correlated with this threshold value by preparation of the 
seedlings in orbit for electron microscopy on ground.  Finally the 
summation of subminimal doses is proven and again correlated with 
the fine structure of statocytes to obtain first information on a 
"memory" of plants for the stimulus gravity.

        *CELL POLARITY AND GRAVITY
 
        The microgravity experiments described below shall elucidate 
the question as to whether gravity is a polarizing factor in 
higher plant cells and if so, what its rank is among other 
polarizing factors.

        *Influence of Gravity on Fruiting Body Development of 
         Fungi 

        The D2 mission provides an excellent opportunity for 
obtaining information on the ultrastructure of fruiting bodies 
grown under micro- and 1-gravity conditions.  These results are 
expected to improve knowledge about the mechanisms of 
graviperception and the influences of weightlessness on fungal 
morphogenesis.

        *Significance of Gravity and Calcium-Ions on the 
         Production of Secondary Metabolites in Cell Suspensions
 
        The influence of gravity and calcium metabolism on 
metabolite production, growth and regeneration capacity of cell 
cultures will be investigated.  Simulation experiments, using a 
clinostat and a centrifuge specifically adapted to cell cultures, 
will be conducted on Earth.  In addition, experiments with calcium 
chelators, calcium ionophores and calmodulin antagonists are 
planned.
 
        In this experiment, for the first time in manned space 
flight, fluid cultures beside solid cultures will be exposed to 
microgravity and cosmic radiation.  The aim of the experiment is 
to improve properties of the yeast by durable fixed genetic 
mutations.  The genome of the HB-L29 yeast, used in the 
experiment, shows two additional chromosomes in comparison to 
cultures investigated up to now.

        *Influence of Conditions in Low Earth Orbit on Expression 
         and Stability of Genetic Information in Bacteria
        *PRODUCTIVITY OF BACTERIA 
        *FLUCTUATION TEST ON BACTERIAL CULTURES 
 
        Unexpectedly, bacteria, when growing in low Earth orbit, 
have shown differences in growth rate and amount of final biomass 
produced as compared to their counterparts on Earth.  These 
earlier studies will be continued to include measurements of the 
yield of specific products, of the stability of genetic 
information and of the re-adaptation to growth at 1-g.

        *Connective tissue biosynthesis in space: Gravity effects on 
collagen synthesis and cell proliferation of cultured 
mesenchymal cells
 
        Astronauts, experiencing long periods of space flight, 
suffer from severe degeneration of bones.  As it seems, lack of 
mechanical load decreases connective tissue biosynthesis in bone 
forming cells.  To test this assumption cultured mesenchymal 
cells, which actively produce connective tissue proteins, will be 
kept under microgravity during the D2 mission. Composition, 
relative amount and structure of synthesized proteins, which 
consist mainly of collagen, will be characterized.  The same will 
be done with control cultures incubated at normal gravity and 
hypergravity.

        *ANTIGEN-SPECIFIC ACTIVATION OF REGULATORY
         T-LYMPHOCYTES TO LYMPHOKINE PRODUCTION
        *GROWTH OF LYMPHOCYTES UNDER MICRO-G CONDITIONS

        An experimental 1-g test system was devised involving the 
foreign antigen-driven stimulation of regulatory T cells by 
antigen-presenting accessory cells.  Under conditions of 
weightlessness, undisturbed antigen-mediated cluster formation 
between responsive T cells can be expected which is anticipated to 
lead to elevated levels of secreted lymphokines.  The amount of 
representative lymphokines produced under micro-g and 1-g 
conditions will be determined.  These measurements might provide 
new insights into the interactive relationship between T cells and 
accessory cells.

        *Enhanced Hybridoma Production Under Microgravity

        During the Spacelab D2 mission, the United States and 
Germany will carry out collaborative studies to evaluate whether 
the microgravity environment can be used to produce cells with 
useful properties. 

        Specifically, the experiments will examine the process of 
cell electrofusion, where electric currents are used to join cells 
with different characteristics to produce hybrids.  These 
experiments will examine the fusion of human blood cells, called 
lymphocytes, with tumor cells. The resulting fusion products, 
hybridoma, may produce proteins that can be used to kill cancerous 
cells. 

        Previous experiments on sounding rockets have shown an 
increase in the efficiency in hybridoma production in 
microgravity.  The joint U.S./German experiments will probe the 
possible causes of this increase. 

        As their contribution to the research, the German Space 
Agency developed the Biolabor, a multi-user cell fusion device.  
The U.S. science team will provide the cell samples and will carry 
out the post-flight analysis.  In addition to the hybridoma 
experiments, Biolabor also will be used to carry out plant cell 
fusion experiments. 

        This experiment will attempt to determine the extent to 
which the microgravity environment will enhance the generation of 
hybrid cells produced by electrofusion.  Dr. David W. Sammons, 
University of Arizona, Tucson, and his German collaborators will 
attempt to fuse B lymphocytes P white blood cells that produce 
antibodies that circulate in the blood stream P with cells from 
myeloma P tumors that afflict bone marrow.  The science team hopes 
to produce hybridoma that efficiently produce highly specific 
antibodies. 

        Experiments carried out in the European Texus sounding 
rocket program have demonstrated that performing cell 
electrofusion in microgravity increases the number of fusion 
events as well as the number of recoverable, viable cell hybrids.  
During the D2 mission, crew members will use the Biolabor hardware 
to carry out experiments to reveal the causes for the increase in 
the efficiency of cell electrofusion during the sounding rocket 
flights. 

        Several days prior to the launch of the Spacelab D2 mission, 
the U.S. science team will begin preparing Myeloma and B 
lymphocyte cells.  The various cell types will be loaded in 
flexible, gas-permeable flasks, which will be stored in incubator 
boxes in the Shuttle middeck 12 hours before launch. 

        On orbit, the cells will be transferred to incubators in the 
Biolabor facility in the Spacelab module.  During the third 
mission day, lymphocytes and myeloma cells will be centrifuged and 
combined in the fusion chambers.  Electric pulses of varying 
lengths will be applied to the different samples.  Following cell-
electrofusion, some of the sample sets will be "fixed" for later 
study.  Others will be incubated for the remainder of the mission.  
Ground control experiments will be carried out in parallel with 
the flight experiments in a laboratory at the NASA Kennedy Space 
Center.

        *CULTURE AND ELECTROFUSION OF PLANT CELL PROTOPLASTS 
         UNDER Microgravity:  MORPHOLOGICAL/BIOCHEMICAL 
         CHARACTERIZATION
 
        Plant cell protoplasts of different origin (leaf tissue, 
cell cultures) and fusion products, formed therefrom by electrical 
cell fusion techniques, will be cultured for about 10 days under 
1-g conditions and compared to identical samples kept under 1-g 
both in orbit (1-g reference centrifuge) and on the ground.  To 
monitor possible morphological and physiological/metabolical 
deviations occurring under 1-g, sample specimen are taken and 
metabolically quenched in defined time intervals.  The analytical 
part will cover microscopy, determination of cellular pool sizes 
of intermediates of energy and carbohydrate metabolism and protein 
analysis.

        *YEAST EXPERIMENT HB-L29/YEAST:  INVESTIGATIONS ON 
          METABOLISM
 
        In this experiment, for the first time in manned space 
flight, fluid cultures (Saccharomyces uvarum var. carlsbergensis) 
beside solid cultures will be exposed to microgravity and cosmic 
radiation.  The purpose of the experiment is to improve properties 
of the yeast by durable fixed genetic mutations.  The genome of 
the HB-L29 yeast used in the experiment shows two additional 
chromosomes in comparison to cultures investigated up to now.  

COSMIC RADIATION EXPERIMENTS

        On the D2 mission, detectors will be worn by the astronauts 
and placed near the biological experiments as control indicators.  
They also will be placed in the biostacks, which are stacks of 
trays containing small biological specimens such as plant seeds, 
insect eggs and bacterial spores, alternating with radiation 
detectors.  The results of these experiments will contribute to 
the assessment of the biological effects of specific cosmic 
radiation and so help to reduce the health risks for future human 
exploration missions.

        *BIOLOGICAL HZE-PARTICLE DOSIMETRY WITH BIOSTACK

        This experiment is part of a radiobiological space research 
program including experiments in space as well as at accelerators 
on Earth.  The program has been specially designed to increase 
knowledge on the importance, effectiveness and hazards to humans 
and to any biological specimen in space of the particles of high 
atomic number and high energy of the cosmic radiation.  Its 
unknown proper biological effectiveness may significantly affect 
the design of the space station and its operation.  Findings of 
earlier Biostack experiments clearly indicate the significance of 
high energy particles.  More detailed information is necessary and 
requires more investigations in this matter.

        *PERSONAL DOSIMETRY:  MEASUREMENT OF THE ASTRONAUT'S 
         IONIZING RADIATION EXPOSURE
 
        Personal dosimetry of the astronauts' ionizing radiation 
exposure is an indispensable part of the biomedical surveillance 
in human spaceflight.  The different components of the cosmic 
radiation field are to be measured with different, passive and 
tissue equivalent, radiation detectors, each specialized for the 
registration of, respectively, the heavy ions, the nuclear 
disintegration stars, and the sparsely ionizing background 
radiation, i.e., the electrons, protons and rays.  Small stacks of 
these detectors are to be attached to the astronauts' bodies in 
the vicinity of potentially critical organs to establish a 
permanent record of the astronauts' exposure to the cosmic 
radiation field.

        *MEASUREMENT OF THE RADIATION ENVIRONMENT INSIDE 
         SPACELAB AT LOCATIONS WHICH DIFFER IN SHIELDING AGAINST 
         COSMIC RADIATION 
 
        The experiment has the objective to document the radiation 
environment inside the Spacelab and to compare the experimental 
data with theoretical predictions.  This will provide radiation 
baseline data required for the flight personnel and any radiation 
sensitive experiment and material.  These data are necessary for 
establishing radiation protection guidelines and standards for the 
presence of people in space.  For this purpose, containers with 
different kinds of radiation detectors will be placed in locations 
which differ in shielding against cosmic radiation.  The analysis 
of the dosimeters will be performed after flight in the 
laboratories of the investigators.

        *Chromosome aberration
 
        Chromosomal aberrations, micronuclei and sister-chromated 
exchanges will be analyzed in the peripheral lymphocytes of 
astronauts.  The analysis will be performed shortly before and 
after the space flight and 4 weeks, 6 months and 1 year after the 
flight.  The data obtained will be used as a biological dosimeter 
for the exposure of astronauts to ionizing radiation during the 
space flight.

        *BIOLOGICAL RESPONSE TO EXTRATERRESTRIAL SOLAR UV 
         RADIATION AND SPACE VACUUM
 
        The photobiological and photobiochemical response to solar 
UV radiation in space will be studied in spores of Bacillus 
subtilis and in DNA isolated from Hemophilus influenzas.  For that 
purpose, 2 exposure trays, accommodating the biological samples 
for exposure to space vacuum and/or to selected intensities and 
wavelengths of extraterrestrial solar UV radiation, will be 
mounted onto the User Support Structure.

User Support Structure (USS) Payloads

        A structure mounted in the Columbia's cargo bay near the 
module provides support for additional experiment facilities which 
can be connected to the module for power and data, but which may 
run independently. 


MATERIALS SCIENCE AUTONOMOUS PAYLOAD (MAUS)

        The Material Science Autonomous Payload (MAUS) is comprised 
of two experiments:  one explores diffusion phenomena of gas 
bubbles in salt melts, while the other performs research of 
complex boiling processes.

        *Pool Boiling
 
        Nucleate pool boiling in theory is strongly gravity 
dependent.  The MAUS experiment with its good zero-g quality 
should confirm results of KC- 135 parabolic flight missions that 
pool boiling is quasi gravity independent.

        *Gas bubbles in glass melts
 
        The shrinking of a single oxygen bubble in a cylindrical 
sample is observed to determine the diffusion coefficient in a 
soda-lime-silica melt.  A camera takes pictures of the bubble in 
certain time intervals.  The diffusion coefficient can be 
calculated from this radius-time dependence by means of a finite 
differences method.

        *Reaction Kinetics in Glass Melts
 
        Goal of these experiments is the determination of diffusion 
coefficients in order to verify mathematical models describing 
mass transport in glass melts. Two types of experiments will be 
conducted:  interdiffusion between glass melts of the system and 
corrosion of silica glass by alkali silicate melts.  Sixteen 
individual samples in four separate furnaces will be processed at 
temperatures of 1470 K and 1520 K for 20 or 40 minutes of 
annealing time.


ATOMIC OXYGEN EXPOSURE TRAY (AOET)

        The Atomic Oxygen Exposure Tray (AOET) is a self-standing 
facility located on the support structure that performs 
experiments in the field of material science.  The AOET uses the 
orbiter as an exposure laboratory to obtain inside reaction rate 
measurements for various materials interacting with atomic rate 
measurements for various materials interaction with atomic oxygen 
with the low-Earth orbital environment. 

        AOET is dedicated to investigate the erosion effects on a 
technological basis.  Erosion is supposed to be a vital problem 
for the realization of future space vehicles like Columbus, the 
European segment of the U.S. Space Station Freedom.  The lifetime 
of its structural materials is defined to 30 years.  Prime 
candidates are fiber reenforced materials which have to be 
protected against erosion. 

        The AOET is a quasi passive sample array mounted onto the 
Unique Support Structure within the cargo bay such that the 
samples are facing the incoming atmospheric flow.  The 124 sample 
plates are either circular or rectangular sized, depending on post 
mission analysis needs.


GALACTIC ULTRAWIDE-ANGLE SCHMIDT SYSTEM CAMERA (GAUSS)

        The Galactic Ultrawide-Angle Schmidt System Camera (GAUSS) 
is an ultraviolet camera used to provide wide-angle, photographic 
coverage of the galaxy.  Pictures taken of the Milky Way galaxy, 
younger stars and the gas clouds, which they warm up, will extend 
the knowledge of our galaxy significantly.  A number of exposure 
of the Earth's atmosphere also are planned when the orbiter bay 
faces the Earth.  The GAUSS camera is a mirror system for the 
ultraviolet with a field of view of 145 degrees.  About 100 
exposures of the Milky Way and the upper atmosphere shall be taken. 


MODULAR OPTOELECTRONIC MULTISPECTRAL STEREO SCANNER

        The Modular Optoelectronic Multispectral Stereo Scanner 
(MOMS) is an advanced camera system for Earth observation.  The 
instrument is located on the USS platform and provides imaging 
data from space for photogrammetric mapping and thematic mapping 
applications.  It is an improved instrument based on MOMS-01 that 
was flown in 1983 and 1984.  

        MOMS-02 improves existing Earth observations with its long-
track, high-performance stereo capabilities and digital images of 
higher geometric resolution and accuracy.  Through the high 
geometric resolution and geometric accuracy of the threefold 
stereo module, it is possible to derive digital terrain models 
with a precision of better than 5 m.  The optimized multispectral 
module aims at improved thematic information.  New understandings 
in applications such as cartography, landuse, ecology and geology 
are expected.

CREW TELESUPPORT EXPERIMENT (CTE)
 
        This experiment combines an onboard computer-based, multi-
media documentation file, including text, graphics and photos, 
with a real-time, graphical communication between the on-orbit 
crewmember and the ground station.  The result of CTE will enhance 
the effectiveness of the following areas:
 
        * On-orbit payload operations
        * Scientific return
        * Crew to ground interaction
        * Contingency maintenance tasks for systems and payloads
 
        Equipment used for the CTE is the interactive Hypermedia 
documentation file stored on an optical disk and a Macintosh 
portable computer equipped with a pen-activated, interactive 
graphics tablet as a peripheral.

Shuttle Amateur Radio EXperiment (SAREX)

        Students in the United States and around the world will have 
a chance to speak via amateur radio with astronauts aboard the 
Space Shuttle Columbia during STS-55.  There also will be voice 
contacts with the general ham community as time permits.  Also 
during the mission, an antenna test will be conducted on orbits 61 
and 62 involving many amateur radio stations in the southern U.S. 
who will measure the exact time of acquistion of signal and loss 
of signal along with other data.

        Shuttle Commander Steve Nagel (call sign N5RAW), Pilot Jerry 
Ross (N5SCW) and payload specialists Hans Schlegel (DG1KIH) and 
Ulrich Walter (DG1KIM) will talk with students in nine schools in 
the United States and with students in France, Australia and South 
Africa using "ham radio."  

        Students in the following U.S. schools will have the 
opportunity to talk directly with orbiting astronauts for 
approximately 4 to 8 minutes:


        *  Meadow Village Elementary, San Antonio, Texas (WA5FRF)
        *  Fairmont Elementary, Deer Park, Texas (N5NBM)
        *  John S. Ward Elementary, Houston (N5EOS)
        *  Cumberland Junior High, Sunnyvale, Calif. (WZ6N)
        *  Mudge Elementary, Fort Knox, Ky. (KE4NS)
        *  Seven Mills and Lotspeich Elementary, Cincinnati (KF8YA)
        *  St. Martin's Episcopal, Metairie, La. (N4MDC)
        *  Trumansburg Middle, Trumansburg, N.Y. (N2PNA)
        *   U.S. Air Force Academy, Colo. (K0MIC)

        The international schools that will communicate with the 
crew are:

        *  Westering High School, Port Elizabeth, South Africa
        *  Sisekelo High School, Swaziland, South Africa
        *  Tamworth High School, New South Wales, Australia
        *  Gladstone State High School, Gladstone,
         Queensland, Australia
        *  French Air Force Academy, Salon de Prov, France

        The astronaut/student radio contact is part of the SAREX 
project, a joint effort by NASA, the American Radio Relay League 
(ARRL) and the Amateur Radio Satellite Corporation (AMSAT).   

        The project, which has flown on seven Shuttle missions, was 
designed to encourage public participation in the space program 
and support the conduct of educational initiatives through a 
program to demonstrate the effectiveness of communications between 
the Shuttle and low-cost ground stations using amateur radio voice 
and digital techniques.

        SAREX is a secondary payload located in Columbia's crew 
cabin.  Another amateur radio experiment, called SAFEX, will be 
aboard the Spacelab D2 module and will be operated by licensed 
German payload specialists.  SAFEX uses an external dual band 2 
meter/70 cm antenna mounted on the ourside of the Spacelab while 
SAREX uses a window-mounted antenna in the Shuttle's cockpit.

        Information about orbital elements, contact times, 
frequencies and crew operating schedules will be available during 
the mission from NASA, ARRL and AMSAT.  

        The ham radio club at the Johnson Space Center (W5RRR) will 
be operating on amateur short wave frequencies, and the ARRL 
station (W1AW) will include SAREX information in its regular voice 
and teletype bulletins.

        There will be a SAREX information desk during the mission in 
the JSC newsroom.  Mission information will be available on the 
computer bulletin board (BBS).  To reach the bulletin board, use 
JSC BBS (8 N 1 1200 baud), dial 7713-483-2500, then type 62511.

        The amateur radio station at the Goddard Space Flight Center 
(WA3NAN) will operate around the clock during the mission, 
providing information and retransmitting live Shuttle air-to-
ground audio.

STS-55 SAREX Frequencies

        Routine SAREX transmissions from the Space Shuttle may be 
monitored on 145.55 MHz for downlink.  This 600 KHz spacing in the 
transmit/receive frequency pair is compatible with amateur VHF 
equipment.

Voice Uplink Frequency
144.91 MHz
144.93
144.95
144.97
144.99

Packet downlink frequency    144.55 MHz
Packet uplink frequency     144.49 

        The Goddard Space Flight Center amateur radio club planned 
HF operating frequencies: 

3.860 MHz                         7.185 MHz
14.295                           21.395 
28.395



STS-55 Crew Biographies

        Steven R. Nagel, 47, Col., USAF, will command STS-55.  
Selected as an astronaut in 1979, Nagel's hometown is Canton, Ill.  
He will be making his fourth space flight.

        Nagel graduated from Canton Senior High School in 1964, 
received a bachelor's degree in aeronautical and astronautical 
engineering from the University of Illinois in 1969 and received a 
master's degree in mechanical engineering from California State 
University in 1978.

        He first flew as a mission specialist on STS-51G in June 
1985, a flight that deployed three commercial communications 
satellites.  His next flight was as Pilot on STS-61A in November 
1985, the first West German-United States cooperative Spacelab 
mission.  His third flight was as Commander of STS-37 in April 
1991, a mission that deployed NASA's Gamma Ray Observatory.  Nagel 
has logged 483 hours in space.

        Terence T. "Tom" Henricks, 41, Col., USAF, will be Pilot of 
STS-55.  Selected as an astronaut in June 1985, Henricks considers 
Woodville, Ohio, his hometown and will be making his second space 
flight.

        Henricks graduated from Woodmore High School in 1970, 
received a bachelor's degree in civil engineering from the Air 
Force Academy in 1974 and received a master's degree in public 
administration from Golden Gate University in 1982.

        Henricks graduated from the Air Force Test Pilot School in 
1983 and was serving as an F-16C test pilot at the time of his 
selection by NASA.  He has logged more than 3,600 hours of flying 
time in 30 different types of aircraft and holds a master 
parachutist rating with 747 jumps to his credit.

        His first space flight was as Pilot of STS-44 in November 
1991, a Department of Defense-dedicated Shuttle flight that 
deployed the Defense Support Program satellite.  He has logged 
more than 166 hours in space.

        Jerry L. Ross, 45, Col., USAF, will be Mission Specialist 1 
(MS1).  Selected as an astronaut in May 1980, Ross' hometown is 
Crown Point, IN, and he will be making his fourth space flight.

        Ross graduated from Crown Point High School in 1966, 
received a bachelor's degree in mechanical engineering from Purdue 
University in 1970 and received a master's degree in mechanical 
engineering from Purdue in 1972.

        Ross' first flight was as a mission specialist on STS-61B in 
November 1985, a mission that deployed three commercial 
communications satellites and on which Ross performed two 
spacewalks to test space station construction methods.  His next 
flight was STS-27 in December 1988, a classified Department of 
Defense-dedicated mission.  
        His third flight was on STS-37 in April 1991, a mission that 
deployed NASA's Gamma Ray Observatory and on which Ross performed 
two spacewalks, one to unstick a balky antenna on the satellite 
and another to evaluate space station hardware.  Ross has logged 
414 hours in space and 23 hours of spacewalk time.

        Charles J. Precourt, 37, Major, USAF, will be Mission 
Specialist 2 (MS2) on STS-55.  Selected as an astronaut in January 
1990, Precourt considers Hudson, Mass., his hometown and will be 
making his first space flight.

        Precourt graduated from Hudson High School in 1973, received 
a bachelor's degree in aeronautical engineering from the Air Force 
Academy in 1977, received a master's degree in engineering 
management from Golden Gate University in 1988 and received a 
master's in national security affairs and strategic studies from 
the Naval War College in 1990.

        Precourt graduated from the Air Force Test Pilot School in 
1985 and served as a test pilot in the F-15E, F-4, A-7 and A-37 
aircraft.  He was selected as an astronaut after graduating from 
the Naval War College and has logged more than 4,300 hours of 
flying time in 35 different types of aircraft.

        Bernard A. Harris, Jr., 36, M.D., will be Mission Specialist 
3 (MS3). Selected as an astronaut in January 1990, Harris was born 
in Temple, Texas, and will be making his first space flight.

        Harris graduated from Sam Houston High School in San Antonio 
in 1974, received a bachelor's degree in biology from the 
University of Houston in 1978 and received a doctorate of medicine 
from Texas Tech School on Medicine in 1982.

        Harris completed a residency in internal medicine at the 
Mayo Clinic in 1985, completed a National Research Council 
Fellowship at NASA's Ames Research Center in 1987 and trained as a 
flight surgeon at the Aerospace School of Medicine at Brooks Air 
Force Base in San Antonio in 1988.

        Harris joined NASA in 1987, serving as a clinical surgeon 
and flight surgeon at the Johnson Space Center until his selection 
as an astronaut.

        Ulrich Walter, 38, will be Payload Specialist 1 (PS1).  
Nominated as a German astronaut by the German space agency in 
1987, Walter was born in Iserlohn, Germany, and will be making his 
first space flight.

        Walter graduated from Iserlohn's Markisches Gymnasium in 
1972, graduated with a degree in physics from the University at 
Cologne in 1980 and received a doctorate in solid state physics 
from the University of Cologne in 1985.  He performed post-
doctoral work at the Argonne National Laboratory in Chicago in 
1986 and at the University of California-Berkley in 1987.

        Hans William Schlegel, 41, will be Payload Specialist 2 
(PS2).  Nominated as a German astronaut in 1987, Schlegel was born 
in Oberlingen, Germany, and will be making his first space flight.

        Schlegel graduated from Hansa Gymnasium in Cologne in 1970 
and received a diploma in physics from the University of Aachen in 
1979.

        From 1979-1986, Schlegel was a member of the academic staff 
at Rheinisch Westfalische Technische Hochschule at the University 
of Aachen as an experimental solid state physicist.  From 1986-
1988, he was a specialist in non-destructive testing methodology 
in the research and development department of the Institut Dr. 
Forster GmbH and Co. KG in Reutlingen, Germany.


MISSION MANAGEMENT FOR STS-55

NASA HEADQUARTERS, WASHINGTON, D.C.

Office of Space Flight

Jeremiah W. Pearson III - Associate Administrator
Bryan O'Connor - Deputy Associate Administrator
Tom Utsman - Space Shuttle Program Director
Leonard Nicholson - Space Shuttle Program Manager (JSC)
Col. Brewster Shaw - Deputy Space Shuttle Program Manager (KSC)
 
Office of Space Science and Applications

Dr. Lennard Fisk - Associate Administrator
Al Diaz - Deputy Associate Administrator
Robert Rhome - Director, Microgravity Science 
  and Applications Division
Dr. Bradley Carpenter - Program Scientist, Microgravity 
  Science and  Applications Division
Joseph Alexander, Acting Director, Life Sciences Division
Dr. William Gilbreath, Program Manager, Life Sciences Division
Dr. Ronald White, Program Scientist, Life Sciences Division

Office of Safety and Mission Quality

Col. Frederick Gregory - Associate Administrator 
Charles Mertz - (Acting) 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
Bascom W. Murrah - Columbia 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



MARSHALL SPACE FLIGHT CENTER, HUNTSVILLE, ALA.

Thomas J. Lee - Director
Dr. J. Wayne Littles - Deputy Director
Alexander A. McCool - Manager, Shuttle Projects Office
Harry G. Craft, Jr. - Manager, Payload 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
Parker Counts - Manager, External Tank Project

JOHNSON SPACE CENTER, HOUSTON

Aaron Cohen - Director
Paul J. Weitz - Acting Director
Daniel Germany - Manager, Orbiter and GFE Projects
Dr. Steven Hawley - Acting Director, Flight Crew Operations
Eugene F. Kranz - 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
Robert R. Meyers, Jr. - Assistant Director
James R. Phelps - Chief, Shuttle Support Office.

DARA
 
Prof. Heinz Stoewer - Program Director
Wilfried Geist - Program Coordinator

DLR
 
Prof. Dr. Walter Kroll - Chairman of Board of Director
Dr. Jurgen Beck - Director of Operations
Norbert Kiehne - Head of Management Department
Dr. Hauke Dodeck - D2 Mission Manager
Werner Gross - Head of Section D2 Administration
Hermann-Josef Kurscheid - Head of Section D2 Integration
Walter Brungs - Head of Section D2 Engineering
Reinhold Karsten - Head of Section D2 Payload 
 Development and Coordination
Horst Schurmanns - Head of Section D2 Quality and
 Mission Assurance
Dr. Klaus Gardy - Head of Section D2 Operations
Ludger Frobel - Head of Section D2 Data Management
Prof. Dr. Peter Sahm - D2 Program Scientist
Dr. Manfred Keller - D2 Mission Scientist
Hans-Ulrich Steimle - Department Head Crew Operations
Dr. Raimund Lentzen - Head of Astronaut Office
Dr. Wolfgang Wyborny - Section Head of DLR Payload Operations
Dr. Franz-Josef Schlude - Head of Manned Space Control Center
Karl Friedl - MSCC D2 Coordination

ESA

F. Engstrom - Director of ESA Space Station and
 Microgravity Programme
G. Seibert - Head of Microgravity and Columbus 
 Utilization Strategy and Planning Division
H. Martinides - Head of Microgravity Payload Division
K. Knott - Head of Columbus Interfaces and Payload Studies 
Division

