Public Affairs Contacts
For Information on the Space Shuttle

Ed Campion
Policy/Management
Headquarters, Wash., DC
202/358-1780

Rob Navias
Mission Operations
Johnson Space Center
Astronauts
Houston
713/483-5111

June Malone
External Tank/SRBs/SSMEs
Marshall Space Flight Center
Huntsville, AL
205/544-7061

Cam Martin
DFRC Landing Information
Dryden Flight Research Center
Edwards, CA 
805/258-3448

For Information on STS-70 Experiments and Activities
Fred Brown
Tracking and Data Relay Satellite (TDRS)
Goddard Space Flight Center
Greenbelt, MD
301/286-7277

Jerry Berg
Inertial Upper Stage (IUS)
Marshall Space Flight Center
Huntsville, AL
205/544-0034

Michael Braukus
Biological Research in Canisters (BRIC)
Bioreactor Development System (BDS)
National Institutes of Health-R-2 (NIH R-2)
Headquarters, Wash., DC 
202/358-1979

Dave Hess
Hand-Held, Earth-Oriented, Cooperative,
Real-Time, User-Friendly, Location Targeting
   and Environmental System (HERCULES)
Microencapsulation in Space-B (MIS-B)
Midcourse Space Experiment (MSX)
Military Application of Ship Tracks (MAST)
Radiation Monitoring Equipment-III (RME-III)
Space Tissue Loss-B (STL-B)
Window Experiment (WINDEX)
Visual Function Tester-4 (VFT-4)
DoD/Johnson Space Center
Houston
713/483-3425   
 
Jim Cast
Commercial Protein Crystal Growth
Headquarters, Wash., DC
202/358-1779

Terri Hudkins
Shuttle Amateur Radio EXperiment    (SAREX)
Headquarters, Wash., DC      
202/358-1977

CONTENTS

GENERAL BACKGROUND
General Release......................................3
Media Services Information...........................6
STS-70 Quick Look....................................8
Development Test Objective/Detailed Supplementary 
Objectives...........................................9
Space Shuttle Abort Modes...........................10
STS-70 Summary Timeline.............................11
Payload and Vehicle Weights.........................12
STS-70 Orbital Events 
Summary.............................................13
STS-70 Crew Responsibilities........................14

BLOCK 1 SPACE SHUTTLE MAIN 
ENGINES.............................................15

CARGO BAY PAYLOADS & ACTIVITIES
Tracking and Data Relay Satellite 
System...............................................17
Inertial Upper Stage.................................25

MIDDECK PAYLOADS
Biological Research In Canisters.....................28
Bioreactor Development System........................30
National Institutes of Health - R-2..................31
Commercial Protein Crystal Growth....................33
Space Tissue Loss-B..................................34

IN-CABIN PAYLOADS
Hand-Held, Earth-Oriented, Cooperative, Real-Time, 
User-Friendly, Location Targeting and Environmental 
System...............................................34
Microencapsulation in Space-B........................35
Midcourse Space Experiment...........................36
Military Applications of Ship Tracks.................36
Radiation Monitoring Equipment-III...................37
Window Experiment....................................37
Visual Function Tester-4.............................38
Shuttle Amateur Radio Experiment.....................39
STS-70 Crew Biographies..............................41

RELEASE:  95-71

DISCOVERY LAUNCH TO MARK 100TH HUMAN SPACEFLIGHT 

     Thirty-four years after Alan B. Shepard's historic 15-
minute sub-orbital flight into space, America will launch 
its 100th human space mission on June 8 with the flight of 
the Space Shuttle Discovery.

     Designated STS-70, the mission is scheduled to be 
launched into a 160-mile circular orbit during a two hour 30 
minute window that opens at 9:01 a.m. EDT on June 8.  The 
mission is scheduled for seven days, 22 hours and 10 
minutes, but Shuttle officials may shorten the flight to 
five days depending on when the mission actually begins so 
that the next Shuttle mission - a historic linkup with the 
Russian space station Mir - can be launched about June 23.  
An eight-day mission would result in a June 16 landing at 
the Kennedy Space Center, FL.  A shortened flight would see 
Discovery touch down on June 13.

     Aboard Discovery will be a five-person crew commanded 
by two-time Shuttle pilot Terence "Tom" Henricks, pilot 
Kevin Kregel and mission specialists Donald Thomas (second 
flight), Nancy Currie (second flight) and Mary Ellen Weber.  
This will be Kregel and Weber's maiden space voyage.  

     Discovery's primary objective is the deployment of the 
Tracking and Data Relay Satellite-G, the last in a series of 
a space-based satellite network that provides 
communications, tracking, telemetry, data acquisition and 
command services essential to Shuttle and low-Earth orbital 
spacecraft missions.

     Approximately six hours after launch, TDRS-G will be 
released out of Discovery's payload bay.  It will be boosted 
to geostationary orbit 22,300 miles above the Earth by a 
powerful 2-stage, 16-ton solid-fueled Inertial Upper Stage, 
positioned at 171 degrees West longitude.

     STS-70 will mark another significant milestone with the 
first flight of the new Block I Space Shuttle main engine.  
Main Engine #1 - engine 2036 - features improvements that 
increase the reliability and safety margins of the main 
engines. SSME's No. 2 and No. 3 are the current design.

     The Block I engine features improvements such as a new 
liquid oxidizer turbopump produced through a casting process 
that eliminates all but six of the 300 welds that exist in 
the current pump.  A new two-duct powerhead improves fluid 
flows within the engine to decrease pressure and loads.  A 
new single-coil heat exchanger in the powerhead eliminates 
all seven weld joints inside the engine, reducing wear, 
maintenance and post-flight inspections.  On STS-73, 
scheduled for launch in late September 1995, all three of 
the SSME's will be of the Block I design.

     With TDRS successfully deployed, Discovery's crew will 
turn their attention to middeck experiments.

     Among the payloads stowed in Discovery's middeck is the 
Commercial Protein Crystal Growth facility in which 
researchers will grow crystals of human alpha interferon 
protein, a protein pharmaceutical that is currently used 
against human viral hepatitus B and C.  The objective is to 
use these crystals to determine the three-dimensional 
structure of molecules using crystallography to assist in 
the development of the next generation of alpha interferon 
drugs.

     A University of Arizona researcher will examine the 
tobacco hornworm to determine how its hormone system and 
muscle formation are affected by zero-gravity in an 
experiment called Biological Research in Canisters-4.  Basic 
information in hormone and muscle development will have a 
direct impact on basic research and development for long 
duration human space missions, as well as potentially 
affecting such areas as insect development and pest control 
on Earth. 

     BRIC-5, a State University of New York at Stony Brook 
experiment, will study the effects of spaceflight on the 
cell division of the daylily.  This research will contribute 
to a better understanding of plant development and 
reproduction, which in turn will directly affect the ability 
to grow plants in space.

     National Institutes of Health-sponsored experiments in 
the middeck will examine the effects of space flight on the 
behavior, muscle, nerve and bone development and circadian 
timing of rats.  Much of this research is directed at 
developing a greater understanding of basic physiological 
processes which could provide insight into a range of 
medical challenges on Earth.

     NASA and the Walter Reed Army Institute are 
collaborating on the space tissue loss-B experiment which 
will investigate the effects of microgravity on 
embryogenesis, using the Medaka fish egg as its biology 
model.

     Also on board are a bevy of DoD-sponsored experiments 
including:

*    Hand-Held, Earth-Oriented, Cooperative, Real-Time, 
User-
Friendly, Location Targeting and Environmental System 
(HERCULES-B), a multispectral video camera-based 
geolocating system; 

*    Military Applications of Ship Tracks (MAST), which will 
take high resolution photographs of ship tracks to assist 
in an understanding of the effect of man-made aerosols on 
clouds and the resulting impact on the climate system; 

*    Microencapsulation in Space (MIS), which will look at a 
novel approach of encapsulating a drug in a biodegradable 
polymer so that as the polymer degrades the drug is 
released at a controlled rate; 

*    Midcourse Space Experiment (MSX), which will support 
the 
DoD's development of surveillance capabilities of 
ballistic missiles during the midcourse of their flight; 

*    Visual Function Tester (VFT), an instrument which could 
help explain why astronauts lose their ability to see 
clearly at close range when in space;

*    Window Experiment (WINDEX), which will study the 
dynamics 
of thruster plumes, Shuttle glow, water dumps and flash 
evaporator system releases, atmospheric night glow and 
aurora to better understand the environment around low-
Earth orbit satellites; and

*    Radiation Monitoring Equipment (RME), prototype 
dosimeter 
instruments which measure exposure to ionizing radiation 
on the Shuttle.

     Students in the U.S. and Argentina will speak to the 
astronauts via the Shuttle Amateur Radio Experiment.  Among 
the schools scheduled to have an opportunity to talk to the 
astronauts are those in Troy and Euclid, OH; Farmingdale and 
Schenectady, NY; Concord, NH; Highland and Grand Rapids, MI; 
New Port Richey, FL, and Fallbrook, CA.

     STS-70 will be the 21st flight of the Orbiter 
Discovery, and the 69th in the Space Shuttle program.

End of general release

MEDIA SERVICES  INFORMATION

NASA Television Transmission

    NASA Television is available through Spacenet-2 
satellite system, transponder 5, channel 9, at 69 degrees 
West longitude, frequency 3880.0 MHz, audio 6.8 Megahertz.

    The schedule for television transmissions from the 
Orbiter and for mission briefings will be available during 
the mission at Kennedy Space Center, FL; Marshall Space 
Flight Center, Huntsville, AL; Dryden Flight Research 
Center, Edwards, CA; Johnson Space Center, Houston; NASA 
Headquarters, Washington, DC.  The television schedule will 
be updated to reflect changes dictated by mission 
operations.

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

Status Reports

    Status reports on countdown and mission progress, on-
orbit activities and landing operations will be produced by 
the appropriate NASA 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 payload team, will 
occur at least once per day.  The updated NASA television 
schedule will indicate when mission briefings are planned.

Access by Internet

    NASA press releases can be obtained automatically by 
sending an Internet electronic mail message to 
domo@hq.nasa.gov.  In the body of the message (not the 
subject line) users should type the words "subscribe press-
release" (no quotes).  The system will reply with a 
confirmation via E-mail of each subscription.  A second 
automatic message will include additional information on the 
service.

    Informational materials also will be available from a 
data repository known as an anonymous FTP (File Transfer 
Protocol) server at ftp.pao.hq.nasa.gov under the directory 
/pub/pao.  Users should log on with the user name 
"anonymous" (no quotes), then enter their E-mail address as 
the password.  Within the /pub/pao directory there will be a 
"readme.txt" file explaining the directory structure.

  The NASA public affairs homepage also is available via the 
Internet.  The page contains images, sound and text (press 
releases, press kits, fact sheets) to explain NASA 
activities.  It also has links to many other NASA pages.  
The URL is: http://www.nasa.gov/hqpao/hqpao_home.html

     Pre-launch status reports from KSC are found under 
ftp.hq.nasa.gov/pub/pao/statrpt/ksc, and mission status 
reports can be found under 
ftp.hq.nasa.gov/pub/pao/statrpt/jsc.  Daily TV schedules can 
be found under ftp.hq.nasa.gov/pub/pao/statrpt/jsc/tvsked.

Access by fax

    An additional service known as fax-on-demand will 
enable users to access NASA informational materials from 
their fax machines.  Users calling (202) 358-3976 may follow 
a series of prompts and will automatically be faxed the most 
recent Headquarters news releases they request.

Access by Compuserve

    Users with Compuserve accounts can access NASA press 
releases by typing "GO NASA" (no quotes) and making a 
selection from the categories offered.

STS-70 QUICK LOOK

Launch Date/Site:     June 8, 1995/KSC Pad 39B
Launch Time:          09:01 a.m. EDT
Launch Window:        2 hours, 30 minutes
Orbiter:              Discovery (OV-103) - 21st flight
Orbit/Inclination:    160 nautical miles/28.45 degrees
Mission Duration:     7 days, 22 hours, 10 minutes
Landing Date:         June 16, 1995
Landing Time:         8:30 a.m. EDT
Primary Landing Site: Kennedy Space Center, FL
Abort Landing Sites:  Return to Launch Site - KSC
                      Transoceanic Abort Landing - Banjul, 
                       The Gambia
                      Ben Guerir, Morocco
                      Moron, Spain
                      Abort Once Around - Edwards Air 
                       Force Base, CA

Crew:    Tom Henricks, Commander (CDR)
         Kevin Kregel, Pilot (PLT)
         Don Thomas, Mission Specialist 1(MS 1)
         Nancy Currie, Mission Specialist 2 (MS 2)
         Mary Ellen Weber, Mission Specialist 3 (MS 3)

Cargo Bay Payloads:  Tracking and Data Relay 
                       Satellite/Inertial Upper Stage

Middeck Payloads: Biological Research in Canisters
                     (BRIC)
                  Bioreactor Development Systems
                     (BDS)
                  Commercial Protein Crystal Growth
                     (CPCG)
                  National Institutes of Health-R-2 
                     (NIH R-2)
                  Space Tissue Loss-B (STL-B)
                  Midcourse Space Experiment (MSX)

In-Cabin Payloads: Hand-Held, Earth-Oriented, 
                     Cooperative, Real-Time, 
                   User-Friendly, Location Targeting 
                     and Environmental System (HERCULES)
                   Microencapsulation in Space-B (MIS-B)
                   Military Application of Ship Tracks 
                     (MAST)
                   Radiation Monitoring Equipment-III
                     (RME-III)
                   Shuttle Amateur Radio Experiment 
                     (SAREX)
                   Window Experiment (WINDEX)
                   Visual Function Tester-4 (VFT-4)

DEVELOPMENT TEST OBJECTIVE/DETAILED SUPPLEMENTARY OBJECTIVES

DTO 301D:  Ascent Structural Capability Evaluation
DTO 305D:  Ascent Compartment Venting Evaluation
DTO 306D:  Descent Compartment Venting Evaluation
DTO 307D:  Entry Structural Capability Evaluation
DTO 312:   External Tank Thermal Protection System 
              Performance
DTO 319D:   Shuttle/Payload Low Frequency Environment
DTO 414:   APU Shutdown Test
DTO 524:   Landing Gear Loads and Brake Stability 
              Evaluation
DTO 656:   PGSC Single Event Upset Monitoring
DTO 677:   Evaluation of Microbial Capture Device, 
              Microgravity
DTO 779:   STS Orbiter Attitude Control Translational 
              Thrusting
DTO 805:   Crosswind Landing Performance
DSO 491:   Characterization of Microbial Transfer 
              Among Crewmembers
DSO 603:   Orthostatic Function During Entry, Landing 
              and Egress
DSO 621:   In Flight Use of Florinef to Improve 
              Orthostatic Intolerance
DSO 624:   Pre and Postflight Measurement of 
              Cardiorespiratory Responses to 
              Submaximal Exercise
DSO 626:   Cardiovascular and Cerebrovascular 
              Responses to Standing Before and 
              After Space Flight
DSO 802:   Educational Video
DSO 901:   Documentary Television
DSO 902:   Documentary Motion Picture Television
DSO 903:   Documentary Still Photography
DSO 904:   Assessment of Human Factors

SPACE SHUTTLE ABORT MODES

     The Space Shuttle launch abort philosophy aims toward 
safe and intact recovery of the flight crew, Orbiter and its 
payload.  Abort modes for STS-70 include:

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

*  Abort-Once-Around (AOA) -- Earlier main engine shutdown 
with the capability to allow one orbit of the Earth before 
landing at the Edwards Air Force Base, CA.

*  TransAtlantic 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, Morocco; 
or Moron, Spain.

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

STS-70 SUMMARY TIMELINE

Flight Day One:   
Launch         
Orbital Maneuvering System-2 & 3 Burn
Secondary Payload Activation 
TDRS-G/IUS Deploy
IUS Ignition

Flight Day Two:
OMS 4 Burn
Visual Function Tester Setup
CPCG Activation
SAREX Setup
HERCULES Setup
WINDEX Setup
Bioreactor Demonstration System Operations

Flight Day Three:
HERCULES Operations
Visual Function Tester Operations
Bioreactor Demonstration System Operations
WINDEX Operations
SAREX Operations

Flight Day Four:
Bioreactor Demonstration System Operations
WINDEX Operations
SAREX Operations
HERCULES Operations

Flight Day Five:
Visual Function Tester Operations
WINDEX Operations
Bioreactor Demonstration System Operations
AMOS Reaction Control System Tests
SAREX Operations

Flight Day Six:
WINDEX Operations
HERCULES Operations
Bioreactor Demonstration System Operations

Flight Day Seven:
Visual Function Tester Operations
HERCULES Operations
Bioreactor Demonstration System Operations
WINDEX Operations

Flight Day Eight:
Visual Function Tester Operations
Flight Control System Checkout
Reaction Control System Hot-Fire
Crew News Conference
Cabin Stow

Flight Day Nine:
Deorbit Prep
Deorbit Burn
Landing

PAYLOAD AND VEHICLE WEIGHTS

Vehicle / Payload                      Pounds    
Orbiter (Discovery) empty and 3 SSMEs  173,885
Tracking and Data Relay 
     Satellite-G Deployable              4,905
Interial Upper Stage - Deployable       32,868
TDRS-G - Airborne Support Equipment      5,586    
BDS                                        155
BRIC                                        30
CPCG                                       116
HERCULES                                   161
MIS                                        120
NIH-R-2                                    133
SAREX                                       27
STL                                         68
DTOs/DSOs                                    5
Shuttle System at SRB Ignition       4,522,790
Orbiter Weight at Landing              195,195

STS-70 ORBITAL EVENTS SUMMARY

EVENT                   MET            
Launch                0/00:00        
OMS-2                 0/00:42        
TDRS-G/IUS Deploy     0/06:12        
Sep-1 Burn            0/06:13        
Sep-2 Burn            0/06:27        
IUS Injection Burn    0/07:12        
OMS-4 Circ Burn       1/03:45        
Deorbit Burn          7:21:08        
KSC Landing           7:22:10        

STS-70 CREW RESPONSIBILITIES

    Primary Payload

TDRS-G/IUS            Thomas, Weber

    Secondary Payloads
WINDEX                      Henricks, Kregel, Currie
STL                         Currie, Weber
RME                         Kregel, Currie
NIH-R (PARE)                Thomas, Currie
MIS-B                       Thomas, Weber
HERCULES                    Henricks, Kregel, Currie
CPCG                        Currie, Weber
BRIC                        Kregel, Currie
BDS                         Weber, Thomas
SAREX                       Thomas, Currie
VFT                         Weber, Henricks
DTO 656   (PGSC)            Thomas, Weber
DTO 779   (Orbiter Control  Henricks, Kregel
DSO 677   (Microgravity)    Currie
DSO 904   (Human Factors)   All
DSO 621   (Orthostatic)     Thomas
DSO 603C  (Landing Ortho)   Thomas
DSO 624   (Cardiovascular)  All

BLOCK 1 SPACE SHUTTLE MAIN ENGINE

     STS-70 will be the first flight for an upgraded version 
of a Space Shuttle Main Engine (SSME).  On this flight, one 
engine will be of a new configuration known as Block 1, 
while the remaining two engines will be of the current SSME 
design.  

     The first flight planned to use three Block 1 engines 
is STS-73, currently targeted for late September 1995.  

     The Block 1 configuration will greatly increase engine 
performance, reliability and safety.  Together the three 
SSMEs produce the almost 1.5 million pounds of thrust which 
assist in carrying the Shuttle system into orbit.  

Engine configuration for STS-70
SSME 2036 is the first Block 1 engine to fly on the Shuttle.
    

     One enhancement to the Block 1 engine is the new high 
pressure liquid oxidizer turbopump built by Pratt & Whitney.  
The pump housing in the new design is produced through a 
unique casting process, eliminating all but six of the 300 
welds that exist in the current pump.  This increases the 
safety margins and reliability of the main engines.  The new 
turbopumps will not require a detailed inspection until they 
have flown 10 times.  The high pressure liquid oxygen pumps 
used in the current SSME must be removed after every flight 
for inspection. 

     Flight certification for the turbopumps, which provide 
the oxidizer to the engine, was completed in March 1995.  
The new pumps underwent a test program equivalent to 40 
Space Shuttle flights, a milestone in the final 
certification of the pumps for flight.   

     The improved pump design also incorporates new ball 
bearings of silicon nitride.  The ceramic bearings are 30 
percent harder and 40 percent lighter than steel and have an 
ultra-smooth finish, thus producing less friction during 
pump operation. 

     Another enhancement to the Block 1 engine is the new 
two-duct powerhead.  The powerhead contains the preburners 
that generate the gas to drive the turbopump turbines.  It 
collects the hot gases of the turbines downstream and ducts 
them into the main injector.  By replacing the three smaller 
fuel ducts in the current design with two enlarged ducts, 
the new design significantly improves fluid flows within the 
engine.  Pressure and loads are decreased, turbulence is 
reduced, maintenance is eliminated and inspections are 
minimized.  The two-duct powerhead is constructed with fewer 
welds, thus eliminating potential weak spots.

    The powerhead also has a single-coil heat exchanger, 
replacing the current two-coil design.  The heat exchanger 
provides pressure to the Shuttle's external tank, enabling 
it to provide propellants to the engines.  The new 
configuration eliminates all seven weld joints inside the 
engine.  Constructed of a continuous piece of stainless 
steel alloy, this reduces wear on the tube and lessens the 
chance of damage.  Maintenance and post-flight inspections 
also are reduced. 

     The SSME project is managed by Marshall Space Flight 
Center.  Pratt and Whitney, West Palm Beach, FL, developed 
and manufactured the new pump.  Rocketdyne, Canoga Park, CA, 
will integrate the pump into the main engine. 

TRACKING AND DATA RELAY SATELLITE SYSTEM
History

    The Tracking and Data Relay Satellite System (TDRSS) 
is a space-based network that provides communications, 
tracking, telemetry, data acquisition and command services 
essential to Shuttle and low-Earth orbital spacecraft 
missions.

    The TDRSS was initiated following studies in the early 
1970s which showed that a system of telecommunications 
satellites, operated from a single ground station, could 
meet the needs of NASA's mission better and more cost-
effectively than the then existing network of tracking and 
communications ground stations located around the world.

    The TDRSS has delivered on the promise, enabling NASA 
to cut telecommunications costs while increasing data 
acquisition and communications contact time with spacecraft 
six-fold.  TDRSS can provide communications services to 
orbital spacecraft over 85 percent of each orbit for most 
satellites, and continuous service for some orbital 
positions. 

    In addition to the Shuttle, TDRSS customers include 
the Compton Gamma Ray Observatory (GRO), Upper Atmosphere 
Research Satellite, Hubble Space Telescope, Earth Radiation 
Budget Satellite, Extreme Ultraviolet Explorer, TOPEX-
POSEIDON, and other non-NASA missions.  Among future TDRSS-
dependent missions are the international Space Station and 
the Earth Observation System.   NASA estimates the value of 
the space missions which will have relied on the TDRSS 
through the end of this decade is in the tens of billions. 

    The TDRSS consists of two major elements:  A 
constellation of geosynchronous satellites and a ground 
terminal complex located at White Sands, New Mexico.  The 
original ground terminal, Cacique, is currently undergoing 
rehabilitation.  When Cacique is returned to service in 
1996, it will be a virtual twin of the new Danzante 
terminal, which became fully operational in March and is 
providing all operational services.  Together, these two 
terminals will eliminate a critical single point of failure 
and provide the capacity to use partially failed Tracking 
and Data Relay Satellite (TDRS) spacecraft to meet NASAs 
communications needs in the future.

Current Status

    NASA's latest Tracking and Data Relay Satellite, TDRS-G, 
is scheduled for launch on board Discovery.  TDRS-G is the 
seventh and final in the first series of communications 
spacecraft that make up the TDRSS.  Although TDRS-G will be 
stored on orbit and not used immediately, it is being 
launched now to take advantage of the experienced crew for 
the critical launch and deployment sequence.  In addition, 
on-orbit storage is less costly than ground storage and 
extended crew retention.

    After Discovery achieves orbit, the TDRS-G spacecraft 
and its attached Inertial Upper Stage (IUS) will be deployed 
from the Shuttle cargo bay.  The IUS consists of two Solid 
Rocket Motors (SRM's) which will inject the TDRS/IUS into 
geostationary orbit.  The IUS SRM-1 will first place the 
TDRS/IUS into a transfer orbit with an apogee near 
geosynchronous altitude.  At the first apogee the IUS SRM-2 
will fire to place the TDRS/IUS in geostationary orbit.  The 
TDRS/IUS 
will be maneuvered to the appropriate orientation and TDRS-G 
will separate from the IUS.  

     Once it is on orbit, the TDRS-G designation will be 
changed to TDRS-7.  Following the spacecraft bus checkout 
and the On-Orbit Test Phase, TDRS-7 will be ready to provide 
service.

    TDRS-1 was launched in April 1983, on board Space 
Shuttle Challenger, and the second TDRS was lost in the 
Challenger accident in January 1986.  TDRS-3 was launched on 
board Space Shuttle Discovery in September 1988, and TDRS-4 
was launched on board Discovery in March 1989.  TDRS-5 was 
launched on board Space Shuttle Atlantis in August 1991.  
TDRS-6 was launched on board Space Shuttle Endeavour in 
January 1993.  
 
   The five orbiting TDRS spacecraft are all functioning, 
but only three (TDRS-4, TDRS-5, and TDRS-6) are fully 
operational.  Because of the flexible capability of the 
TDRSS, following the successful launch and checkout of TDRS-
G, the TDRSS constellation will be reconfigured. 

    TDRS-1 is presently positioned at 275 degrees West 
longitude and is operated from New Mexico via the remote 
TDRSS ground terminal located in the Deep Space Network 
Complex in Canberra, Australia.  TDRS-1 is used primarily to 
provide service to the Compton GRO, which has a failed tape 
recorder.  Although TDRS-1 sustained significant damage 
during its launch in 1983, resulting from a failure of the 
launch vehicle upper stage, this spacecraft has provided 
excellent service for many years and continues to serve in a 
limited capacity well beyond its planned seven year 
lifetime.  

     Present plans call for TDRS-3 to replace TDRS-1 at 275 
degrees West longitude, southeast of Sri Lanka, to continue 
support to GRO as well as provide added support for the 
STS/MIR rendezvous activities, and potential support to 
Space Station.  TDRS-1 will be repositioned to 139 degrees 
West longitude and may be used to support science 
investigations in the South Pole region.  TDRS-5 at 174 
degrees West longitude, southwest of Hawaii, and TDRS-4 at 
41 degrees West longitude, East of Brazil, are designated as 
the prime operational spacecraft and provide the bulk of the 
support to NASA TDRS customers.  TDRS-6, now located at 46 
degrees West longitude, has its user support payload turned 
off to preserve lifetime and serves as an on-orbit reserve 
spacecraft.  After TDRS-G is deployed in geostationary orbit 
and successfully checked out, it will be positioned at 171 
degrees West longitude.
 
     The successful launch and checkout of TDRS-G will give 
NASA the essential requirement of having two fully 
operational satellites and two fully operational "ready 
reserve" satellites.  Because of NASA's critical dependence 
on TDRSS, at least one fully-functional spacecraft must be 
available in reserve to replace a failed operational 
spacecraft.  This will assure that NASA communications, 
telemetry and data acquisition capabilities required by 
space missions will not be jeopardized.

   TDRS-G is the last of a generation of seven spacecraft, 
built by TRW of Redondo Beach, CA, that make up the initial 
series of communication satellites for NASA.  Future system 
needs will be supported by the TDRS-H, I, J spacecraft, the 
next series of satellites, whose initial launch is planned 
for 1999. 

TDRS Spacecraft Launch and Operational Status

Spacecraft            Mission             Status

TDRS-1                STS-6
                    April 5, 1983   Partially operational

TDRS-2                51-L
                 January 1986       Lost in the Challenger 
                                     Accident

TDRS-3             STS-26 
                September 29, 1988  Partially operational

TDRS-4             STS-29 
                March 13, 1989      Fully operational

TDRS-5             STS-43
                August 2, 1991      Fully operational

TDRS-6            STS-54
                January 13, 1993    Fully operational

Current Position   
             
TDRS-1    275 degrees West         

TDRS-3    62 degrees West 
        
TDRS-4    41 degrees West (over the Atlantic Ocean off 
             Brazil) 

TDRS-5    174 degrees West (East of Gilbert Islands and 
             South of Hawaii)       

TDRS-6    46 degrees West

Reconfigured Position after TDRS-G (7) Checkout

TDRS-1    139 degrees East

TDRS-3    275 degrees West

TDRS-4    44 degrees West

TDRS-5    174 degrees West

TDRS-6    46 degrees West

TDRS-7    171 degrees West

Deployment Sequence

    TDRS-G will be deployed from Discovery approximately six 
hours after launch on orbit five (over the Pacific north of 
Hawaii).  Injection burn to geostationary orbit will be 
initiated at 77 degrees East longitude (Indian Ocean, south 
of India), placing the satellite in orbit at 178 degrees 
West longitude (over the Pacific near the Gilbert Islands).

     The STS-70 crew elevates the IUS/TDRS to 29 degrees in 
the payload bay for preliminary tests and then raises it to 
58 degrees for deployment.  A spring-loaded ejection system 
is used for deploying the IUS/TDRS.

     The first burn of the IUS booster will take place one 
hour after deployment, or about seven hours after launch.  
The second and final burn (to circularize the orbit) will 
take place five and one half hours after the first burn, 
approximately 12 1/2  hours into the mission.  Separation of 
the booster and satellite will occur at 13 hours after 
launch.

     Upon reaching geostationary orbit, the deployment of 
appendages and antennas is started.  The deployment sequence 
is:

    1.    Deploy solar arrays.
    2.    Deploy Space-to-Ground Link (STGL) boom.
    3.    Deploy Solar Sail boom.
    4.    Separation of IUS and TDRS.
    5.    Release Single Access (SA) booms.
    6.    Position SA antennas.
    7.    Open SA antennas.
     
    During steps five, six and seven, Earth acquisition is 
taking place concurrently.

     The TDRS is three-axis stabilized with the Multiple 
Access (MA) fixed antennas pointing constantly at the Earth 
while the solar arrays track the Sun.

Communication System

     The TDRS' do not process customer traffic.  Rather, 
they operate as "bent pipe" repeaters, relaying signals and 
data between the user spacecraft and the ground terminal and 
vice versa without processing.

     Nominally, the TDRSS is intended to meet the 
requirements of up to 24-customer spacecraft, including the 
Space Shuttle, simultaneously.  It provides two types of 
service:  (1) MA which can relay data from as many as 20 low 
data rate (100 bits per second to 50 kilobits per second) 
customer satellites simultaneously and (2) single access 
antennas which provide two high data rate channels (300 
megabits per second) from both the East and West locations.

     The White Sands Complex (WSC), provides a location with 
a clear line-of-sight to the TDRS' and a place where rain 
conditions have limited interference with the availability 
of the Ku-band uplink and downlink channels.  The WSC is 
operated for NASA by Allied Signal Technical Services 
Corporation; Columbia, MD, and GTE Government Systems Corp., 
Needham Heights, MA.

      Other associated facilities located at the Goddard 
Space Flight Center (GSFC) include:  the Network Control 
Center, which provides the primary interface with customer 
satellites to schedule service and act as the focal point 
for NASA user communications with the WSC; the Flight 
Dynamics Facility, which provides antenna pointing 
information for user spacecraft and the TDRS; and, the NASA 
Communications (NASCOM) Network, a global system which 
provides operational communications support to all NASA 
projects. 

     NASCOM offers voice and data links with the Space 
Network, the Ground Networks, and the user spacecraft 
control centers and data processing facilities.  For TDRSS, 
NASCOM provides a common carrier interface through Earth 
terminals to link GSFC, White Sands, and the Johnson Space 
Center in Houston.

    NASA's Office of Space Communications, Washington, DC, 
has overall management responsibility of these tracking, 
data acquisition and communications facilities.

TDRS Components

     The TDRS' are composed of three distinct modules:  An 
equipment module, a communications payload module and an 
antenna module.  The modular design reduces the cost of 
individual design and construction efforts that, in turn, 
lower the cost of each satellite.

     The equipment module housing the subsystems that 
operate the satellite is located in the lower hexagon 
portion of the main body of the spacecraft.  The attitude 
control subsystem stabilizes the satellite to provide 
accurate antenna pointing and proper orientation of the 
solar panels to the Sun.  The electrical power subsystems 
consist of two solar panels that provide a ten-year power 
supply of approximately 1,700 watts.  The thermal control 
subsystem consists of surface coatings and controlled 
electric heaters.

     The payload module, located on the upper hexagon 
portion of the main body of the spacecraft, is composed of 
the electronic equipment required to provide communications 
between the user spacecraft and the ground.  The receivers 
and transmitters for single access services are mounted in 
compartments on the back of the SA antennas.

     The antenna module is composed of five antenna systems:  
two SA, the MA arrays, STGL, and the S-band omni for 
satellite health and housekeeping. 

     For SA service, each TDRS has two dual-feed S-band, Ku-
band parabolic (umbrella-like) antennas.  These antennas are 
free to be positioned in two axes, directing the radio beam 
to orbiting user spacecraft below.  These antennas are used 
primarily to relay communications to and from user 
spacecraft.  The high data rate provided by these antennas 
is available to users on a time-shared basis.  Each antenna 
is capable of supporting two-user spacecraft services 
simultaneously--one at S-band and one at Ku-band--provided 
both users are within the beam width of the antenna.

     The MA antenna array, consisting of 30 elements, is 
hard-mounted on the spacecraft body on the surface of the 
antenna module facing the Earth.

     Another antenna, a 6.5-foot (2-meter) parabolic 
reflector, provides the prime link for relaying 
transmissions to and from the ground terminal at Ku-band.

THE INERTIAL UPPER STAGE (IUS)

     The Inertial Upper Stage (IUS) will be used on Space 
Shuttle mission STS-70 to boost NASA's TDRS-G Tracking and 
Data Relay Satellite from low-Earth orbit to geosynchronous 
orbit, some 22,300 statute miles (35,000 kilometers) from 
Earth. 

Background    

     The IUS was originally designed as a temporary stand-in 
for a reusable space tug.  The IUS was then named the 
Interim Upper Stage.  The word "Inertial" (signifying the 
guidance technique) later replaced "Interim" when it was 
observed that the IUS would be needed through the 1990s.     

     The IUS was developed and built by the Boeing Aerospace 
Co., Seattle, WA, under contract to the Air Force Material 
Command's Space and Missile Systems Center.  The Space and 
Missile Systems Center is executive agent for all Department 
of Defense activities pertaining to the Space Shuttle system 
and provides the IUS to NASA for Space Shuttle use.  For 
NASA missions, the IUS program is managed by the Marshall 
Space Flight Center, Huntsville, AL.    

     NASA's most recent use of an IUS was on the STS-54 
mission of the Space Shuttle (launched Jan. 13, 1993), which 
successfully transported the TDRS-F satellite to 
geosynchronous orbit.  It also has boosted the Galileo probe 
on a journey to explore Jupiter, the Magellan spacecraft to 
Venus, and the Ulysses toward a polar orbit of the Sun. 

Specifications    

     The IUS is a two-stage, solid rocket propelled, three-
axis stabilized vehicle for placing spacecraft in a high-
Earth orbit or on an escape trajectory for an interplanetary 
mission.      

     The IUS is 17 feet (5.18 meters) long and 9.25 feet 
(2.8 meters) in diameter, with an overall weight of 
approximately 32,500 pounds (14,742 kilograms).  The IUS 
consists of a first stage comprised of a large solid rocket 
motor containing 21,400 pounds (9,707 kilograms) of 
propellant and generating approximately 42,000 pounds 
(188,496 newtons) of thrust and an interstage.  The second 
stage consists of a solid rocket motor with 6,000 pounds 
(2,722 kilograms) of propellant generating approximately 
18,000 pounds (80,784 newtons) of thrust, and an equipment 
support section.      

     The large solid rocket motor is the longest thrusting 
duration solid rocket motor ever developed for space 
application, with the capability to fire for as long as 150 
seconds.  Mission requirements determine the thrust level 
and burn duration of the solid rocket motors.  These factors 
are controlled by tailoring the solid propellant load.    

     The equipment support section houses the avionics 
systems of the IUS.  These systems provide guidance, 
navigation, control, telemetry, command and data management, 
reaction control and electrical power.  All mission-critical 
components of the avionics system, along with thrust vector 
actuators, reaction control thrusters, motor igniter and 
pyrotechnic stage separation equipment are redundant to 
assure reliability of better than 98 percent.    

     The IUS employs Airborne Support Equipment for 
installation in the Space Shuttle as well as operation and 
deployment from the orbiter.  The Airborne Support Equipment 
consists of mechanical, avionics, and structural equipment 
located in the orbiter.  The Airborne Support Equipment 
structurally attaches the IUS and the payload to the orbiter 
payload bay, provides interface for the IUS and payload 
checkout and elevates the IUS/payload for deployment from 
the Orbiter.

     The TDRS spacecraft is attached to the IUS at eight 
attachment points provided on the forward surface of the 
forward ring of the Equipment Support Section.  The eight-
point attachment provides substantial load-carrying 
capability while minimizing the transfer of heat across the 
connecting points.  Power, command and data transmission 
between the two are provided by several IUS interface 
connectors. 

     In addition, the IUS provides an insulation blanket of 
multiple layered, double-aluminized Kapton and polyester net 
spacers across the IUS/TDRS interface.  The outer layer of 
the blanket, facing the TDRS spacecraft, is a special 
Teflon-coated fabric called Beta cloth.  The blankets are 
vented toward and into the IUS cavity, which in turn is 
vented to the orbiter payload bay.  There is no gas flow 
between the spacecraft and the IUS.  The thermal blankets 
are grounded to the IUS structure to prevent electrostatic 
charge buildup. 

Flight Sequence

     After the orbiter payload bay doors are opened in 
orbit, the orbiter will maintain a preselected attitude to 
keep the payload within thermal requirements and 
constraints.    

     On-orbit predeployment checkout begins, followed by an 
IUS command link check and spacecraft communications command 
check.  Orbiter trim maneuvers normally are performed at 
this time.

     Forward payload restraints will be released and the aft 
frame of the airborne support equipment will tilt the 
IUS/TDRS to an angle of 29 degrees from the payload bay.  
This will extend the TDRS into space just outside the 
orbiter payload bay, allowing direct communication with 
Earth during systems checkout.  The orbiter will then be 
maneuvered to the deployment attitude.  If a problem has 
developed at this point within the orbiter, the TDRS 
spacecraft or the IUS, the IUS and spacecraft can be 
restowed and potentially recycled for additional deployment 
attempts.      

     Prior to deployment, the spacecraft electrical power 
source will be switched from orbiter power to IUS internal 
power by the orbiter flight crew.  After verifying that the 
spacecraft is on IUS internal power and that all IUS/TDRS 
predeployment operations have been successfully completed, a 
"go/no-go" decision for IUS/TDRS deployment will be sent to 
the crew.     

     When the orbiter flight crew is given a "go" decision, 
they will activate the pyrotechnic devices that disconnect 
the IUS/TDRS umbilical cables.  The crew will then command 
the eletromechanical tilt actuator to raise the tilt table 
to a 58-degree deployment position.    

     During deployment, the orbiter's thrusters will be 
inhibited and a pyrotechnic separation device initiated to 
physically separate the IUS/TDRS spacecraft combination from 
the tilt table and orbiter.  Compressed springs provide the 
force to push the IUS/TDRS from the orbiter payload bay at 
approximately 4.2 inches (0.10 meters) per second.  The 
deployment is normally performed in the shadow of the 
orbiter or in Earth eclipse.      

     The tilt table will be lowered to minus six degrees 
after IUS and its spacecraft are deployed.  Approximately 19 
minutes after IUS/TDRS deployment, the orbiter's engines 
will be ignited to move the orbiter away from the IUS/TDRS.    

     At this point, the IUS/TDRS is controlled by the IUS 
onboard computers.  Approximately 10 minutes after the 
IUS/TDRS is deployed from the orbiter, the IUS onboard 
computer will send out signals used by the IUS and/or TDRS 
to begin mission sequence events.      

     The IUS will maneuver to the required thermal attitude 
and perform any required spacecraft thermal control 
maneuvers.      

     At approximately 45 minutes after deployment from the 
orbiter, the pyrotechnic inhibits for the solid rocket motor 
will be removed.  The belly of the orbiter has been oriented 
towards the IUS/TDRS combination to protect the orbiter 
windows from the IUS's plume.      

     When the proper transfer orbit opportunity is reached, 
the IUS computer will send the signal to ignite the first-
stage motor.  This is expected at approximately 60 minutes 
after deployment (L+7 hours, 13 minutes).  After firing 
approximately 146 seconds and prior to reaching the apogee 
point of its trajectory, the IUS first stage will expend its 
fuel.  While coasting, the IUS will perform any maneuvers 
needed by TDRS for thermal protection or communications.  
When this is completed, the IUS first stage and interstage 
will be separated from the IUS second stage.      

     Approximately six hours, 12 minutes after deployment 
(L+12:30), the second-stage motor will be ignited, thrusting 
for about 108 seconds.  After second-stage burn is 
completed, the IUS stabilizes the TDRS while the solar 
arrays and two antennas are deployed.  Once the TDRS has 
completed its deployment activities, the IUS second stage 
will be separated and then perform a final 
collision/contamination avoidance maneuver before 
deactivating. 

BIOLOGICAL RESEARCH IN CANISTERS  (BRIC-4 / BRIC-5)

     Research on plant growth and development, as well as 
research on the hormone system of insects, is an important 
part of the scientific mission of STS-70.  Biological 
Research in Canisters (BRIC) experiments, designed to 
examine the effects of microgravity on a wide range of 
physiological processes in plants, insects, and small 
invertebrate animals, are part of the Small Payloads 
Program.  Research in the "quick turn around" (on average 
one year or less) BRIC program has provided basic scientific 
information on a range of important topics, from plant 
metabolism affecting food crops to information on the 
processes of insect development and pest control.  

     Previous BRIC experiments have focused on starch 
metabolism in plant seedlings (BRIC-1 & 3), on development 
in plant tissue culture (BRIC-2), and on ways that hormones 
affect the development of gypsy moths from worm-like 
juveniles to winged adults (BRIC-1).  BRIC payloads are 
flown in canisters located in lockers on the Shuttle's 
middeck.  These canisters are simple carriers for small 
biological payloads and afford the investigator the 
opportunity to expose their samples to a microgravity 
environment for extended periods of time.

BRIC-4

     Dr. Marc E. Tischler of the University of Arizona 
College of Medicine will examine the tobacco hornworm to 
determine how its hormone system and muscle formation 
processes are affected by an altered gravitational field.  
In his study entitled "Effects of Microgravity on Tobacco 
Hornworm During Metamorphosis", Dr. Tischler will examine 
the hormone system of the tobacco hornworm (Manduca sexta).  

     Previous studies on the juvenile tobacco hornworm 
showed alterations in chemical building blocks (amino 
acids), rate of adult development and flight muscle size as 
a result of exposure to microgravity.  All of these 
parameters are dependent on the levels of the hormone 
Ecdysone.  In normally-developing tobacco hornworms, 
Ecdysone release occurs near the outset of adult 
development.  Ground studies indicate that altered 
orientation of the developing insect within the first 96 
hours produces significant changes.  Dr. Tischler's study 
also will examine the synthesis of protein necessary to form 
muscle in the developing tobacco hornworm during flight.

     Spaceflight has been shown to affect the hormone 
systems of humans, animals and insects, as well as 
increasing muscle degeneration of crew members.  This study 
will examine a biological specimen whose hormone system and 
muscle formation appear to be sensitive to an altered 
gravitational field.  This will add to the knowledge base of 
gravitational biology and the space life sciences by 
shedding light on the interactive role of gravity on a 
variety of biological mechanisms.  Basic information in 
hormone and muscle development will have a direct impact on 
basic research and development for long duration human space 
flight, as well as potentially affecting such areas as 
insect development and pest control on Earth.

     In addition, there has been a science-educational 
outreach effort associated with the study of insect 
development.  College undergraduates, high school students 
and elementary schools throughout the Tucson, AZ, area are 
involved in a Manduca outreach project.  This outreach 
program began three years ago with a single elementary 
school which was provided with young caterpillars, and 
artificial diet and instructions on maintaining the insects.  
To date, hundreds of students in the Tucson area have 
studied the tobacco hornworm in the classroom.  This 
outreach project has proven to be a strong bridge between 
the University and its local public schools and has served 
to get elementary students excited about science and the 
space program.

BRIC-5

     In the experiment, "Plant Embryos and Fidelity of Cell 
Division in Space", Dr. Abraham D. Krikorian of the State 
University of New York at Stony Brook, will test whether the 
cell division changes observed in the daylily (Hemerocallis 
cultivar. Autumn Blaze) are the result of the direct effects 
of microgravity or indirect effects such as water 
availability.  

     This research is important because human exploration of 
space depends on our ability to grow plants in microgravity.  
Long duration space missions require a large supply of food 
and water.  It will not be possible to store the necessary 
volume or mass of food required for extended space missions.  
As a result, it is critical that food production systems be 
developed for use in flight.  Current efforts in a range of 
biotechnologies are dependent on the ability to use and 
manipulate these systems in space.  

     To develop these food production systems, which are 
dependent on individual plants, plant cells must be able to 
grow normally.  Dividing and developing plant cells need to 
process and pass on accurate genetic information to new 
plants.  The extent to which such growth and development 
will occur in microgravity is a key concern for modern plant 
biotechnologies in space.

     Preliminary results from the Plant Cell Research 
experiment aboard STS-47 and Proembryogenesis in Space 
experiment aboard STS-65 have shown genetic abnormalities 
occur to plants during space flight.  Mechanisms of 
information transfer or signaling through various parts of 
the cell do not occur normally in space.  Because ground 
based studies indicate that water related activity can 
impact the integrity of chromosomes, it is possible that the 
results observed in STS-47 and STS-65 are not due to the 
direct 
effect upon the plants but on the indirect effects mediated
by water availability to the plant cells.  

     This experiment will use daylily cells as a model 
system to test the impact of the changes in water 
availability and activity on plant reproduction.  Plant 
development entails an orderly progression of cellular 
events both in terms of time and space.  Previous studies 
have demonstrated that microgravity has adverse effects on 
plant cell function.  Work from Cosmos 782 and 1129 
indicated that while the broad events of plant development 
proceeded in space, the progression was slowed and there 
were fewer later stages generated in the plant population.  

     One of the major indirect effects of microgravity on 
plant development may be on water.  In microgravity water 
does not go to the bottom of a container; it floats, is 
affected by air currents and stays on the sides of 
containers.  This affects the availability of water for 
plant growth and development.  Changes in water relations in 
microgravity affect moisture availability, surface tension, 
buoyancy driven convection, gas diffusion and 
stratification.

     This research will contribute to our understanding of 
plant development and reproduction, which in turn, will 
directly affect our ability to grow plants in space.  The 
research also will support a better understanding of the 
basic processes of plant genetics in general, which may 
provide benefits here on Earth, particularly in arid 
environments.

BIOREACTOR DEVELOPMENT SYSTEM (BDS)

     Just as gravity affects the manner in which crystals 
grow and materials are processed, Earth's pull also can 
alter the development of cells and tissues. Microgravity, 
however, can provide life science researchers with the 
opportunity to grow cells into three-dimensional tissue 
pieces that are not achievable using conventional tissue 
culture methods on Earth.

     The Bioreactor Demonstration System is designed to use 
ground-based and space-bioreactor systems to grow individual 
cells into organized tissue that is morphologically and 
functionally similar to the original tissue or organ.

     The BDS is composed of a device developed at the 
Johnson Space Center that uses a rotating cylinder to 
suspend cells and tissues in a growth medium, simulating 
some aspects of microgravity.  The system, which is already 
being used extensively in ground-based research, also 
provides for gas and nutrient exchange.

     The purpose of the flight experiment is to demonstrate 
the performance of the bioreactor in actual mircrogravity.  
As such, the primary goal is to assess the fluid dynamic 
characteristics of the bioreactor in microgravity. 

     This includes not only the motion of various sizes of 
small particles in the bioreactor under different 
conditions, but also the ability of the bioreactor to 
provide the environment and metabolic support required to 
grow and maintain mammalian cell cultures in microgravity.

     The experiment protocol uses colon cancer cells as a 
test of the bioreactor performance.  At specified times 
during the flight, the STS-70 crew members will inject color 
producing substances to document fluid movement in the 
reactor, and various-sized beads to estimate the tissue size 
that could be supported in the bioreactor.  Crew members 
also will perform off-line measurements of pH, glucose and 
carbon dioxide content within the bioreactor and will record 
the results of the system's performance.

     Investigators anticipate the fluid dynamics analysis 
will show sufficient mixing to support tissue growth with 
minimal cell damage.  They also hope the system will allow 
the colon cancer cells to metabolize glucose, producing 
acid, thereby demonstrating the function of the pH sensor.  
BDS also will demonstrate the bioreactor's ability to 
provide oxygen and glucose and remove waste products.

     The BDS Team consists of Stanley J. Kleis, Ph.D., 
engineering principal investigator; J. Milburn Jessup, M.D., 
cell science principal investigator; Richard Saur, mission 
manager; and Neal R. Pellis, Ph.D., program director.

NATIONAL INSTITUTES OF HEALTH-R-2

Space Flight Effects on Mammalian Development

Principal Investigator:
Jeffrey Alberts, Ph.D.
Department of Psychology
Indiana University, Bloomington, IN     

    This project emphasizes features of the rat's 
behavior and physiology that are known to contribute
to successful pregnancy, labor, delivery and the onset
 of postnatal care - especially lactation.  Lacking 
the challenge of working against gravity and
disruption of specific behaviors, such as self-grooming,
may compromise the female's ability to give birth and provide 
sufficient milk.  Development of vestibular (balance)
function in all species begins well before birth.  The
use of pregnant animals exposed to microgravity will 
eliminate the effects of gravity from direct input during 
the development of this system.  
Examination of the behavior of the offspring after birth is 
expected to provide information about the earliest 
development of the vestibular system under gravity as 
compared to microgravity circumstances.

Neuromuscular Development and Regulation of Myosin 
Expression

Sue C. Bodine-Fowler, Ph.D. 
Department of Orthopedics
University of California, San Diego
VA Medical Center
La Jolla, CA 
    
         The purpose of this experiment is to determine 
whether 
gravity is required prior to birth for the normal 
development of muscles.  Prior to birth, muscle cells 
migrate to the limbs and form specific muscles which become 
innervated by axons whose cell bodies are in the spinal 
cord.  The muscle fibers within the muscle go through a 
series of changes until they reach their adult state.  This 
process of muscle specialization is initiated prior to birth 
and continues through the first month after birth.  This 
study will determine whether exposure to microgravity during 
embryonic development affects the normal development of 
muscles and nerves by examining the innervation of muscles 
by nerves, the morphological development of muscles and 
the differentiation of muscle fibers into adult types.  
These experiments will provide valuable information 
regarding how muscles develop.

Effect of Space flight on the Development of the Circadian 
Timing System

Charles A. Fuller, Ph.D.
Section of Neurobiology, Physiology and Behavior 
University of California, Davis, CA 

         Development of the neurologic system, particularly 
the retina and its connections in the brain, and the 
circadian timing system, the internal "clock" which regulates 
sleep-wake cycles and other daily physiologic functions, begins 
well before birth.  The circadian timing system is an 
important temporal organizer controlling both the physiology 
and behavior of organisms.  For example, conditions such as 
jet-lag, shift-work and some sleep and mental disorders are 
frequently associated with dysfunction of the circadian 
timing system.  The exposure of developing rat offspring to 
microgravity may lead to alterations in these systems, which 
may increase our fundamental understanding of the 
development and operation of these systems.

Effect of Microgravity on Bone Development

Nicola C. Partridge, Ph.D. 
Saint Louis University Medical Center
Department of Pharmacological and Physiological Science
St. Louis, MO 

    Under conditions of weightlessness, humans and 
experimental animals show loss of bone mass accompanied by 
excretion of calcium in urine.  The development of skeletal 
bone also may be affected by exposure to microgravity in 
utero (before birth).  If so, different enzymes and proteins 
(tissue plasminogen activator, plasmin, collagenase, etc.) 
important for bone development may appear at altered times 
and at altered levels.  The present study will investigate 
the expression of these enzymes in fetal and postnatal rats 
exposed to microgravity in utero.  Such findings would shed 
light on the importance and role of gravity in developing 
skeletal bone.  The information gained may help in the 
therapeutic intervention of bone diseases on Earth, such as 
osteoporosis.

Histological Effects of Microgravity on Rat Body Wall 
Musculature

Richard Wassersug, Ph.D.
Department of Anatomy and Neurobiology    
Dalhousie University     
Halifax, Nova Scotia, Canada
    
    Postural muscles in the hind limbs of rodents 
deteriorate dramatically (i.e., decondition) under extended 
periods of weightlessness.  The muscles of the body wall of 
rodents and other quadrupeds are themselves postural muscles 
that help elevate the abdomen and flex the spine during 
locomotion.  Additionally, these muscles are extremely 
important in a variety of visceral functions that require 
large increases in abdominal pressure (e.g., coughing, 
defecation, parturition, etc.).  If these muscles 
deteriorate, as do hind limb postural muscles, then this may 
severely compromise the ability of animals to give normal 
vaginal birth as a result of being exposed to microgravity.  
Greater understanding of the basic physiological processes 
involved in this research could provide insight into a range 
of medical challenges from diseases involving severe muscle 
degeneration, to helping accident victims who are 
immobilized with bedrest for extended periods of time, to 
developing countermeasures for severe muscle degeneration.

COMMERCIAL PROTEIN CRYSTAL CROWTH 

    The Commercial Protein Crystal Growth (CPCG) experiment 
aboard STS-70 is sponsored by the Center for Macromolecular 
Crystallography (CMC) based at the University of Alabama at 
Birmingham.  The CMC is one of 11 NASA Centers for the 
Commercial Development of Space and forms a bridge between 
NASA and private industry by developing methods for the 
crystallization of macromolecules in microgravity.  These 
crystals are used to determine the three-dimensional 
structure of the molecules by x-ray crystallography.  The 
structural information not only provides a greater 
understanding of the functions of macromolecules in living 
organisms, but it also provides scientific insight into the 
development of new drugs.

    By the technique of protein crystallography, crystals 
of purified proteins are grown in the laboratory and x-ray 
diffraction data are collected on these crystals.  The 
three-dimensional structure is then determined by analysis 
of these data.  Unfortunately, crystals grown in the gravity 
environment of Earth frequently have internal defects that 
make such analysis difficult or impossible.  Space-grown 
crystals often have fewer defects and are much better than 
their Earth-grown counterparts.

     The protein crystal growth experiment on STS-70 will 
consist of the Protein Crystallization Facility (PCF).  The 
objective of the PCF experiment, contained in a thermal 
control enclosure located in Discovery's middeck, will be to 
crystalize human alpha interferon protein.  Alpha interferon 
is a protein pharmaceutical that currently is used against 
human viral hepatitus B and C.  The objective is to discover 
the next generation alpha interferon pharmaceuticals and 
formulations.

     For the eight PCF flights to date, seven yielded larger 
space-grown crystals and five yielded crystals of superior 
x-ray quality.  Two yielded crystals, though larger than 
their Earth-grown counterparts, that were too small for x-
ray analysis; thus, their x-ray diffraction quality could 
not be assessed.  On the SPACEHAB 1 and 2 missions with the 
PCF, the CMC grew crystals of human insulin of exceptional 
quality.  These crystals provided the pharmaceutical 
industry with the most detailed picture ever seen for this 
important protein, the key medication for diabetes.  
Industry will now use this structural information to develop 
a novel and improved time-release insulin formulation.

     With continued research, the commercial applications 
developed using protein crystal growth have phenomenal 
potential, and the number of proteins that need study 
exceeds tens of thousands.  Current research, with the aid 
of pharmaceutical companies, may lead to a whole new 
generation of drugs which could help treat diseases such as 
cancer, rheumatoid arthritis, periodontic disease, 
influenza, septic shock, emphysema, aging and AIDS.

     A number of pharmaceutical companies partner with the 
CMC, including: 
*    BioCryst Pharmaceuticals, Inc. 
*    Eli Lilly and Co.
*    Schering-Plough
*    DuPont Merck Pharmaceuticals
*    Eastman Kodak
*    Upjohn Co.
*    Smith Kline Beecham Pharmaceuticals
*    Vertex Pharmaceuticals, Inc.  

     Principal Investigator for the STS-70 Commercial 
Protein Crystal Growth experiment is Dr. Larry DeLucas, 
Director of the CMC.

SPACE TISSUE LOSS - B (STL-B)

     The STL-B experiment is a collaborative research 
project between Walter Reed Army Institute of Research, 
Washington, DC, and the NASA Life & Microgravity Sciences 
and Applications Div., Washington DC.  The researchers:  Dr. 
Debra Wolgemuth, Columbia Univ.; Dr Carey Phillips, Bowdoin 
College; and Dr William Wiesmann, WRAIR, are investigating 
the effects of microgravity on embryogenesis.  Their 
analysis is centered on the evaluation of a very well 
described and understood biology model, the Medaka fish egg.  
The study focuses on evaluating the micro-gravity effect at 
the molecular level.  Of particular interest is the digital 
image capture of the gastrolation development phase via 
the STL-B on board video microscope and telemetry to the 
investigators on the ground.  This follow-up experiment will 
help validate previous STS-59 findings as well as provide 
additional definition to the model for future space biology 
experimentation.

     STL-B is a DOD payload and is being flown under the 
direction of the DOD Space Test Program.

HAND-HELD, EARTH-ORIENTED, COOPERATIVE, REAL-TIME, USER-
FRIENDLY, LOCATION TARGETING, AND ENVIRONMENTAL SYSTEM 
(HERCULES)

     HERCULES-B is the third generation of a space-based 
geolocating system.  For this configuration, a XYBION 
multispectral video camera has been integrated with the 
HERCULES geolocation hardware.  The second generation, 
HERCULES-A, used NASA's Electronic Still Camera (ESC) and 
was flown twice (STS-53 and 56).  HERCULES-B will allow the 
system to respond to requirements that exploit multispectral 
techniques.

     The geolocation part of the system, built by the Naval 
Research Laboratory, calculates and tags every frame of 
video with latitude and longitude with an accuracy of three 
nautical miles.  The multispectral video camera is a high 
resolution (38 line pairs/mm) XYBION IMC-301 image 
intensifying camera.  The XYBION was integrated by the Night 
Vision and Electronic Sensors Directorate. This camera will 
allow multispectral imagery @ 15 meter Ground Sampling 
Distance (GSD) from the Shuttle in the 500-900 nanometer 
spectral region.  The camera uses filter wheels that rotate 
in the optical path at 300 rpm.  Several filter wheels (each 
with six filters), suggested by the Environmental Research 
Institute of Michigan and the Office of Naval Research, will 
be provided to the crew to be changed during the mission.  
The camera also has a 'panchromatic mode' that allows high 
shutter speed imagery to be obtained. In this mode, the high 
shutter speeds (<100 microseconds) will allow the effects of 
Orbiter and operator motion to be decreased.  With the 
longest focal length lens (1800 mm), GSDs of three meters 
are anticipated based on laboratory and field measurements.  
Various focal length lenses (320-1830 mm) will be used in 
panchromatic mode which will allow a wide variety of fields 
of view and GSDs.

     This system will be used to locate a wide variety of 
features on the ground.

     HERCULES is a DOD payload and is being flown under the 
direction of the DOD Space Test Program.

MICROENCAPSULATION IN SPACE - B (MIS-B)

     Microencapsulation in Space (MIS) makes its second 
space flight aboard the Space Shuttle Discovery.  The 
purpose of this project, developed at Southern Research 
Institute and sponsored by the U.S. Army Dental Research 
Detachment, Walter Reed Army Institute of Research, is to 
produce a novel pharmaceutical (microencapsulated 
antibiotic) in weightless conditions using equipment that 
has been improved since the first MIS flight in 1992 (STS-
53).

     The same experiment will be conducted using newly 
designed equipment which should improve the yield of the 
microspheres.  In the experiment, the drug (ampicillin) is 
entrapped within a biodegradable polymer, so that as the 
polymer degrades in the body, the drug is released at a 
controlled rate.  In the 1992 Space Shuttle experiment, the 
microcapsules were perfectly shaped, more homogeneous, and 
free of residual solvents, thus purer than those made in 
gravity, but the yield was small.

     Microencapsulated antibiotics, which are capable of 
providing precise and predictable sustained drug release 
rates, control wound infections more effectively than 
systemically administered antibiotics and do so in vivo 
after a single application to infected wounds.  The 
microencapsulated formulations provide high antibiotic 
concentrations in the wound site over a prolonged period of 
time, during which the polymeric carrier biodegrades into 
carbon dioxide in water.  The end result is that all 
microorganisms in the wound are killed by the antibiotic, 
and the drug carrier (polymer) dissolves in the body leaving 
no residue.

     According to Dr. Thomas Tice of Southern Research 
Institute, who is principal investigator, "The space 
environment should result in a greater versatility for 
microencapsulation methodologies, thereby allowing a more 
successful use of procedures presently used on Earth.  Some 
pharmaceuticals that have failed to encapsulate on Earth 
should successfully encapsulate in space."

     Dr. Jean Setterstrom, an Army scientist who has worked 
closely with Southern Research on microencapsulated 
antibiotics for over 15 years, stated that the Army has 
supported this project because they recognize the potential 
of microencapsulation technology in targeting drugs in 
newer, more powerful ways to get enhanced pharmaceutical 
efficacy with fewer adverse effects in vivo.  This offers 
dramatically improved treatment modalities for deployed 
soldiers ranging from better therapeutic drugs to 
prophylactic vaccines.

MIDCOURSE SPACE EXPERIMENT (MSX)

     MSX is a Department of Defense program sponsored by the 
Ballistic Missile Defense Office, designed to support the 
development of surveillance capabilities of ballistic 
missiles during the midcourse of their flight.  The 
principal instrument of the program is a satellite in a 99 
degree inclination, 898 kilometer altitude polar orbit.  The 
imaging and spectrographic sensors carried by the MSX 
satellite cover a broad range of spectral regions from the 
far ultraviolet to the long wave infrared.  The MSX Shuttle 
experiments are flown under the direction of the Defense 
Department's Space Test Program and involve using the MSX 
satellite to observe the plumes from Shuttle engine burns 
and the Shuttle body, representative of a resident space 
object (RSO), against Earth and space backgrounds.

     STS-70 will be the first Shuttle mission involving the 
MSX program.  This mission occurs during the MSX satellite's 
on-orbit checkout phase following its launch.  The MSX 
experiment for this mission involves a checkout of the 
satellite's ability to acquire, track, and accurately point 
at the Shuttle against Earth and space backgrounds.  This 
capability is critical to the success of follow-on 
experiments related to plume and resident space object (RSO) 
characterization.

     The MSX Shuttle Plume Observations involve observing 
the Shuttle while various Reaction Control System or Orbital 
Maneuvering System engines are fired in specified 
combinations, at various angles to the path of the Shuttle, 
and for specified durations.  Images and spectra of the 
resulting plumes are observed in ultraviolet, visible, and 
infrared wavelength regions.  The data will be used to 
understand the fundamental processes producing plume.  The 
resulting understanding will be incorporated into models to 
predict what can be observed by space-based sensors from a 
wide variety of missile systems.

     The MSX Shuttle RSO experiments involve acquiring and 
tracking the Shuttle body against a space, Earth limb, or 
hard Earth background.  The data will be used to develop the 
capability for operational surveillance systems to acquire 
and track objects against a variety of backgrounds.

MILITARY APPLICATIONS OF SHIP TRACKS (MAST)

     The Office of Naval Research (ONR) is sponsoring the 
Military Applications of Ship Tracks (MAST) experiment on 
STS-70.  MAST, which flew for the first time on STS-65 in 
July 1994, is part of a five-year research program developed 
by ONR to examine the effects of ships on the marine 
environment.  The Naval Postgraduate School, Monterey, CA, 
will conduct the experiment at the Johnson Space Center 
during the mission.  

     The objective of MAST is to determine how pollutants 
generated by ships modify the reflective properties of 
clouds.  Ship tracks are observed in satellite imagery as 
long, narrow, curvilinear cloud features that have greater 
brightness than the surrounding clouds.  The STS-70 crew 
will photograph ship tracks using large format, handheld 
cameras.  These high-resolution photographs will provide 
insight into the processes of ship track production on a 
global scale.  MAST will help in understanding the effects 
of man-made aerosols on clouds and the resulting impact on 
the climate system.  

     MAST is a DOD payload and is being flown under the 
direction of the DOD Space Test Program.

RADIATION MONITORING EQUIPMENT -III (RME-III)

     RME stands for Radiation Monitoring Equipment, the name 
given to prototype dosimeter instruments flown on the Space 
Shuttle.  RME-III has been successfully flown on various 
Space Shuttle missions since STS-31.  RME is being 
integrated and flown on the STS-70 mission under the 
direction of the Defense Department's Space Test Program.  
It has been flown in conjunction with other radiation 
experiments, such as the CREAM (Cosmic Radiation Effects and 
Activation Monitor) and SAM (Shuttle Activation Monitor).

     RME-III is an instrument which measures the exposure to 
ionizing radiation on the Space Shuttle.  It displays the 
dose rate and total accumulated radiation dose to the 
operator, while simultaneously registering the number of 
radiation interactions and dose accumulated at ten second 
intervals.  This data is stored in RME-III's memory 
module(s), for follow-up analysis upon return to Earth.  The 
radiation detector used in the instrument is a spatial 
ionization chamber called a tissue equivalent proportional 
counter (TEPC) which effectively simulates a target size of 
a few microns of tissue, the dimensions of a typical human 
cell.  For this reason, TEPC-based instruments such as the 
RME-III are called micro-dosimeter instruments.

     The data obtained from the RME-III are archived and are 
being used to update and refine models of the space 
radiation environment in low-Earth orbit.  This will assist 
space mission planners to more accurately assess risk and 
safety factors in future long-term space missions, such as 
the international Space Station.  RME-III also has been used 
to measure radiation exposure in high altitude aircraft, 
such as the Concorde.

WINDOW EXPERIMENT (WINDEX)

     The objective of WINDEX is to gain an understanding of 
the chemistry and dynamics near a Low-Earth-Orbit (LEO) 
satellite.  This information will prevent misinterpretation 
of the measurements of the Earth, solar system, and stars 
from LEO platforms.  This knowledge also will prevent damage 
to sensitive systems and solar arrays during rendezvous and 
docking operations.

     WINDEX will record the dynamics of thruster plumes, 
Shuttle glow, water dumps, atmospheric nightglow, aurora, 
and flash evaporator system (FES) releases.  Thruster plumes 
provide the largest perturbations on the LEO environment.  
Thruster firings can enhance the local densities of gases by 
several orders of magnitude and introduce numerous non-
natural elements.  These non-natural elements react with the 
atmosphere or with the spacecraft systems in the plume 
cloud.  WINDEX would like to record the high speed (<  sec) 
phenomena associated with the start-up and shut-down 
transients of the thruster as well as observe how these 
transients affect the Shuttle glow.  Shuttle glow can be an 
indicator of the flow field around the Shuttle.  
Measurements of the Shuttle glow will help us understand the 
chemistry around the Shuttle and obtain a measure of the 
optical contamination of LEO based sensors.  Low-light level 
spectrally resolved images will provide this information.  
Water dumps, FES releases, and fuel cell purges also are a 
major contributor to the non-natural environment around a 
LEO satellite.  WINDEX will look at water dumps to identify 
particle size and freezing dynamics of liquid water releases 
in the LEO environment.  In order to separate the optical 
emissions of the near-field glow or plume data from the 
natural background, WINDEX must obtain atmospheric nightglow 
information.  WINDEX will accomplish this by obtaining 
spectrally resolved images of limb and nadir night glow.  
This data will identify the dynamics of the middle and upper 
atmosphere (50 - 300 Km altitude).  Information on the 
aurora will also help define the natural background 
environment of LEO platforms.

     WINDEX is integrated and flown under the direction of 
the DOD Space Test Program.

VISUAL FUNCTION TESTER - 4 (VFT-4)

     Since the Gemini space flights three decades ago, some 
of NASA's Shuttle astronauts have described a loss in their 
ability to see clearly at close range when in space.  
Interestingly enough, most of the astronauts experiencing 
this change were in their early forties and could see 
clearly without reading glasses when they were on the 
ground.  Vision scientists at Human Systems Center's 
Armstrong Laboratory at Wright-Patterson AFB want to know 
why.

     The next step in seeking the answers begins when the 
Discovery begins its eight-day mission, carrying with it an 
instrument that measures the range of how close and far away 
the human eye can see clearly while in near zero gravity 
conditions, often referred to as microgravity.  The 
instrument, called the Vision Function Tester - 4 (VFT-4), 
was invented and patented by two Armstrong Laboratory 
scientists, Dr. H. Lee Task and Colonel Louis Genco.

     Based on astronauts' accounts, the reasons why eyesight 
may change in space have been narrowed to two possible 
explanations.  VFT-4 gives researchers a chance to get 
first-hand information and test those ideas.  One theory put 
forth by the Principal Investigator, Lt .Col. Gerald 
Gleason, a vision scientist with the Visual Displays Systems 
Branch, Human Engineering Division, Crew Systems 
Directorate, is that the eye is like a water balloon.  Rest 
it on a table and it gets longer as it flattens out (which 
is the normal condition on Earth).  Put that balloon in 
space and it shortens, becoming more round.  The eye could 
do the same thing and when it shortens it becomes far-
sighted, causing more difficulty seeing objects up close.  
In addition to taking pre-and post-flight measurements of 
two astronauts' eyes using the Vision Function Tester, the 
participating astronauts will use the instrument daily 
throughout the Shuttle flight.  The information gathered 
during these 30-minute sessions will also help Armstrong 
scientists evaluate how quickly the eye adjusts in space and 
how it is affected over time.  

     The results of the Shuttle experiments are relevant to 
the Department of Defense as the information will be used to 
better simulate a microgravity environment on the ground.  
In turn, contact lenses or reading glasses may be prescribed 
to compensate for the changes astronauts and military pilots 
experience in microgravity.

     VFT-4 is integrated and flown aboard the Space Shuttle 
under the direction of the Department of Defense Space Test 
Program.  This program is open to all experiments within the 
DOD desiring space flight.  The vision experiments aboard 
Discovery are the second in a series of a projected five to 
be conducted aboard Space Shuttle missions over the next two 
years.

SHUTTLE AMATEUR RADIO EXPERIMENT (SAREX)

     Students in the U.S. and Argentina will have a chance 
to speak via amateur radio with astronauts aboard the 
Discovery.  Ground-based amateur radio operators ("hams") 
will be able to contact the Shuttle through automated 
computer-to-computer amateur (packet) radio links.  There 
also will be voice contacts with the general ham community 
as time permits.  

     The radio contacts are part of the SAREX (Shuttle 
Amateur Radio EXperiment) project, a joint effort by NASA, 
the American Radio Relay League (ARRL), and the Radio 
Amateur Satellite Corporation (AMSAT).   

     The project, which has flown on 17 previous Shuttle 
missions, is 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.

     Space Shuttle Mission Specialist Donald Thomas (call 
sign KC5FVF) will talk with students in 10 schools in the 
U.S. and Argentina using "ham radio."  

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

 *  Hook Elementary School, Troy, OH (KA8CBE)
 *  East Memorial Elementary School, Farmingdale, NY (N2PSG)
 *  Concord High School, Concord, NH (N1JHJ)
 *  Schenectady Museum Amateur Radio Station, Schenectady, NY
       (WB2CRZ)
 *  Euclid High School, Euclid, OH (WA8WKQ)
 *  Milford High School, Highland, MI (N8IHO)
 *  ITT Technical Institute, Grand Rapids, MI (WJ8F)
 *  Gulf Middle School, New Port Richey, FL (KD4SSU)
 *  Fallbrook Union High School, Fallbrook, CA (KM6WF)
 *  Colegio San Nicolas, Santa Fe, Argentina (LU2FCY)

     Several audio and digital communication services have 
been developed to disseminate Shuttle and SAREX-specific 
information during the flight.

     The ARRL ham radio station (W1AW) will include SAREX 
information in its regular voice and teletype bulletins.

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

     Information about orbital elements, contact times, and 
crew operating schedules will be available during the 
mission from NASA ARRL (Steve Mansfield, 203/666-1541) and 
AMSAT (Frank Bauer, 301/286-8496).  AMSAT will provide 
information bulletins for interested parties on Internet and 
amateur packet radio.

     Current Keplerian elements to track the Shuttle are 
available from the NASA Spacelink computer information 
system (BBS), (205) 895-0028 or via Internet 
spacelink.msfc.nasa.gov., and the ARRL BBS (203) 666-0578.  
The latest element sets and mission information also are 
available via the Johnson Space Center (JSC) ARC BBS or the 
Goddard Space Flight Center (GSFC) BBS.  The JSC number is 
(713) 244-5625, 9600 Baud or less.  The GSFC BBS is 
available via Internet.  The address is 
wa3nan.gsfc.nasa.gov.

STS-70 SAREX Frequencies

     Routine SAREX transmissions from the Space Shuttle may 
be monitored on a worldwide downlink frequency of 145.55 
MHz.  

The voice uplink frequencies are (except Europe):
     144.91 MHz
     144.93
     144.95
     144.97
     144.99

The voice uplink frequencies for Europe are:
     144.70
     144.75
     144.80

Note:   The astronauts will not favor any one of the above 
frequencies.  Therefore, the ability to talk to an astronaut 
depends on selecting one of the above frequencies chosen by 
the astronaut.

The worldwide amateur packet frequencies are:

Packet downlink    145.55 MHz
Packet uplink      144.49 MHz

The GSFC amateur radio club planned HF operating 
frequencies: 

3.860 MHz   7.185 MHz
14.295     21.395 
28.650

STS-70 CREW BIOGRAPHIES

Terence Tom Henricks
Commander

     Air Force Colonel Terence "Tom" Henricks, 42, will 
serve as commander of Discovery. 

     Born in Bryan, OH, Henricks considers Woodville, OH, to 
be his hometown. Henricks received a bachelor's degree in 
civil engineering from the United States Air Force Academy 
in 1974, and a master's in public administration from Golden 
Gate University in 1982.  He has logged 747 parachute jumps 
and more than 4,700 hours flying time.

     Henricks completed his pilot training at Craig Air 
Force Base in Selma, AL, and F-4 conversion training at 
Homestead Air Force Base in Miami, FL.  He then flew in F-4 
fighter squadrons in England and Iceland.  He attended the 
USAF Test Pilot School in 1983 and remained at Edwards AFB, 
CA, as an F-16C test pilot and chief of the 57th Fighter 
Weapons Wing Operating Location until he was selected as an 
astronaut in 1985. 

     Since joining NASA, Henricks has re-evaluated Shuttle 
landing sites around the world; served as assistant manager 
for Engineering Integration in the Shuttle Program Office; 
worked as lead astronaut of the Shuttle Avionics Integration 
Laboratory at the Johnson Space Center and of the Vehicle 
Test and Checkout Office at the Kennedy Space Center.

     Henricks has served as pilot of two space flights.  His 
first mission was STS-44 in November 1991.  The primary 
mission was to deploy the Defense Support Program satellite 
with an Inertial Upper Stage rocket booster.  His second 
mission, STS-55 in April 1993, was a cooperative Spacelab 
mission with the German Space Agency which included 89 
different experiments in materials processing, life 
sciences, robotics, technology, astronomy and Earth mapping.

     Henricks has logged over 405 hours in space.

Kevin Kregel
Pilot

     Pilot Kevin Kregel, 38, will be making his first space 
flight.  Kregel, who was born in New York City, considers 
Amityville, NY, to be his hometown.

     Kregel earned a bachelor's degree in astronautical 
engineering from the U.S. Air Force Academy in 1978 and a 
master's degree in public administration from Troy State 
University in 1988.

     Kregel earned his pilot's wings in 1979 at Williams Air 
Force Base, AZ.  From 1980 to 1983, he was assigned to F-111 
aircraft at RAF Lakenheath.  While serving as an exchange 
officer flying A-6E aircraft with the U.S. Navy at NAS 
Whidbey Island in Seattle, WA, and aboard the USS Kitty 
Hawk, Kregel made 66 carrier landings during a cruise of the 
Western Pacific.  His next assignment was another exchange 
tour at the U.S. Naval Test Pilot School at Patuxent River, 
MD.  Upon graduation he was assigned to Eglin AFB, FL, 
conducting weapons and electronic systems testing on the F-
111, F15 and the initial weapons certification test of the 
F15E aircraft.

     Kregel resigned from active duty in 1990 to take a 
position as an aerospace engineer and instructor pilot at 
JSC's Ellington Field offices.  His primary responsibilities 
included flying as an instructor pilot in the Shuttle 
Training Aircraft and conducting the initial flight test of 
the T-38 avionics upgrade.

     Selected as an astronaut in March 1992, Kregel has 
served as the Astronaut Support Personnel Team at the 
Kennedy Space Center.

Donald Thomas,
Mission Specialist 1

     Cleveland native Donald Thomas, Ph.D., 40, will be 
making his second flight as Mission Specialist 1.

     Thomas holds a bachelor's degree in physics from Case 
Western Reserve University in 1977, and master's and 
doctorate degrees in materials science from Cornell 
University in 1980 and 1982, respectively. 

     Following his graduation, Thomas joined AT&T Bell 
Laboratories in Princeton, N.J., working as a senior member 
of the technical staff.  He also served as an adjunct 
professor in the Physics Department of Trenton State 
College.  He holds two patents and has authored several 
technical papers.

     Thomas left AT&T in 1987 to work for Lockheed 
Engineering and Sciences Company in Houston, where his 
responsibilities involved reviewing materials used in the 
Shuttle payloads.  In 1988, he joined the Johnson Space 
Center as a materials engineer, working on analysis of 
advanced composite materials for use on the Space Station.  
He also was principal investigator for the Microgravity 
Disturbances Experiment on STS-32.

     Thomas was selected as an astronaut in January 1990.  
His first mission, STS-65 in July 1994, was a 15-day 
Spacelab flight which included 80 experiments focusing on 
materials and life sciences research in space.  With the 
completion of that mission, Thomas has logged almost 354 
hours in space.

Nancy Currie
Mission Specialist 2

     Army Major Nancy Currie, 36, will make her second space 
flight as Mission Specialist 2 during STS-70.

     Born in Wilmington, DE, Currie considers Troy, OH, to 
be her hometown.  She received a bachelor's degree in 
biological science from Ohio State University in 1980 and a 
master's in safety engineering from the University of 
Southern California in 1985.

     Following her graduation from Ohio State University, 
Currie served as a neuropathology research assistant at the 
OSU College of Medicine.  She was commissioned as a 
lieutenant in the U.S. Army in July 1981 and has served in a 
variety of leadership positions including helicopter 
instructor pilot, section leader, platoon leader and Brigade 
flight standardization Officer.  As a senior army aviator, 
Currie has logged over 3,300 flying hours in a variety of 
rotary-wing and fixed-wing aircraft.  She has instructed in 
all phases of rotary-wing flight, including combat skills 
and night vision goggle operations.
 
     She was assigned to the Johnson Space Center in 
September 1987 as a flight simulation engineer on the 
Shuttle Training Aircraft and was subsequently selected as 
an astronaut in 1990.  Since joining the astronaut corps, 
she has served as the lead for flight crew equipment, the 
Remote Manipulator System and as a spacecraft communicator.

     Her first space flight occurred in June 1993 on STS-57.  
The primary objective of the mission was to retrieve the 
European Retrievable Carrier satellite.  The mission also 
featured the first flight of the Spacehab module, carrying 
22 microgravity experiments and featured a space walk by two 
crew members..

After the one flight, Currie has accumulated 239 hours in 
space.

Mary Ellen Weber
Mission Specialist 3

     Rounding out the STS-70 crew will be Mary Ellen Weber, 
Ph.D., 32, who will serve as Mission Specialist 3. 

     Born in Cleveland, OH, Weber considers Bedford Heights, 
OH, to be her hometown.  She holds a bachelors degree in 
chemical engineering from Purdue in 1984 and a doctorate in 
physical chemistry from the University of California-
Berkeley in 1988.

     During her undergraduate studies at Purdue, Weber held 
engineering internships at Ohio Edison, Delco Electronics 
and 3M.  After her graduation, she joined Texas Instruments 
to research new techniques in microelectronics 
manufacturing.  In 1990, she was assigned to SEMATECH, a 
U.S. semiconductor manufacturing consortium in Austin, TX, 
to develop novel high-density plasma reactors for silicon 
etching.  This work led to a further assignment at Applied 
Materials and Technology in Santa Clara, CA, to develop a 
world-class plasma etcher.  She holds one patent and has 
published eight technical papers.  She also is a national 
competitive sky diver with over 1,900 jumps.

     Weber was selected as an astronaut in March 1992.  
Since then she has assisted in Shuttle processing and 
launches for the Astronaut Office and has worked in the 
Shuttle Avionics Integration Laboratory.

     STS-70 is her first space mission.