yee@trident.arc.nasa.gov (Peter E. Yee) (09/16/90)
1
PUBLIC AFFAIRS CONTACTS
Mark Hess/Ed Campion
Office of Space Flight
NASA Headquarters, Washington, D.C.
(Phone: 202/453-8536)
Paula Cleggett-Haleim/Michael Braukus
Office of Space Science and Applications
NASA Headquarters, Washington, D.C.
(Phone: 202/453-1547)
Debra Rahn
International Affairs
NASA Headquarters, Washington, D.C.
(Phone: 202/453-8455)
Robert J. MacMillin
Jet Propulsion Laboratory
Pasadena, Calif.
(Phone: 818/354-5011)
Randee Exler
Goddard Space Flight Center,
Greenbelt, Md.
(Phone: 301/286-7277)
Nancy Lovato
Ames-Dryden Flight Research Facility,
Edwards, Calif.
(Phone: 805/258-3448
James Hartsfield
Johnson Space Center,
Houston, Texas
(Phone: 713/483-5111)
Lisa Malone/Pat Phillips
Kennedy Space Center, Fla.
(Phone: 407/867-2468)
Jerry Berg
Marshall Space Flight Center,
Huntsville, Ala.
(Phone: 205/544-0034)
CONTENTS
GENERAL RELEASE 3
GENERAL INFORMATION 5
STS-41 QUICK LOOK 6
PAYLOAD AND VEHICLE WEIGHTS 7
TRAJECTORY SEQUENCE OF EVENTS 8
SPACE SHUTTLE ABORT MODES 9
SUMMARY OF MAJOR ACTIVITIES 10
THE ULYSSES MISSION 11
Mission Summary 11
Ulysses Spacecraft 12
Scientific Experiments 14
Tracking and Data Acquisition 17
Ulysses Management 18
CHROMEX-2 18
Results from CHROMEX-1 19
SOLID SURFACE COMBUSTION EXPERIMENT 20
SHUTTLE SOLAR BACKSCATTER ULTRAVIOLET INSTRUMENT 20
INTELSAT SOLAR ARRAY COUPON 21
PHYSIOLOGICAL SYSTEMS EXPERIMENT 22
INVESTIGATIONS INTO POLYMER MEMBRANE PROCESSING 23
VOICE COMMAND SYSTEM 25
RADIATION MONITORING EQUIPMENT-III 26
CREW BIOGRAPHIES 26
MISSION MANAGEMENT TEAM 28
RELEASE: 90-122
ULYSSES DEPLOYMENT HIGHLIGHTS STS-41 MISSION
Space Shuttle mission STS-41 will be highlighted by deployment of the
Ulysses spacecraft on a 5-year journey to become the first probe to explore
the polar regions of the sun.
Current scheduling indicates a likelihood of launching on Oct. 8 or 9,
but a few days either side are possible, depending on actual test and
preparation time needed. The actual launch date will be set at the flight
readiness review, scheduled for Sept. 24-25. Landing is planned at
Edwards Air Force Base, Calif. The 4-day mission will be Discovery's 11th
flight.
After being deployed from Discovery under the oversight of Mission
Specialist Thomas D. Akers, a two-stage Inertial Upper Stage and a single-
stage Payload Assist Module will boost Ulysses on a trajectory that will take
it to Jupiter in 16 months. Upon arrival, in addition to making some
scientific studies of the giant planet, the spacecraft will receive a gravity
assist from Jupiter into a solar orbit almost perpendicular to the plane in
which the planets orbit. Ulysses is scheduled to make its first observations
of the sun's southern pole between June and October 1994 and continue on
to observe the northern solar pole between June and September 1995.
Also in Discovery's payload bay will be the Airborne Electrical Support
Equipment, an electrical generating system mounted on the side of the bay
to supply power to Ulysses. The Intelsat Solar Array Coupon, samples of
solar array materials mounted on Discovery's Remote Manipulator System,
is designed to study the effects of atomic oxygen wear on solar panels in
preparation for a future Shuttle mission to rescue the stranded Intelsat
satellite. The Shuttle Solar Backscatter Ultraviolet (SSBUV) experiment
also will be in Discovery's payload bay, mounted in two Get Away Special
containers. SSBUV will help fine tune the atmospheric ozone
measurements made by satellites already in orbit by providing a calibration
of their backscatter ultraviolet instruments.
- more -
Discovery also will carry the Chromosome and Plant Cell Division in
Space experiment, a study of plant root growth patterns in microgravity;
the Investigations into Polymer Membrane Processing experiment, a study
of materials processing in microgravity; the Physiological Systems
Experiment, an investigation of how microgravity affects bone calcium, body
mass and immune cell function; the Radiation Monitoring Experiment to
record radiation levels in orbit; the Solid Surface Combustion Experiment,
a study of flames in microgravity; and the Voice Command System, a
development experiment in voice commanding the Shuttle's onboard
television cameras.
Commanding Discovery will be Richard N. Richards, Capt., USN.
Robert D. Cabana, Lt. Col., USMC, is pilot. Richards will be making his
second space flight, after serving as pilot of STS-28. Cabana will be making
his first flight.
Mission specialists are William M. Shepherd, Capt., USN; Bruce
Melnick, Cmdr., USCG; and Thomas D. Akers, Major, USAF. Shepherd is
making his second flight, after being aboard STS-27. STS-41 will be
Melnick's and AkerUs first space flight.
Built by Dornier GmbH of West Germany, Ulysses is a joint project of
the European Space Agency (ESA) and NASA.
(End of general release. Background information follows.)
- more -
GENERAL INFORMATION
NASA Select Television Transmission
NASA Select television is available on Satcom F-2R, Transponder 13,
located at 72 degrees west longitude; frequency 3960.0 MHz, audio 6.8
MHz.
The schedule for television transmission from the orbiter and for the
change-of-shift briefings from Johnson Space Center, Houston, will be
available during the mission at Kennedy Space Center, Fla.; Marshall
Space Flight Center, Huntsville, Ala.; Johnson Space Center; and NASA
Headquarters, Washington, D.C. The TV schedule will be updated daily
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 TV schedule may
obtained by dialing 202/755-1788. This service is updated daily at
noon EDT.
Status Reports
Status reports on countdown and mission progress, on-orbit
activities and landing operations will be produced by the appropriate
NASA news center.
Briefings
An STS-41 mission press briefing schedule will be issued prior to
launch. During the mission, flight control personnel will be on 8-hour
shifts. Change-of-shift briefings by the off-going flight director will
occur at approximately 8-hour intervals.
STS-41 QUICK LOOK
Launch Date and Site:
Oct. 5, 1990
Kennedy Space Center, Fla., Pad 39-B
Launch Window: 7:35 a.m. - 9:53 a.m. EDT
Orbiter: Discovery (OV-103)
Orbit: 160 x 160 nautical miles, 28.45 degree inclination
Landing Date/Time: 9:42 a.m. EDT, Oct. 9, 1990
Primary Landing Site: Edwards Air Force Base, Calif.
Abort Landing Sites:
Return to Launch Site - Kennedy Space Center, Fla.
Transoceanic Abort Landing - Ben Guerir, Morocco
Abort Once Around - Edwards Air Force Base, Calif.
Crew:
Richard N. Richards, Commander
Robert D. Cabana, Pilot
Bruce E. Melnick, Mission Specialist 1
William M. Shepherd, Mission Specialist 2
Thomas D. Akers, Mission Specialist 3
Cargo Bay Payloads:
Ulysses/IUS/PAM-S
SSBUV
Intelsat Solar Array Coupon
Middeck Payloads:
Solid Surface Combustion Experiment (SSCE)
Investigations into Polymer Membrane Processing (IPMP)
Chromosome and Plant Cell Division in Space (CHROMEX-2)
Physiological Systems Experiment (PSE)
Voice Command System (VCS)
Radiation Monitoring Experiment-III (RME-III)
VEHICLE AND PAYLOAD WEIGHTS
Pounds
Orbiter (Discovery) empty 151,265
Remote Manipulator System (payload bay) 1,180
Ulysses/IUS/PAM-S (payload bay) 44,024
Airborne Electrical Support Equipment, RTG cooling
system (payload bay) 203
IUS Support Equipment (payload bay) 260
Shuttle Solar Backscatter Ultraviolet Instrument (SSBUV)
(payload bay) 1,215
Chromosome and Plant Cell Division in Space (CHROMEX) 85
Investigations into Polymer Membrane Processing (IPMP) 33
Physiological Systems Experiment (PSE) 132
Radiation Monitoring Experiment-III (RME-III) 23
Solid Surface Combustion Experiment (SSCE) 140
Voice Command System (VCS) 45
Orbiter and Cargo at SRB Ignition 256,330
Total Vehicle at SRB Ignition 4,524,982
Orbiter Landing Weight 197,385
TRAJECTORY SEQUENCE OF EVENTS
EVENT
MET
(d/h:m:s) RELATIVE
VELOCITY
(fps)
MACH
ALTITUDE
(ft)
Launch
00/00:00:00
Begin Roll Maneuver
00/00:00:07 136 .1 400
End Roll Maneuver
00/00:00:19 417 .37 3,483
SSME Throttle Down
to 65%
00/00:00:28 665 .6 7,900
Max. Dyn. Pressure
(Max Q)
00/00:00:51 1,146 1.11 26,448
SSME Throttle Up to
104%
00/00:00:58 1,325 1.29 33,950
SRB Staging
00/00:02:05 4,144 3.76 156,585
Main Engine Cutoff
(MECO)
00/00:08:30 24,455 22.3 361,210
Zero Thrust
00/00:08:38
24,509 22.28 363,225
ET Separation
00/00:08:50
OMS 2 Burn
00/00:39:55 221
42 sec. 160 x 160
nm
Ulysses/IUS Deploy
(orbit 5)
00/06:01:00
OMS 3 Burn
00/06:16:00 31
16 sec. 160 x 177
nm
OMS 4 Burn
00/22:56:00 35 160 x 156
nm
Deorbit Burn
(orbit 65)
04/01:08:00 278
Landing (orbit 66)
04/02:07:00
Apogee, Perigee at MECO: 157 x 35
Apogee, Perigee post-OMS 2: 160 x 160
Apogee, Perigee post deploy: 160 x 177
SPACE SHUTTLE ABORT MODES
Space Shuttle launch abort philosophy is to achieve a safe and intact
recovery of the flight crew, orbiter and its payload.
Abort modes include:
% Abort-To-Orbit (ATO)
Partial loss of main engine thrust late enough to permit
reaching a minimal 105-nautical mile orbit with orbital
maneuvering system engines.
% Abort-Once-Around (AOA)
Earlier main engine shutdown with the capability to allow one
orbit around before landing at Edwards Air Force Base, Calif.;
White Sands Space Harbor (Northrup Strip), N. Mex.; or the
Shuttle Landing Facility (SLF) at Kennedy Space Center, Fla..
% Trans-Atlantic Abort Landing (TAL)
Loss of two main engines midway through powered flight would
force a landing at Ben Guerir, Morocco; Moron, Spain; or
Banjul, The Gambia.
% Return-To-Launch-Site (RTLS)
Early shutdown of one or more engines and without enough
energy to reach Ben Guerir, would result in a pitch around and
thrust back toward KSC until within gliding distance of the
Shuttle Landing Facility.
STS-41 contingency landing sites are Edwards AFB, White Sands,
Kennedy Space Center, Ben Guerir, Moron and Banjul.
SUMMARY OF MAJOR ACTIVITIES
Day One
Ascent
Post-insertion checkout
Pre-deploy checkout
Ulysses/IUS deploy
CHROMEX-2
Detailed science objective (DSO)/detailed test objective
(DTO)
Physiological systems experiment (PSE)
SSBUV outgassing
Day Two
Air Force Maui Optical Site (AMOS) calibration test
Ulysses/IUS backup deploy opportunity
CHROMEX-2
DSO/DTO
RMS powerup and checkout
SSBUV Earth views
Voice command system (VCS) test #1
Day Three
CHROMEX-2
DTO
SSBUV Earth views
VCS test #2
Day Four
CHROMEX-2
DSO/DTO
SSBUV Earth views
VCS test #3
Flight control system (FCS) checkout
Reaction control system (RCS) hotfire
Cabin stow
Day Five
CHROMEX-2 status
DSO/DTO
PSE status
SSBUV Earth views
SSBUV deactivation
Deorbit preparation
Deorbit burn
Landing at EAFB
ULYSSES MISSION
Ulysses is a joint mission conducted by the European Space Agency
(ESA) and NASA to study the polar regions of the sun and the interplanetary
space above the poles. The spacecraft will be the first to achieve a flight
path nearly perpendicular to the ecliptic, the plane in which Earth and the
other planets orbit the sun.
Throughout its 5-year mission, Ulysses will study three general areas of
solar physics: the sun itself, magnetic fields and streams of particles
generated by the sun and interplanetary space above the sun.
The Ulysses spacecraft, a ground control computer system and a
spacecraft operations team are provided by ESA, while Space Shuttle
launch, tracking and data collection during the mission are being
performed by NASA and the Jet Propulsion Laboratory (JPL). Scientific
instruments aboard the craft have been provided by scientific teams in both
Europe and the United States.
ULYSSES MISSION SUMMARY
After astronauts release Ulysses from Discovery's payload bay at an
altitude of 160 nautical miles, a two-stage engine, the Inertial Upper Stage
(IUS), attached to Ulysses will ignite, sending the craft on its initial
trajectory.
After the IUS separates, a smaller booster engine, the Payload Assist
Module (PAM-S), will fire. Before the PAM-S fires, it will spin Ulysses up to
a rate of 70 revolutions per minute (rpm). After the engine burn concludes,
the spin rate will slow to about 7 rpm. Boom deployment will further slow
the spin rate to about 5 rpm. Ulysses will continue to spin at this rate
throughout the remainder of the mission.
The booster engines will send Ulysses first to Jupiter, which the craft
will encounter in February 1992. As Ulysses flies past Jupiter at about 30
degrees north Jovian latitude, the gravity of the giant planet will alter the
craft's trajectory so Ulysses dives downward and away from the ecliptic
plane.
In its orbit around the sun, Ulysses flight path will take it from a
maximum distance from the sun of 5.4 astronomical units (AU), or about
500 million miles, to a closest approach of 1.3 AU, or about 120 million
miles.
The spacecraft will reach 70 degrees south solar latitude in June 1994,
beginning its transit of the sun's south polar regions. The craft will spend
about 4 months south of that latitude at a distance of about 200 million
miles from the sun.
In February 1995, Ulysses will cross the sun's equator, followed by its 4-
month pass of the sun's northern polar region beginning in June 1995.
End of mission is scheduled for Sept. 30, 1995.
THE ULYSSES SPACECRAFT
Ulysses' systems and scientific instruments are contained within a main
spacecraft bus measuring 10.5 by 10.8 by 6.9 feet. Communication with
Earth is maintained via a 5.4-foot-diameter, parabolic high-gain antenna.
After release from Discovery's cargo bay, the 807-pound spacecraft will
deploy an 18.2-foot radial boom carrying several experiment sensors, as
well as a 238-foot dipole wire boom and a 26.2-foot axial boom, which serve
as antennas for a radio wave-plasma wave experiment.
The Ulysses spacecraft's main computer is its onboard data handling
system, responsible for processing commands received from the ground as
well as managing and passing on all data from each of Ulysses' science
instruments. This system includes: a decoder unit, which processes
incoming signals from the spacecraft radio and passes on commands to
other systems; a central terminal unit, which distributes commands,
monitors and collects data on spacecraft systems, and stores and passes on
data from Ulysses' science instruments; remote units, which handle input-
output to and from spacecraft systems; and the data storage unit, two tape
recorders. Each of the tape recorders can store 45.8 million bits of data --
representing 16 to 64 hours of data-taking, depending on how often data
are sampled.
Another system, attitude and orbit control, is responsible for
determining the Ulysses craft's attitude in space, as well as firing thrusters
to control the attitude and spin rate. This system includes a redundant
computer, sun sensors and the reaction control system, including eight
thrusters and the hydrazine fuel system. Ulysses' load of 73 pounds of
monopropellant hydrazine fuel is stored in a single diaphragm tank
mounted on the spacecraft's spin axis.
The spacecraft's telecommunications system includes two S-band
receivers, two 5-watt S-band transmitters, two 20-watt X-band
transmitters, the high-gain antenna and two smaller low-gain antennas.
The high-gain antenna is used to transmit in either S band or X band as
well as to receive in S band. The low-gain antennas are used both to
transmit and receive in the S band. The spacecraft receives commands
from Earth on a frequency of 2111.607 MHz in the S band. The craft can
transmit to Earth on 2293.148 MHz in the S band or on 8408.209 MHz in
the X band.
(pages 13 and 13-A are drawings of the Ulysses spacecraft and
mission profile.)
Ulysses' power source is a radioisotope thermo-electric generator
(RTG), similar to RTGs flown on previous solar system exploration missions.
RTGs are required for these deep-space missions because solar arrays large
enough to generate sufficient power so far from the sun would be too large
and too heavy to be launched by available means. In the RTG, heat
produced by the natural decay of plutonium-238 is converted into
electricity by thermocouples.
SCIENTIFIC EXPERIMENTS
Ulysses' scientific payload is composed of nine instruments. In addition,
the spacecraft radio will be used to conduct a pair of experiments over and
above its function of communicating with Earth, bringing the total number
of experiments to 11. Finally, two other investigation teams will conduct
interdisciplinary studies.
The experiments are:
-- Magnetic fields. This investigation will measure the strength and
direction of the sun's polar magnetic fields, which are poorly known
because they are difficult to observe from Earth. These measurements
will help identify specific regions of the corona, the outer portion of the
sun's atmosphere, from which the solar wind originates. They also will
be important in understanding the propagation of energetic particles of
both solar and galactic origin, which are guided by the magnetic field.
Principal investigator of the experiment is Dr. Andre Balogh of Imperial
College, London.
-- Solar-wind plasma. The solar wind is a fully ionized gas, or "plasma,"
consisting of electrons and the positively charged atoms (ions) from
which the electrons have been removed. This experiment will measure
the basic properties of these ions and electrons such as speed, density
and temperature. The outflowing solar wind is expected to be different,
and possibly simpler, in the sun's polar regions than near the equator.
If this is true, it should be easier to relate the observed solar-wind
particles to conditions in the region of the sun where they originated.
Dr. Samuel J. Bame of Los Alamos National Laboratory is principal
investigator.
-- Solar-wind ion-composition spectrometer (SWICS). This investigation
will detect heavy ions (elements up to and including iron) which exist
in the corona and which constitute a minor but important constituent of
the solar wind. By measuring the composition, temperature and degree
of ionization of this component, it should be possible to infer the
temperature of the corona in the source region. This investigation will
also detect solar-wind ions that have been accelerated or energized in
interplanetary space, possibly including the sun's polar regions. Dr.
George Gloeckler of the University of Maryland and Dr. Johannes Geiss
of Universitt Bern, Switzerland, are co-principal investigators.
-- Heliospheric instrument for spectra, composition and anisotropy at low
energies. This energetic particle detector will measure the
composition and properties of low-energy solar-wind ions that have
been accelerated to higher energies than those observed by the SWICS.
Such particles can be energized at the sun as part of the process that
produces solar flares or in interplanetary space. The investigation will
determine whether such particles exist in the sun's polar regions. If so,
the measurements can be used to further study their origin, storage in
the corona and subsequent propagation into space. Dr. Louis J.
Lanzerotti of Bell Laboratories, New Jersey, is principal investigator.
-- Energetic-particle composition and neutral gas. An array of charged-
particle telescopes on Ulysses will detect medium-energy charged
particles and determine their composition, relative abundances,
energies and direction of travel. Charged particles in this energy range
mark a transition between solar particles and cosmic-ray particles
which are accelerated elsewhere in the galaxy and travel vast distances
to reach the solar system. A separate instrument will detect neutral
helium atoms entering the solar system from interstellar space and will
determine their speed, direction of arrival, temperature and density.
Dr. Erhardt Keppler of the Max-Planck-Institut fuer Aeronomie in
Lindau, Germany, is principal investigator.
-- Cosmic and solar particle investigation. This experiment covers even
higher-energy cosmic rays as well as detecting energetic solar and
interplanetary particles. Cosmic rays, which have been studied for many
years near the solar equator, are likely to have preferred access to the
equatorial zone of the solar system by way of the sun's polar regions.
This experiment may measure the properties of the cosmic rays before
they are strongly modified by their interaction with the solar-
interplanetary magnetic field. At present, the properties of cosmic rays
at these energies are not known as they exist in interstellar space. Dr.
John A. Simpson of the University of Chicago is principal investigator.
-- Solar X-rays and cosmic gamma rays. This experiment will detect X-
rays which are emitted sporadically from the vicinity of solar active
regions. Although these X-rays have been observed for many years by
spacecraft above the Earth's atmosphere, the altitude in the solar
atmosphere at which the radiation is emitted and its directivity, which
would help identify the source mechanism, are unknown. As Ulysses
travels pole-ward, the sun will cut off or "occult" radiation at low
altitudes and affect how the intensity varies with direction to the
source. Cosmic gamma-ray bursts were detected about 20 years ago but
their origin has remained obscure. By accurately timing their arrival at
Ulysses and at Earth, their source location can be pinpointed precisely
to see what astrophysical objects or bodies give rise to them. Dr. Kevin
Hurley of the University of California, Berkeley, and Dr. Michael
Sommer of the Max-Planck-Institut fuer Extraterrestrische Physik in
Garching, Germany, are co-principal investigators.
-- Unified radio and plasma-wave experiment. Two sets of long,
deployable antennas are used to measure high-frequency radio waves
emitted from solar active regions as well as lower-frequency "plasma"
waves generated in the solar wind near the spacecraft. The radio-wave
observations will be used to diagnose the space medium between the
sun's polar regions and Ulysses. Observations of the locally generated
waves will provide information about the internal workings of the polar
wind, particularly the instabilities that transfer energy between the
waves and their constituent particles. Dr. Robert G. Stone of the NASA
Goddard Space Flight Center, Greenbelt, Md., is principal investigator.
-- Cosmic dust. From the speed and direction of the small particles
detected by this experiment, their interplanetary trajectories can be
deduced. Mass and charge of the dust particles also will be measured so