STS-34 PRESS KIT
GALILEO MISSION EVENTS
EARTH TO JUPITER
FIRST EARTH PASS
SECOND EARTH PASS
The probe at Jupiter
The orbiter at Jupiter
Spacecraft scientific activities
Probe scientific activities
Orbiter scientific activities
WHY JUPITER INVESTIGATIONS ARE IMPORTANT
GALILEO ORBITER AND PROBE SCIENTIFIC INVESTIGATIONS
STS-34 INERTIAL UPPER STAGE (IUS-19)
Airborne Support Equipment
Equipment Support Section
IUS Avionics Subsystems
IUS Solid Rocket Motors
Reaction Control System
IUS to Spacecraft Interfaces
SHUTTLE SOLAR BACKSCATTER ULTRAVIOLET INSTRUMENT (SSBUV)
GROWTH HORMONE CONCENTRATIONS AND DISTRIBUTION IN PLANTS
SHUTTLE ATLANTIS TO DEPLOY GALILEO PROBE TOWARD JUPITER
Space Shuttle mission STS-34 will deploy the Galileo planetary
exploration spacecraft into low-Earth orbit starting Galileo on its journey
to explore Jupiter. Galileo will be the second planetary probe deployed
from the Shuttle this year following Atlantis' successful launch of
Magellan toward Venus exploration in May.
Following deployment about 6 hours after launch, Galileo will be
propelled on a trajectory, known as Venus-Earth-Earth Gravity Assist
(VEEGA) by an Air Force-developed, inertial upper stage (IUS). Galileo's
trajectory will swing around Venus, the sun and Earth before Galileo
makes it's way toward Jupiter.
Flying the VEEGA track, Galileo will arrive at Venus in February 1990.
During the flyby, Galileo will make measurements to determine the
presence of lightning on Venus and take time-lapse photography of Venus'
cloud circulation patterns. Accelerated by Venus' gravity, the spacecraft
will head back to Earth.
Enroute, Galileo will activate onboard remote-sensing equipment to
gather near-infrared data on the composition and characteristics of the
far side of Earth's moon. Galileo also will map the hydrogen distribution
of the Earth's atmosphere.
Acquiring additional energy from the Earth's gravitational forces,
Galileo will travel on a 2-year journey around the sun spending 10 months
inside an asteroid belt. On Oct. 29, 1991, Galileo wlll pass within 600
miles of the asteroid Gaspra.
On the second Earth flyby in December 1992, Galileo will photograph
the north pole of the moon in an effort to determine if ice exists.
Outbound, Galileo will activate the time-lapse photography system to
produce a "movie" of the moon orbiting Earth.
Racing toward Jupiter, Galileo will make a second trek through the
asteroid belt passing within 600 miles of asteroid Ida on Aug. 29, 1993.
Science data gathered from both asteroid encounters will focus on surface
geology and composition.
Five months prior to the Dec. 7, 1995, arrival at Jupiter, Galileo's
atmospheric probe, encased in an oval heat shield, will spin away from the
orbiter at a rate of 5 revolutions per minute (rpm) and follow a ballistic
trajectory aimed at a spot 6 degrees north of Jupiter's equator. The probe
will enter Jupiter's atmosphere at a shallow angle to avoid burning up like
a meteor or ricocheting off the atmosphere back into space.
At approximately Mach 1 speed, the probe's pilot parachute will deploy,
removing the deceleration module aft cover. Deployment of the main
parachute will follow, pulling the descent module out of the aeroshell to
expose the instrument-sensing elements. During the 75-minute descent
into the Jovian atmosphere, the probe will use the orbiter to transmit
data back to Earth. After 75 minutes, the probe will be crushed under the
heavy atmospheric pressure.
The Galileo orbiter will continue its primary mission, orbiting around
Jupiter and four of its satellites, returning science data for the next 22
Galileo's scientific goals include the study of the chemical
composition, state and dynamics of the Jovian atmosphere and satellites,
and the investigation of the structure and physical dynamics of the
powerful Jovian magnetosphere.
Overall responsibility for management of the project, including orbiter
development, resides at NASA's Jet Propulsion Laboratory, Pasadena,
Calif. The NASA Ames Research Center, Mountain View, Calif., manages
the probe system. JPL built the 2,500-lb. spacecraft and Hughes Aircraft
Co. built the 740-lb. probe.
Modifications made to Galileo since flight postponement in 1986
include the addition of sunshields to the base and top of the antenna, new
thermal control surfaces, blankets and heaters. Because of the extended
length of the mission, the electrical circuitry of the thermoelectric
generator has been revised to reduce power demand throughout the
mission to assure adequate power supply for mission completion.
Joining Galileo in the payload bay of Atlantis will be the Shuttle Solar
Backscatter Ultraviolet (SSBUV) instrument. The SSBUV is designed to
provide calibration of backscatter ultraviolet instruments currently being
flown on free-flying satellites. SSBUV's primary objective is to check the
calibration of the ozone sounders on satellites to verify the accuracy of
the data set of atmospheric ozone and solar irradiance data.
The SSBUV is contained in two Get Away Special canisters in the
payload bay and weighs about 1219 lbs . One canister contains the SSBUV
spectrometer and five supporting optical sensors. The second canister
houses data, command and power systems. An interconnecting cable
provides the communication link between the two canisters.
The Galileo probe arrived at the Spacecraft Assembly and
Encapsulation Facility (SAEF) 2 on April 17 and the spacecraft arrived on
May 16. While at SAEF-2, the spacecraft and probe were joined and tested
together to verify critical connections. Galileo was delivered to the
Vertical Processing Facility (VPF) on Aug. 1. The Inertial Upper Stage
(IUS) was delivered to the VPF on July 30. The Galileo/IUS were joined
together on Aug. 3 and all integrated testing was performed during the
second week of August.
Galileo is a NASA spacecraft mission to Jupiter to study the planet's
atmosphere, satellites and surrounding magnetosphere. It was named for
the Italian renaissance scientist who discovered Jupiter's major moons by
using the first astronomical telescope.
This mission will be the first to make direct measurements from an
instrumented probe within Jupiter's atmosphere and the first to conduct
long-term observations of the planet and its magnetosphere and satellites
from orbit around Jupiter. It will be the first orbiter and atmospheric
probe for any of the outer planets. On the way to Jupiter, Galileo also will
observe Venus, the Earth-moon system, one or two asteroids and various
phenomena in interplanetary space.
Galileo will be boosted into low-Earth orbit by the Shuttle Atlantis and
then boosted out of Earth orbit by a solid rocket Inertial Upper Stage. The
spacecraft will fly past Venus and twice by the Earth, using gravity
assists from the planets to pick up enough speed to reach Jupiter. Travel
time from launch to Jupiter is a little more than 6 years.
In December 1995, the Galileo atmospheric probe will conduct a brief,
direct examination of Jupiter's atmosphere, while the larger part of the
craft, the orbiter, begins a 22-month, 10-orbit tour of major satellites
and the magnetosphere, including long-term observations of Jupiter
throughout this phase.
The 2-ton Galileo orbiter spacecraft carries 9 scientific instruments.
There are another six experiments on the 750-pound probe. The spacecraft
radio link to Earth serves as an additional instrument for scientific
measurements. The probe's scientific data will be relayed to Earth by the
orbiter during the 75-minute period while the probe is descending into
Jupiter's atmosphere. Galileo will communicate with its controllers and
scientists through NASAUs Deep Space Network, using tracking stations in
California, Spain and Australia.
GALILEO MISSION EVENTS
Launch Window (Atlantis and IUS).....................Oct. 12 to Nov. 21, 1989
(Note: for both asteroids, closes in mid-October)
Venus flyby ( 9,300 mi).............................*Feb. 9, 1990
Venus data playback..................................Oct. 1990
Earth 1 flyby ( about 600 mi).......................*Dec. 8, 1990
Asteroid Gaspra flyby (600 mi)......................*Oct. 29, 1991
Earth 2 flyby (200 mi)..............................*Dec. 8, 1992
Asteroid Ida flyby (600 mi).........................*Aug. 28, 1993
Probe release........................................July 1995
Jupiter arrival......................................Dec. 7, 1995
(includes Io flyby, probe entry and relay, Jupiter orbit insertion)
Orbital tour of Galilean satellites Dec '95-Oct '97
*Exact dates may vary according to actual launch date
EARTH TO JUPITER
Galileo will make three planetary encounters in the course of its
gravity-assisted flight to Jupiter. These provide opportunities for
scientific observation and measurement of Venus and the Earth-moon
system. The mission also has a chance to fly close to one or two
asteroids, bodies which have never been observed close up, and obtain data
on other phenomena of interplanetary space.
Scientists are currently studying how to use the Galileo scientific
instruments and the limited ability to collect, store and transmit data
during the early phase of flight to make the best use of these
opportunities. Instruments designed to observe Jupiter's atmosphere from
afar can improve our knowledge of the atmosphere of Venus and sensors
designed for the study of Jupiter's moons can add to our information about
our own moon.
The Galileo spacecraft will approach Venus early in 1990 from the
night side and pass across the sunlit hemisphere, allowing observation of
the clouds and atmosphere. Both infrared and ultraviolet spectral
observations are planned, as well as several camera images and other
remote measurements. The search for deep cloud patterns and for
lightning storms will be limited by the fact that all the Venus data must
be tape-recorded on the spacecraft for playback 8 months later.
The spacecraft was originally designed to operate between Earth and
Jupiter, where sunlight is 25 times weaker than at Earth and
temperatures are much lower. The VEEGA mission will expose the
spacecraft to a hotter environment from Earth to Venus and back.
Spacecraft engineers devised a set of sunshades to protect the craft. For
this system to work, the front end of the spacecraft must be aimed
precisely at the Sun, with the main antenna furled for protection from the
Sun's rays until after the first Earth flyby in December 1990. This
precludes the use of the Galileo high-gain antenna and therefore,
scientists must wait until the spacecraft is close to Earth to receive the
recorded Venus data, transmitted through a low-gain antenna.
FIRST EARTH PASS
Approaching Earth for the first time about 14 months after launch, the
Galileo spacecraft will observe, from a distance, the nightside of Earth
and parts of both the sunlit and unlit sides of the moon. After passing
Earth, Galileo will observe Earth's sunlit side. At this short range,
scientific data are transmitted at the high rate using only the
spacecraft's low-gain antennas. The high-gain antenna is to be unfurled
like an umbrella, and its high-power transmitter turned on and checked
out, about 5 months after the first Earth encounter.
Nine months after the Earth passage and still in an elliptical solar
orbit, Galileo will enter the asteroid belt, and two months later, will have
its first asteroid encounter. Gaspra is believed to be a fairly
representative main-belt asteroid, about 10 miles across and probably
similar in composition to stony meteorites.
The spacecraft will pass within about 600 miles at a relative speed of
about 18,000 miles per hour. It will collect several pictures of Gaspra
and make spectral measurements to indicate its composition and physical
SECOND EARTH PASS
Thirteen months after the Gaspra encounter, the spacecraft will have
completed its 2-year elliptical orbit around the Sun and will arrive back
at Earth. It will need a much larger ellipse (with a 6-year period) to reach
as far as Jupiter. The second flyby of Earth will pump the orbit up to that
size, acting as a natural apogee kick motor for the Galileo spacecraft.
Passing about 185 miles above the surface, near the altitude at which
it had been deployed from the Space Shuttle almost three years earlier,
Galileo will use Earth's gravitation to change the spacecraft's flight
direction and pick up about 8,000 miles per hour in speed.
Each gravity-assist flyby requires about three rocket-thrusting
sessions, using Galileo's onboard retropropulsion module, to fine-tune the
flight path. The asteroid encounters require similar maneuvers to obtain
the best observing conditions.
Passing the Earth for the last time, the spacecraft's scientific
equipment will make thorough observations of the planet, both for
comparison with Venus and Jupiter and to aid in Earth studies. If all goes
well, there is a good chance that Galileo will enable scientists to record
the motion of the moon about the Earth while the Earth itself rotates.
Nine months after the final Earth flyby, Galileo may have a second
asteroid-observing opportunity. Ida is about 20 miles across. Like
Gaspra, Ida is believed to represent the majority of main-belt asteroids in
composition, though there are believed to be differences between the two.
Relative velocity for this flyby will be nearly 28,000 miles per hour, with
a planned closest approach of about 600 miles.
Some 2 years after leaving Earth for the third time and 5 months
before reaching Jupiter, Galileo's probe must separate from the orbiter.
The spacecraft turns to aim the probe precisely for its entry point in the
Jupiter atmosphere, spins up to 10 revolutions per minute and releases
the spin-stabilized probe. Then the Galileo orbiter maneuvers again to
aim for its own Jupiter encounter and resumes its scientific
measurements of the interplanetary environment underway since the
launch more than 5 years before.
While the probe is still approaching Jupiter, the orbiter will have its
first two satellite encounters. After passing within 20,000 miles of
Europa, it will fly about 600 miles above Io's volcano-torn surface,
twenty times closer than the closest flyby altitude of Voyager in 1979.
The Probe at Jupiter
The probe mission has four phases: launch, cruise, coast and
entry-descent. During launch and cruise, the probe will be carried by the
orbiter and serviced by a common umbilical. The probe will be dormant
during cruise except for annual checkouts of spacecraft systems and
instruments. During this period, the orbiter will provide the probe with
electric power, commands, data transmission and some thermal control.
Six hours before entering the atmosphere, the probe will be shooting
through space at about 40,000 mph. At this time, its command unit
signals "wake up" and instruments begin collecting data on lightning, radio
emissions and energetic particles.
A few hours later, the probe will slam into Jupiter's atmosphere at
115,000 mph, fast enough to jet from Los Angeles to New York in 90
seconds. Deceleration to about Mach 1 -- the speed of sound -- should
take just a few minutes. At maximum deceleration as the craft slows
from 115,000 mph to 100 mph, it will be hurtling against a force 350
times Earth's gravity. The incandescent shock wave ahead of the probe
will be as bright as the sun and reach searing temperatures of up to
28,000 degrees Fahrenheit. After the aerodynamic braking has slowed the
probe, it will drop its heat shields and deploy its parachute. This will
allow the probe to float down about 125 miles through the clouds, passing
from a pressure of 1/10th that on Earth's surface to about 25 Earth
About 4 minutes after probe entry into JupiterUs atmosphere, a pilot
chute deploys and explosive nuts shoot off the top section of the probe's
protective shell. As the cover whips away, it pulls out and opens the main
parachute attached to the inner capsule. What remains of the probe's
outer shell, with its massive heat shield, falls away as the parachute
slows the instrument module.
From there on, suspended from the main parachute, the probe's capsule
with its activated instruments floats downward toward the bright clouds
The probe will pass through the white cirrus clouds of ammonia
crystals - the highest cloud deck. Beneath this ammonia layer probably lie
reddish-brown clouds of ammonium hydrosulfides. Once past this layer,
the probe is expected to reach thick water clouds. This lowest cloud layer
may act as a buffer between the uniformly mixed regions below and the
turbulent swirl of gases above.
Jupiter's atmosphere is primarily hydrogen and helium. For most of its
descent through Jupiter's three main cloud layers, the probe will be
immersed in gases at or below room temperature. However, it may
encounter hurricane winds up to 200 mph and lightning and heavy rain at
the base of the water clouds believed to exist on the planet. Eventually,
the probe will sink below these clouds, where rising pressure and
temperature will destroy it. The probe's active life in Jupiter's
atmosphere is expected to be about 75 minutes in length. The probe
batteries are not expected to last beyond this point, and the relaying
orbiter will move out of reach.
To understand this huge gas planet, scientists must find out about its
chemical components and the dynamics of its atmosphere. So far,
scientific data are limited to a two-dimensional view (pictures of the
planet's cloud tops) of a three-dimensional process (Jupiter's weather).
But to explore such phenomena as the planet's incredible coloring, the
Great Red Spot and the swirling shapes and high-speed motion of its
topmost clouds, scientists must penetrate Jupiter's visible surface and
investigate the atmosphere concealed in the deep-lying layers below.
A set of six scientific instruments on the probe will measure, among
other things, the radiation field near Jupiter, the temperature, pressure,
density and composition of the planet's atmosphere from its first faint
outer traces to the hot, murky hydrogen atmosphere 100 miles below the
cloud tops. All of the information will be gathered during the probe's
descent on an 8-foot parachute. Probe data will be sent to the Galileo
Orbiter 133,000 miles overhead then relayed across the half billion miles
to Deep Space Network stations on Earth.
To return its science, the probe relay radio aboard the orbiter must
automatically acquire the probe signal below within 50 seconds, with a
success probability of 99.5 percent. It must reacquire the signal
immediately should it become lost.
To survive the heat and pressure of entry, the probe spacecraft is
composed of two separate units: an inner capsule containing the
scientific instruments, encased in a virtually impenetrable outer shell.
The probe weighs 750 pounds. The outer shell is almost all heat shield
The Orbiter at Jupiter
After releasing the probe, the orbiter will use its main engine to go
into orbit around Jupiter. This orbit, the first of 10 planned, will have a
period of about 8 months. A close flyby of Ganymede in July 1996 will
shorten the orbit, and each time the Galileo orbiter returns to the inner
zone of satellites, it will make a gravity-assist close pass over one or
another of the satellites, changing Galileo's orbit while making close
observations. These satellite encounters will be at altitudes as close as
125 miles above their surfaces. Throughout the 22-month orbital phase,
Galileo will continue observing the planet and the satellites and continue
gathering data on the magnetospheric environment.
Galileo's scientific experiments will be carried out by more than 100
scientists from six nations. Except for the radio science investigation,
these are supported by dedicated instruments on the Galileo orbiter and
probe. NASA has appointed 15 interdisciplinary scientists whose studies
include data from more than one Galileo instrument.
The instruments aboard the probe will measure the temperatures and
pressure of Jupiter's atmosphere at varying altitudes and determine its
chemical composition including major and minor constituents (such as
hydrogen, helium, ammonia, methane, and water) and the ratio of hydrogen
to helium. Jupiter is thought to have a bulk composition similar to that of
the primitive solar nebula from which it was formed. Precise
determination of the ratio of hydrogen to helium would provide an
important factual check of the Big Bang theory of the genesis of the
Other probe experiments will determine the location and structure of
Jupiter's clouds, the existence and nature of its lightning, and the amount
of heat radiating from the planet compared to the heat absorbed from
In addition, measurements will be made of Jupiter's numerous radio
emissions and of the high-energy particles trapped in the planet's
innermost magnetic field. These measurements for Galileo will be made
within a distance of 26,000 miles from Jupiter's cloud tops, far closer
than the previous closest approach to Jupiter by Pioneer 11. The probe
also will determine vertical wind shears using Doppler radio
measurements made of probe motions from the radio receiver aboard the
Jupiter appears to radiate about twice as much energy as it receives
from the sun and the resulting convection currents from Jupiter's internal
heat source towards its cooler polar regions could explain some of the
planet's unusual weather patterns.
Jupiter is over 11 times the diameter of Earth and spins about two and
one-half times faster -- a jovian day is only 10 hours long. A point on the
equator of Jupiter's visible surface races along at 28,000 mph. This rapid
spin may account for many of the bizarre circulation patterns observed on
Spacecraft Scientific Activities
The Galileo mission and systems were designed to investigate three
broad aspects of the Jupiter system: the planet's atmosphere, the
satellites and the magnetosphere. The spacecraft is in three segments to
focus on these areas: the atmospheric probe; a non-spinning section of the
orbiter carrying cameras and other remote sensors; and the spinning main
section of the orbiter spacecraft which includes the propulsion module,
the communications antennas, main computers and most support systems
as well as the fields and particles instruments, which sense and measure
the environment directly as the spacecraft flies through it.
Probe Scientific Activities
The probe will enter the atmosphere about 6 degrees north of the
equator. The probe weighs just under 750 pounds and includes a
deceleration module to slow and protect the descent module, which
carries out the scientific mission.
The deceleration module consists of an aeroshell and an aft cover
designed to block the heat generated by slowing from the probe's arrival
speed of about 115,000 miles per hour to subsonic speed in less than 2
minutes. After the covers are released, the descent module deploys its
8-foot parachute and its instruments, the control and data system, and
the radio-relay transmitter go to work.
Operating at 128 bits per second, the dual L-band transmitters send
nearly identical streams of scientific data to the orbiter. The probe's
relay radio aboard the orbiter will have two redundant receivers that
process probe science data, plus radio science and engineering data for
transmission to the orbiter communications system. Minimum received
signal strength is 31 dBm. The receivers also measure signal strength and
Doppler shift as part of the experiments for measuring wind speeds and
atmospheric absorption of radio signals.
Probe electronics are powered by long-life, high-discharge-rate
34-volt lithium batteries, which remain dormant for more than 5 years
during the journey to Jupiter. The batteries have an estimated capacity of
about 18 amp-hours on arrival at Jupiter.
Orbiter Scientific Activities
The orbiter, in addition to delivering the probe to Jupiter and relaying
probe data to Earth, will support all the scientific investigations of
Venus, the Earth and moon, asteroids and the interplanetary medium,
Jupiter's satellites and magnetosphere, and observation of the giant
The orbiter weighs about 5,200 pounds including about 2,400 pounds of
rocket propellant to be expended in some 30 relatively small maneuvers
during the long gravity-assisted flight to Jupiter, the large thrust
maneuver which puts the craft into its Jupiter orbit, and the 30 or so trim
maneuvers planned for the satellite tour phase.
The retropropulsion module consists of 12 10-newton thrusters, a
single 400-newton engine, and the fuel, oxidizer, and pressurizing-gas
tanks, tubing, valves and control equipment. (A thrust of 10 newtons
would support a weight of about 2.2 pounds at Earth's surface). The
propulsion system was developed and built by
Messerschmitt-Bolkow-Blohm and provided by the Federal Republic of
The orbiter's maximum communications rate is 134 kilobits per second
(the equivalent of about one black-and-white image per minute); there are
other data rates, down to 10 bits per second, for transmitting engineering
data under poor conditions. The spacecraft transmitters operate at
S-band and X-band (2295 and 8415 megahertz) frequencies between Earth
and on L-band between the probe.
The high-gain antenna is a 16-foot umbrella-like reflector unfurled
after the first Earth flyby. Two low-gain antennas (one pointed forward
and one aft, both mounted on the spinning section) are provided to support
communications during the Earth-Venus-Earth leg of the flight and
whenever the main antenna is not deployed and pointed at Earth. The
despun section of the orbiter carries a radio relay antenna for receiving
the probe's data transmissions.
Electrical power is provided to Galileo's equipment by two radioisotope
thermoelectric generators. Heat produced by natural radioactive decay of
plutonium 238 dioxide is converted to approximately 500 watts of
electricity (570 watts at launch, 480 at the end of the mission) to operate
the orbiter equipment for its 8-year active period. This is the same type
of power source used by the Voyager and Pioneer Jupiter spacecraft in
their long outer-planet missions, by the Viking lander spacecraft on Mars
and the lunar scientific packages left on the Moon.
Most spacecraft are stabilized in flight either by spinning around a
major axis or by maintaining a fixed orientation in space, referenced to
the sun and another star. Galileo represents a hybrid of these techniques,
with a spinning section rotating ordinarily at 3 rpm and a "despun" section
which is counter-rotated to provide a fixed orientation for cameras and
other remote sensors.
Instruments that measure fields and particles, together with the main
antenna, the power supply, the propulsion module, most of the computers
and control electronics, are mounted on the spinning section. The
instruments include magnetometer sensors mounted on a 36-foot boom to
escape interference from the spacecraft; a plasma instrument detecting
low-energy charged particles and a plasma-wave detector to study waves
generated in planetary magnetospheres and by lightning discharges; a
high-energy particle detector; and a detector of cosmic and Jovian dust.
The despun section carries instruments and other equipment whose
operation depends on a fixed orientation in space. The instruments include
the camera system; the near-infrared mapping spectrometer to make
multispectral images for atmosphere and surface chemical analysis; the
ultraviolet spectrometer to study gases and ionized gases; and the
photopolarimeter radiometer to measure radiant and reflected energy. The
camera system is expected to obtain images of Jupiter's satellites at
resolutions from 20 to 1,000 times better than Voyager's best.
This section also carries a dish antenna to track the probe in Jupiter's
atmosphere and pick up its signals for relay to Earth. The probe is carried
on the despun section, and before it is released, the whole spacecraft is
spun up briefly to 10 rpm in order to spin-stabilize the probe.
The Galileo spacecraft will carry out its complex operations, including
maneuvers, scientific observations and communications, in response to
stored sequences which are interpreted and executed by various on-board
computers. These sequences are sent up to the orbiter periodically
through the Deep Space Network in the form of command loads.
Galileo communicates with Earth via NASA's Deep Space Network
(DSN), which has a complex of large antennas with receivers and
transmitters located in the California desert, another in Australia and a
third in Spain, linked to a network control center at NASAUs Jet Propulsion
Laboratory in Pasadena, Calif. The spacecraft receives commands, sends
science and engineering data, and is tracked by Doppler and ranging
measurements through this network.
At JPL, about 275 scientists, engineers and technicians, will be
supporting the mission at launch, increasing to nearly 400 for Jupiter
operations including support from the German retropropulsion team at
their control center in the FGR. Their responsibilities include spacecraft
command, interpreting engineering and scientific data from Galileo to
understand its performance, and analyzing navigation data from the DSN.
The controllers use a set of complex computer programs to help them
control the spacecraft and interpret the data.
Because the time delay in radio signals from Earth to Jupiter and back
is more than an hour, the Galileo spacecraft was designed to operate from
programs sent to it in advance and stored in spacecraft memory. A single
master sequence program can cover 4 weeks of quiet operations between
planetary and satellite encounters. During busy Jupiter operations, one
program covers only a few days. Actual spacecraft tasks are carried out
by several subsystems and scientific instruments, many of which work
from their own computers controlled by the main sequence.
Designing these sequences is a complex process balancing the desire to
make certain scientific observations with the need to safeguard the
spacecraft and mission. The sequence design process itself is supported
by software programs, for example, which display to the scientist maps of
the instrument coverage on the surface of an approaching satellite for a
given spacecraft orientation and trajectory. Notwithstanding these aids,
a typical 3-day satellite encounter may take efforts spread over many
months to design, check and recheck. The controllers also use software
designed to check the command sequence further against flight rules and
The spacecraft regularly reports its status and health through an
extensive set of engineering measurements. Interpreting these data into
trends and averting or working around equipment failures is a major task
for the mission operations team. Conclusions from this activity become
an important input, along with scientific plans, to the sequence design
process. This too is supported by computer programs written and used in
the mission support area.
Navigation is the process of estimating, from radio range and Doppler
measurements, the position and velocity of the spacecraft to predict its
flight path and design course-correcting maneuvers. These calculations
must be done with computer support. The Galileo mission, with its
complex gravity-assist flight to Jupiter and 10 gravity-assist satellite
encounters in the Jovian system, is extremely dependent on consistently
In addition to the programs that directly operate the spacecraft and
are periodically transmitted to it, the mission operations team uses
software amounting to 650,000 lines of programming code in the sequence
design process; 1,615,000 lines in the telemetry interpretation; and
550,000 lines of code in navigation. These must all be written, checked,
tested, used in mission simulations and, in many cases, revised before the
mission can begin.
Science investigators are located at JPL or other university laboratories
and linked by computers. From any of these locations, the scientists can
be involved in developing the sequences affecting their experiments and,
in some cases, in helping to change preplanned sequences to follow up on
unexpected discoveries with second looks and confirming observations.
Jupiter is the largest and fastest-spinning planet in the solar system.
Its radius is more than 11 times Earth's, and its mass is 318 times that of
our planet. Named for the chief of the Roman gods, Jupiter contains more
mass than all the other planets combined. It is made mostly of light
elements, principally hydrogen and helium. Its atmosphere and clouds are
deep and dense, and a significant amount of energy is emitted from its
The earliest Earth-based telescopic observations showed bands and
spots in Jupiter's atmosphere. One storm system, the Red Spot, has been
seen to persist over three centuries.
Atmospheric forms and dynamics were observed in increasing detail
with the Pioneer and Voyager flyby spacecraft, and Earth-based infrared
astronomers have recently studied the nature and vertical dynamics of
Sixteen satellites are known. The four largest, discovered by the
Italian scientist Galileo Galilei in 1610, are the size of small planets.
The innermost of these, Io, has active sulfurous volcanoes, discovered by
Voyager 1 and further observed by Voyager 2 and Earth-based infrared
astronomy. Io and Europa are about the size and density of Earth's moon (3
to 4 times the density of water) and probably rocky inside. Ganymede and
Callisto, further out from Jupiter, are the size of Mercury but less than
twice as dense as water. Their cratered surfaces look icy in Voyager
images, and they may be composed partly of ice or water.
Of the other satellites, eight (probably captured asteroids) orbit
irregularly far from the planet, and four (three discovered by the Voyager
mission in 1979) are close to the planet. Voyager also discovered a thin
ring system at Jupiter in 1979.
Jupiter has the strongest planetary magnetic field known. The
resulting magnetosphere is a huge teardrop-shaped, plasma-filled cavity
in the solar wind pointing away from the sun. JupiterUs magnetosphere is
the largest single entity in our solar system, measuring more than 14
times the diameter of the sun. The inner part of the magnetic field is
doughnut- shaped, but farther out it flattens into a disk. The magnetic
poles are offset and tilted relative to Jupiter's axis of rotation, so the
field appears to wobble with Jupiter's rotation (just under 10 hours),
sweeping up and down across the inner satellites and making waves
throughout the magnetosphere.
WHY JUPITER INVESTIGATIONS ARE IMPORTANT
With a thin skin of turbulent winds and brilliant, swift-moving clouds,
the huge sphere of Jupiter is a vast sea of liquid hydrogen and helium.
Jupiter's composition (about 88 percent hydrogen and 11 percent helium
with small amounts of methane, ammonia and water) is thought to
resemble the makeup of the solar nebula, the cloud of gas and dust from
which the sun and planets formed. Scientists believe Jupiter holds
important clues to conditions in the early solar system and the process of
Jupiter may also provide insights into the formation of the universe
itself. Since it resembles the interstellar gas and dust that are thought
to have been created in the "Big Bang," studies of Jupiter may help
scientists calibrate models of the beginning of the universe.
Though starlike in composition, Jupiter is too small to generate
temperatures high enough to ignite nuclear fusion, the process that
powers the stars. Some scientists believe that the sun and Jupiter began
as unequal partners in a binary star system. (If a double star system had
developed, it is unlikely life could have arisen in the solar system.) While
in a sense a "failed star," Jupiter is almost as large as a planet can be. If
it contained more mass, it would not have grown larger, but would have
shrunk from compression by its own gravity. If it were 100 times more
massive, thermonuclear reactions would ignite, and Jupiter would be a
For a brief period after its formation, Jupiter was much hotter, more
luminous, and about 10 times larger than it is now, scientists believe.
Soon after accretion (the condensation of a gas and dust cloud into a
planet), its brightness dropped from about one percent of the Sun's to
about one billionth -- a decline of ten million times.
In its present state Jupiter emits about twice as much heat as it
receives from the Sun. The loss of this heat -- residual energy left over
from the compressive heat of accretion -- means that Jupiter is cooling
and losing energy at a tremendously rapid rate. Temperatures in Jupiter's
core, which were about 90,000 degrees Fahrenheit in the planet's hot,
early phase, are now about 54,000 degrees Fahrenheit, 100 times hotter
than any terrestrial surface, but 500 times cooler than the temperature at
the center of the sun. Temperatures on Jupiter now range from 54,000
degrees Fahrenheit at the core to minus 248 degrees Fahrenheit at the top
of the cloud banks.
Mainly uniform in composition, Jupiter's structure is determined by
gradations in temperature and pressure. Deep in Jupiter's interior there is
thought to be a small rocky core, comprising about four percent of the
planet's mass. This "small" core (about the size of 10 Earths) is
surrounded by a 25,000-mile-thick layer of liquid metallic hydrogen.
(Metallic hydrogen is liquid, but sufficiently compressed to behave as
metal.) Motions of this liquid "metal" are the source of the planet's
enormous magnetic field. This field is created by the same dynamo effect
found in the metallic cores of Earth and other planets.
At the outer limit of the metallic hydrogen layer, pressures equal three
million times that of Earth's atmosphere and the temperature has cooled
to 19,000 degrees Fahrenheit.
Surrounding the central metallic hydrogen region is an outer shell of
"liquid" molecular hydrogen. Huge pressures compress Jupiter's gaseous
hydrogen until, at this level, it behaves like a liquid. The liquid hydrogen
layer extends upward for about 15,000 miles. Then it gradually becomes
gaseous. This transition region between liquid and gas marks, in a sense,
where the solid and liquid planet ends and its atmosphere begins.
From here, Jupiter's atmosphere extends up for 600 more miles, but
only in the top 50 miles are found the brilliant bands of clouds for which
Jupiter is known. The tops of these bands are colored bright yellow, red
and orange from traces of phosphorous and sulfur. Five or six of these
bands, counterflowing east and west, encircle the planet in each
hemisphere. At one point near Jupiter's equator, east winds of 220 mph
blow right next to west winds of 110 mph. At boundaries of these bands,
rapid changes in wind speed and direction create large areas of turbulence
and shear. These are the same forces that create tornados here on Earth.
On Jupiter, these "baroclinic instabilities" are major phenomena, creating
chaotic, swirling winds and spiral features such as White Ovals.
The brightest cloud banks, known as zones, are believed to be higher,
cooler areas where gases are ascending. The darker bands, called belts,
are thought to be warmer, cloudier regions of descent.
The top cloud layer consists of white cirrus clouds of ammonia
crystals, at a pressure six-tenths that of Earth's atmosphere at sea level
(.6 bar). Beneath this layer, at a pressure of about two Earth atmospheres
(2 bars) and a temperature of near minus 160 degrees Fahrenheit, a
reddish-brown cloud of ammonium hydrosulfide is predicted.
At a pressure of about 6 bars, there are believed to be clouds of water
and ice. However, recent Earth-based spectroscopic studies suggest that
there may be less water on Jupiter than expected. While scientists
previously believed Jupiter and the sun would have similar proportions of
water, recent work indicates there may be 100 times less water on
Jupiter than if it had a solar mixture of elements. If this is the case,
there may be only a thin layer of water-ice at the 6 bar level.
However, Jupiter's cloud structure, except for the highest layer of
ammonia crystals, remains uncertain. The height of the lower clouds is
still theoretical -- clouds are predicted to lie at the temperature levels
where their assumed constituents are expected to condense. The Galileo
probe will make the first direct observations of Jupiter's lower
atmosphere and clouds, providing crucial information.
The forces driving Jupiter's fast-moving winds are not well understood
yet. The classical explanation holds that strong currents are created by
convection of heat from Jupiter's hot interior to the cooler polar regions,
much as winds and ocean currents are driven on Earth, from equator to
poles. But temperature differences do not fully explain wind velocities
that can reach 265 mph. An alternative theory is that pressure
differences, due to changes in the thermodynamic state of hydrogen at
high and low temperatures, set up the wind jets.
Jupiter's rapid rotation rate is thought to have effects on wind
velocity and to produce some of Jupiter's bizarre circulation patterns,
including many spiral features. These rotational effects are known as
manifestations of the Coriolis force. Coriolis force is what determines
the spin direction of weather systems. It basically means that on the
surface of a sphere (a planet), a parcel of gas farther from the poles has a
higher rotational velocity around the planet than a parcel closer to the
poles. As gases then move north or south, interacting parcels with
different velocities produce vortices (whirlpools). This may account for
some of Jupiter's circular surface features.
Jupiter spins faster than any planet in the solar system. Though 11 times
Earth's diameter, Jupiter spins more than twice as fast (once in 10 hours),
giving gases on the surface extremely high rates of travel -- 22,000 mph
at the equator, compared with 1000 mph for air at Earth's equator.
Jupiter's rapid spin also causes this gas and liquid planet to flatten
markedly at the poles and bulge at the equator.
Visible at the top of Jupiter's atmosphere are eye-catching features
such as the famous Great Red Spot and the exotic White Ovals, Brown
Barges and White Plumes. The Great Red Spot, which is 25,000 miles wide
and large enough to swallow three Earths, is an enormous oval eddy of
swirling gases. It is driven by two counter-flowing jet streams, which
pass, one on each side of it, moving in opposite directions, each with
speeds of 100-200 mph. The Great Red Spot was first discovered in 1664,
by the British scientist Roger Hook, using Galileo's telescope. In the three
centuries since, the huge vortex has remained constant in latitude in
Jupiter's southern equatorial belt. Because of its stable position,
astronomers once thought it might be a volcano.
Another past theory compared the Great Red Spot to a gigantic
hurricane. However, the GRS rotates anti-cyclonically while hurricanes
are cyclonic features (counterclockwise in the northern hemisphere,
clockwise in the southern) -- and the dynamics of the Great Red Spot
appear unrelated to moisture.
The Great Red Spot most closely resembles an enormous tornado, a huge
vortex that sucks in smaller vortices. The Coriolis effect created by
Jupiter's fast spin, appears to be the key to the dynamics that drive the
The source of the Great Red Spot's color remains a mystery. Many
scientists now believe it to be caused by phosphorus, but its spectral line
does not quite match that of phosphorus. The GRS may be the largest in a
whole array of spiral phenomena with similar dynamics. About a dozen
white ovals, circulation patterns resembling the GRS, exist in the
southern latitudes of Jupiter and appear to be driven by the same forces.
Scientists do not know why these ovals are white.
Scientists believe the brown barges, which appear like dark patches on
the planet, are holes in the upper clouds, through which the reddish-brown
lower cloud layer may be glimpsed. The equatorial plumes, or white
plumes, may be a type of wispy cirrus anvil cloud.
Mass,lbs. 5,242 744
Propellant, lbs. 2,400 none
Height (in-flight) 15 feet 34 inches
Inflight span 30 feet
Instrument payload 10 instruments 6 instruments
Payload mass, lbs. 260 66
Electric power, watts 570-480 730
(RTGs) (Lithium-sulfur battery)
The Galileo Project is managed for NASA's Office of Space Science and
Applications by the NASA Jet Propulsion Laboratory, Pasadena, Calif. This
responsibility includes designing, building, testing, operating and tracking
Galileo. NASA's Ames Research Center, Moffett Field, Calif. is responsible
for the atmosphere probe, which was built by Hughes Aircraft Company, El
The probe project and science teams will be stationed at Ames during
pre-mission, mission operations, and data reduction periods. Team
members will be at Jet Propulsion Laboratory for probe entry.
The Federal Republic of Germany has furnished the orbiter's
retropropulsion module and is participating in the scientific
investigations. The radioisotope thermoelectric generators were designed
and built for the U.S. Department of Energy by the General Electric
GALILEO ORBITER AND PROBE SCIENTIFIC INVESTIGATIONS
Listed by experiment/instrument and including the Principal Investigator
and scientific objectives of that investigation:
Atmospheric Structure; A. Seiff, NASA's Ames Research Center;
temperature, pressure, density, molecular weight profiles;
Neutral Mass Spectrometer; H. Niemann, NASA's Goddard Space Flight
Center; chemical composition
Helium Abundance; U. von Zahn, Bonn University, FRG; helium/hydrogen
Nephelometer; B. Ragent, NASA's Ames Research Center; clouds,
Net Flux Radiometer; L. Sromovsky, University of Wisconsin-Madison;
thermal/solar energy profiles
Lightning/Energetic Particles; L. Lanzerotti, Bell Laboratories; detect
lightning, measuring energetic particles
ORBITER (DESPUN PLATFORM)
Solid-State Imaging Camera; M. Belton, National Optical Astronomy
Observatories (Team Leader); Galilean satellites at 1-km resolution or
Near-Infrared Mapping Spectrometer; R. Carlson, NASA's Jet Propulsion
Laboratory; surface/atmospheric composition, thermal mapping
Ultraviolet Spectrometer; C. Hord, University of Colorado; atmospheric
Photopolarimeter Radiometer; J. Hansen, Goddard Institute for Space
Studies; atmospheric particles, thermal/reflected radiation
ORBITER (SPINNING SPACECRAFT SECTION)
Magnetometer; M. Kivelson, University of California at Los Angeles;
strength and fluctuations of magnetic fields
Energetic Particles; D. Williams, Johns Hopkins Applied Physics
Laboratory; electrons, protons, heavy ions in magnetosphere and
Plasma; L. Frank, University of Iowa; composition, energy, distribution of
Plasma Wave; D. Gurnett, University of Iowa; electromagnetic waves and
Dust; E. Grun, Max Planck Institute; mass, velocity, charge of submicron
Radio Science - Celestial Mechanics; J. Anderson, JPL (Team Leader);
masses and motions of bodies from spacecraft tracking;
Radio Science - Propagation; H. T. Howard, Stanford University; satellite
radii, atmospheric structure both from radio propagation
F. P. Fanale; University of Hawaii
P. Gierasch; Cornell University
D. M. Hunten; University of Arizona
A. P. Ingersoll; California Institute of Technology
H. Masursky; U. S. Geological Survey
D. Morrison; Ames Research Center
M. McElroy; Harvard University
G. S. Orton; NASA's Jet Propulsion Laboratory
T. Owen; State University of New York, Stonybrook
J. B. Pollack; NASA's Ames Research Center
C. T Russell; University of California at Los Angeles
C. Sagan; Cornell University
G. Schubert; University of California at Los Angeles
J. Van Allen; University of Iowa
STS-34 INERTIAL UPPER STAGE (IUS-19)
The Inertial Upper Stage (IUS) will again be used with the Space
Shuttle, this time to transport NASA's Galileo spacecraft out of Earth's
orbit to Jupiter, a 2.5-billion-mile journey.
The IUS has been used previously to place three Tracking and Data
Relay Satellites in geostationary orbit as well as to inject the Magellan
spacecraft into its interplanetary trajectory to Venus. In addition, the
IUS has been selected by the agency for the Ulysses solar polar orbit
After 2 1/2 years of competition, Boeing Aerospace Co., Seattle, was
selected in August 1976 to begin preliminary design of the IUS. The IUS
was developed and built under contract to the Air Force Systems
Command's Space Systems Division. The Space Systems Division is
executive agent for all Department of Defense activities pertaining to the
Space Shuttle system. NASA, through the Marshall Space Flight Center,
Huntsville, Ala., purchases the IUS through the Air Force and manages the
integration activities of the upper stage to NASA spacecraft.
IUS-19, to be used on mission STS-34, is a two-stage vehicle weighing
approximately 32,500 lbs. Each stage has a solid rocket motor (SRM),
preferred over liquid-fueled engines because of SRM's relative simplicity,
high reliability, low cost and safety.
The IUS is 17 ft. long and 9.25 ft. in diameter. It consists of an aft
skirt, an aft stage SRM generating approximately 42,000 lbs. of thrust, an
interstage, a forward-stage SRM generating approximately 18,000 lbs. of
thrust, and an equipment support section.
Airborne Support Equipment
The IUS Airborne Support Equipment (ASE) is the mechanical, avionics
and structural equipment located in the orbiter. The ASE supports the IUS
and the Galileo in the orbiter payload bay and elevates the combination for
final checkout and deployment from the orbiter.
The IUS ASE consists of the structure, electromechanical mechanisms,
batteries, electronics and cabling to support the Galileo/IUS. These ASE
subsystems enable the deployment of the combined vehicle; provide,
distribute and/or control electrical power to the IUS and spacecraft;
provide plumbing to cool the radioisotope thermoelectric generator (RTG)
aboard Galileo; and serve as communication paths between the IUS and/or
spacecraft and the orbiter.
The IUS structure is capable of supporting loads generated internally
and also by the cantilevered spacecraft during orbiter operations and the
IUS free flight. It is made of aluminum skin-stringer construction, with
longerons and ring frames.
Equipment Support Section
The top of the equipment support section contains the spacecraft
interface mounting ring and electrical interface connector segment for
mating and integrating the spacecraft with the IUS. Thermal isolation is
provided by a multilayer insulation blanket across the interface between
the IUS and Galileo.
The equipment support section also contains the avionics which
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.
IUS Avionics Subsystems
The avionics subsystems consist of the telemetry, tracking and
command subsystems; guidance and navigation subsystem; data
management; thrust vector control; and electrical power subsystems.
These subsystems include all the electronic and electrical hardware used
to perform all computations, signal conditioning, data processing and
formatting associated with navigation, guidance, control, data and
redundancy management. The IUS avionics subsystems also provide the
equipment for communications between the orbiter and ground stations as
well as electrical power distribution.
Attitude control in response to guidance commands is provided by
thrust vectoring during powered flight and by reaction control thrusters
while coasting. Attitude is compared with guidance commands to
generate error signals. During solid motor firing, these commands gimble
the IUS's movable nozzle to provide the desired pitch and yaw control. The
IUS's roll axis thrusters maintain roll control. While coasting, the error
signals are processed in the computer to generate thruster commands to
maintain the vehicle's altitude or to maneuver the vehicle.
The IUS electrical power subsystem consists of avionics batteries, IUS
power distribution units, a power transfer unit, utility batteries, a
pyrotechnic switching unit, an IUS wiring harness and umbilical and
staging connectors. The IUS avionics system provides 5-volt electrical
power to the Galileo/IUS interface connector for use by the spacecraft
IUS Solid Rocket Motors
The IUS two-stage vehicle uses a large solid rocket motor and a small
solid rocket motor. These motors employ movable nozzles for thrust
vector control. The nozzles provide up to 4 degrees of steering on the
large motor and 7 degrees on the small motor. The large motor is the
longest-thrusting duration SRM ever developed for space, with the
capability to thrust as long as 150 seconds. Mission requirements and
constraints (such as weight) can be met by tailoring the amount of
propellant carried. The IUS-19 first-stage motor will carry 21,488 lb. of
propellant; the second stage 6,067 lb.
Reaction Control System
The reaction control system controls the Galileo/IUS spacecraft attitude
during coasting, roll control during SRM thrustings, velocity impulses for
accurate orbit injection and the final collision-avoidance maneuver after
separation from the Galileo spacecraft.
As a minimum, the IUS includes one reaction control fuel tank with a
capacity of 120 lb. of hydrazine. Production options are available to add a
second or third tank. However, IUS-19 will require only one tank.
IUS To Spacecraft Interfaces
Galileo is physically attached to the IUS at eight attachment points,
providing 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 a multilayer insulation blanket
of aluminized Kapton with polyester net spacers across the Galileo/IUS
interface, along with an aluminized Beta cloth outer layer. All IUS
thermal 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.
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 are normally performed at this time.
Forward payload restraints will be released and the aft frame of the
airborne-support equipment will tilt the Galileo/IUS to 29 degrees. This
will extend the payload into space just outside the orbiter payload bay,
allowing direct communication with Earth during systems checkout. The
orbiter then will be maneuvered to the deployment attitude. If a problem
has developed within the spacecraft or IUS, the IUS and its payload can be
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 Galileo/IUS predeployment operations have been successfully
completed, a GO/NO-GO decision for deployment will be sent to the crew
from ground support.
When the orbiter flight crew is given a "Go" decision, they will
activate the ordnance that separates the spacecraft's umbilical cables.
The crew then will command the electromechanical tilt actuator to raise
the tilt table to a 58-degree deployment position. The orbiter's RCS
thrusters will be inhibited and an ordnance-separation device initiated to
physically separate the IUS/spacecraft combination from the tilt table.
Six hours, 20 minutes into the mission, compressed springs provide the
force to jettison the IUS/Galileo from the orbiter payload bay at
approximately 6 inches per second. The deployment is normally performed
in the shadow of the orbiter or in Earth eclipse.
The tilt table then will be lowered to minus 6 degrees after IUS and its
spacecraft are deployed. A small orbiter maneuver is made to back away
from IUS/Galileo. Approximately 15 minutes after deployment, the
orbiter's OMS engines will be ignited to move the orbiter away from its
After deployment, the IUS/Galileo is controlled by the IUS onboard
computers. Approximately 10 minutes after IUS/Galileo deployment from
the orbiter, the IUS onboard computer will send out signals used by the
IUS and/or Galileo to begin mission sequence events. This signal will also
enable the IUS reaction control system. All subsequent operations will be
sequenced by the IUS computer, from transfer orbit injection through
spacecraft separation and IUS deactivation.
After the RCS has been activated, the IUS will maneuver to the
required thermal attitude and perform any required spacecraft thermal
At approximately 45 minutes after deployment from the orbiter, the
ordnance inhibits for the first SRM will be removed. The belly of the
orbiter already will have been oriented towards the IUS/Galileo to protect
orbiter windows from the IUS's plume. The IUS will recompute the first
ignition time and maneuvers necessary to attain the proper attitude for
the first thrusting period. When the proper transfer orbit opportunity is
reached, the IUS computer will send the signal to ignite the first stage
motor 60 minutes after deployment. After firing approximately 150
seconds, the IUS first stage will have expended its propellant and will be
separated from the IUS second stage.
Approximately 140 seconds after first-stage burnout, the second-
stage motor will be ignited, thrusting about 108 seconds. The IUS second
stage then will separate and perform a final collision/contamination
avoidance maneuver before deactivating.
SHUTTLE SOLAR BACKSCATTER ULTRAVIOLET INSTRUMENT
The Shuttle Solar Backscatter Ultraviolet (SSBUV) instrument was
developed by NASA to calibrate similar ozone measuring space-based
instruments on the National Oceanic and Atmospheric Administration's
TIROS satellites (NOAA-9 and -11).
The SSBUV will help scientists solve the problem of data reliability
caused by calibration drift of solar backscatter ultraviolet (SBUV)
instruments on orbiting spacecraft. The SSBUV uses the Space Shuttle's
orbital flight path to assess instrument performance by directly
comparing data from identical instruments aboard the TIROS spacecraft,
as the Shuttle and the satellite pass over the same Earth location within a
1-hour window. These orbital coincidences can occur 17 times per day.
The SBUV measures the amount and height distribution of ozone in the
upper atmosphere. It does this by measuring incident solar ultraviolet
radiation and ultraviolet radiation backscattered from the Earth's
atmosphere. The SBUV measures these parameters in 12 discrete
wavelength channels in the ultraviolet. Because ozone absorbs in the
ultraviolet, an ozone measurement can be derived from the ratio of
backscatter radiation at different wavelengths, providing an index of the
vertical distribution of ozone in the atmosphere.
Global concern over the depletion of the ozone layer has sparked
increased emphasis on developing and improving ozone measurement
methods and instruments. Accurate, reliable measurements from space
are critical to the detection of ozone trends and for assessing the
potential effects and development of corrective measures.
The SSBUV missions are so important to the support of Earth science
that six additional missions have been added to the Shuttle manifest for
calibrating ozone instruments on future TIROS satellites. In addition, the
dates of the four previously manifested SSBUV flights have been
The SSBUV instrument and its dedicated electronics, power, data and
command systems are mounted in the Shuttle's payload bay in two Get
Away Special canisters, an instrument canister and a support canister.
Together, they weigh approximately 1200 lb. The instrument canister
holds the SSBUV, its specially designed aspect sensors and in-flight
calibration system. A motorized door assembly opens the canister to
allow the SSBUV to view the sun and Earth and closes during the in-flight
The support canister contains the power system, data storage and
command decoders. The dedicated power system can operate the SSBUV
for a total of approximately 40 hours.
The SSBUV is managed by NASA's Goddard Space Flight Center,
Greenbelt, Md. Ernest Hilsenrath is the principal investigator.
GROWTH HORMONE CONCENTRATIONS AND DISTRIBUTION IN PLANTS
The Growth Hormone Concentration and Distribution in Plants (GHCD)
experiment is designed to determine the effects of microgravity on the
concentration, turnover properties, and behavior of the plant growth
hormone, Auxin, in corn shoot tissue (Zea Mays).
Mounted in foam blocks inside two standard middeck lockers, the
equipment consists of four plant cannisters, two gaseous nitrogen
freezers and two temperature recorders. Equipment for the experiment,
excluding the lockers, weighs 97.5 pounds.
A total of 228 specimens (Zea Mays seeds) are "planted" in special
filter, paper-Teflon tube holders no more than 56 hours prior to flight.
The seeds remain in total darkness throughout the mission.
The GHCD experiment equipment and specimens will be prepared in a
Payload Processing Facility at KSC and placed in the middeck lockers. The
GHCD lockers will be installed in the orbiter middeck within the last 14
hours before launch.
No sooner than 72 hours after launch, mission specialist Ellen Baker
will place two of the plant cannisters into the gaseous nitrogen freezers
to arrest the plant growth and preserve the specimens. The payload will
be restowed in the lockers for the remainder of the mission.
After landing, the payload must be removed from the orbiter within 2
hours and will be returned to customer representatives at the landing site.
The specimens will be examined post flight for microgravity effects.
The GHCD experiment is sponsored by NASA Headquarters, the Johnson
Space Center and Michigan State University.
The Polymer Morphology (PM) experiment is a 3M-developed organic
materials processing experiment designed to explore the effects of
microgravity on polymeric materials as they are processed in space.
Since melt processing is one of the more industrially significant
methods for making products from polymers, it has been chosen for study
in the PM experiment. Key aspects of melt processing include
polymerization, crystallization and phase separation. Each aspect will be
examined in the experiment. The polymeric systems for the first flight of
PM include polyethelyne, nylon-6 and polymer blends.
The apparatus for the experiment includes a Fournier transform
infrared (FTIR) spectrometer, an automatic sample manipulating system
and a process control and data acquisition computer known as the Generic
Electronics Module (GEM). The experiment is contained in two separate,
hermetically sealed containers that are mounted in the middeck of the
orbiter. Each container includes an integral heat exchanger that transfers
heat from the interior of the containers to the orbiter's environment. All
sample materials are kept in triple containers for the safety of the
The PM experiment weighs approximately 200 lb., occupies three
standard middeck locker spaces (6 cubic ft., total) in the orbiter and
requires 240 watts to operate.
Mission specialists Franklin R. Chang-Diaz and Shannon W. Lucid are
responsible for the operation of the PM experiment on orbit. Their
interface with the PM experiment is through a small, NASA-supplied
laptop computer that is used as an input and output device for the main PM
computer. This interface has been programmed by 3M engineers to manage
and display the large quantity of data that is available to the crew. The
astronauts will have an active role in the operation of the experiment.
In the PM experiment, infrared spectra (400 to 5000 cm-1) will be
acquired from the FTIR by the GEM computer once every 3.2 seconds as the
materials are processed on orbit. During the 100 hours of processing
time, approximately 2 gigabytes of data will be collected. Post flight, 3M
scientists will process the data to reveal the effects of microgravity on
the samples processed in space.
The PM experiment is unique among material processing experiments in
that measurements characterizing the effects of microgravity will be
made in real time, as the materials are processed in space.
In most materials processing space experiments, the materials have
been processed in space with little or no measurements made during
on-orbit processing and the effects of microgravity determined post
The samples of polymeric materials being studied in the PM experiment
are thin films (25 microns or less) approximately 25 mm in diameter. The
samples are mounted between two infrared transparent windows in a
specially designed infrared cell that provides the capability of thermally
processing the samples to 200 degrees Celsius with a high degree of
thermal control. The samples are mounted on a carousel that allows them
to be positioned, one at a time, in the infrared beam where spectra may be
acquired. The GEM provides all carousel and sample cell control. The first
flight of PM will contain 17 samples.
The PM experiment is being conducted by 3M's Space Research and
Applications Laboratory. Dr. Earl L. Cook is 3M's Payload Representative
and Mission Coordinator. Dr. Debra L. Wilfong is PM's Science Coordinator,
and James E. Steffen is the Hardware Coordinator.
The PM experiment, a commercial development payload, is sponsored by
NASA's Office of Commercial Programs. The PM experiment will be 3M's
fifth space experiment and the first under the company's 10-year Joint
Endeavor Agreement with NASA for 62 flight experiment opportunities.
Previous 3M space experiments have studied organic crystal growth from
solution (DMOS/1 on mission STS 51-A and DMOS/2 on STS 61-B) and
organic thin film growth by physical vapor treatment (PVTOS/1 on STS
51-I and PVTOS/2 on mission STS-26).
Zero Gravity Growth of Ice Crystals From Supercooled Water With Relation
To Temperature (SE82-15)
This experiment, proposed by Tracy L. Peters, formerly of Ygnacio High
School, Concord, Calif., will observe the geometric ice crystal shapes
formed at supercooled temperatures, below 0 degrees Celsius, without the
influence of gravity.
Liquid water has been discovered at temperatures far below water's
freezing point. This phonomenon occurs because liquid water does not
have a nucleus, or core, around which to form the crystal. When the ice
freezes at supercold temperatures, the ice takes on many geometric
shapes based on the hexagon. The shape of the crystal primarily depends
on the supercooled temperature and saturation of water vapor. The shapes
of crystals vary from simple plates to complex prismatic crystals.
Many scientists have tried to determine the relation between
temperature and geometry, but gravity has deformed crystals, caused
convection currents in temperature-controlled apparatus, and caused
faults in the crystalline structure. These all affect crystal growth by
either rapid fluctuations of temperature or gravitational influence of the
The results of this experiment could aid in the design of radiator cooling
and cryogenic systems and in the understanding of high-altitude
meteorology and planetary ring structure theories.
Peters is now studying physics at the University of California at Berkeley.
His teacher advisor is James R. Cobb, Ygnacio High School; his sponsor is
Boeing Aerospace Corp., Seattle.
Peters also was honored as the first four-time NASA award winner at the
International Science and Engineering Fair (ISEF), which recognizes
student's creative scientific endeavors in aerospace research. At the
1982 ISEF, Peters was one of two recipients of the Glen T. Seaborg Nobel
Prize Visit Award, an all-expense-paid visit to Stockholm to attend the
Nobel Prize ceremonies, for his project "Penetration and Diffusion of
MESOSCALE LIGHTNING EXPERIMENT
The Space Shuttle will again carry the Mesoscale Lightning Experiment
(MLE), designed to obtain nighttime images of lightning in order to better
understand the global distribution of lightning, the interrelationships
between lightning events in nearby storms, and relationships between
lightning, convective storms and precipitation.
A better understanding of the relationships between lightning and
thunderstorm characteristics can lead to the development of applications
in severe storm warning and forecasting, and early warning systems for
lightning threats to life and property.
In recent years, NASA has used both Space Shuttle missions and
high-altitude U-2 aircraft to observe lightning from above convective
storms. The objectives of these observations have been to determine
some of the baseline design requirements for a satellite-borne optical
lightning mapper sensor; study the overall optical and electrical
characteristics of lightning as viewed from above the cloudtop; and
investigate the relationship between storm electrical development and
the structure, dynamics and evolution of thunderstorms and thunderstorm
The MLE began as an experiment to demonstrate that meaningful,
qualitative observations of lightning could be made from the Shuttle.
Having accomplished this, the experiment is now focusing on quantitative
measurements of lightning characteristics and observation simulations
for future space-based lightning sensors.
Data from the MLE will provide information for the development of
observation simulations for an upcoming polar platform and Space Station
instrument, the Lightning Imaging Sensor (LIS). The lightning experiment
also will be helpful for designing procedures for using the Lightning
Mapper Sensor (LMS), planned for several geostationary platforms.
In this experiment, Atlantis' payload bay camera will be pointed
directly below the orbiter to observe nighttime lightning in large, or
mesoscale, storm systems to gather global estimates of lightning as
observed from Shuttle altitudes. Scientists on the ground will analyze the
imagery for the frequency of lightning flashes in active storm clouds
within the camera's field of view, the length of lightning discharges, and
cloud brightness when illuminated by the lightning discharge within the
If time permits during missions, astronauts also will use a handheld
35mm camera to photograph lightning activity in storm systems not
directly below the Shuttle's orbital track.
Data from the MLE will be associated with ongoing observations of
lightning made at several locations on the ground, including observations
made at facilities at the Marshall Space Flight Center, Huntsville, Ala.;
Kennedy Space Center, Fla.; and the NOAA Severe Storms Laboratory,
Norman, Okla. Other ground-based lightning detection systems in
Australia, South America and Africa will be intergrated when possible.
The MLE is managed by the Marshall Space Flight Center. Otha H. Vaughan
Jr., is coordinating the experiment. Dr. Hugh Christian is the project
scientist, and Dr. James Arnold is the project manager.
The IMAX project is a collaboration between NASA and the Smithsonian
Institution's National Air and Space Museum to document significant space
activities using the IMAX film medium. This system, developed by the
IMAX Systems Corp., Toronto, Canada, uses specially designed 70mm film
cameras and projectors to record and display very high definition
large-screen color motion pictures.
IMAX cameras previously have flown on Space Shuttle missions 41-C,
41-D and 41-G to document crew operations in the payload bay and the
orbiter's middeck and flight deck along with spectacular views of space
Film from those missions form the basis for the IMAX production, "The
Dream is Alive." On STS 61-B, an IMAX camera mounted in the payload bay
recorded extravehicular activities in the EAS/ACCESS space construction
The IMAX camera, most recently carried aboard STS-29, will be used on
this mission to cover the deployment of the Galileo spacecraft and to
gather material on the use of observations of the Earth from space for
future IMAX films.
AIR FORCE MAUI OPTICAL SITE CALIBRATION TEST
The Air Force Maui Optical Site (AMOS) tests allow ground-based
electro-optical sensors located on Mt. Haleakala, Maui, Hawaii, to collect
imagery and signature data of the orbiter during cooperative overflights.
Scientific observations made of the orbiter while performing Reaction
Control System thruster firings, water dumps or payload bay light
activation are used to support the calibration of the AMOS sensors and the
validation of spacecraft contamination models. AMOS tests have no
payload-unique flight hardware and only require that the orbiter be in
predefined attitude operations and lighting conditions.
The AMOS facility was developed by Air Force Systems Command
(AFSC) through its Rome Air Development Center, Griffiss Air Force Base,
N.Y., and is administered and operated by the AVCO Everett Research
Laboratory, Maui. The principal investigator for the AMOS tests on the
Space Shuttle is from AFSC's Air Force Geophysics Laboratory, Hanscom
Air Force Base, Mass. A co-principal investigator is from AVCO.
Flight planning and mission support activities for the AMOS test
opportunities are provided by a detachment of AFSC's Space Systems
Division at Johnson Space Center, Houston. Flight operations are
conducted at JSC Mission Control Center in coordination with the AMOS
facilities located in Hawaii.
SENSOR TECHNOLOGY EXPERIMENT
The Sensor Technology Experiment (STEX) is a radiation detection
experiment designed to measure the natural radiation background. The
STEX is a self-contained experiment with its own power, sensor, computer
control and data storage. A calibration pack, composed of a small number
of passive threshold reaction monitors, is attached to the outside of the
Sponsored by the Strategic Defense Initiative Organization, the STEX
package weighs approximately 50 pounds and is stowed in a standard
middeck locker throughout the flight.
PAYLOAD AND VEHICLE WEIGHTS
Vehicle/Payload Weight (Pounds)
Orbiter (Atlantis) Empty 172,018
Galileo/IUS (payload bay) 43,980
Galileo support hardware (middeck) 59
SSBUV (payload bay) 637
SSBUV support 578
Orbiter and Cargo at SRB Ignition 264,775
Total Vehicle at SRB Ignition 4,523,810
Orbiter Landing Weight 195,283
SPACEFLIGHT TRACKING AND DATA NETWORK
Primary communications for most activities on STS-34 will be
conducted through the orbiting Tracking and Data Relay Satellite System
(TDRSS), a constellation of three communications satellites in
geosynchronous orbit 22,300 miles above the Earth. In addition, three
NASA Spaceflight Tracking and Data Network (STDN) ground stations and
the NASA Communications Network (NASCOM), both managed by Goddard
Space Flight Center, Greenbelt, Md., will play key roles in the mission.
Three stations -- Merritt Island and Ponce de Leon, Florida and the
Bermuda -- serve as the primary communications during the launch and
ascent phases of the mission. For the first 80 seconds, all voice,
telemetry and other communications from the Space Shuttle are relayed to
the mission managers at Kennedy and Johnson Space Centers by way of the
Merritt Island facility.
At 80 seconds, the communications are picked up from the Shuttle and
relayed to the two NASA centers from the Ponce de Leon facility, 30 miles
north of the launch pad. This facility provides the communications
between the Shuttle and the centers for 70 seconds, or until 150 seconds
into the mission. This is during a critical period when exhaust from the
solid rocket motors "blocks out" the Merritt Island antennas.
The Merritt Island facility resumes communications to and from the
Shuttle after those 70 seconds and maintains them until 6 minutes, 30
seconds after launch when communications are "switched over" to
Bermuda. Bermuda then provides the communications until 11 minutes
after liftoff when the TDRS-East satellite acquires the Shuttle.
TDRS-West acquires the orbiter at launch plus 50 minutes.
The TDRS-East and -West satellites will provide communications with
the Shuttle during 85 percent or better of each orbit. The TDRS-West
satellite will handle communications with the Shuttle during its descent
and landing phases.
STS-34 CARGO CONFIGURATION (illustration)
Donald E. Williams, 47, Capt., USN, will serve as commander. Selected
as an astronaut in January 1978, he was born in Lafayette, Ind.
Williams was pilot for STS-51D, the fourth flight of Discovery,
launched April 12, 1985. During the mission, the seven-member crew
deployed the Anik-C communications satellite for Telesat of Canada and
the Syncom IV-3 satellite for the U.S. Navy. A malfunction in the Syncom
spacecraft resulted in the first unscheduled extravehicular, rendezvous
and proximity operation for the Space Shuttle in an attempt to activate
He graduated from Otterbein High School, Otterbein, Ind., in 1960 and
received his B.S. degree in mechanical engineering from Purdue University
in 1964. Williams completed his flight training at Pensacola, Fla.,
Meridian, Miss., and Kingsville, Texas, and earned his wings in 1966.
During the Vietnam Conflict, Williams completed 330 combat missions.
He has logged more than 5,400 hours flying time, including 5,100 in jets,
and 745 aircraft carrier landings.
Michael J. McCulley, 46, Cdr., USN, will be pilot on this flight. Born in
San Diego, McCulley considers Livingston, Tenn., his hometown. He was
selected as a NASA astronaut in 1984. He is making his first Space
McCulley graduated from Livingston Academy in 1961. He received B.S.
and M.S. degrees in metallurgical engineering from Purdue University in
After graduating from high school, McCulley enlisted in the U.S. Navy
and subsequently served on one diesel-powered and two nuclear-powered
submarines. Following flight training, he served tours of duty in A-4 and
A-65 aircraft and was selected to attend the Empire Test Pilots School in
Great Britain. He served in a variety of test pilot billets at the Naval Air
Test Center, Patuxent River, Md., before returning to sea duty on the USS
Saratoga and USS Nimitz.
He has flown more than 50 types of aircraft, logging more than 4,760
hours, and has almost 400 carrier landings on six aircraft carriers.
Shannon W. Lucid, 46, will serve as mission specialist (MS-1) on this,
her second Shuttle flight. Born in Shanghai, China, she considers Bethany,
Okla., her hometown. Lucid is a member of the astronaut class of 1978.
Lucid's first Shuttle mission was during STS 51-G, launched from the
Kennedy Space Center on June 17, 1985. During that flight, the crew
deployed communications satellites for Mexico, the Arab League and the
Lucid graduated from Bethany High School in 1960. She then attended
the University of Oklahoma where she received a B.S. degree in chemistry
in 1963, an M.S. degree in biochemistry in 1970 and a Ph.D. in biochemistry
Before joining NASA, Lucid held a variety of academic assignments
such as teaching assistant at the University of Oklahoma's department of
chemistry; senior laboratory technician at the Oklahoma Medical Research
Foundation; chemist at Kerr-McGee in Oklahoma City; graduate assistant in
the University of Oklahoma Health Science Center's department of
biochemistry; and molecular biology and research associate with the
Oklahoma Medical Research Foundation in Oklahoma City. Lucid also is a
commercial, instrument and multi-engine rated pilot.
Franklin Chang-Diaz, 39, will serve as MS-2. Born in San Jose, Costa
Rica, Chang-Diaz also will be making his second flight since being
selected as an astronaut in 1980.
Chang-Diaz made his first flight aboard Columbia on mission STS 61-C,
launched from KSC Jan. 12, 1986. During the 6-day flight he participated
in the deployment of the SATCOM KU satellite, conducted experiments in
astrophysics and operated the materials science laboratory, MSL-2.
Chang-Diaz graduated from Colegio De La Salle, San Jose, Costa Rica, in
1967, and from Hartford High School, Hartford, Conn., in 1969. He received
a B.S. degree in mechanical engineering from the University of Connecticut
in 1973 and a Ph.D. in applied plasma physics from the Massachusetts
Institute of Technology in 1977.
While attending the University of Connecticut, Chang-Diaz also worked
as a research assistant in the physics department and participated in the
design and construction of high-energy atomic collision experiments.
Upon entering graduate school at MIT, he became heavily involved in the
United State's controlled fusion program and conducted intensive research
in the design and operation of fusion reactors. In 1979, he developed a
novel concept to guide and target fuel pellets in an inertial fusion reactor
chamber. In 1983, he was appointed as visiting scientist with the MIT
Plasma Fusion Center which he visits periodically to continue his research
on advanced plasma rockets.
Chang-Diaz has logged more than 1,500 hours of flight time, including
1,300 hours in jet aircraft.
Ellen S. Baker, 36, will serve as MS-3. She will be making her first
Shuttle flight. Baker was born in Fayetteville, N.C., and was selected as
an astronaut in 1984.
Baker graduated from Bayside High School, New York, N.Y., in 1970. She
received a B.A. degree in geology from the State University of New York at
Buffalo in 1974, and an M.D. from Cornell University in 1978.
After medical school, Baker trained in internal medicine at the
University of Texas Health Science Center in San Antonio, Texas. In 1981,
she was certified by the American Board of Internal Medicine.
Baker joined NASA as a medical officer at the Johnson Space Center in
1981 after completing her residency. That same year, she graduated with
honors from the Air Force Aerospace Medicine Primary Course at Brooks
Air Force Base in San Antonio. Prior to her selection as an astronaut, she
served as a physician in the Flight Medicine Clinic at JSC.
NASA PROGRAM MANAGEMENT
Richard H. Truly
James R. Thompson Jr.
NASA Deputy Administrator
William B. Lenoir
Acting Associate Administrator for Space Flight
George W.S. Abbey
Deputy Associate Administrator for Space Flight
Arnold D. Aldrich
Director, National Space Transportation Program
Leonard S. Nicholson
Deputy Director, NSTS Program
(located at Johnson Space Center)
Robert L. Crippen
Deputy Director, NSTS Operations
(located at Kennedy Space Center)
David L. Winterhalter
Director, Systems Engineering and Analyses
Gary E. Krier
Director, Operations Utilization
Joseph B. Mahon
Deputy Associate Administrator
for Space Flight (Flight Systems)
Charles R. Gunn
Director, Unmanned Launch Vehicles
and Upper Stages
George A. Rodney
Associate Administrator for Safety, Reliability,
Maintainability and Quality Assurance
Charles T. Force
Associate Administrator for Operations
Dr. Lennard A. Fisk
Associate Administrator for Space Science
Assistant Deputy Associate Administrator
Deputy Associate Administrator for
Space Science and Applications
Dr. Geoffrey A. Briggs
Director, Solar System Exploration Division
Robert F. Murray
Manager, Galileo Program
Dr. Joseph Boyce
Galileo Program Scientist
Johnson Space Center
Paul J. Weitz
Richard A. Colonna
Manager, Orbiter and GFE Projects
Donald R. Puddy
Director, Flight Crew Operations
Eugene F. Kranz
Director, Mission Operations
Henry O. Pohl
Charles S. Harlan
Director, Safety, Reliability and Quality Assurance
Kennedy Space Center
Forrest S. McCartney
Thomas E. Utsman
Jay F. Honeycutt
Director, Shuttle Management
Robert B. Sieck
George T. Sasseen
Shuttle Engineering Director
Conrad G. Nagel
Atlantis Flow Director
James A. Thomas
Director, Safety, Reliability and
John T. Conway
Director, Payload Managerment
Marshall Space Flight Center
Thomas J. Lee
Dr. J. Wayne Littles
G. Porter Bridwell
Manager, Shuttle Projects Office
Dr. George F. McDonough
Director, Science and Engineering
Alexander A. McCool
Director, Safety, Reliability and Quality Assurance
Royce E. Mitchell
Manager, Solid Rocket Motor Project
Cary H. Rutland
Manager, Solid Rocket Booster Project
Jerry W. Smelser
Manager, Space Shuttle Main Engine Project
G. Porter Bridwell
Acting Manager, External Tank Project
Sidney P. Saucier
Manager, Space Systems Projects Office
Stennis Space Center
Bay St. Louis, Miss.
Roy S. Estess
Gerald W. Smith
William F. Taylor
J. Harry Guin
Director, Propulsion Test Operations
Edward L. Tilton III
Director, Science and Technology Laboratory
John L. Gasery Jr.
Chief, Safety/Quality Assurance
and Occupational Health
Jet Propulsion Laboratory
Dr. Lew Allen
Dr. Peter T. Lyman
Laboratory Director for Flight Projects
Assistant Laboratory Director for Flight Projects
Richard J. Spehalski
Manager, Galileo Project
William J. O'Neil
Manager, Science and Mission Design,
Dr. Clayne M. Yeates
Deputy Manager, Science and Mission Design,
Dr. Torrence V Johnson
Galileo Project Scientist
Neal E. Ausman Jr.
Mission Operations and Engineering Manager
A. Earl Cherniack
Orbiter Spacecraft Manager
Matthew R. Landano
Deputy Orbiter Spacecraft Manager
William G. Fawcett
Orbiter Science Payload Manager
Ames Research Center
Mountain View, Calif.
Dr. Dale L. Compton
Dr. Joseph C. Sharp
Acting Director, Space Research Directorate
Chief, Space Exploration Projects Office
Dr. Lawrence Colin
Dr. Richard E. Young
Ames-Dryden Flight Research Facility
Martin A. Knutson
Theodore G. Ayers
Deputy Site Manager
Thomas C. McMurtry
Chief, Research Aircraft Operations Division
Larry C. Barnett
Chief, Shuttle Support Office
Goddard Space Flight Center
Dr. John W. Townsend
Director, Flight Projects
Dale L. Fahnestock
Director, Mission Operations and Data Systems
Daniel A. Spintman
Chief, Networks Division
Gary A. Morse
Dr. Robert D. Hudson
Head, Atmospheric Chemistry and Dynamics
SSBUV Principal Investigator
Jon R. Busse
Director, Engineering Directorate
Robert C. Weaver Jr.
Chief, Special Payloads Division
Neal F. Barthelme
SSBUV Mission Manager