UPCOMING PLANETARY PROBES - MISSIONS AND SCHEDULES
Information on upcoming or currently active missions not mentioned below
would be welcome. Sources: NASA fact sheets, Cassini Mission Design
team, ISAS/NASDA launch schedules, press kits.
ASCA (ASTRO-D) - Japanese (ISAS) Advanced Satellite for Cosmology and
Astrophysics. ASCA is an X-ray astronomy satellite launched into Earth
orbit on 2/20/93. Equipped with large-area wide-wavelength (1-20
Angstrom) X-ray telescope, X-ray CCD cameras, and imaging gas
scintillation proportional counters.
CASSINI - Saturn orbiter and Titan atmosphere probe. Cassini is a joint
NASA/ESA project designed to accomplish an exploration of the Saturnian
system with its Cassini Saturn Orbiter and Huygens Titan Probe. Cassini
is scheduled for launch aboard a Titan IV/Centaur in October of 1997.
After gravity assists of Venus, Earth and Jupiter in a VVEJGA
trajectory, the spacecraft will arrive at Saturn in June of 2004. Upon
arrival, the Cassini spacecraft performs several maneuvers to achieve an
orbit around Saturn. Near the end of this initial orbit, the Huygens
Probe separates from the Orbiter and descends through the atmosphere of
Titan. The Orbiter relays the Probe data to Earth for about 3 hours
while the Probe enters and traverses the cloudy atmosphere to the
surface. After the completion of the Probe mission, the Orbiter
continues touring the Saturnian system for three and a half years. Titan
synchronous orbit trajectories will allow about 35 flybys of Titan and
targeted flybys of Iapetus, Dione and Enceladus. The objectives of the
mission are threefold: conduct detailed studies of Saturn's atmosphere,
rings and magnetosphere; conduct close-up studies of Saturn's
satellites, and characterize Titan's atmosphere and surface.
One of the most intriguing aspects of Titan is the possibility that its
surface may be covered in part with lakes of liquid hydrocarbons that
result from photochemical processes in its upper atmosphere. These
hydrocarbons condense to form a global smog layer and eventually rain
down onto the surface. The Cassini orbiter will use onboard radar to
peer through Titan's clouds and determine if there is liquid on the
surface. Experiments aboard both the orbiter and the entry probe will
investigate the chemical processes that produce this unique atmosphere.
The Cassini mission is named for Jean Dominique Cassini (1625-1712), the
first director of the Paris Observatory, who discovered several of
Saturn's satellites and the major division in its rings. The Titan
atmospheric entry probe is named for the Dutch physicist Christiaan
Huygens (1629-1695), who discovered Titan and first described the true
nature of Saturn's rings.
Key Scheduled Dates for the Cassini Mission (VVEJGA Trajectory)
-------------------------------------------------------------
10/06/97 - Titan IV/Centaur Launch
04/21/98 - Venus 1 Gravity Assist
06/20/99 - Venus 2 Gravity Assist
08/16/99 - Earth Gravity Assist
12/30/00 - Jupiter Gravity Assist
06/25/04 - Saturn Arrival
01/09/05 - Titan Probe Release
01/30/05 - Titan Probe Entry
06/25/08 - End of Primary Mission
(Schedule last updated 7/22/92)
CLEMENTINE - joint mission of the Strategic Defense Initiative
Organization and NASA to flight test sensors developed by Lawrence
Livermore for SDI. The spacecraft, which is being built by the Naval
Research Lab, will be launched in late January 1994 and will go into a
400 km by 8300 km orbit of the Moon for a 2 month mapping mission.
Instruments onboard include UV to mid-IR imagers, including an imaging
lidar that may be able to also obtain altimetric data for the middle
latitudes of the Moon. In early May the spacecraft will be sent out of
lunar orbit toward a flyby (11 km/sec ?) of the 4 km x 1 km asteroid
1620 Geographos on August 31 at less than 100 km.
GALILEO - Jupiter orbiter and atmosphere probe, in transit. Has returned
the first resolved images of an asteroid, Gaspra, while in transit to
Jupiter. Efforts to unfurl the stuck High-Gain Antenna (HGA) have
essentially been abandoned. JPL has developed a backup plan using data
compression (JPEG-like for images, lossless compression for data from
the other instruments) which should allow the mission to achieve
approximately 70% of its original objectives.
Galileo Schedule
----------------
10/18/89 - Launch from Space Shuttle
02/09/90 - Venus Flyby
10/**/90 - Venus Data Playback
12/08/90 - 1st Earth Flyby
05/01/91 - High Gain Antenna Unfurled
07/91 - 06/92 - 1st Asteroid Belt Passage
10/29/91 - Asteroid Gaspra Flyby
12/08/92 - 2nd Earth Flyby
05/93 - 11/93 - 2nd Asteroid Belt Passage
08/28/93 - Asteroid Ida Flyby
07/02/95 - Probe Separation
07/09/95 - Orbiter Deflection Maneuver
12/95 - 10/97 - Orbital Tour of Jovian Moons
12/07/95 - Jupiter/Io Encounter
07/18/96 - Ganymede
09/28/96 - Ganymede
12/12/96 - Callisto
01/23/97 - Europa
02/28/97 - Ganymede
04/22/97 - Europa
05/31/97 - Europa
10/05/97 - Jupiter Magnetotail Exploration
HITEN (MUSES-A) - Japanese (ISAS) lunar probe launched 1/24/90. Made
multiple lunar flybys and released Hagoromo, a smaller satellite, into
lunar orbit. This mission made Japan the third nation to orbit a
satellite around the Moon. Hiten impacted the lunar surface on 4/10/93.
MAGELLAN - Venus radar mapping mission. Has mapped almost the entire
surface at high resolution. Currently (4/93) collecting a global gravity
map.
MARS OBSERVER - Mars orbiter including 1.5 m/pixel resolution camera.
Launched 9/25/92 on a Titan III/TOS booster. MO is currently (4/93) in
transit to Mars, arriving on 8/24/93. Operations will start 11/93 for
one martian year (687 days).
TOPEX/Poseidon - Joint US/French Earth observing satellite, launched
8/10/92 on an Ariane 4 booster. The primary objective of the
TOPEX/POSEIDON project is to make precise and accurate global
observations of the sea level for several years, substantially
increasing understanding of global ocean dynamics. The satellite also
will increase understanding of how heat is transported in the ocean.
ULYSSES- European Space Agency probe to study the Sun from an orbit over
its poles. Launched in late 1990, it carries particles-and-fields
experiments (such as magnetometer, ion and electron collectors for
various energy ranges, plasma wave radio receivers, etc.) but no camera.
Since no human-built rocket is hefty enough to send Ulysses far out of
the ecliptic plane, it went to Jupiter instead, and stole energy from
that planet by sliding over Jupiter's north pole in a gravity-assist
manuver in February 1992. This bent its path into a solar orbit tilted
about 85 degrees to the ecliptic. It will pass over the Sun's south pole
in the summer of 1993. Its aphelion is 5.2 AU, and, surprisingly, its
perihelion is about 1.5 AU-- that's right, a solar-studies spacecraft
that's always further from the Sun than the Earth is!
While in Jupiter's neigborhood, Ulysses studied the magnetic and
radiation environment. For a short summary of these results, see
*Science*, V. 257, p. 1487-1489 (11 September 1992). For gory technical
detail, see the many articles in the same issue.
OTHER SPACE SCIENCE MISSIONS (note: this is based on a posting by Ron
Baalke in 11/89, with ISAS/NASDA information contributed by Yoshiro
Yamada (yamada@yscvax.ysc.go.jp). I'm attempting to track changes based
on updated shuttle manifests; corrections and updates are welcome.
1993 Missions
o ALEXIS [spring, Pegasus]
ALEXIS (Array of Low-Energy X-ray Imaging Sensors) is to perform
a wide-field sky survey in the "soft" (low-energy) X-ray
spectrum. It will scan the entire sky every six months to search
for variations in soft-X-ray emission from sources such as white
dwarfs, cataclysmic variable stars and flare stars. It will also
search nearby space for such exotic objects as isolated neutron
stars and gamma-ray bursters. ALEXIS is a project of Los Alamos
National Laboratory and is primarily a technology development
mission that uses astrophysical sources to demonstrate the
technology. Contact project investigator Jeffrey J Bloch
(jjb@beta.lanl.gov) for more information.
o Wind [Aug, Delta II rocket]
Satellite to measure solar wind input to magnetosphere.
o Space Radar Lab [Sep, STS-60 SRL-01]
Gather radar images of Earth's surface.
o Total Ozone Mapping Spectrometer [Dec, Pegasus rocket]
Study of Stratospheric ozone.
o SFU (Space Flyer Unit) [ISAS]
Conducting space experiments and observations and this can be
recovered after it conducts the various scientific and
engineering experiments. SFU is to be launched by ISAS and
retrieved by the U.S. Space Shuttle on STS-68 in 1994.
1994
o Polar Auroral Plasma Physics [May, Delta II rocket]
June, measure solar wind and ions and gases surrounding the
Earth.
o IML-2 (STS) [NASDA, Jul 1994 IML-02]
International Microgravity Laboratory.
o ADEOS [NASDA]
Advanced Earth Observing Satellite.
1995
o MUSES-B (Mu Space Engineering Satellite-B) [ISAS]
Conducting research on the precise mechanism of space structure
and in-space astronomical observations of electromagnetic waves.
1996
o PLANET-B [ISAS]
Mars orbiter to study the structure and motions of the Martian
atmosphere and its interaction with the solar winds.
1997
o LUNAR-A [ISAS]
Elucidating the crust structure and thermal construction of the
moon's interior.
Proposed Missions:
o Advanced X-ray Astronomy Facility (AXAF)
Possible launch from shuttle in 1995, AXAF is a space
observatory with a high resolution telescope. It would orbit for
15 years and study the mysteries and fate of the universe.
o Earth Observing System (EOS)
Possible launch in 1997, 1 of 6 US orbiting space platforms to
provide long-term data (15 years) of Earth systems science
including planetary evolution.
o Mercury Observer
Possible 1997 launch.
o Lunar Observer
Possible 1997 launch, would be sent into a long-term lunar
orbit. The Observer, from 60 miles above the moon's poles, would
survey characteristics to provide a global context for the
results from the Apollo program.
o Space Infrared Telescope Facility
Possible launch by shuttle in 1999, this is the 4th element of
the Great Observatories program. A free-flying observatory with
a lifetime of 5 to 10 years, it would observe new comets and
other primitive bodies in the outer solar system, study cosmic
birth formation of galaxies, stars and planets and distant
infrared-emitting galaxies
o Mars Rover Sample Return (MRSR)
Robotics rover would return samples of Mars' atmosphere and
surface to Earch for analysis. Possible launch dates: 1996 for
imaging orbiter, 2001 for rover.
o Fire and Ice
Possible launch in 2001, will use a gravity assist flyby of
Earth in 2003, and use a final gravity assist from Jupiter in
2005, where the probe will split into its Fire and Ice
components: The Fire probe will journey into the Sun, taking
measurements of our star's upper atmosphere until it is
vaporized by the intense heat. The Ice probe will head out
towards Pluto, reaching the tiny world for study by 2016.
NEXT: FAQ #10/13 - Controversial questions