SPACE/NEW_PROBES - Upcoming Planetary Probes - Missions and Schedules

Last-modified: $Date: 94/03/01 17:24:41 $

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, built by the Naval Research Lab, was

launched on January 25 to 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.

EARTH OBSERVING SYSTEM (EOS) - Multiple orbiting platforms to provide

long-term data of Earth systems science including planetary evolution.

First platform launch 1997?

GALILEO - Jupiter orbiter and atmosphere probe, in transit. Has returned

the first resolved images of an asteroid, Gaspra, while in transit to

Jupiter. Images of the August 1993 encounter with the asteroid Ida are

being returned slowly at present. Efforts to unfurl the stuck High Gain

Antenna (HGA) have essentially been abandoned. JPL has developed a

backup plan using enhancements of the receiving antennas in the Deep

Space Network and data compression (JPEG-like for images, lossless

compression for data from the other instruments) on the spacecraft. This

should allow Galileo to achieve approximately 70% of its original

science objectives with the much lower speed Low Gain Antenna. Longterm

Jovian weather monitoring, which is imagery intensive, will suffer the

most.

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 (was to have) 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 and is working on a global gravity map.

Magellan recently executed an 80-day aerobraking program to lower and

circularize its orbit.

MARS OBSERVER - Mars orbiter including 1.5 m/pixel resolution camera.

Launched 9/25/92 on a Titan III/TOS booster. Contact was lost with MO on

8/21/93 while it was preparing for entry into Mars orbit. The spacecraft

has been written off. Mars Surveyor, a replacement mission to achieve

most of MO's science goals, is scheduled to launch in November 1996.

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 1994. 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 (various sources; corrections and updates

are solicited. Launch dates are usually tentative, and most shuttle

missions are not listed even when they have some science content).

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 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 Space Radar Lab [April, Shuttle]

Gather radar images of Earth's surface.

o Polar Auroral Plasma Physics [May, Delta II rocket]

June, measure solar wind and ions and gases surrounding the

Earth.

o IML-2 (NASDA) [July, Shuttle]

International Microgravity Laboratory (Spacelab mission).

o Space Radar Lab [August, Shuttle]

Followon to SRL-01.

o ADEOS [NASDA]

Advanced Earth Observing Satellite.

1995

o SL-M (Spacelab - MIR) [May, Shuttle, MIR]

Space Shuttle docking with Russian MIR station. Life sciences

mission (Spacelab).

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.

o NEAR [NASA]

Discovery-class mission to rendezvous with near-Earth asteroid

Eros in 1998. Will orbit Eros for a year to determine size,

shape, mass, magnetic field, and measure composition and surface

structure.

o VSOP (VLBI Space Observatory Program) [NASDA]

Scheduled to be launched ~8/96. NASA is building 3 specialized

tracking stations to record the wideband radioastronomy data

that this spacecraft will produce.

o Mars Surveyor [November, NASA]

Replacement for Mars Observer including most MO instruments. To

be launched on a Delta II booster and begin Mars science

operations in 1/98. Followon landers and orbiters are planned

for launch about every 2 years for the following decade.

1997

o LUNAR-A [ISAS]

Elucidating the crust structure and thermal construction of the

moon's interior.

o RADIOASTRON [Russian space agency]

Same purpose as 1996 VSOP mission. NRAO is building similar

ground stations for tracking. These two spacecraft will

coobserve radio sources in conjunction with ground based VLBA

radio telescopes.

2003

o ROSETTA [ESA]

Asteroid flyby and comet rendezvous (potential target comets are

Schwassmann-Wachmann 3, Wirtanen, Finlay and Brooks 2 for a

launch in the time interval 2002-2004). After rendezvous,

the spacecraft will stay with the comet along its trajectory

into the inner solar system through perihelion (the orbital

point nearest to the Sun) to study the material that constitutes

the comet, and the cometary processes that evolve with the

decreasing distance from the Sun. A Surface Science Station will

be deployed onto the comets' nucleus surface to provide the

means for in-situ studies of the nucleus.

2006

o FIRST (Far InfraRed Space Telescope) [ESA]

Large (3-meter mirror) space observatory.

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 Clementine II

Preliminary studies for a Clementine II mission have been done

by JPL. These studies envision a launch in July 1995, flyby of

the asteroid Eros on March 13, 1996, and flyby of the asteroid

Toutatis on October 4, 1996. Clementine would deply a probe to

impact Toutatis, and imagery and other measurements of the

impact crater and debris would help analyze the composition of

the asteroid.

o Pluto Fast Flyby (PFF)

Possible launch in 1999-2000 (if a 1996 new start is

authorized). Calls for launch of two ~110-150 kg spacecraft

using Titan IV/Centaur or Proton (both with additional solid

kick stages) in 1999-2000 and encounters with Pluto and Charon

around 2006-8. Flybys would be at 12-18 km/second; data would be

recorded onboard the probes during the short encounters and

returned to Earth slowly (due to low power, small antenna sizes,

and large distances) over the next year or so.

Science objectives include characterizing global geology and

geomorphology of Pluto and Charon, mapping both sides of each

body, and characterizing Pluto's atmosphere (the atmosphere is

freezing out as Pluto moves away from the Sun, so launching

early and minimizing flight time is critical for this

objective). The 7 kilogram instrument package might include a

CCD imaging camera, IR mapping spectrometer, UV spectrometer,

and radio science occultation experiments.

The PFF spacecraft would be highly miniaturized descendant of

the present class of outer solar system platforms, breaking the

trend of increasingly complex and expensive probes such as

Galileo and Cassini.

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

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This is a static and possibly incomplete copy of the USEnet SCI.SPACE Frequently Asked Questions (FAQ) document dated March 1994 (before the material was copyrighted). The official copyrighted and and up-to-date FAQ is maintained by Jon Leech (leech@cs.unc.edu) and is posted to Network News and available via the World Wide Web . KSC's Hypertext converter last run Thursday June 15 10:23:25 EDT 1995