Internet Info 1997 December/Internet_Info_CD-ROM_Walnut_Creek_December_1997.iso/infoguide/resources/astronomy/faq9

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Archive-name: space/new_probes
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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
        ([e-mail]) 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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