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Mission Information

MISSION_NAME GALILEO
MISSION_NAME_OR_ALIAS GALILEO MILLENNIUM MISSION (GMM)
MISSION_START_DATE 1977-10-01
MISSION_STOP_DATE 2003-09-21
MISSION_DESCRIPTION
 
  Mission Overview
  ================
    The Galileo mission utilized a single launch of a combined
    Orbiter and Probe using the space shuttle Atlantis and an
    inertial upper stage (IUS) to inject the Galileo spacecraft on
    its interplanetary trajectory to Jupiter.  The launch occurred
    October 18, 1989.  Since the IUS did not have the energy to
    inject Galileo on a direct trajectory to Jupiter, the spacecraft
    was launched first towards Venus for the first leg of its
    Venus-Earth-Earth gravity assist (VEEGA) trajectory.
 
    Target-of-opportunity science observations were made at Venus
    (closest approach February 10, 1990), the first Earth encounter
    (closest approach to Earth and Moon December 8 and 9, 1990), the
    asteroid Gaspra (closest approach October 29, 1991), the second
    Earth encounter (closest approach to Earth and Moon December 8,
    1992), the asteroid Ida (closest approach August 28, 1993), and
    distant observations of the impact of comet Shoemaker-Levy 9 into
    Jupiter's atmosphere from July 16-22, 1994.
 
    The Probe separated from the Orbiter on July 13, 1995.  After
    this time, the Probe proceeded on a ballistic trajectory to its
    entry point (6.54 deg north latitude, 4.46 west longitude) into
    the atmosphere of Jupiter.  The Orbiter used its 400 Newton
    engine on July 27, 1995 to perform a deflection maneuver to keep
    from following the Probe into the atmosphere of Jupiter, and to
    retarget the Orbiter to the proper encounter conditions required
    for the Jupiter Orbit Insertion phase of the mission.
 
    A close flyby (892 kilometer altitude) of the Jovian satellite
    Io occurred at 17:45:58 UT on Dec 7, 1995, during the Jupiter
    Orbit Insertion phase.  This flyby allowed fields and particles
    science observations to be made and slowed the Orbiter down
    relative to Jupiter by nearly 200 meters/second in order to
    reduce the propellant required during the Jupiter Orbit Insertion
    (JOI).  Remote sensing observations of Io were not made at this
    time due to an anomaly with the onboard tape recorder associated
    with high speed recording that was not well understood at the
    time of the flyby.  Perijove at 4.00 Jupiter radii occurred at
    21:53:44 UT on the same day.  A few minutes after perijove
    passage, the Probe entered the Jovian atmosphere and began
    relaying data back to the Orbiter.
 
    The Probe mission and data relay lasted 58.6 minutes, after
    which JOI was performed, slowing the Orbiter down relative to
    Jupiter by about 630 meters/second.  The initial orbit period was
    about 200 days.  A large 400 Newton engine burn was performed at
    the first apojove in order to raise perijove from 4 Jupiter radii
    to about 9 Jupiter radii, thus allowing the mission to complete
    10 targeted satellite encounters without exceeding the allowed
    total accumulated radiation exposure at the spacecraft.  This
    limit would have been exceeded after three orbits if perijove had
    been allowed to stay at 4 Jupiter radii, where the radiation
    environment is very severe.
 
    Prime Mission orbital operations consisted of 10 targeted satellite
    encounters over 24 months. During the course of the satellite
    tour, the orientation, shape and size of the spacecraft orbits
    around the Jovian system, referred to as petals because of how
    the spacecraft orbits appear on an equatorial projection of the
    Jovian satellite tour trajectory, were controlled almost
    exclusively by gravity assists of the satellites themselves.
    The orbit periods were pumped down by successive encounters
    with the satellites from the initial 200 days to approximately
    35-40 days between encounters.  During the 9th orbit, when the
    orbit petal orientation was approximately in the anti-sun
    direction, the period was again pumped up to about 100 days
    which allowed one of the primary objectives, probing the Jovian
    magnetotail, to be accomplished.  After this magnetotail orbit,
    the period was again pumped down, by gravity assist encounters
    with the Jovian satellites, to 35-40 days for the final
    targeted encounters.  (Refer to GLLMS1991, GLLSRD1989, and
    GLLIOM1992).
 
    The Galileo Europa Mission (GEM) was a low cost follow-on to the
    Galileo Prime Mission that uses the Galileo spacecraft to continue
    focused studies of the Jovian system.  The mission is divided
    into three main phases or campaigns:  Europa Campaign, Perijove
    Campaign and Io Campaign.  Each had a different and very specific
    scientific focus. Towards the end of the GEM an additional mission
    extension was proposed to NASA to keep the Galileo spacecraft in
    operation through the Jupiter flyby of the Cassini spacecraft in
    December 2000. The orbital tour was extended to prolong the Io
    phase by 2 orbits and to add another 2 orbits for Galileo and
    Cassini collaborative science.
 
    The Galileo Millennium Mission (GMM) was a follow on to the GEM
    mission, with a greatly reduced budget. The mission was designed
    to continue the exploration of Io and the inner Jovian
    magnetosphere, and to dispose of the spacecraft in an
    environmentally friendly manner (Jupiter impact). Jupiter impact
    occurred on September 21, 2003 at approximately 19:07 UTC. The
    last science packets were received a few hour earlier at
    14:31:54 UTC.
 
    The Galileo orbits were named by concatenating the first letter
    of the name of the primary target in each orbit with the orbit
    number.  Thus, the fourth Jupiter orbit, in which Europa is the
    primary target, is called E4.  The project defined orbits
    according to spacecraft command load boundaries rather than the
    normal convention of apoapsis to apoapsis. The navigation team
    did not always adhere to this convention, causing some confusion.
 
    The PDS organized the data and data delivery schedule around the
    project defined orbit boundaries.  Table 1 contains information
    about the full Galileo orbital tour.
 
    _______________________________________________________________
    Table 1                  Orbital Facts
    _______________________________________________________________
           Periapsis    Periapsis     Satellite         Satellite
    Orbit  Range* (Rj)  Date/Time     Closest Approach  Flyby
          (Rj=71492km)    (UT)        Date/Time (UT)    Alt** (km)
    _______________________________________________________________
    J0      4.00     95-341 21:53:44  95-341 17:45:58      896
    G1     11.03     96-180 00:31:26  96-179 06:29:07      838
    G2     10.65     96-251 13:37:54  96-250 18:59:34      264
    C3      9.21     96-311 13:31:07  96-309 13:34:28     1138
    E4      9.16     96-354 03:21:58  96-354 06:52:58      688
    J5      9.05     97-020 00:26:57       N/A             N/A
    E6      9.12     97-051 20:54:15  97-051 17:06:10      582
    G7      9.12     97-094 11:03:38  97-095 07:09:58     3104
    G8      9.27     97-128 11:41:46  97-127 15:56:10     1606
    C9     10.77     97-178 11:52:22  97-176 13:47:50      421
    C10     9.17     97-261 23:10:00  97-260 00:18:55      538
    E11     8.97     97-311 00:42:01  97-310 20:31:44     2039
    E12     8.80     97-350 06:34:53  97-350 12:03:20      201
    J13     8.86     98-041 23:09:15       N/A             N/A
    E14     8.84     98-088 07:59:13  98-088 13:21:05     1644
    E15     8.85     98-152 02:34:42  98-151 21:12:57     2514
    E16     8.85     98-202 00:17:59  98-202 05:03:45     1834
    E17     8.91     98-269 08:26:27  98-269 03:54:20     3582
    E18     8.94     98-326 07:30:52  98-326 11:38:26     2271
    E19     9.11     99-032 05:02:10  99-032 02:19:50     1439
    C20     9.37     99-123 17:00:11  99-125 13:56:18     1321
    C21     7.27     99-183 05:04:52  99-181 07:46:50     1048
    C22     7.32     99-224 10:58:31  99-226 08:30:52     2299
    C23     6.54     99-257 19:57:37  99-259 17:27:02     1052
    I24     5.55     99-284 02:02:37  99-284 04:33:03      611
    I25     5.7      99-330 02:07:41  99-330 03:59:15      300
    E26     5.8      00-004 03:32:58  00-003 17:59:56      360
    I27     5.9      00-053 12:30:23  00-053 13:46:36      200
    G28     6.7      00-142 04:52:29  00-141 10:10:18      900
    G29     7.5      00-364 03:26:31  00-363 08:25:27     2338
    C30     7.3      01-143 17:32:51  01-145 11:23:58      138
    I31     5.9      01-218 04:52:11  01-218 04:59:21      194
    I32     5.8      01-288 23:55:59  01-289 01:23:21      184
    I33     5.5      02-017 16:22:31  02-017 14:08:23      100
    A34     2.0      02-309 07:23:22  02-309 06:18:26      914
    J35     0.9      03-264 18:57     03-264 19:07:00      N/A
 
 
    *  Range is measured from center of mass
    ** Altitude is computed by subtracting a satellite radius from a
       measured range. Variations in reported values may be
       attributed to differences in the radius value subtracted
       (estimates improve).
 
    The failed deployment of the Galileo High Gain Antenna
    necessitated fundamental changes in how the spacecraft acquired
    and transmitted data back to Earth if more than a fraction of the
    science objectives were to be met.  Changes were required to both
    the spacecraft software (Command Data System (CDS) and Attitude
    and Articulation Command System (AACS)) and many of the science
    instruments software.  The mission can be described in terms of
    three distinct sets of flight software (FSW) which are commonly
    called Phase 0 FSW, Phase 1 FSW, and Phase 2A FSW.  The Galileo
    flight software phases should not be confused with Mission Phases
    which will be describe later.
 
    Phase 0: Initial spacecraft flight software configuration at
    launch.  Telemetry was sent in a Time-Division-Multiplex (TDM) or
    Fixed-format mode.  The data rates in this phase were designed to
    be supported by the high gain antenna and had very limited
    capability to return science data at telemetry rates below 7.68
    kbps.  The Phase 0 flight software was patched on June 15, 1993
    to increase the memory readout block size from 32 bytes to 80
    bytes.
 
    Phase 1: The Phase 1 flight software consisted of minor
    modifications of Phase 0 to improve the data return from the
    Galileo probe.  It was loaded onto the spacecraft January 30
    through February 12, 1995.  The changes provided for: the
    capability to write edited Probe symbol data and Doppler wind
    data to the extended memory of the primary onboard computer, new
    downlink telemetry rates at 8 bps and 16 bps, a new 7.68 kbps
    Probe data record format, 80 byte memory readouts to decrease
    data return time, and more robust fault protection during the
    time of Relay/JOI.
 
    Phase 2A: The Phase 2 flight software is fundamentally different
    from the Phase 0 flight software.  The purpose of the changes was
    to utilize the low gain antenna more effectively to return
    science data.  There were two major categories of change: 1) to
    return data from the tape recorder in a more efficient and
    autonomous fashion, and 2) to provide a real time capability for
    the fields and particles science instruments.  More than 58% of
    the onboard computer memory was loaded with new code.  The new
    capabilities included packetized telemetry with advanced
    Reed-Solomon encoding, 8 downlink rates from 8 to 160 bps, new
    tape recorder record formats, automated and adaptive playback
    modes, science data selection, sampling, summation and
    compression, and 9 low rate real-time science downlink formats.
 
    Real time editing of optical navigation images was also
    provided.  Eight of the science instruments also developed new
    flight software in support of the changing spacecraft
    capabilities in Phase 2.  Select science instruments were
    provided with automated loading of their onboard stored, mode
    dependent software.  While the Phase 2 flight software was in
    testing, problems were discovered with the tape recorder.
 
    Additional features were added to the flight software to manage
    the tape recorder to avoid the known failure mechanisms and to
    avoid unwrapping the tape which had been damaged in the
    spacecraft anomaly of October 11, 1995.  The final flight
    software delivery which included the tape recorder modifications
    was called Phase 2A.  The Phase 2A flight software was loaded
    onto the spacecraft from May 18-22, 1996.  The instrument Phase 2
    software loads were completed by May 26, 1996.
 
    Numerous anomalies occurred on the Orbiter during this mission
    that impacted data return but did not fundamentally change the
    mission. Some of the science objectives listed below were not
    achieved as a result of these anomalies.  Please check the
    Galileo Europa Mission instrument host catalog for additional
    information on spacecraft anomalies.
 
 
  Mission Phases
  ==============
 
    LAUNCH AND DEPLOYMENT
    ---------------------
      Galileo was launched on October 18, 1989 at 16:53:39 GMT
      aboard the Space Shuttle Atlantis (OV-104), flight STS-34.
      An Inertial Upper Stage (IUS-19) placed Galileo on its Earth-
      to-Venus trajectory.  Following the IUS burn, Galileo
      configured itself for solo flight and separated from the IUS
      on October 19, 1989 at 01:06:53 GMT.  (Refer to [GLLMS1991]).
      After IUS separation, the spacecraft underwent an outgassing
      period prior to powering on the science instruments.  The
      instruments were turned on later and data were acquired to
      verify that each instrument was operational.  The commanding
      of this process was more complicated than most command
      sequences since the exact launch date and time were not known
      in advance.  The launch and deployment mission phase covers
      the same time period as was covered by the command sequences
      LAUNCH and EV0 (Earth-Venus 0).
 
      Spacecraft Id                  : GO
      Target Name                    : VENUS
      Mission Phase Start Time       : 1989-10-17T00:00:00
      Mission Phase Stop Time        : 1989-10-26T16:00:00
 
 
    INTERPLANETARY CRUISE
    ---------------------
      The trajectory of the spacecraft from Earth to Jupiter was
      dictated by the limited propulsion capability allowed within
      the Space Shuttle to boost the spacecraft from Earth orbit to
      an interplanetary trajectory.  This limit prevented a direct
      trajectory from Earth to Jupiter; instead a 'VEEGA' trajectory
      was used to achieve the energy necessary to send Galileo to
      Jupiter.  The acronym VEEGA is from the trajectory description:
      Venus-Earth-Earth Gravity Assist.  In this trajectory, Galileo
      passes Venus once, then flies by Earth twice, thus obtaining
      three gravity assists before heading toward Jupiter.  (Refer to
      [SSR1992].) The Earth-Jupiter Cruise phase includes the
      following phases: Earth-Venus Cruise, Venus Encounter,
      Venus-Earth Cruise, Earth1 Encounter, Earth-Earth Cruise,
      Gaspra Encounter, Earth2 Encounter, Earth-Jupiter Cruise, Ida
      Encounter, Shoemaker-Levy 9 Encounter, Probe Release.
 
      Spacecraft Id                  : GO
      Target Name                    : JUPITER
      Target Name                    : VENUS
      Target Name                    : EARTH
      Target Name                    : IDA
      Target Name                    : GASPRA
      Target Name                    : SL9
      Mission Phase Start Time       : 1989-10-26T16:00:00
      Mission Phase Stop Time        : 1995-10-09T00:00:00
 
 
    EARTH-VENUS CRUISE
    ------------------
      The Earth-Venus Cruise phase occurred during the
      Interplanetary Cruise phase.  It lasted from the end of the
      Launch sequence to February 19, 1990.  This phase included
      the encounter with the planet Venus.
 
      Spacecraft Id                  : GO
      Target Name                    : VENUS
      Mission Phase Start Time       : 1989-10-26T16:00:00
      Mission Phase Stop Time        : 1990-02-19T00:00:00
 
 
    4-DAY CHECKOUT
    --------------
      The 4-Day Checkout phase occurred during the Earth-Venus
      portion of Interplanetary Cruise phase.  This was the first
      time the science instruments were turned on and permitted to
      check their health after launch.  Calibration data exists for
      all instruments from this period.
 
      Spacecraft Id                  : GO
      Target Name                    : N/A
      Mission Phase Start Time       : 1989-12-27T00:00:00
      Mission Phase Stop Time        : 1989-12-31T00:00:00
 
 
    VENUS ENCOUNTER
    ---------------
      The Venus Encounter phase occurred during the Interplanetary
      Cruise phase.  A 12-day single load sequence provided the
      sequencing resources for the Venus encounter.  Most of the
      data gathered were put onto the onboard tape recorder, since
      the high gain antenna had to remain furled behind its
      sunshade during this near-sun activity, and the low gain
      antenna did not have the performance for real-time science
      data transmission to Earth during the Venus encounter.  The
      Venus encounter data were played back to Earth in November
      1990, when Galileo was close enough to Earth that science
      data rates could be achieved over the low gain antenna.
      Upstream energetic particles were detected, bowshock
      crossings were indicated, and the plasma wave instrument saw
      evidence of lightning discharges.  Eighty-one images by the
      Solid State Imaging experiment were taken, which proved
      useful in atmospheric motion studies.  In addition, the Venus
      encounter yielded radio tracking data which have been
      analyzed by the Radio Science (Celestial Mechanics) Team to
      obtain a mass estimate for Venus.  In contrast to the other
      experiments, the Radio Science data were not stored on the
      spacecraft recorder, but were available in real time on Earth
      for analysis.  (Refer to [GLLMS1991]).  Closest approach to
      Venus occurred February 10, 1990 at an altitude of 16,123 km.
      at 05:58:48 UTC.
 
      Spacecraft Id                  : GO
      Target Name                    : VENUS
      Time of closest approach       : 1990-02-10T05:58:48
      Mission Phase Start Time       : 1990-02-07T00:00:00
      Mission Phase Stop Time        : 1990-02-19T00:00:00
 
 
    VENUS-EARTH CRUISE
    ------------------
      The Venus-Earth Cruise phase occurred during the
      Interplanetary Cruise phase.  It included the interplanetary
      cruise from Venus, around the sun, and back to and past the
      Earth.  This phase also included the first Earth encounter.
      The primary science gathering during this period was
      performed through EUV, DDS, MAG and the USO Redshift
      experiments.  In November 1990, as the spacecraft approached
      the first Earth encounter, the three DMS tracks of Venus data
      were successfully played back.
 
      The High-Gain Antenna Deployment planned for April 11, 1991
      was unsuccessful, most likely due to an incomplete release of
      three HGA ribs.  Future attempts for rib release were then
      scheduled for Earth-Earth Cruise.
 
      Spacecraft Id                  : GO
      Target Name                    : EARTH
      Target Name                    : MOON
      Mission Phase Start Time       : 1990-02-19T00:00:00
      Mission Phase Stop Time        : 1991-04-29T00:00:00
 
 
    EARTH1 ENCOUNTER
    ----------------
      The first Earth gravity assist occurred on December 8, 1990
      at a flyby altitude of 960 km at 20:34:35 UTC.  The Moon
      encounter occurred on December 9, 1990 at a flyby altitude of
      346,608 km at 2:28:21 UTC.
 
      The spacecraft trajectory took Galileo virtually up the
      Earth's magnetotail, providing unprecedented opportunity for
      fields and particles measurements.  The plasma science
      experiment results brought into question the validity of the
      previous assumption that the bulk flows of the ion and
      electron plasmas in the distant magnetotail are identical.
      Spectral mapping observations of Australia and Antarctica
      were made by the near infrared mapping spectrometer.  A first
      ever time-lapse movie, in six colors, of the rotating Earth
      over a period slightly greater than one day was made by the
      Solid State Imaging experiment.  Multispectral imaging of the
      western nearside and eastern farside of the Moon were
      obtained by the SSI.  These data showed that Orientale Basin
      ejecta deposits are similar to typical highlands deposits
      such as the soils at the Apollo 16 site, while observations
      of the South Pole-Aitken basin interior contain
      characteristics that appear distinctively different from that
      of nearside maria, thus providing new information on mare
      deposits on the limb and farside of the Moon.
 
      Spacecraft Id                  : GO
      Target Name                    : EARTH
      Time of closest approach       : 1990-12-08T20:34:35
      Target Name                    : MOON
      Time of closest approach       : 1990-12-09T02:28:21
      Mission Phase Start Time       : 1990-11-08T00:00:00
      Mission Phase Stop Time        : 1990-12-16T00:00:00
 
 
    EARTH-EARTH CRUISE
    ------------------
      The Earth-Earth cruise phase occurred during the
      Interplanetary Cruise phase.  It included the interplanetary
      cruise from Earth, around the sun, and back to and past the
      Earth a second time.  Key activities included the on-going
      HGA Recovery effort, which proved unsuccessful, encounters
      with the asteroid Gaspra as well as with Earth, collection of
      cruise science data, SSI cover and EPD shade deployments and
      opportunities for radio science experiments at spacecraft
      conjunction and opposition.
 
      Spacecraft Id                  : GO
      Target Name                    : EARTH
      Target Name                    : MOON
      Target Name                    : GASPRA
      Mission Phase Start Time       : 1991-04-29T00:00:00
      Mission Phase Stop Time        : 1993-04-12T00:00:00
 
 
    GASPRA ENCOUNTER
    ----------------
      The Gaspra Encounter phase occurred during the Interplanetary
      Cruise phase and the Earth-Earth Cruise phase.  On 29 October
      1991 Galileo passed Gaspra at a distance of approximately
      1,600 km and a speed of approximately 30,000 km per hour.
      Color and black and white images were taken of Gaspra as well
      as measurements to indicate composition and physical
      properties.  The data were stored on the spacecraft tape
      recorder and later played back to Earth.
 
      Spacecraft Id                  : GO
      Target Name                    : GASPRA
      Time of closest approach       : 1991-10-29T22:36:46
 
 
    EARTH2 ENCOUNTER
    ----------------
      The Earth2 Encounter phase occurred during the Interplanetary
      Cruise phase and the Earth-Earth Cruise phase.  The second
      Earth encounter provided an opportunity to gather Earth and
      Lunar science and perform instrument calibrations.
      Additionally, during this period Galileo participated in the
      GOPEX deep space laser communication experiment.  The flyby
      altitude of Moon was 110,267 km on December 8, 1990 at
      3:57:45 UTC.  The flyby altitude of the Earth was
      approximately 304 km at 15:09:25 UTC.
 
      Spacecraft Id                  : GO
      Target Name                    : EARTH
      Time of closest approach       : 1992-12-08T15:09:25
      Target Name                    : MOON
      Time of closest approach       : 1992-12-08T03:57:45
      Mission Phase Start Time       : 1992-11-08T00:00:00
      Mission Phase Stop Time        : 1992-12-20T00:00:00
 
 
    EARTH-JUPITER CRUISE
    --------------------
      The Earth-Jupiter Cruise phase occurred during the
      Interplanetary Cruise phase.  It covered the period from
      April 12, 1993 to October 8, 1995.  The second Earth
      encounter places the spacecraft on a direct trajectory to
      Jupiter.  Again, the spacecraft passed through the Asteroid
      Belt.  This transit included an August 1993 encounter with
      the 32-km.-diameter, S-type, main-belt asteroid, Ida.  The
      Earth-Jupiter Cruise phase included the following phases: Ida
      Encounter, Shoemaker-Levy 9 Encounter, Probe Release and ODM.
 
      Spacecraft Id                  : GO
      Target Name                    : JUPITER
      Target Name                    : IDA
      Target Name                    : SL9
      Mission Phase Start Time       : 1993-04-12T00:00:00
      Mission Phase Stop Time        : 1995-10-09T00:00:00
 
 
    IDA ENCOUNTER
    -------------
      The Ida Encounter phase occurred during the Interplanetary
      Cruise phase and the Earth-Jupiter Cruise phase.  Galileo
      flew by Ida in the southern hemisphere (75 degrees south
      ecliptic latitude) on the asteroid's dark side, passing
      approximately 2400 km (1500 mi) from the center of the
      asteroid while traveling at a speed relative to the asteroid
      of 12.4 km/sec (27,700 mph).  During closest approach, Ida
      appeared from Earth to be located at Right Ascension: 196.7
      degrees; Declination: -8.0 degrees toward the constellation
      Virgo.  Ida is 3-4 degrees northwest of Spica, Virgo's
      brightest star.
 
      Spacecraft Id                  : GO
      Target Name                    : IDA
      Time of closest approach       : 1993-08-28T16:52:05
 
 
    SHOEMAKER-LEVY 9 ENCOUNTER
    --------------------------
      The Shoemaker-Levy 9 Encounter phase occurred during the
      Interplanetary Cruise phase and the Earth-Jupiter Cruise
      phase.  Shoemaker-Levy 9 was a comet that broke into multiple
      pieces during its passage by Jupiter in July 1992.  On July
      16,1994 these fragments began to impact Jupiter.  It is
      estimated that between 20 and 25 struck the planet.
      Observations were made by the following instruments: NIMS,
      SSI, PPR, PWS, UVS (there was no EUV data).  MAG and DDS
      conducted observations over a longer period of time.
 
      Spacecraft Id                  : GO
      Target Name                    : SL9
      Mission Phase Start Time       : 1994-07-16T00:00:00
      Mission Phase Stop Time        : 1994-07-22T00:00:00
 
 
    PROBE RELEASE AND ODM
    ---------------------
      The Probe Release Encounter phase occurred during the
      Interplanetary Cruise phase and the Earth-Jupiter Cruise
      phase.  The Probe was released on July 13, 1995 at 05:30:00
      UTC, which was ~150 days before Jupiter Orbit Insertion
      (JOI).  Fourteen days after release, July 27th, the Orbiter
      performed an Orbit Deflection Maneuver (ODM) of about 60
      m/sec to place it on a trajectory which overflew the Probe
      during its entry and descent.  The ODM was the first use of
      the 400 N engine.
 
      Spacecraft Id                  : GP
      Spacecraft Id                  : GO
      Target Name                    : JUPITER
      Mission Phase Start Time       : 1995-07-05T00:00:00
      Mission Phase Stop Time        : 1995-07-31T00:00:00
 
 
    JUPITER ORBIT OPERATIONS
    ------------------------
      The Jupiter Orbit Operations phase encompasses all mission phases
      where the spacecraft was acquiring Jupiter science data. It
      includes all of the Jupiter approach, Prime mission, GEM mission,
      and GMM mission phases through impact on September 19, 2003.
 
      Spacecraft Id                  : GO
      Target Name                    : JUPITER
      Target Name                    : AMALTHEA
      Target Name                    : IO
      Target Name                    : CALLISTO
      Target Name                    : GANYMEDE
      Target Name                    : EUROPA
      Mission Phase Start Time       : 1995-10-09T00:00:00
      Mission Phase Stop Time        : 2003-09-21T19:07:00
 
 
    PRIME MISSION ORBIT OPERATIONS
    ------------------------------
      Jupiter arrival occurred on December 7, 1995.  Arrival day at
      Jupiter was characterized by a rapid series of high-priority
      engineering and science events.  Much of the science that was
      unique to this orbit (science requiring remote sensing data)
      was lost due to an anomaly with the onboard tape recorder.
      No science data were acquired during the 32,000 km
      non-targeted encounter of Europa.  About 4 1/2 hours after
      the Europa fly-by, the spacecraft then flew within about 1000
      km of Io.  Fields and particles data were recorded for
      approximately 3 hours in the vicinity of Io.  The flyby was
      also designed to provide a gravity assist which reduced the
      delta-V necessary to achieve orbit around Jupiter.
 
      The probe entry occurred a little over 4 hours after the Io
      encounter.  During the descent of the Probe its data were
      relayed to the Orbiter.  Probe Relay lasted 58.6 minutes and
      was followed about one hour later by the JOI burn.  Probe
      data were played back from the tape recorder on the orbiter
      twice over the next several months to ensure that no Probe
      data were lost.  Another hour of fields and particles science
      data were recorded after probe relay in conjunction with the
      JOI maneuver.
 
      At apojove of the insertion orbit, a large Perijove Raise
      Maneuver (PJR) increased the perijove altitude of the orbit
      and targeted the spacecraft for its first encounter.  After
      this time, the trajectory was primarily shaped by close
      encounters with Ganymede, Callisto, and Europa.  Ten such
      close encounters, one per orbit, plus a one-month 'phasing
      orbit' which occurred between the Europa 4 encounter and the
      Europa 6 encounter were planned over the 24 months of the
      orbital mission.  There was no targeted encounter during the
      phasing orbit.  There were several non-targeted encounters
      (at ranges of tens to hundreds of thousands of kilometers) of
      the Galilean satellites, Jovian atmospheric and
      magnetospheric measurements throughout the tour, and a large
      'tail petal' orbit designed to explore the Jovian
      magnetotail.
 
      Spacecraft Id                  : GO
      Target Name                    : JUPITER
      Target Name                    : IO
      Target Name                    : CALLISTO
      Target Name                    : GANYMEDE
      Target Name                    : EUROPA
      Mission Phase Start Time       : 1995-10-09T00:00:00
      Mission Phase Stop Time        : 1997-12-15T00:00:00
 
 
    JUPITER APPROACH
    ----------------
      The Jupiter Approach phase occurred during the Jupiter Orbit
      Operations phase.  An image of Jupiter was taken on approach;
      however, shortly afterwards there was an anomaly with the
      onboard tape recorder which prohibited the return of that
      image.  The only science data acquired on approach was from
      DDS, EUV and MAG.
 
      Spacecraft Id                  : GO
      Target Name                    : JUPITER
      Mission Phase Start Time       : 1995-10-09T00:00:00
      Mission Phase Stop Time        : 1995-12-03T00:00:00
 
 
    JUPITER 0 ORBIT
    ---------------
      The Jupiter 0 Orbit phase occurred during the Jupiter Orbit
      Operations phase.  Jupiter arrival occurred on December 7,
      1995.  Arrival day at Jupiter was characterized by a rapid
      series of high-priority engineering and science events.  Much
      of the science that was unique to this orbit (science
      requiring remote sensing data) was lost due to an anomaly
      with the onboard tape recorder.  No science data were
      acquired during the 32,000 km non-targeted encounter of
      Europa.  About 4 1/2 hours after the Europa fly-by, the
      spacecraft then flew within about 1000 km of Io.  Fields and
      particles data were recorded for approximately 3 hours in the
      vicinity of Io.  The flyby was also designed to provide a
      gravity assist which reduced the delta-V necessary to achieve
      orbit around Jupiter.
 
      The probe entry occurred a little over 4 hours after the Io
      encounter.  During the descent of the Probe its data were
      relayed to the Orbiter.  Probe Relay lasted 58.6 minutes and
      was followed about one hour later by the JOI burn.  Probe
      data were played back from the tape recorder on the orbiter
      twice over the next several months to ensure that no Probe
      data were lost.  Another hour of fields and particles science
      data were recorded after probe relay in conjunction with the
      JOI maneuver.
 
      At apojove of the insertion orbit, a large Perijove Raise
      Maneuver (PJR) increased the perijove altitude of the orbit
      and targeted the spacecraft for its first encounter.
 
      Spacecraft Id                  : GO
      Target Name                    : JUPITER
      Target Name                    : IO
      Mission Phase Start Time       : 1995-12-03T00:00:00
      Mission Phase Stop Time        : 1996-06-23T00:00:00
 
 
    IO 0 ENCOUNTER
    --------------
      The Io 0 encounter phase occurred during the Jupiter 0 Orbit
      operations phase.  The spacecraft flew past Io at an altitude
      of less than 900 km.  Much of the science that was unique to
      this orbit (science requiring remote sensing data) was lost
      due to an anomaly with the onboard tape recorder.  This was
      the only close flyby of Io during the mission.  Fields and
      particles data were recorded for approximately 3 hours in the
      vicinity of Io.  Another hour of fields and particles science
      data were recorded after probe relay while still in the Io
      torus.  In addition to providing science data, the flyby was
      designed to provide a gravity assist which reduced the
      delta-V necessary to achieve orbit around Jupiter.
 
      Spacecraft Id                  : GO
      Target Name                    : IO
      Time of closest approach       : 1995-12-07T17:45:58
      Mission Phase Start Time       : 1995-12-03T00:00:00
      Mission Phase Stop Time        : 1996-01-03T00:00:00
 
 
    PROBE
    -----
      The Probe phase occurred during the Jupiter Orbit Operations
      phase.  The probe entry occurred a little over 4 hours after
      the Io encounter.  During the descent of the Probe its data
      were relayed to the Orbiter where is was stored on tape.  The
      data were later replayed and transmitted to Earth.  The Probe
      Relay lasted 58.6 minutes and was followed about one hour
      later by the JOI burn.  For a more complete description of
      the Galileo Probe mission, please refer to [YOUNGETAL1996].
 
      Spacecraft Id                  : GP
      Spacecraft Id                  : GO
      Target Name                    : JUPITER
      Mission Phase Start Time       : 1995-12-07T22:01:00
      Mission Phase Stop Time        : 1995-12-07T23:22:00
 
 
    GANYMEDE 1 ORBIT
    ----------------
      Spacecraft Id                  : GO
      Target Name                    : GANYMEDE
      Mission Phase Start Time       : 1996-06-23T00:00:00
      Mission Phase Stop Time        : 1996-09-01T00:00:00
 
 
    GANYMEDE 1 ENCOUNTER
    --------------------
      Objectives: Wake, Alfven Wing, start of first magnetospheric
      mini-tour, remote Io torus observations, plasma sheet
      crossing at 25 Rj, Ganymede and Europa geology and
      atmospheric properties, Io monitoring, distant Callisto
      observations, gravity, Great Red Spot, Jupiter northern and
      southern aurora, Io footprint, reduce period.
      Altitude: 838 km, Latitude: 30.39 degrees
 
      Spacecraft Id                  : GO
      Target Name                    : GANYMEDE
      Time of closest approach       : 1996-06-27T06:29:07
      Mission Phase Start Time       : 1996-06-23T00:00:00
      Mission Phase Stop Time        : 1996-06-30T00:00:00
 
 
    GANYMEDE 2 ORBIT
    ----------------
      Spacecraft Id                  : GO
      Target Name                    : GANYMEDE
      Mission Phase Start Time       : 1996-09-01T00:00:00
      Mission Phase Stop Time        : 1996-11-02T00:00:00
 
 
    GANYMEDE 2 ENCOUNTER
    --------------------
      Objectives: North Alfven wing, Jovian radio emissions, first
      mini-tour of Jovian magnetosphere continues, remote Io torus,
      plasma sheet crossing at 40 Rj, unique Ganymede north polar
      pass, Europa low- phase global images, Io monitoring,
      Callisto, Amalthea, stratospheric circulation, Jupiter
      southern aurora, Shoemaker-Levy 9 remnant material images,
      gravity, reduce inclination.
      Altitude: 264 km, Latitude: 79.29 degrees
 
      Spacecraft Id                  : GO
      Target Name                    : GANYMEDE
      Time of closest approach       : 1996-09-06T18:59:34
      Mission Phase Start Time       : 1996-09-01T00:00:00
      Mission Phase Stop Time        : 1996-09-08T00:00:00
 
 
    CALLISTO 3 ORBIT
    ----------------
      Spacecraft Id                  : GO
      Target Name                    : CALLISTO
      Mission Phase Start Time       : 1996-11-02T00:00:00
      Mission Phase Stop Time        : 1996-12-15T00:00:00
 
 
    CALLISTO 3 ENCOUNTER
    --------------------
      Objectives: Wake and Alfven Wing, completion of first
      mini-tour of Jovian magnetosphere, Jupiter aurora, remote Io
      torus, Callisto Asgard Basin, Europa non-targeted encounter -
      volcanism observations, closest Io approach of tour, gravity,
      UVS counter-rotate, white oval observations, Jupiter northern
      aurora, Jupiter atmosphere during solar occultation.
      Altitude: 1138 km, Latitude: 13.19 degrees
 
      Spacecraft Id                  : GO
      Target Name                    : CALLISTO
      Time of closest approach       : 1996-11-04T13:34:28
      Mission Phase Start Time       : 1996-11-02T00:00:00
      Mission Phase Stop Time        : 1996-11-11T00:00:00
 
 
    EUROPA 4 ORBIT
    --------------
      Spacecraft Id                  : GO
      Target Name                    : EUROPA
      Mission Phase Start Time       : 1996-12-15T00:00:00
      Mission Phase Stop Time        : 1997-02-16T00:00:00
 
 
    EUROPA 4 ENCOUNTER
    ------------------
      Objectives: Wake and northern Alfven wing, north to south
      plasma sheet crossing, remote Io torus, excellent Europa
      dayside and nightside coverage, Io partial eclipse, Jupiter
      rings, Amalthea, Thebe, Adrastea, northern equatorial belt
      hot spot, Europa & Jupiter occultations, Jupiter northern
      aurora.
      Altitude: 688 km, Latitude: -1.65 degrees
 
      Spacecraft Id                  : GO
      Target Name                    : EUROPA
      Time of closest approach       : 1996-12-19T06:52:58
      Mission Phase Start Time       : 1996-12-15T00:00:00
      Mission Phase Stop Time        : 1996-12-22T00:00:00
 
 
    EUROPA 6 ORBIT
    --------------
      Spacecraft Id                  : GO
      Target Name                    : EUROPA
      Mission Phase Start Time       : 1997-02-16T00:00:00
      Mission Phase Stop Time        : 1997-03-30T00:00:00
 
 
    EUROPA 6 ENCOUNTER
    ------------------
      Objectives: South Alfven wing, Jupiter magnetic equator
      crossing, Europa Argiope Linea and other lineated regions, Io
      plume monitoring, Jupiter rings, Thebe, Amalthea, south
      equatorial belt-zone region, Jupiter northern aurora, Europa,
      Io, and Jupiter occultations.
      Altitude: 582 km, Latitude: -17.02 degrees
 
      Spacecraft Id                  : GO
      Target Name                    : EUROPA
      Time of closest approach       : 1997-02-20T17:06:10
      Mission Phase Start Time       : 1997-02-16T00:00:00
      Mission Phase Stop Time        : 1997-02-23T00:00:00
 
 
    GANYMEDE 7 ORBIT
    ----------------
      Spacecraft Id                  : GO
      Target Name                    : GANYMEDE
      Mission Phase Start Time       : 1997-03-30T00:00:00
      Mission Phase Stop Time        : 1997-05-04T00:00:00
 
 
    GANYMEDE 7 ENCOUNTER
    --------------------
      Objectives: North Alfven Wing, first dawn-side plasma sheet
      at 46 Rj, start of second mini-tour of Jovian magnetosphere,
      Ganymede high-energy impact regions (Kittu, etc.), Europa
      non-targeted encounter, Callisto full-color mosaic, visually
      clear or Brown Barge regions, Jupiter northern aurora.
      Altitude: 3104 km, Latitude: 55.80 degrees
 
      Spacecraft Id                  : GO
      Target Name                    : GANYMEDE
      Time of closest approach       : 1997-04-05T07:09:58
      Mission Phase Start Time       : 1997-03-30T00:00:00
      Mission Phase Stop Time        : 1997-04-06T00:00:00
 
 
    GANYMEDE 8 ORBIT
    ----------------
      Spacecraft Id                  : GO
      Target Name                    : GANYMEDE
      Mission Phase Start Time       : 1997-05-04T00:00:00
      Mission Phase Stop Time        : 1997-06-22T00:00:00
 
 
    GANYMEDE 8 ENCOUNTER
    --------------------
      Objectives: Upstream wake crossing, continue second mini-tour
      of Jovian magnetosphere, plasma sheet/Jupiter aurora at 20
      Rj, Ganymede surface morphology: Osiris, Tiamat Sulcus, etc.,
      Callisto non-targeted encounter south pole, Metis, Elara,
      south polar haze zone, Jupiter northern and southern aurora,
      Io footprint, Ganymede & Jupiter occultations.
      Altitude: 1606 km, Latitude: 28.27 degrees
 
      Spacecraft Id                  : GO
      Target Name                    : GANYMEDE
      Time of closest approach       : 1997-05-07T15:56:10
      Mission Phase Start Time       : 1997-05-04T00:00:00
      Mission Phase Stop Time        : 1997-05-11T00:00:00
 
 
    CALLISTO 9 ORBIT
    ----------------
      Spacecraft Id                  : GO
      Target Name                    : CALLISTO
      Mission Phase Start Time       : 1997-06-22T00:00:00
      Mission Phase Stop Time        : 1997-09-14T00:00:00
 
 
    CALLISTO 9 ENCOUNTER
    --------------------
      Objectives: Unique deep magnetotail passage of 143 Rj,
      continue second mini-tour of Jovian magnetosphere, Jupiter
      aurora, Callisto Valhalla multi-ringed structure, Ganymede
      non-targeted encounter, Metis, Adrastea, Amalthea, Thebe,
      Great Red Spot, equatorial plume head, Io footprint, high
      solar phase angle of Jovian atmosphere, Callisto & Jupiter
      occultations.
      Altitude: 421 km, Latitude: 1.96 degrees
 
      Spacecraft Id                  : GO
      Target Name                    : CALLISTO
      Time of closest approach       : 1997-06-25T13:47:50
      Mission Phase Start Time       : 1997-06-22T00:00:00
      Mission Phase Stop Time        : 1997-06-29T00:00:00
 
 
    CALLISTO 10 ORBIT
    -----------------
      Spacecraft Id                  : GO
      Target Name                    : CALLISTO
      Mission Phase Start Time       : 1997-09-14T00:00:00
      Mission Phase Stop Time        : 1997-11-02T00:00:00
 
 
    CALLISTO 10 ENCOUNTER
    ---------------------
      Objectives: Wake and Alfven Wing, continue second mini-tour
      of Jovian magnetosphere, Jupiter magnetic equator crossing,
      Callisto global and bright limb observations, Io aurora and
      Jupiter rings during solar occultation, Europa volcanism
      survey, Amalthea, Thebe, Adrastea, Metis, north polar haze
      region, Jupiter aurora and lightning during solar
      occultation.
      Altitude: 538 km, Latitude: 4.60 degrees
 
      Spacecraft Id                  : GO
      Target Name                    : CALLISTO
      Time of closest approach       : 1997-09-17T00:18:55
      Mission Phase Start Time       : 1997-09-14T00:00:00
      Mission Phase Stop Time        : 1997-09-20T00:00:00
 
 
    EUROPA 11 ORBIT
    ---------------
      Spacecraft Id                  : GO
      Target Name                    : EUROPA
      Mission Phase Start Time       : 1997-11-02T00:00:00
      Mission Phase Stop Time        : 1997-12-15T00:00:00
 
 
    EUROPA 11 ENCOUNTER
    -------------------
      Objectives: Combined Europa fly-by and magnetic equator
      crossing for fields & particles instruments, end of second
      mini-tour of Jovian magnetosphere, Jupiter auroral map
      campaign, Brown Barge campaign, northern aurora oval,
      lightning detection campaign, ring observations, Io
      monitoring, Europa Pwyll, Mannann'an wedge and bright planes,
      Earth occultation.
      Altitude: 2039 km, Latitude: 25.73 degrees N
 
      Spacecraft Id                  : GO
      Target Name                    : EUROPA
      Time of closest approach       : 1997-11-06T20:31:44
      Mission Phase Start Time       : 1997-11-02T00:00:00
      Mission Phase Stop Time        : 1997-11-09T00:00:00
 
 
 
    EUROPA CAMPAIGN
    ---------------
 
      The Europa campaign was comprised of eight (E12-E19) close
      fly-bys ranging in flyby altitudes from 200 to 3600 km.  The
      latitudes achieved during these flybys range from -43 degrees to
      +42 degrees.  Extensive remote sensing and fields and particles
      science data gathering was attempted at each of these encounters
      except for E13 which was too close to solar conjunction.  E13
      flyby science was limited to the collection of geophysical data
      via the  radio system (Doppler).  E13 cruise was used for E12 data
      playback during those during those periods where the Sun-Earth-
      Craft (SEC) angle is greater than 7 degrees.  Spacecraft safings
      in the E16 and E18 orbits severly compromised the planned science
      return from those orbits. After the spacecraft was reconfigured
      from safing the remainder of the orbits were used to return data
      not played back from the preceding orbit and to acquire fields &
      particles real time science data.  The primary science objective
      in the Europa phase was the return of unique Europa data.
      However, Jupiter atmospheric observations were added to two
      orbits.
 
    Spacecraft Id                  : GO
    Target Name                    : EUROPA
    Mission Phase Start Time       : 1997-12-15T00:00:00
    Mission Phase Stop Time        : 1999-05-02T00:00:00
    Spacecraft Operations Type     : ORBITER
 
 
    EUROPA 12 ORBIT
    ---------------
    Spacecraft Id                  : GO
    Target Name                    : EUROPA
    Mission Phase Start Time       : 1997-12-15T00:00:00
    Mission Phase Stop Time        : 1998-02-09T00:00:00
 
 
    EUROPA 12 ENCOUNTER
    -------------------
      Objectives: Europa's Pwyll crater, Conamara Chaos, search for
      hot spots and tenuous atmosphere, surface composition maps,
      mottled wedges terrain, dark lineas, plateaus,
      satellite/magnetosphere interaction, gravity field measurement.
      Closest Galileo flyby to any celestial body.  Jupiter's upper
      atmosphere energy budget and longitudinal spectral scans.  Io
      eclipse, Ganymede Gilgamesh basin. Inner magnetosphere survey.
      Altitude: 201.0 km, Latitude: -8.66 degrees
 
    Spacecraft Id                  : GO
    Target Name                    : EUROPA
    Time of closest approach       : 1997-12-16T12:03:20
    Mission Phase Start Time       : 1997-12-15T00:00:00
    Mission Phase Stop Time        : 1997-12-17T00:00:00
 
 
    EUROPA 13 ORBIT
    ---------------
    Spacecraft Id                  : GO
    Target Name                    : EUROPA
    Mission Phase Start Time       : 1998-02-09T00:00:00
    Mission Phase Stop Time        : 1998-03-28T00:00:00
 
 
    EUROPA 14 ORBIT
    ---------------
    Spacecraft Id                  : GO
    Target Name                    : EUROPA
    Mission Phase Start Time       : 1998-03-28T00:00:00
    Mission Phase Stop Time        : 1998-05-30T00:00:00
 
 
    EUROPA 14 ENCOUNTER
    -------------------
      Objectives: Europa's Mannann'an crater, Tyre macula, triple
      bands, dark spots, bright plains, day and night thermal maps,
      surface composition maps, search for tenuous atmosphere,
      satellite/magnetosphere interaction, gravity field measurement.
      Jupiter's north polar aurora and longitudinal spectral scans.
      Io full disk, north and south pole, eclipse, and torus.
      Ganymede global coverage.  Callisto surface composition map.
      Inner magnetosphere survey.
      Altitude: 1644.1 km, Latitude: 12.21 degrees
 
    Spacecraft Id                  : GO
    Target Name                    : EUROPA
    Time of closest approach       : 1998-03-29T13:21:05
    Mission Phase Start Time       : 1998-03-28T00:00:00
    Mission Phase Stop Time        : 1998-03-31T00:00:00
 
 
    EUROPA 15 ORBIT
    ---------------
    Spacecraft Id                  : GO
    Target Name                    : EUROPA
    Mission Phase Start Time       : 1998-05-30T00:00:00
    Mission Phase Stop Time        : 1998-07-20T00:00:00
 
 
    EUROPA 15 ENCOUNTER
    -------------------
      Objectives: Europa's Cilix masif, rough terrain, near terminator,
      day and night thermal maps, surface composition maps, search for
      tenuous atmosphere, satellite/magnetosphere interaction, gravity
      field measurement.  Jupiter's upper atmosphere energy budget, and
      longitudinal spectral scans.  Io surface monitoring, Kanehekili
      plume, high-solar phase map, eclipse, torus, surface composition,
      tenuous atmosphere. Inner magnetosphere survey.
      Altitude: 2514.5 km, Latitude: 15.00 degrees
 
    Spacecraft Id                  : GO
    Target Name                    : EUROPA
    Time of closest approach       : 1998-05-31T21:12:57
    Mission Phase Start Time       : 1998-05-30T00:00:00
    Mission Phase Stop Time        : 1998-06-03T00:00:00
 
 
    EUROPA 16 ORBIT
    ---------------
    Spacecraft Id                  : GO
    Target Name                    : EUROPA
    Mission Phase Start Time       : 1998-07-20T00:00:00
    Mission Phase Stop Time        : 1998-09-25T00:00:00
 
 
    EUROPA 16 ENCOUNTER
    -------------------
      Objectives: Europa's Agenor linea, Thrace macula, Taliesen
      crater, dissected terrain, wedges, near-terminator, day and
      night thermal maps, surface composition maps, satellite/
      magnetosphere interaction, gravity field measurement.
      Jupiter cloud structure, atmospheric dynamics and waves,
      upper atmosphere energy budget, hot maps, longitudinal
      spectral scans.  Io monitoring and torus. Ganymede
      composition map.  Inner magnetosphere survey.
      Altitude: 1834.2 km, Latitude: -25.65 degrees
 
    Spacecraft Id                  : GO
    Target Name                    : EUROPA
    Time of closest approach       : 1998-07-21T05:03:45
    Mission Phase Start Time       : 1998-07-20T00:00:00
    Mission Phase Stop Time        : 1998-07-29T00:00:00
 
 
    EUROPA 17 ORBIT
    ---------------
    Spacecraft Id                  : GO
    Target Name                    : EUROPA
    Mission Phase Start Time       : 1998-09-25T00:00:00
    Mission Phase Stop Time        : 1998-11-21T00:00:00
 
 
    EUROPA 17 ENCOUNTER
    -------------------
      Objectives: Europa's Thynia linea, south pole, strike-slip
      faults, near terminator, day and night thermal maps,
      surface composition maps, tenuous atmosphere, gravity field
      measurement.  Jupiter ring observations, south pole aurora,
      longitudinal spectral scans, merging white oval, and wave
      structure.  Io torus and Pele.  Inner magnetosphere survey.
      Altitude: 3582.4 km, Latitude: -42.43 degrees
 
    Spacecraft Id                  : GO
    Target Name                    : EUROPA
    Time of closest approach       : 1998-09-26T03:54:20
    Mission Phase Start Time       : 1998-09-25T00:00:00
    Mission Phase Stop Time        : 1998-09-28T00:00:00
 
    EUROPA 18 ORBIT
    ---------------
    Spacecraft Id                  : GO
    Target Name                    : EUROPA
    Mission Phase Start Time       : 1998-11-21T00:00:00
    Mission Phase Stop Time        : 1999-01-31T00:00:00
 
 
    EUROPA 18 ENCOUNTER
    -------------------
      Objectives: Europa's Radamanthys, south pole plains, north
      pole pits and plateaus, massifs, bright and dark plains,
      global and regional polarimetry maps, surface composition
      maps, tenuous atmosphere, gravity field measurement.
      Jupiter upper atmosphere energy budget and longitudinal spectral
      scans.  Io surface monitoring, polarimetry and torus.
      Ganymede polarimetry.  Inner magnetosphere survey including
      extended dusk side measurements.
      Altitude: 2270.8 km, Latitude: 41.34 degrees
 
    Spacecraft Id                  : GO
    Target Name                    : EUROPA
    Time of closest approach       : 1998-11-22T11:38:26
    Mission Phase Start Time       : 1998-11-21T00:00:00
    Mission Phase Stop Time        : 1999-11-24T00:00:00
 
 
    EUROPA 19 ORBIT
    ---------------
    Spacecraft Id                  : GO
    Target Name                    : EUROPA
    Mission Phase Start Time       : 1999-01-31T00:00:00
    Mission Phase Stop Time        : 1999-05-02T00:00:00
 
 
    EUROPA 19 ENCOUNTER
    -------------------
      Objectives: Europa plume search, hexagonal ice terrain,
      near terminator, dark spots, mottled terrain, bright plains,
      global and regional polarimetry maps, surface composition maps,
      tenuous atmosphere, satellite/magnetosphere interaction,
      gravity field measurement.  Jupiter cloud structure and
      dynamics, stratosphere, upper atmosphere/aurora energy
      budget, hot maps, longitudinal spectral scans.
      Io polarimetry and torus.  Ganymede polarimetry.
      Inner magnetosphere survey.
      Altitude: 1439.4 km, Latitude: 30.52 degrees
 
    Spacecraft Id                  : GO
    Target Name                    : EUROPA
    Time of closest approach       : 1999-02-01T02:19:50
    Mission Phase Start Time       : 1999-01-31T00:00:00
    Mission Phase Stop Time        : 1999-02-11T00:00:00
 
 
    PERIJOVE REDUCTION CAMPAIGN
    ---------------------------
 
      The perijove reduction campaign was comprised of four low
      altitude flybys of Callisto (C20-C23).  During this campaign,
      the spacecraft perijove is reduced from 9.4 Rj (before C20) to
      5.5 Rj (after C23), which sets up the spacecraft trajectory
      for the subsequent encounters with Io at 5.9 Rj.  The primary
      science objectives for this phase were in-situ studies of the
      torus and selected atmospheric observation.
 
    Spacecraft Id                  : GO
    Target Name                    : TORUS
    Mission Phase Start Time       : 1999-05-02T00:00:00
    Mission Phase Stop Time        : 1999-10-10T00:00:00
    Spacecraft Operations Type     : ORBITER
 
 
    CALLISTO 20 ORBIT
    -----------------
    Spacecraft Id                  : GO
    Target Name                    : CALLISTO
    Mission Phase Start Time       : 1999-05-02T00:00:00
    Mission Phase Stop Time        : 1999-06-29T00:00:00
 
 
    CALLISTO 20 ENCOUNTER
    ---------------------
      Objectives: 2 hr perijove sample (plasma transport mechanisms),
      inner magnetosphere survey including dusk region, Io torus.
      Jupiter cloud structure and dynamics, atmospheric wave
      structure, stratosphere composition, upper atmosphere and
      aurora energy budgets, hot maps, longitudinal spectral scans.
      Callisto composition, crater statistics, dark flows, radio
      science Earth occultation. Io monitoring and composition.
      Europa eclipse.
      Altitude: 1321.4 km, Latitude: 2.78 degrees
 
    Spacecraft Id                  : GO
    Target Name                    : CALLISTO
    Time of closest approach       : 1999-05-05T13:56:18
    Mission Phase Start Time       : 1999-05-02T00:00:00
    Mission Phase Stop Time        : 1999-05-07T00:00:00
 
 
    CALLISTO 21 ORBIT
    -----------------
    Spacecraft Id                  : GO
    Target Name                    : CALLISTO
    Mission Phase Start Time       : 1999-06-29T00:00:00
    Mission Phase Stop Time        : 1999-08-11T00:00:00
 
 
    CALLISTO 21 ENCOUNTER
    ---------------------
      Objectives: 2 hour perijove sample (plasma transport mechanisms),
      inner magnetosphere survey. Jupiter longitudinal spectral scans.
      Callisto dark material, ring structures, thermal maps, and
      surface composition.  Io global composition, thermal  and
      visual maps, and plume inventory.
      Altitude: 421 km, Latitude: 1.96 degrees
 
    Spacecraft Id                  : GO
    Target Name                    : CALLISTO
    Time of closest approach       : 1999-06-30T07:46:50
    Mission Phase Start Time       : 1999-06-29T00:00:00
    Mission Phase Stop Time        : 1999-07-03T00:00:00
 
 
    CALLISTO 22 ORBIT
    -----------------
    Spacecraft Id                  : GO
    Target Name                    : CALLISTO
    Mission Phase Start Time       : 1999-08-11T00:00:00
    Mission Phase Stop Time        : 1999-09-13T00:00:00
 
 
    CALLISTO 22 ENCOUNTER
    ---------------------
      Objectives: 6 hr perijove sample (plasma transport), chorus
      wave samples (plasma acceleration), inner magnetosphere survey,
      Io torus.  Jupiter cloud structure and dynamics, regional maps,
      stratosphere composition, aurora energy budgets, hot maps, and
      longitudinal spectral scans.  Callisto radio science Earth
      occultation.  Io plume inventory. Europa distant global.
      Amalthea best resolution of Galileo mission.
      Altitude: 2299.3 km, Latitude: -2.3 degrees
 
    Spacecraft Id                  : GO
    Target Name                    : CALLISTO
    Time of closest approach       : 1999-08-14T08:30:52
    Mission Phase Start Time       : 1999-08-11T00:00:00
    Mission Phase Stop Time        : 1999-08-14T00:00:00
 
 
    CALLISTO 23 ORBIT
    -----------------
    Spacecraft Id                  : GO
    Target Name                    : CALLISTO
    Mission Phase Start Time       : 1999-09-13T00:00:00
    Mission Phase Stop Time        : 1999-10-10T00:00:00
 
 
    CALLISTO 23 ENCOUNTER
    ---------------------
      Objectives: Fields & particles dedicated orbit.  Io torus
      7 hr recorded sample, 7.6-6.5 Jupiter radii. Chorus wave
      samples (plasma acceleration), inner-outer magnetosphere
      12 day survey including dusk region.  Callisto radio science
      Earth occultation.  Jupiter north pole aurora energy budgets.
      Altitude: 1052.4 km, Latitude: 0.099 degrees
 
    Spacecraft Id                  : GO
    Target Name                    : CALLISTO
    Time of closest approach       : 1999-09-16T17:27:02
    Mission Phase Start Time       : 1999-09-13T00:00:00
    Mission Phase Stop Time        : 1999-09-17T00:00:00
 
 
 
    IO CAMPAIGN
    -----------
 
      The Io phase had 3 Io flybys (I24,I25,I27) and one Europa flyby
      (E26).  The first two Io encounters (I24 and I25) were viewed by
      the project as the equivalent to Prime Mission objective.  The
      first of the encounters is characterized by a near-equatorial
      flyby of Io followed by near continuous DSN coverage for data
      return.  This encounter was optimized for the return of remote
      sensing data not acquired during the J0 orbit in the Prime
      Mission.  A deterministic maneuver (delta V ~ 9 m/s) was required
      to link the first Io encounter to the second.  The second
      encounter is characterized by a near-polar flyby of Io optimized
      to distinguish if Io has an intrinsic magnetic field.
 
    Spacecraft Id                  : GO
    Target Name                    : IO
    Mission Phase Start Time       : 1999-10-10T00:00:00
    Mission Phase Stop Time        : 2000-05-20T00:00:00
    Spacecraft Operations Type     : ORBITER
 
 
    IO 24 ORBIT
    -----------
    Spacecraft Id                  : GO
    Target Name                    : IO
    Mission Phase Start Time       : 1999-10-10T00:00:00
    Mission Phase Stop Time        : 1999-11-25T00:00:00
 
 
    IO 24 ENCOUNTER
    ---------------
      Objectives: Io gravity field measurement for interior structure,
      high resolution thermal mapping (PPR), imaging volcanic plumes of
      Pillan and Pele, high resolution imaging of volcanic centers Loki,
      Pele, Pillan, Colchis, Tohil, Prometheus, Zamama, Dorian, Amirani,
      Skythia, Gish Bar.  Io global and regional radiometry and
      polarimetry, regional near-infrared spectral mapping.  Io auroral
      emissions, surface properties, and atmospheric species.  Jupiter-
      Io magnetosphere coupling, inner magnetosphere survey including
      dusk region, Io torus energetics, Io torus morphology.  Jupiter
      atmosphere wave structure.
      Altitude: 611.2 km, Latitude: 4.51 degrees
 
    Spacecraft Id                  : GO
    Target Name                    : IO
    Time of closest approach       : 1999-10-11T04:33:03
    Mission Phase Start Time       : 1999-10-10T00:00:00
    Mission Phase Stop Time        : 1999-10-14T00:00:00
 
 
    IO 25 ORBIT
    -----------
    Spacecraft Id                  : GO
    Target Name                    : IO
    Mission Phase Start Time       : 1999-11-25T00:00:00
    Mission Phase Stop Time        : 2000-01-02T00:00:00
 
 
    IO 25 ENCOUNTER
    ---------------
      Objectives: Io gravity field measurement for interior structure,
      highest resolution imaging of Io during GEM, first south polar
      coverage, imaging and monitoring of volcanic features, global and
      regional thermal maps, regional near-infrared spectral mapping,
      Io auroral emissions, atmospheric and surface properties.
      Highest resolution imaging of Amalthea. Jupiter/Io magnetospheric
      coupling, inner magnetosphere survey, Io torus morphology, polar
      Io magnetic field measurements.  First opportunity for imaging
      Europa's Jupiter-facing hemisphere.  Europa high resolution north
      polar imaging of lineaments, dark band pairs, and flow features,
      polarimetry for surface textures.
      Altitude: 300 km, Latitude: -76.6 degrees
 
    Spacecraft Id                  : GO
    Target Name                    : IO
    Time of closest approach       : 1999-11-26T04:05:22
    Mission Phase Start Time       : 1999-11-25T00:00:00
    Mission Phase Stop Time        : 1999-11-27T00:00:00
 
 
    EUROPA 26 ORBIT
    ---------------
    Spacecraft Id                  : GO
    Target Name                    : EUROPA
    Mission Phase Start Time       : 2000-01-02T00:00:00
    Mission Phase Stop Time        : 2000-02-20T00:00:00
 
 
    EUROPA 26 ENCOUNTER
    -------------------
      Objectives: Observe Europa's interaction with the Jovian
      magnetosphere and examine any induced magnetic field in Europa.
      Europa terminator map. Images of Amalthea, Thebe and Metis.
      Observations of Loki on Io. Continue return of I25 playback data.
      Altitude: 360 km, Latitude: -46.6 degrees
 
    Spacecraft Id                  : GO
    Target Name                    : EUROPA
    Time of closest approach       : 2000-01-03T17:59:56
    Mission Phase Start Time       : 2000-01-01T00:00:00
    Mission Phase Stop Time        : 2000-01-05T00:00:00
 
 
    IO 27 ORBIT
    -----------
    Spacecraft Id                  : GO
    Target Name                    : IO
    Mission Phase Start Time       : 2000-02-20T00:00:00
    Mission Phase Stop Time        : 2000-05-17T00:00:00
 
 
    IO 27 ENCOUNTER
    ---------------
      Objectives: Io Isum Mons and Zamama, 3-color global, high
      resolution spectral maps of Pele, Tohil Mons, Amirani, SO2 frost,
      polarimetry and spectral mapping of Mulungu region, torus
      morphology, aurora and surface and atmospheric properties,
      global and regional thermal mapping, gravity field measurements.
      Jupiter/Io magnetospheric coupling, inner magnetosphere survey.
      Jupiter atmosphere wave structure.  Complete I25 torus data
      return.
      Altitude: 200 km, Latitude: 18.3 degrees.
 
    Spacecraft Id                  : GO
    Target Name                    : IO
    Time of closest approach       : 2000-02-22T13:46:36
    Mission Phase Start Time       : 2000-02-20T00:00:00
    Mission Phase Stop Time        : 2000-02-25T00:00:00
 
 
 
 
    GALILEO-CASSINI PHASE
    ---------------------
 
      During the Cassini phase the Galileo flyby geometry changes
      considerably in order to decrease the radiation dosage
      experienced by the spacecraft.  The Cassini phase is so named
      as both Galileo and the Cassini spacecraft are in favorable
      positions both inside and outside of Jupiter's magnetosphere.
      This allows a dual-spacecraft simultaneous study of the Jovian
      system for the first time.
 
    Spacecraft Id                  : GO
    Target Name                    : TORUS
    Mission Phase Start Time       : 2000-05-17T00:00:00
    Mission Phase Stop Time        : 2001-02-05T00:00:00
    Spacecraft Operations Type     : ORBITER
 
 
    GANYMEDE 28 ORBIT
    -----------------
    Spacecraft Id                  : GO
    Target Name                    : GANYMEDE
    Mission Phase Start Time       : 2000-05-20T00:00:00
    Mission Phase Stop Time        : 2000-12-27T00:00:00
 
 
    GANYMEDE 28 ENCOUNTER
    ---------------------
      Objectives: Jupiter/Ganymede magnetospheric coupling,
      measurements of Jovian magnetosphere for comparison with
      contemporaneous solar wind measurements by Cassini. Coordinated
      investigation of Jovian aurora and auroral variability, high
      resolution images of the Great Red Spot for characterization of
      wind speeds, high northern latitude occultation of Earth. Ganymede
      high resolution imaging, global mapping to complete longitudinal
      coverage, limb scan and Earth occultation for detection of an
      atmosphere.  Low-phase, high tilt ring observations. Io color
      imaging and volcano monitoring. Europa global color imaging.
      Altitude: 808  km, Latitude: -13.8 degrees
 
    Spacecraft Id                  : GO
    Target Name                    : GANYMEDE
    Time of closest approach       : 2000-05-20T10:10:18
    Mission Phase Start Time       : 2000-05-17T00:00:00
    Mission Phase Stop Time        : 2000-06-13T00:00:00
 
 
    GANYMEDE 29 ORBIT
    -----------------
    Spacecraft Id                  : GO
    Target Name                    : GANYMEDE
    Mission Phase Start Time       : 2000-12-27T00:00:00
    Mission Phase Stop Time        : 2001-05-22T00:00:00
 
 
    GANYMEDE 29 ENCOUNTER
    ---------------------
      Objectives: Jupiter/Ganymede magnetospheric coupling,
      measurements of the dusk-side magnetosphere in collaboration with
      Cassini observations obtained while traversing the magnetosphere.
      Ganymede auroral features, regional and high-resolution
      observations, global observations, eclipse thermal maps. Jupiter
      atmospheric motion collaborative observations with Cassini,
      near-infrared spectral mapping, Great Red Spot, north equatorial
      belt and hot spot observations. Io sodium cloud and eclipse.
      Jovian main ring.  Io, Europa and Callisto global images
      complementing Cassini views.
      Altitude: 2338  km, Latitude: -14.8 degrees
 
    Spacecraft Id                  : GO
    Target Name                    : GANYMEDE
    Time of closest approach       : 2000-12-28T08:43:07
    Mission Phase Start Time       : 2000-12-26T00:00:00
    Mission Phase Stop Time        : 2001-02-05T00:00:00
 
 
 
    IO CAMPAIGN (GMM)
    -----------------
 
      The Io Phase is comprised of four (C30, I31, I32, and I33)
      encounters, one of Callisto and the others of Io, at flyby
      altitudes of 100 to 200 km. The Callisto gravity assist sets up
      high latitude flybys for I31 and I32 enabling both fields and
      particles measurements of a potential intrinsic magnetic field
      and unique remote sensing opportunities. With each successive
      passage, the orbit migrates farther to the sunward side of
      Jupiter. A trajectory correction is planned near I33 apojove
      to effect a plane change and decrease orbital inclination.
 
    Spacecraft Id                  : GO
    Target Name                    : IO
    Mission Phase Start Time       : 2001-05-22T00:00:00
    Mission Phase Stop Time        : 2002-01-20T00:00:00
    Spacecraft Operations Type     : ORBITER
 
 
    CALLISTO 30 ORBIT
    -----------------
    Spacecraft Id                  : GO
    Target Name                    : CALLISTO
    Mission Phase Start Time       : 2001-05-22T00:00:00
    Mission Phase Stop Time        : 2001-08-04T00:00:00
 
 
    CALLISTO 30 ENCOUNTER
    ---------------------
      Objectives: Make a close flyby of Callisto, using its gravity
      assist to lower perijove and set up two polar and one
      mid-latitude flybys of Io. Science objectives include Global
      Color Imaging, Regional and targeted observations of key geologic
      features, Temperature scans to monitor surface warming,
      Ionosphere measurements during occultation. Callisto induced
      magnetic field. Surface-magnetosphere interactions, Real-time
      science monitoring of the inner Jovian magnetosphere and Io
      torus, Jupiter cloud dynamics, electron density profiles and the
      white oval.  Other targets include Ganymede thermal maps, and
      near-terminator imaging, and monitoring Io volcanic activity in
      daylight and eclipse.
      Altitude: 123 km, Latitude: 13.3 degrees
 
    Spacecraft Id                  : GO
    Target Name                    : CALLISTO
    Time of closest approach       : 2001-05-25T11:23:55
    Mission Phase Start Time       : 2001-05-22T00:00:00
    Mission Phase Stop Time        : 2001-05-27T00:00:00
 
 
    IO 31 ORBIT
    ---------------
    Spacecraft Id                  : GO
    Target Name                    : IO
    Mission Phase Start Time       : 2001-08-04T00:00:00
    Mission Phase Stop Time        : 2001-10-14T00:00:00
 
 
    IO 31 ENCOUNTER
    ---------------
      Objectives: Tvashtar Plume and lava flow imaging and
      compositional Mapping, Global Color Imaging, Temperature
      maps of Io and its volcanoes. Real time science monitoring
      of the inner Jovian magnetosphere and Io Torus, and North
      Polar pass to study Io magnetic field North Polar pass to
      study Io magnetic field.  For Jupiter a Study of cloud
      dynamics of hot spots, Feature track study of equatorial
      waves, and Jupiter Occultation to yield electron density
      profiles of Jovian ionosphere. Callisto/other target
      objectives include Satellite Polarimetry and Sub-Jovian
      Hemisphere Imaging.
      Altitude: 200 km, Latitude: 77.5 degrees North
 
    Spacecraft Id                  : GO
    Target Name                    : IO
    Time of closest approach       : 2001-08-06T04:58:48
    Mission Phase Start Time       : 2001-08-04T00:00:00
    Mission Phase Stop Time        : 2001-08-09T00:00:00
 
 
    IO 32 ORBIT
    ---------------
    Spacecraft Id                  : GO
    Target Name                    : IO
    Mission Phase Start Time       : 2001-10-14T00:00:00
    Mission Phase Stop Time        : 2002-01-15T00:00:00
 
 
    IO 32 ENCOUNTER
    ---------------
      Objectives: Io global and regional color maps, Regional and
      targeted observations of hot spots, thermal emissions and
      volcanic activity, SO2 distribution of the Chaac region and
      temperature maps.  Jupiter observations include white oval
      monitoring, and Vortex regions at the poles, imaging of Gossimer
      rings, and global sampling. Monitoring of the inner Jovian
      magnetosphere and Io Torus with dayside sampling for
      magnetospheres and transition region of the ion plasma. Other
      targets include Europa polarimetry.
      Altitude: 181 km, Latitude 78.6 degrees north.
 
    Spacecraft Id                  : GO
    Target Name                    : IO
    Time of closest approach       : 2001-10-16T01:22:53
    Mission Phase Start Time       : 2001-10-14T00:00:00
    Mission Phase Stop Time        : 2001-10-29T00:00:00
 
 
    IO 33 ORBIT
    ---------------
    Spacecraft Id                  : GO
    Target Name                    : IO
    Mission Phase Start Time       : 2002-01-15T00:00:00
    Mission Phase Stop Time        : 2002-11-02T00:00:00
 
 
    IO 33 ENCOUNTER
    ---------------
      Objectives: Io includes global views, high resolution volcanic
      centers (Kanehekili, Prometheus, Pillan, and Marduk). Thermal
      mapping and Io gravity experiments. Jupiter observations include
      the occultation, white oval, pole to pole thermal maps, and
      global mapping. Magnetospheric interactions with Io - continuous
      recording for 5 1/4 hours, Realtime science for 24 days around
      closest approach, Crossing Ribbon Region of Io Torus.  Other
      targets include Europa polarimetry.
      Altitude 100 km, Latitude 43.6 degrees north.
 
 
    Spacecraft Id                  : GO
    Target Name                    : IO
    Time of closest approach       : 2002-01-17T14:08:53
    Mission Phase Start Time       : 2002-01-15T00:00:00
    Mission Phase Stop Time        : 2002-01-20T00:00:00
 
 
 
    INNER JUPITER PHASE
    -------------------
      During the final phase, the spacecraft samples the Jupiter
      magnetic field down to two RJ, passes through the gossamer
      rings, and performs a 914km flyby of Amalthea with a possible
      nontargetted flyby of another minor satellite. The closest
      approach geometry at Amalthea provides the best chance at
      achieving high priority gravity data. After I33, the spacecraft
      is on a ballistic trajectory for a Jupiter impact on the 35th
      orbit. GMM operations end 28 February 2003 allowing sufficient
      time for Amalthea data return. Fields and particles instruments
      were left on and acquiring RTS data at the end of the mission.
      The spacecraft will be periodically monitored until Jupiter
      impact. A short sequence that allows for some RTS data to be
      collected during the Jupiter impact orbit was placed on the
      spacecraft before the end of mission.
 
    Spacecraft Id                  : GO
    Target Name                    : JUPITER
    Mission Phase Start Time       : 2002-11-02T00:00:00
    Mission Phase Stop Time        : 2003-09-21T00:00:00
    Spacecraft Operations Type     : ORBITER
 
 
    AMALTHEA 34 ORBIT
    ---------------
    Spacecraft Id                  : GO
    Target Name                    : JUPITER
    Mission Phase Start Time       : 2002-11-02T00:00:00
    Mission Phase Stop Time        : 2003-09-21T00:00:00
 
 
    AMALTHEA 34 ENCOUNTER
    ---------------
      Objectives: Magnetosphere observations include realtime sampling
      and Monitoring of the inner Jovian magnetosphere and Io Torus
      with dayside sampling, and Transition region of the ion plasma.
      The Amalthea orbit includes Jupiter impact on 2003-09-21.
 
    Spacecraft Id                  : GO
    Target Name                    : JUPITER
    Time of closest approach       : 2002-11-05T06:19:37
    Mission Phase Start Time       : 2002-11-02T00:00:00
    Mission Phase Stop Time        : 2002-11-08T00:00:00
 
    JUPITER 35 ORBIT
    ---------------
    Spacecraft Id                  : GO
    Target Name                    : JUPITER
    Mission Phase Start Time       : 2003-09-21T00:00:00
    Mission Phase Stop Time        : 2003-09-21T19:07:00
MISSION_OBJECTIVES_SUMMARY
 
  Mission Objectives Overview
  ===========================
    Mission Objectives Summary
    ==========================
      The Galileo mission was designed to make long-term investigations
      of the Jovian system using a spacecraft consisting of a Probe and
      an Orbiter.  The Probe, after being released on the initial
      approach to Jupiter, entered the Jovian atmosphere and made
      in-situ measurements.  The Probe data were relayed to Earth by
      the Orbiter.  The Orbiter then entered orbit around Jupiter for a
      23-month, 10-satellite encounter tour of the Jovian system.
      The Galileo Europa Mission continued to operate the Orbiter for an
      additional 24-month, 13-satellite encounter tour,  leading into an
      additional extension. The Galileo Millennium Mission (GMM)
      continued for an additional 3 years, from January 2000 until
      January 2003, adding another 9 targeted satellite encounters to
      the Galileo spacecraft tour.
 
 
      Specific science objectives of the Galileo mission were:
 
      Jovian Atmosphere: Determine and investigate the chemical
      composition; structure to at least 10 bars; radiative heat
      balance; circulation and dynamics; nature of cloud particles.
 
      Gaspra, Ida, and Galilean Satellites: Characterize the
      morphology, geology and physical state; investigate the surface
      mineralogy and surface distribution of minerals.
 
      Galilean Satellites: Determine the gravitational and magnetic
      fields and dynamic properties; study the atmospheres, ionospheres
      and extended gas clouds; study the magnetospheric interactions of
      the satellites.
 
      Jovian Magnetosphere: Characterize the vector magnetic fields and
      the energy spectra, composition and angular distribution of
      plasma and energetic particles, including plasma wave phenomena,
      out to 150 Rj.
 
 
      Specific science objectives of the Galileo Europa Mission were:
 
      Europa Campaign: Study and characterize the crust, atmosphere and
      implications for possible subsurface ocean of Europa; study and
      characterize the interaction between Europa and Jupiter's
      magnetosphere; provide information that will support future
      missions to Europa.
 
      Perijove Reduction Campaign: Explore and map the Io plasma torus
      from Europa's orbit to Io's orbit; study and characterize the role
      of water in the dynamics of Jupiter's atmosphere; characterize
      regional volcanic activity on Io in preparation for the Io
      encounter campaign.
 
      Io Campaign: Study Io's internal structure, volcanic processes,
      atmosphere and magnetospheric environment at high resolution.
 
 
      Specific science objectives of the Galileo Millennium Mission were:
 
      Additional science for the Io Campaign from GEM: Observe Europa's
      interaction with the Jovian magnetosphere and examine any induced
      magnetic field in Europa during the E26 orbit; study Io's internal
      structure, volcanic processes, atmosphere and magnetospheric
      environment at high resolution in I27.
 
      Cassini Phase: Takes advantage of the unique opportunity presented
      by having a pair of spacecraft explore the Jupiter system
      simultaneously. Observations include joint magnetospheric/solar
      wind measurements, satellite and atmospheric remote sensing, and
      dust stream observations.
 
      Io Phase: Capitalizes on Galileo's proven ability to operate
      in the high radiation environment near Jupiter and on previous
      observations of Io's dramatic volcanic activity. Observations
      include high-latitude measurements of magnetospheric interactions,
      searching for intrinsic and/or induced magnetic field signatures,
      and studying the nature and extent of volcanism at both new and
      previously active sites.
 
      Inner Jupiter System Phase: A final high-risk, high-payoff plunge
      through the inner system, by Amalthea and only one Jupiter Radius
      above the cloud tops. Observations include Amalthea mass
      determination, in situ measurements of ring particles, inner
      magnetospheric plasma and radiation data, and determination of
      the current rate of secular change in Jupiter's magnetic field.
REFERENCE_DESCRIPTION Chapman, C.R., Galileo Encounter With the Planet Earth: Imaging Results,AGU-MSA 1991 Spring Meeting, EOS Transactions, American Geophysical Union,April 23, 1991.

Clarke, T.C., Earth and Moon Encounters by the Galileo Jupiter Orbiter,Proceedings of IGARSS '88 Symposium, Edinburgh, Scotland, September 13-16,1988, ESA SP-284, August 1988.

Clarke, T.C., and F.P. Fanale, Galileo: the Earth Encounters, The PlanetaryReport, Volume 9, number 5, The Planetary Society, September 1989, (replaced byCLARKE&FANALE1989).

Fanale, F.P., Galileo's Earth-Moon Encounter Set for December 8, EOSTransactions, Volume 71, Number 47, American Geophysical Union, November 20,1990.

Frank, L.A., K.L. Ackerson, and W.R. Patterson, Plasma Measurements at EarthWith the Galileo Spacecraft, AGU Spring Meeting, Baltimore, Maryland, May 1991.

Wolf, A.A., Jet Propulsion Laboratory Interoffice Memorandum GLL-NAV-92-90,Satellite Tour 92-14A Data Package, May 12, 1992, (replaced by WOLF1992).

O'Neil, W.J., Project Galileo Mission Status, 42nd Congress of theInternational Astronautical Federation, IAF-91-468, Oct 5-11, 1991, (replacedby ONEIL1991).

Casani, J.R., Galileo Project Plan, PD 625-1 Revision C, JPL D-1284, January1985, (replaced by CASANI1985).

Clarke, T.C., and C.M. Clayne, Galileo Science Requirements Document 625-50,Rev. C, Jet Propulsion Laboratory, Pasadena, California, January 18, 1989,(replaced by CLARKE&CLAYNE1989).

Head, J.W., D.B. Campbell, C. Elachi, J.E. Guest, D.P. McKenzie, R.S. Saunders,G.G. Schaber, and G. Schubert, Galileo Solid State Imaging Experiment Resultsfor the Moon, AGU-MSA 1991 Spring Meeting, EOS Transactions, AmericanGeophysical Union, April 23, 1991.

Ingersoll, A., and R. Thompson, A Global View of Earth From Galileo, AGU-MSA1991 Spring Meeting, EOS Transactions, American Geophysical Union, April 23,1991, (replaced by INGERSOLL&THOMP1991).

D'Amario, L.A., L.E. Bright, and A.A. Wolf, Space Science Reviews, Volume 60Numbers 1-4, 1992, The Galileo Mission, Kluwer Academic Publishers, 1992.

Young, R.E., M.A. Smith and C.K. Sobeck, Galileo Probe: In Situ Observations ofJupiter's Atmosphere, Science 272, pp. 837-838, 1996.