Mission Information
MISSION_START_DATE 2011-08-05T12:00:00.000Z
The majority of the text in this file
was extracted from the Juno Mission Plan Document, S. Stephens, 29 March
2011.[JPL D-35556]

Mission Overview

  Prime Mission
  Juno launched on August 5, 2011. The spacecraft used a delta V - EGA
  trajectory consisting of deep space maneuvers on August 30, and September
  14, 2012 followed by an Earth gravity assist on 9 October 2013 at an
  altitude of ~500 km. Juno arrived at Jupiter in July 2016 using a 53.5-day
  capture orbit prior to commencing operations for a prime mission comprising
  32 high inclination, high eccentricity orbits of Jupiter.  The orbit is
  polar (~90deg inclination) with a periapsis altitude of ~4,500 km and a
  semi-major axis of ~57 RJ giving an orbital period of about 53 days.
  Data were not acquired during Jupiter Orbit Insertion (Perijove 0) nor
  during Perijove 2. 

  The primary science is acquired during a period of several hours centered
  on each periapsis although fields and particles data are acquired at
  generally lower rates for the remaining apoapsis portion of each orbit.
  Some of the periapses are dedicated to microwave radiometry of Jupiter's
  deep atmosphere by turning the spin axis of Juno so as to optimize the
  microwave radiometry field of view on Jupiter with other orbits optimized
  for gravity measurements to determine the structure of Jupiter's interior.
  All orbits include fields and particles measurements of the planet's auroral

  Juno is spin stabilized with a rotation rate of ~2 revolutions per minute
  (RPM). For the radiometry orbits the spin axis is precisely perpendicular to
  the orbit plane so that the radiometer fields of view pass through the
  nadir.  For gravity passes, the spin axis is aligned to the Earth direction,
  allowing for Doppler measurements through the periapsis portion of the 
  orbit.  Provision is made for a tilted attitude between these two when the
  radiometry tilt exceeds the allowable off-sun angle for power 
  considerations. The orbit plane is initially very close to perpendicular to
  the Sun-Jupiter line and evolves over the mission. The apoapsis passes
  through the anti-sunward direction, but a modest inclination change was used
  to avoid an umbral eclipse. Data acquired during the periapsis passes are
  recorded and played back over the subsequent apoapsis portion of the orbit.

  Extended Mission
  The extended mission adds an additional 40 orbits (76 orbits total) to 
  continue the orbital tour through September 2025.  The orbital period at 
  the beginning of the extended mission is ~43 days and is reduced by a close 
  flyby of Europa at orbit 45 in the fall of 2022 to ~38 days and further 
  reduced by two close flybys of Io at orbit 57 and 58 in early 2024 to ~33 
  days. Juno's northward perijove precession reduces the altitude over 
  Jupiter's northern hemisphere and enables close flybys of Ganymede, Europa, 
  Io and Jupiter's ring system as well as the study of Jupiter's northern 
  hemisphere. The longitude of the perijoves is controlled only through orbit 
  58. After Io, the mapping of the magnetic and gravity field is no longer 
  controlled via orbital maneuvers.   During the extended mission, the 
  perijove local time rotates from about 9 hours at perijove 35 to about 2 
  hours. The latitude of perijove continues to precess from about 29 degrees 
  north on perijove 35 to about 64 degrees north.

  Extended Mission Instrumentation
  Juno's instrument complement includes Gravity Science using the X- and 
  Ka-bands to determine the structure of Jupiter's interior; vector fluxgate
  magnetometer (MAG) to study the magnetic dynamo and interior of Jupiter as
  well as to explore the polar magnetosphere; and a microwave radiometer (MWR)
  experiment covering 6 wavelengths between 1.3 and 50 cm to perform deep
  atmospheric sounding and composition measurements. The MAG investigation
  includes Advanced Stellar Compasses (ASCs) mounted on optical benches
  including the fluxgate magnetometers (FGMs) in order to directly provide
  attitude information that does not rely on understanding how the solar
  panel inboard of the MAG boom flexes. The ASCs can provide some imaging of
  various non-stellar objects to enhance science or to provide outreach

  The instrument complement also includes a suite of fields and particle
  instruments to study the polar magnetosphere and Jupiter's aurora. This 
  suite includes an energetic particle detector (JEDI), a Jovian auroral
  (plasma) distributions experiment (JADE), a radio and plasma wave instrument
  (Waves), an ultraviolet spectrometer (UVS), and a Jupiter infrared auroral
  mapping instrument (JIRAM). During the extended mission, the Stellar
  Reference Unit (SRU) can image Jupiter's ring system, lightning, satellites
  and auroras as well as record radiation noise.  The JunoCam is a camera 
  included for education and public outreach and can provide images of 
  Jupiter's atmosphere, satellites and rings.  During the EM, the data are 
  archived in the PDS along with the other mission data.

  Scott Bolton is the Juno Principal Investigator.  The Science Team members
  responsible for the delivery and operation of the instruments are listed

    Instrument                                      Acronym   Lead Co-I
    ----------------------------------------------  --------  ---------
    Gravity Science                                 GRAV      Folkner
    Magnetometer                                    MAG       Connerney
    Microwave Radiometer                            MWR       Janssen
    Jupiter Energetic Particle Detector Instrument  JEDI      Mauk
    Jovian Auroral Distributions Experiment         JADE      Allegrini
    Radio and plasma wave instrument                Waves     Kurth
    Ultraviolet Imaging Spectrograph                UVS       Gladstone
    Jovian Infrared Auroral Mapper                  JIRAM     Adriani
    Juno color, visible-light camera                JUNOCAM   Hansen
    Stellar Reference Unit                          SRU       Becker
    Advanced Stellar Compass                        ASC       Joergensen

Mission Phases

    The Launch phase starts at L-40 min (Launch-40 min), and covers the
    interval from launch, through initial ground station acquisition, until
    the establishment of a pre-defined, stable, and slowly changing Sun-
    pointed attitude when cruise attitude control algorithms and ephemerides
    can be used. The end of the Launch phase is determined by post-launch
    health and safety assessments.  The boundary is at L+3 days, after initial
    acquisition and after confirmation that the Flight System is safe and in
    a power-positive, thermally stable, and commandable attitude.

    Target Name              :  N/A
    Mission Phase Start Time :  2011-08-05 (2011-217)
    Mission Phase Stop Time  :  2011-08-08 (2011-220)

    The Inner Cruise 1 phase lasts from post-Launch establishment of a pre-
    defined and stable Sun-pointed attitude when cruise attitude control
    algorithms and ephemerides can be used, until after initial spacecraft and
    instrument checkouts have been performed and the spacecraft has gotten far
    enough from the Sun to allow Earth-pointing instead of Sun-pointing. TCM 1
    (the first planned trajectory correction maneuver) was deemed not 
    necessary, hence, was not executed.  The phase spans the interval from L+3
    to L+66 days.

    Target Name              :  SOLAR_SYSTEM
    Mission Phase Start Time :  2011-08-08 (2011-220)
    Mission Phase Stop Time  :  2011-10-10 (2011-283)

    The Inner Cruise 2 phase spans the period from L+66 days until L+663
    days.  The Deep Space Maneuvers (DSMs) occur during this phase, near
    aphelion of Juno's first orbit about the Sun, on the way to Earth Flyby
    and then Jupiter.  There is increased DSN (Deep Space Network) coverage
    associated with the DSMs and a cleanup TCM. DSMs 1 and 2 occur on 
    2012-08-30 and 2010-09-14.

    Target Name              :  SOLAR_SYSTEM
    Mission Phase Start Time :  2011-10-10 (2011-283)
    Mission Phase Stop Time  :  2013-05-29 (2013-149)

    The Inner Cruise 3 phase spans the interval from L+663 days to L+823
    days.  The duration of this cruise phase is 160 days.  Featured in this
    phase is Earth Flyby (EFB), which gives Juno a gravity assist (providing
    7.3 km/s of deltaV) on its way to Jupiter. It occurs as the spacecraft is
    completing one elliptical orbit around the Sun and includes perihelion.
    Three TCMs were planned before EFB (the last of which was deemed not
    necessary) and one after EFB. There is increased DSN coverage associated
    with the 4 maneuvers and EFB.  The Inner Cruise 3 phase is focused on
    performing the required maneuvers, as well as an integrated operations
    exercise around Earth Flyby, subject to Flight System constraints.
    Closest approach to Earth occurs on 2013-10-09 at 19:21 UTC.

    Target Name              :  EARTH, SOLAR_SYSTEM
    Mission Phase Start Time :  2013-05-29 (2013-149)
    Mission Phase Stop Time  :  2013-11-05 (2013-309)

    Earth Closest Approach   :  2013-10-09T19:21 (2013-282)

    The Outer Cruise phase lasts from L+823 days until the start of Jupiter
    Approach at Jupiter Orbit Insertion (JOI)-6 months (JOI-182 days or
    L+1614 days). The duration of this cruise phase is 791 days, which is
    over 2 years.

    Target Name              :  SOLAR_SYSTEM
    Mission Phase Start Time :  2013-11-05 (2013-309)
    Mission Phase Stop Time  :  2016-01-05 (2016-005)

    The Jupiter Approach phase lasts the final 6 months of cruise before
    Jupiter Orbit Insertion and is an opportunity for final Flight System and
    instrument checkouts as well as science observations to start exercising
    the ground system and Flight System, although orbit insertion preparations
    limit instrument activities close to JOI. There are more frequent
    maneuvers approaching JOI, starting with a TCM at JOI-5 months, and
    correspondingly increasing DSN coverage. The 178-day Jupiter Approach
    phase is preceded by a 26-month Outer Cruise phase.   Jupiter Approach
    starts 3 months after the project is fully staffed up in preparation for
    JOI and the 1.3 years of science orbits.   The phase ends at JOI-4 days,
    which is the start of the JOI critical sequence.

    Target Name:             :  JUPITER, SOLAR_SYSTEM
    Mission Phase Start Time :  2016-01-05 (2016-005)
    Mission Phase Stop Time  :  2016-07-01 (2016-183)

    The JOI phase encompasses the JOI critical sequence. It begins 4 days
    before the start of the orbit insertion maneuver and ends 1 hour after the
    start.  JOI, the second critical event of the mission, occurs at closest
    approach to Jupiter, and slows the spacecraft enough to let it be captured
    by Jupiter into a 53.8-day orbit.  A cleanup burn at JOI+8.6d during the
    Capture Orbits phase is required to clean up JOI maneuver execution
    errors. DSN coverage is continuous during the JOI phase.

    Target Name              :  N/A
    Mission Phase Start Time :  2016-07-01 (2016-183)
    Mission Phase Stop Time  :  2016-07-05 (2016-187)

    Perijove 0               :  2016-07-05T02:47:32 (2016-187)    

    The Science Orbits phase includes Orbit 0 through Orbit 35.  Orbit N is
    defined from apojove (AJ) N-1 through apojove N, and includes perijove
    (PJ) N.  Orbit numbering starts before the Science Orbits phase.  JOI
    occurs at PJ0, so Orbit 0 lasts from PJ0 through AJ0 (including a JOI 
    cleanup maneuver at JOI+8.6d).  Orbit 1 includes PJ1, and runs from AJ0
    through AJ1. Orbit 2 includes PJ2, and runs from AJ1 through AJ2. Orbit
    3 includes PJ3, and runs from AJ2 through AJ3. Early orbital science was
    baselined in Orbits 0, 1, 2, and 3, except for the JOI keepout zone.
    Orbit 4 is the first science orbit. It includes PJ4 (and the first OTM at 
    PJ4+7.5h), and runs from AJ3 through AJ4.  The flyby of Ganymede (PJ34)
    reduced the orbital period from about 53 days to about 43 days.  Small
    (up to 8 m/s) orbit trim maneuvers (OTMs) are planned after each set of 
    perijove science observations, at PJ+4h, PJ+6h, or PJ+7.5h in Orbits 4
    through 34, to target the perijove longitude required for science
    observations in the next orbit. 

    Radiation accumulation increases substantially as the orbital line of
    apsides rotates and perijove latitude increases from 3 degrees at JOI to
    36 (TBD) degrees at PJ35. 

    Target Name              :  JUPITER 
    Mission Phase Start Time :  2016-07-05 00:00:00 (2016-187)
    Mission Phase Stop Time  :  2021-07-03 00:00:00 (2021-184)

    Perijove 1               :  2016-08-27 12:50:44 (2016-240)
    Perijove 2               :  2016-10-19 18:10:54 (2016-293)
    Perijove 3               :  2016-12-11 17:03:41 (2016-346)
    Perijove 4               :  2017-02-02 12:57:09 (2017-033)
    Perijove 5               :  2017-03-27 08:51:52 (2017-086)
    Perijove 6               :  2017-05-19 06:00:45 (2017-139)
    Perijove 7               :  2017-07-11 01:54:51 (2017-192)
    Perijove 8               :  2017-09-01 21:48:57 (2017-244)
    Perijove 9               :  2017-10-24 17:43:00 (2017-297)
    Perijove 10              :  2017-12-16 17:57:39 (2017-350)
    Perijove 11              :  2018-02-07 13:51:49 (2018-038)
    Perijove 12              :  2018-04-01 09:45:57 (2018-091)
    Perijove 13              :  2018-05-24 05:40:07 (2018-144)
    Perijove 14              :  2018-07-16 05:17:38 (2018-197)
    Perijove 15              :  2018-09-07 01:11:55 (2018-250)
    Perijove 16              :  2018-10-29 21:06:15 (2018-302)
    Perijove 17              :  2018-12-21 17:00:25 (2018-355)
    Perijove 18              :  2019-02-12 16:19:48 (2019-043)
    Perijove 19              :  2019-04-06 12:13:58 (2019-096)
    Perijove 20              :  2019-05-29 08:08:13 (2019-149)
    Perijove 21              :  2019-07-21 04:02:44 (2019-202)
    Perijove 22              :  2019-09-12 03:40:47 (2019-254)
    Perijove 23              :  2019-11-03 23:32:56 (2019-307)
    Perijove 24              :  2019-12-26 16:58:59 (2019-360)
    Perijove 25              :  2020-02-17 17:51:36 (2020-048)
    Perijove 26              :  2020-04-10 14:24:34 (2020-101)
    Perijove 27              :  2020-06-02 10:19:55 (2020-154)
    Perijove 28              :  2020-07-25 06:15:21 (2020-207)
    Perijove 29              :  2020-09-16 02:10:49 (2020-260)
    Perijove 30              :  2020-11-08 01:49:39 (2020-313)
    Perijove 31              :  2020-12-30 21:45:12 (2020-365)
    Perijove 32              :  2021-02-21 17:40:31 (2021-052)
    Perijove 33              :  2021-04-15 13:36:26 (2021-105)
    Perijove 34              :  2021-06-08 07:46:00 (2021-159)
    Perijove 35              :  2021-07-21 08:15:05 (2021-202)

    Satellite flybys less than 150,000 km (Prime Mission)

    Satellite  PJ               CA Time(UTC) and Altitude(km)

    Ganymede   24            :  2019-12-26 02:14:57 (2019-360)    97100
    Europa     26            :  2020-04-10 05:39:08 (2020-101)   142564
    Ganymede   34            :  2021-06-07 16:56:08 (2021-158)     1053
    Ganymede   35            :  2021-07-20 16:48:30 (2021-201)    49992

  Using the same orbit numbering scheme as in the Prime Mission, the Extended
  Mission begins on 1 August 2021 and extends to orbit 76, through September 
  2025.  The Extended Mission includes a close Europa flyby during orbit 45
  which reduces the orbital period to about 38 days. Close flybys of Io
  occur on orbits 57 and 58, reducing the period to about 33 days. Note that
  times are from the reference trajectory and are not be be construed as 
  as-flown, reconstructed times.  

    Perijove 36              :  2021-09-02 22:42:52 (2021-245)
    Perijove 37              :  2021-10-16 17:13:32 (2021-289)
    Perijove 38              :  2021-11-29 14:13:30 (2021-333)
    Perijove 39              :  2022-01-12 10:32:57 (2022-012)
    Perijove 40              :  2022-02-25 01:58:52 (2022-056)
    Perijove 41              :  2022-04-09 15:49:15 (2022-099)
    Perijove 42              :  2022-05-23 02:15:50 (2022-143)
    Perijove 43              :  2022-07-05 09:17:23 (2022-186)
    Perijove 44              :  2022-08-17 14:45:33 (2022-229)
    Perijove 45              :  2022-09-29 17:11:55 (2022-272)
    Perijove 46              :  2022-11-06 21:38:28 (2022-310)
    Perijove 47              :  2022-12-15 03:23:23 (2022-349)
    Perijove 48              :  2023-01-22 05:43:30 (2023-022)
    Perijove 49              :  2023-03-01 05:53:19 (2023-060)
    Perijove 50              :  2023-04-08 08:13:24 (2023-098)
    Perijove 51              :  2023-05-16 07:22:37 (2023-136)
    Perijove 52              :  2023-06-23 06:55:05 (2023-174)
    Perijove 53              :  2023-07-31 09:05:43 (2023-212)
    Perijove 54              :  2023-09-07 11:58:02 (2023-250)
    Perijove 55              :  2023-10-15 10:52:59 (2023-288)
    Perijove 56              :  2023-11-22 12:16:48 (2023-326)
    Perijove 57              :  2023-12-30 12:36:21 (2023-364)
    Perijove 58              :  2024-02-03 21:47:31 (2024-034)
    Perijove 59              :  2024-03-07 15:52:50 (2024-067)
    Perijove 60              :  2024-04-09 08:53:21 (2024-100)
    Perijove 61              :  2024-05-12 06:48:48 (2024-133)
    Perijove 62              :  2024-06-14 03:33:09 (2024-166)
    Perijove 63              :  2024-07-17 01:13:18 (2024-199)
    Perijove 64              :  2024-08-18 21:13:01 (2024-231)
    Perijove 65              :  2024-09-20 18:50:25 (2024-264)
    Perijove 66              :  2024-10-23 14:45:47 (2024-297)
    Perijove 67              :  2024-11-25 09:38:25 (2024-330)
    Perijove 68              :  2024-12-28 07:02:23 (2024-363)
    Perijove 69              :  2025-01-30 03:32:11 (2025-030)
    Perijove 70              :  2025-03-04 02:25:53 (2025-063)
    Perijove 71              :  2025-04-06 00:13:33 (2025-096)
    Perijove 72              :  2025-05-08 21:51:02 (2025-128)
    Perijove 73              :  2025-06-10 21:20:34 (2025-161)
    Perijove 74              :  2025-07-13 19:36:22 (2025-194)
    Perijove 75              :  2025-08-15 18:55:46 (2025-227)
    Perijove 76              :  2025-09-17 17:29:08 (2025-260)

    Satellite flybys less than 150,000 km (Extended Mission)

    Satellite  PJ               CA Time(UTC) and Altitude(km)

    Europa     37            :  2021-10-16 08:46:28 (2021-289)    81360
    Europa     40            :  2022-02-24 18:15:43 (2022-055)    46982
    Io         41            :  2022-04-09 11:43:39 (2022-099)   105820
    Io         43            :  2022-07-05 04:55:57 (2022-186)    86131
    Europa     45            :  2022-09-29 09:36:29 (2022-272)      355
    Io         47            :  2022-12-14 23:16:09 (2022-348)    63743
    Io         49            :  2023-03-01 01:32:07 (2023-060)    51522
    Io         51            :  2023-05-16 03:10:08 (2023-136)    35556
    Io         53            :  2023-07-31 04:57:16 (2023-212)    22203
    Io         55            :  2023-10-15 06:47:22 (2023-288)    11641
    Io         57            :  2023-12-30 08:36:01 (2023-364)     1498
    Io         58            :  2024-02-03 17:48:36 (2024-034)     1497
    Io         60            :  2024-04-09 04:58:04 (2024-100)    17346
    Io         65            :  2024-09-20 15:54:42 (2024-264)   124146
    Io         67            :  2024-11-25 05:35:34 (2024-330)    85734
    Io         72            :  2025-05-08 18:14:06 (2025-128)    92656


    Target Name              :  JUPITER
    Mission Phase Start Time :  2021-07-03 00:00:00 (2021-184)
    Mission Phase Stop Time  :  2025-09-17 00:00:00 (2025-260)
  Prime Mission Objectives

  Juno's science objectives encompass four scientific themes:
  origin, interior structure, atmospheric composition and dynamics, and polar
  magnetosphere.  These are based on Appendix E to the New Frontiers Program
  Plan: Program Level Requirements for the Juno Project (PLRA).  Juno 
  addresses science objectives central to three NASA Science divisions: Solar
  System (Planetary), Earth-Sun System (Heliophysics), and Universe 

  Juno's primary science goal of understanding the formation,
  evolution, and structure of Jupiter is directly related to the conditions in
  the early solar system which led to the formation of our planetary system. 
  The mass of Jupiter's solid core and the abundance of heavy elements in the
  atmosphere discriminate among models for giant planet formation.  Juno
  constrains the core mass by mapping the gravitational field, and measures
  through microwave sounding the global abundances of oxygen (water) and
  nitrogen (ammonia). Juno reveals the history of Jupiter by mapping the
  gravitational and magnetic fields with sufficient resolution to constrain
  Jupiter's interior structure, the source region of the magnetic field, and
  the nature of deep convection. By sounding deep into Jupiter's atmosphere,
  Juno determines to what depth the belts and zones penetrate.  Juno provides
  the first survey and exploration of the three-dimensional structure of
  Jupiter's polar magnetosphere.  The overall goal of the Juno mission is to
  improve our understanding of the solar system by understanding the origin
  and evolution of Jupiter.

  Juno investigates the formation and origin of Jupiter's atmosphere and the
  potential migration of planets through the measurement of Jupiter's global
  abundance of oxygen (water) and nitrogen (ammonia).

    a) Constrain the global O/H ratio (water abundance) in Jupiter's

    b) Constrain the global N/H ratio (ammonia) in Jupiter's atmosphere.

  Juno investigates variations in Jupiter's deep atmosphere related to
  meteorology, composition, temperature profiles, cloud opacity, and
  atmospheric dynamics.

    a) Determine microwave opacity as a function of latitude and altitude 

    b) Determine depths of cloud and atmospheric features such as zones,
       belts, and spots, and map dynamical variations.

    c) Characterize microwave opacity of the polar atmosphere region.

  Juno investigates the fine structure of Jupiter's magnetic field, providing
  information on its internal structure and the nature of the dynamo.

    a) Map the magnetic field of Jupiter, globally, by direct measurement
       of the field at close-in radial distances.

    b) Determine the magnetic spectrum of the field, providing information
       on the dynamo core radius.

    c) Investigate secular variations (long-term time variability) of the
       magnetic field.

  Juno gravity sounding explores the distribution of mass inside the planet.

    a) Determine the gravity field to provide constraints on the mass of the 

    b) Determine the gravity field to detect the centrifugal response of the
       planet to its own differential rotation (winds) at depths of kilobars
       and greater.

    c) Investigate the response to tides raised by the Jovian satellites.

  Juno explores Jupiter's three-dimensional polar magnetosphere and aurorae.

    a) Investigate the primary auroral processes responsible for particle

    b) Characterize the field-aligned currents that transfer angular momentum
       from Jupiter to its magnetosphere.

    c) Identify and characterize auroral radio and plasma wave emissions
       associated with particle acceleration.

    d) Characterize the nature, location, and spatial scale of auroral

  Extended Mission Objectives
  During the Extended Mission (EM) phase, Juno will address the following
  science objectives: 

    Investigate Jupiter's northern latitudes, gather information on its
    water/ammonia abundance, polar cyclones, ionospheric profile (electron
    and neutral temperature), and variability of lightning.

  Interior structure:
    Investigate shearing, characterize shallow dynamo, dilute core, and the
    interior/atmosphere coupling.

    Explore the polar magnetopause and probe the polar cap auroral

  Ring studies:
    Characterize the ring dust and the ring plasma environment.

    Investigate the 3-D structure and dynamics of its magnetosphere and

    Investigate the ice shell and characterize surface sputtering.

    Constrain the global magma ocean, monitor volcanic activity, and
    characterize magnetospheric interaction.

  Investigate variation of water abundance as a function of latitude. 
  Determine if the northern pole of Jupiter is unique in composition.

  Characterize atmospheric composition, vertical structure, and dynamics of
  the northern hemisphere. Investigate the transition from zonal jets to
  vortices at mid-latitudes and the culmination that leads to vortex crystals
  at the poles. Monitor long-term changes and roots of vortex patterns. 

  Characterize temporal and spatial variability of Jovian lightning to
  investigate the role of thunderstorms on the shallow and deep atmospheric

  Investigate Jupiter's upper atmosphere, ionosphere and auroral heating and
  energy transfer to lower latitudes.

  Investigate the shearing of the Great Blue Spot (GBS), and the source depth
  of the GBS dynamo region.

  Investigate the dynamo source depth, characterize small spatial scale
  features in the northern hemisphere, constrain convective stability of a
  double layer dynamo.

  Constrain and characterize the dilute core and constrain the existence of a
  compact inner core.

  Investigate the coupling between the interior structure, magnetic field and
  deep atmosphere. 

  Investigate the 3-D structure of Ganymede's magnetosphere and its
  interaction with the Jovian magnetosphere over a wide range of magnetic
  latitudes. Provide constraints on the density and composition of Ganymede's
  ionosphere and exosphere over a range of latitudes and altitudes Ganymede
  and its magnetosphere. 

  Investigate the upper 10 km of Europa's ice shell to characterize the
  variations in thickness and identify regions of subsurface water.  
  Characterize variations in density, temperature, and purity of the 
  subsurface ice to distinguish geologic processes within the ice shell to
  probe how terrain types are associated with subsurface-surface exchange.
  Investigate surface sputtering effects on Europa and atmosphere.
  Search for evidence of shallow, near-surface thermal anomalies indicative
  of recent geological activity (warm diapirs) and/or near surface melt or
  trapped water. Investigate surface sputtering effects on Europa and

  Investigate Io's interior via tidal gravitational response to Jupiter's
  gravity and magnetic induction. Address current stability of the Laplace
  resonance that controls tidal heating.

  Investigate the local environment of Io and its interaction with Jupiter's

  Investigate and monitor Io volcanic activity, composition, topography, heat
  flow and lava temperatures, including high latitudes.  Map surface changes
  relative to previous missions to constrain resurfacing rates. 

  Investigate Io's atmospheric pickup ions, sublimation, volcanic sources,
  and supply of various species to Io torus.

  Characterize the dust population of Jupiter's ring system. Characterize
  density and size distribution of micron-sized dust between Jupiter's ring
  and the planet extending into the halo region. Study interactions between
  ring particles and low- and high-energy charged particles. Investigate ring
  particle density distribution relative to equatorial plane. Constrain
  charging environment close to the ring.

  Determine the spatial and temporal variability of the Io and Europa plasma
  tori in order to address the transport of mass and energy through Jupiter's
  inner magnetosphere. Explore the region near Jupiter's polar magnetopause
  to investigate the interconnection and accessibility to the interplanetary
  medium. Characterize Jupiter's auroral acceleration region by searching
  beneath altitudes accessed during Juno's prime mission.