Mission Information
MISSION_NAME HAYABUSA
MISSION_ALIAS HAYABUSA
MISSION_START_DATE 2003-05-09T12:00:00.000Z
MISSION_STOP_DATE 2010-06-13T12:00:00.000Z
MISSION_DESCRIPTION
Mission Overview
  ================

  The Hayabusa spacecraft was successfully launched atop a Japanese M-V
  launch vehicle on May 9, 2003.  The mission plan was to have the
  spacecraft briefly alight upon the surface of near-Earth asteroid 25143
  Itokawa, fire pellets into the surface, collect the surface material
  ejecta and bring these surface samples back to Earth for intensive study.
  Japan's Institute of Space and Astronautical Science (ISAS) and NASA
  agreed to cooperate on the Hayabusa (aka MUSES-C) mission.  Before
  launch, the mission name was MUSES-C, which stood for Mu Space
  Engineering Spacecraft, a space engineering spacecraft launched by a Mu
  rocket developed by ISAS, with C referring to it being the third in the
  series.  Just after launch, the mission was renamed Hayabusa (Japanese
  for falcon).


  Science Goals
  =============

  The overall science goal of the mission was to significantly advance
  our understanding of Earth's closest neighbors, the near-Earth asteroids.
  Some of these objects continue to pass closer to the Earth than the moon
  itself.  They represent the left over building blocks of the inner solar
  system formation process some 4.6 billion years ago and if we wish to
  understand the chemical mix from which the inner planets, including
  Earth, formed then the study of near-Earth asteroids is key.  Most
  objects in the inner portion of the asteroid belt have similar spectral
  characteristics.  These asteroids, including Itokawa, are so-called
  S-type objects that are rich in the minerals olivine and pyroxene.  By
  carrying out a detailed elemental composition of the surface samples,
  scientists will thereafter know the likely composition of existing, and
  newly discovered, S-type asteroids.  Asteroid compositions run the gamut
  from carbon-rich fragile structures, to fractured silicate rock and
  slabs of solid iron.  These objects will need to be studied to determine
  which among them are the most accessible to spacecraft and which are the
  richest in mineral wealth.  Another reason for investigating near-Earth
  asteroids is to understand their compositions and structures to
  successfully deflect an object that is found on an Earth threatening
  trajectory.


  Technology Goals
  ================

  Technology tests: Although the science return to date from the Hayabusa
  mission is rich, the mission's main goals are not scientific but rather
  the testing of four new technologies including 1.) a demonstration of
  the four ion engines in interplanetary space for up to 18,000 hours
  2.) use of the on board camera systems to autonomously guide the
  spacecraft during the asteroid rendezvous 3.) a demonstration of a
  sample collection device for retrieval of surface materials
  4.) a demonstration of the sample capsule's ability to carry out an
  Earth atmosphere entry direct from an interplanetary trajectory.

  Although there are four ion engines onboard the Hayabusa spacecraft,
  up to three of them operate simultaneously.  The fourth is a backup
  engine.  These ion engines operate when xenon fuel is first ionized via
  a microwave device.  The resulting xenon positive ions are then
  accelerated across a charged high voltage grid (providing the thrust)
  and finally a stream of electrons is used to neutralize the accelerated
  xenon ions.  Even when all three ion engines are operating full bore,
  they are only capable of accelerating the spacecraft to a very modest
  12 meters per second per day.  The force they generate is 20,000 times
  less than a traditional spacecraft thruster that burns chemical fuel
  (e.g., hydrazine).  However, while chemical thrusters operate for only
  a few seconds, these ion engines thrust continuously over many months
  and by so doing, they are capable of pushing the spacecraft to its
  September 2005 rendezvous with Itokawa.

  This is the first flight of a spacecraft with these advanced ion
  engines, the first attempt at a touch and go, autonomous landing on an
  asteroid's surface, and the first attempt of an asteroid surface sample
  return to Earth.

  Reaction Wheel Failure
  ======================

  To maintain spacecraft attitude, the Hayabusa spacecraft was equipped
  with three momentum wheels mounted in three orthogonal directions and
  hydrazine attitude control thrusters on the corners of the spacecraft.
  In late July 2005, one of the reaction wheels failed and a second wheel
  failed in early October 2005.  That left only the z-axis reaction wheel
  operational for the remainder of the mission.  The spacecraft made an
  unplanned surface landing November 20 and a planned touchdown 5 days
  later.  Just after lifting off from the surface the second time, the
  hydrazine attitude fuel was exhausted as it leaked into space causing a
  spin up of the spacecraft.  Radio contact with the spacecraft was lost
  on December 8, 2005 and a signal restored on January 23, 2006.  With
  communications re-established, the cold xenon gas jets from the canted
  neutralizers were used to restore attitude control by firing the
  neutralizer gas at specific times during the spacecraft spin cycle.  The
  high data rate was restored on February 25, 2006.  After the April 25,
  2006 departure from Itokawa, the Hayabusa spacecraft maintained attitude
  control via a careful balancing of the effects from the single
  operational momentum wheel, vectoring of the ion engines and the
  radiation pressure acting upon the solar panels. [KUNINAKAETAL2007]

  Instruments
  ===========

  Using three of the four ion engines at a time, Hayabusa flew past the
  Earth on May 19, 2004 to boost its velocity.  The spacecraft then caught
  up to the target asteroid in September 2005, a potato shaped near-Earth
  object named 25143 Itokawa, after the Japanese rocket pioneer, Hideo
  Itokawa (1912 - 1999).  During the three month operations period
  (September - November), the Hayabusa science instruments were designed
  to undertake an intensive study of the asteroid's surface.  These
  instruments are the science camera (AMICA); the surface hopper (MINERVA);
  the near infrared and x-ray spectrometers (NIRS, XRS); the Lidar
  altimeter (LIDAR); and the sample collection and return systems.

  AMICA: The Asteroid Multiband Imaging Camera was used to map the
  entire portion of the asteroid's surface that is observable in sunlight.
  The asteroid's size, shape, volume, and rotation characteristics were
  determined and a (negative) search was carried out for any neighboring
  satellites or dust rings that may have been closely orbiting Itokawa.
  Making observations with a set of colored filters (see Table 1),
  AMICA looked for slight differences in color over the asteroid's surface
  - color differences that might indicate changes in mineralogical
  composition.  The AMICA images will also be used to determine the optical
  properties of the surface materials at image resolutions well below one
  meter, provide constraints upon the surface particle sizes, and reveal
  the history of impacts from other asteroids or comets.  Results from the
  AMICA instrument are reported in [SAITOETAL2006].  A description of the
  AMICA instrument and its calibration is provided in [ISHIGUROETAL2010].

  Table 1:  AMICA filter bandpasses:

  filter:   central wavelength (nm):   FWHM (nm):
    ul         381                      45
    b          429                     108
    v          553                      72
    w          700                      70
    x          861                      81
    p          960                      75
    zs        1008                      66
  WIDE         650                     300

  MINERVA:  Japanese engineers developed a surface hopper that could take
  close up images and thermal measurements of the asteroid's surface
  during, and in between, 10-meter hops about the surface.  About the size
  of a small can, the MINERVA hopper had six sun sensors (photodiodes) and
  an electric turntable that was designed to first orient the tiny
  spacecraft toward the sun thus allowing its solar panels to power it up.
  Once oriented properly, the thermal sensors were designed to determine
  Itokawa's surface temperature and then a rotating torque wheel would have
  spun within MINERVA causing the outside of the tiny spacecraft to counter
  rotate, dig into the surface and hop about 10 meters.  Once a hop was
  complete, additional surface temperature measurements would have been
  made and two of the three onboard cameras would have taken very
  high-resolution surface images in stereo.  The third camera, with a
  longer focal length than the other two, was designed to image the
  asteroid's surface while MINERVA was above the surface during mid-hop.
  Provided the Hayabusa spacecraft was within 20 kilometers, MINERVA's
  images and temperature data could have been radioed to the Hayabusa
  spacecraft and then relayed back to Earth.  It was designed to last
  three asteroid days or 36 hours.  MINERVA's final weight was 591 g and
  its diameter and height were 12 and 10 cm respectively.  Its three
  cameras (320 x 240 px) had adjustable shutter speeds.  The data rate was
  9.6 Kbits/s but due to the spacecraft's slight velocity away from the
  asteroid, MINERVA entered into a solar orbit rather than descending to the
  asteroid's surface. No asteroid data were received from this instrument.
  A description of the MINERVA lander is reported in [YOSHIMITSUETAL1999].

  NIRS and X-Ray Spectrometers: The on board, near infrared spectrometer
  examined the asteroid's spectral features in the near infrared region
  of the spectrum.  Whereas the near-infrared spectrometer relied upon
  meteorite analogs to identify the surface minerals of Itokawa, the x-ray
  spectrometer measured the elemental composition of these minerals
  directly.  Solar x-rays excite the individual elements of the asteroid's
  surface minerals and the resulting x-ray spectral features were
  identified and measured by the on board x-ray spectrometer.  Some of the
  expected elements include iron, silicon, manganese, calcium, aluminum and
  sodium.  By noting the relative abundances of these elements in the
  asteroid's surface minerals and comparing these abundances to those
  measured in various types of meteorites on Earth, a link can be forged
  between the composition of this type of rocky asteroid and the meteorites
  on Earth that likely represent the collision fragments of such asteroids.
  Thereafter, the composition can be inferred for newly discovered
  asteroids that are spectrally similar to the large group of S-type
  asteroids like Itokawa.  Results from the NIRS and X-Ray Spectrometer
  instruments are reported in [ABEETAL2006], [KITAZATOETAL2008],
  [OKADAETAL2006].

  LIDAR:  The LIDAR instrument measures the round-trip time of flight of
  infrared laser pulses transmitted from the Hayabusa spacecraft to the
  surface of Itokawa. The instrument operates in a single autonomous mode,
  in which it produces ranging measurements.  Surface topography estimates
  can be derived from these data, given appropriate corrections for the
  position and attitude of the spacecraft.  The principal components of
  LIDAR are a diode-pumped, Nd:YAG laser transmitter that emits 1.064
  micrometer wavelength laser pulses, a 0.126 m diameter telescope, a
  silicon avalanche photodiode detector, and a time interval unit with 14
  nsec resolution. During the long Home Position phase (~7km from Itokawa)
  of the misson, LIDAR provides measurements of the topography of Itokawa
  within approximately 12x4.9 m footprints.  Results from the LIDAR
  instrument are reported in [MUKAIETAL2007].

  Sample Collection and Return to Earth: The definitive work on this
  asteroid's composition will be done in Earth-based laboratories after the
  Hayabusa spacecraft returned its precious samples in June 2010.  After
  several weeks during which an initial mapping and reconnaissance phase
  was undertaken, the Hayabusa spacecraft was designed to descend to the
  surface of the asteroid, fire a 5 gram pellet of Tantalum into the
  asteroid's surface and immediately collect and store the resulting
  ejecta.  Tantalum, a rare non-corrosive metal, is used because it is
  very resistance to change and any tantalum found in the collected sample
  will be easily identified. This sampling maneuver could be done up to
  three times.  Because the light travel time between the asteroid and
  Earth was about 18 minutes at the time of the sampling, the spacecraft
  must act without human intervention.  As described below, there was no
  evidence that these pellets were successfully fired but the spacecraft
  did land upon the asteroid's surface so that some surface material was
  disturbed to an extent that allowed some of it to enter the
  sample collection chamber.  The landing attempts are outlined in
  [YANOETAL2006].

  On April 25, 2007, the Hayabusa spacecraft departed from the asteroid
  and in June of 2010, the spacecraft approached Earth and ejected the
  small (40 centimeters diameter) aluminum sample return capsule.  The
  sample container entered the Earth's atmosphere at about 12 kilometers
  per second, using ablative shielding to withstand the intense heat
  generated by atmospheric friction, and eventually parachuted down to the
  ground near Woomera Australia.  Eager scientists then collected the
  capsule and took it back to Japan so the asteroid surface samples could be
  carefully removed and distributed to the scientific community for study.
  These sample studies will be carried out using a variety of composition
  measuring devices in Earth based laboratories - devices that are not
  limited to the modest mass, volume, power, and data rates that can be
  accommodated by the Hayabusa spacecraft.  Furthermore, as more advanced
  future instrumentation is developed and new hypotheses arise, archived
  samples from the asteroid will be available for new measurements.
  Preliminary ground-based sample analyses were reported by
  [NAKAMURAETAL2011], [EBIHARAETAL2011], [YURIMOTOETAL2011],
  [NOGUCHIETAL2011],[TSUCHIYAMAETAL2011], and [NAGAOETAL2011]

  The instruments, with acronym and Principal Investigator (PI) or Team
  Leader (TL), are summarized below:

  Instrument                          Acronym    PI/TL
  ---------------------------------   -------    ------------
  Asteroid Multiband Imaging Camera     AMICA    Tsuko Nakamura, Jun Saito
  Near Infrared Spectrometer            NIRS     Masanao Abe
  LIDAR                                 LIDAR    Tadashi Mukai
  X-Ray Spectrometer                    XRS      Manabu Kato
  MINERVA                               MINERVA  Sho Sasaki


  Target Asteroid
  ===============

  Asteroid 25143 Itokawa:  The orbit of the Hayabusa target body, 25143
  Itokawa, has a low inclination with respect to the Earth's orbital plane
  (1.7 deg.) so it is one of the more accessible asteroids for a
  spacecraft rendezvous.  Fortunately, this asteroid made a close Earth
  approach to within six million kilometers in late March 2001 and an even
  closer Earth approach to within 2 million kilometers in late June 2004.
  Optical, infrared, and radar observations were undertaken in 2001 and
  2004.  The ground-based radar observations indicated that the object has
  a potato shape of approximate dimensions 548 x 312 x 276 meters
  [OSTROETAL2004] while ground-based optical and infrared data suggest
  that Itokawa is an S-type asteroid with a composition analogous to
  either an LL ordinary chondrite, or a primitive achondrite meteorite
  [BINZELETAL2001], [SEKIGUICHIETAL2001], [ABELLETAL2007].  In either case
  the asteroid appeared to be largely a silicate rock with a relatively
  low abundance of iron.  Detailed spectral observations obtained by the
  Hayabusa spacecraft were not able to definitively rule out either
  compositional interpretation [ABEETAL2006]. The spacecraft imaging
  confirmed the general dimensions of the asteroid.  Tables 2 and 3
  provide the orbital and physical characteristics for near-Earth asteroid
  25143 Itokawa as reported in [FUJIWARAETAL2006], [DEMURAETAL2006].


  Table 2.  Physical Characteristics of Target Body, 25143 Itokawa from
  spacecraft measurements.

  Magnitude (Abs.)                   19.1
  Spectral Type                      S
  Albedo                             0.3
  Size (km)                          550 x 298 x 244 meters (bounding box)
  Rotation Period                    12.1 hrs
  Temp. at Subsolar Point            217-445 K

  Table 3.  Orbital Elements

  Semi-Major Axis (AU)               1.324
  Eccentricity                       0.280
  Inclination (deg)                  1.72
  Perihelion (AU)                    0.95
  Aphelion (AU)                      1.62
  Orbital Period (years)             1.52


  References
  ==========

  Abe, M., T. Mukai, N. Hirata, O.S. Barnouin-Jha, A.F. Cheng, and 11
  others, Near-infrared spectral results of asteroid Itokawa from the
  Hayabusa spacecraft, Science 312, 1334-1338, 2006.

  Binzel, R.P., A.S. Rivkin, S.J. Bus, J.M. Sunshine, T.H. Burbine,
  MUSES-C target asteroid (25143) 1998 SF36: A reddened ordinary chondrite,
  Meteoritics and Planetary Science 36, 1167-1172, 2001.

  Demura, H., S. Kobayashi, E. Nemoto, N. Matsumoto, M. Furuya, and 15
  others, Pole and global shape of 25143 Itokawa, Science 312, 1347-1349,
  2006.

  Ebihara, M., S. Sekimoto, N. Shirai, Y. Hamajima, M. Yamamoto, and 17
  Others, Neutron Activation Analysis of a Particle Returned from Asteroid
  Itokawa, Science 333, 1119-1121, 2011.

  Fujiwara, A., J. Kawaguchi, D.K. Yeomans, M. Abe, T. Mukai, and 17
  others, The rubble-pile asteroid Itokawa as observed by Hayabusa,
  Science 312, 1330-1334, 2006.

  Ishiguro, M., R. Nakamura, D.J. Tholen, N. Hirata, H. Demura, and 10
  others, The Hayabusa Spacecraft Asteroid Multi-band Imaging Camera (AMICA),
  Icarus 207, 714-731, 2010.

  Kitazato, K., B.E. Clark, M. Abe, S. Abe, Y. Takagi, and 5 others,
  Near-infrared spectrophotometry of Asteroid 25143 Itokawa from NIRS on
  the Hayabusa spacecraft, Icarus 194, 137-145, 2008.

  Kuninaka, Hitoshi, K. Nishiyama, Y. Shimizu, T. Yamada, H. Koizumi.
  Re-ignition of Microwave Discharge Ion Engines on Hayabusa for Homeward
  Journey.  The 30th International Electric Propulsion Conference,
  Florence, Italy, Sept. 17-20, 2007.

  Mukai, T., S. Abe, N. Hirata, R. Nakamura, O.S. Barnouin-Jha, and
  11 others, An overview of the LIDAR observations of asteroid 25143
  Itokawa,  Advances in Space Research 40, 187-192, 2007.

  Nagao, K., R. Okazaki, T. Nakamura, Y.N. Miura, T. Osawa, and 21
  Others, Irradiation History of Itokawa Regolith Material Deduced from
  Noble Gases in the Hayabusa Samples, Science 333, 1128-1131, 2011.

  Nakamura, T., T. Noguchi, M. Tanaka, M.E. Zolensky, M. Kimura, and
  17 others, Itokawa Dust Particles: A Direct Link Between S-Type
  Asteroids and Ordinary Chondrites, Science 333, 1113-1116, 2011.

  Noguchi, T., T. Nakamura, M. Kimura, M.E. Zolensky, M. Tanaka, and 13
  Others, Incipient Space Weathering Observed on the Surface of Itokawa
  Dust Particles, Science 333, 1121-1125, 2011.

  Okada, T., K. Shirai, Y. Yamamoto, T. Arai, K. Ogawa, and 2 others,
  X-ray fluorescence spectrometry of asteroid Itokawa by Hayabusa,  Science
  312, 1338-1341, 2006.

  Ostro, S.J., L.A.M. Benner, M.C. Nolan, C. Magri, J.D. Giorgini, and 11
  others, Radar observations of asteroid 25143 Itokawa (1998 SF36),
  Meteoritics and Planetary Science 39, 407-424, 2004.

  Saito, J., H. Miyamoto, R. Nakamura, M. Ishiguro, T. Michikami, and 29
  others, Detailed images of asteroid 25143 Itokawa from Hayabusa, Science
  312, 1341-1344, 2006.

  Sekiguichi, T., M. Sterzik, N. Ageorges, and O. Hainaut (2001). IAU
  Circular 7598, dated 2001 March 10.

  Tsuchiyama, A., M. Uesugi, T. Matsushima, T. Michikami, T. Kadono, and
  28 others, Three-Dimensional Structure of Hayabusa Samples: Origin and
  Evolution of Itokawa Regolith, Science 333, 1125-1128, 2011.

  Yano, H., T. Kubota, M. Miyamoto, T. Okada, D. Scheeres, and 15 others,
  Touchdown of the Hayabusa spacecraft at the Muses Sea on Hayabusa,
  Science 312, 1350-1353, 2006.

  Yoshimitsu, T., T. Kubota, I. Nakatani, T. Adachi, H. Saito, Hopping
  Rover 'MINERVA' for Asteroid Exploration, ESA SP-440, 83-88, 1999.

  Yurimoto, H., K-I Abe, M. Abe, M. Ebihara, A. Fujimura, and 28 others,
  Oxygen Isotopic Compositions of Asteroidal Materials Returned from Itokawa
  by the Hayabusa Mission, Science 333, 1116-1119, 2011.


  Mission Phases
  ==============

    LAUNCH
    ------
      Mission Phase Start Time  : 2003-05-09
      Mission Phase Stop Time   : 2003-05-09

      --------------------------  ----------  ----------------------------
      Event                       Date        Description
      --------------------------  ----------  ----------------------------
      Launch                      2003-05-09  at 13 hrs, 29 min. JST, M-V
                                              launch vehicle, Kagoshima
                                              Japan


    CRUISE TO ASTEROID
    ------------------
      Mission Phase Start Time  : 2003-05-10
      Mission Phase Stop Time   : 2005-09-11

      --------------------------  ----------  ----------------------------
      Event                       Date        Description
      --------------------------  ----------  ----------------------------
      Solar flare                 2003-11     Solar panel efficiency
                                              degraded

      TCM-1                       2004-04-20  14 cm/s, chemical thrust

      Trim maneuver 3             2004-05-12  Trim maneuvers 0-2 were
                                              canceled

      Earth flyby                 2004-05-19  06:21:40 UTC, Altitude above
                                              Earth's surface = 3725 km

      Reaction wheel failure      2005-07-31  Y-axis wheel ceases to
                                              operate


    SPACECRAFT AT GATE POSITION
    ---------------------------
      Mission Phase Start Time  : 2005-09-12
      Mission Phase Stop Time   : 2005-09-29

      --------------------------  ----------  ----------------------------
      Event                       Date        Description
      --------------------------  ----------  ----------------------------
      Itokawa arrival             2005-09-12  Spacecraft 20 km from
                                              asteroid. Approach speed =
                                              0.2 mm/s


    SPACECRAFT NEAR HOME POSITION
    -----------------------------
      Mission Phase Start Time  : 2005-09-30
      Mission Phase Stop Time   : 2005-12-07

      --------------------------  ----------  ----------------------------
      Event                       Date        Description
      --------------------------  ----------  ----------------------------
      Descent to Home position    2005-09-30  6.8 km from surface of
                                              asteroid

      Reaction wheel failure      2005-10-02  23:08 UTC, X-axis wheel
                                              ceases to operate

      1st descent rehearsal       2005-11-04  Asteroid center-of-mass
                                              determined

      Navigation & Guidance       2005-11-09  Navigation and guidance
                                              practice 1st target
                                              marker released (to
                                              space)

      MINERVA released            2005-11-12  Released into solar orbit

      Sampling attempt            2005-11-19  1st (unsuccessful) sampling
                                              attempt LRF detects
                                              surface feature and
                                              attempts emergency abort.
                                              However, S/C attitude
                                              outside permitted range
                                              to tolerate departure
                                              acceleration - autonomous
                                              decision to continue
                                              descent but S/C never
                                              entered TD mode because
                                              Fan Bean Sensor detected
                                              obstacle and disabled
                                              triggering - no pellets
                                              fired into surface.  Only
                                              Doppler data available.
                                              Unknown to ground
                                              controllers, S/C bounces
                                              once and sits on surface
                                              for ~30 min. before
                                              emergency abort command
                                              received from ground.

      2nd sampling attempt        2005-11-25  Fan Beam Sensor disengaged
                                              and no target marker
                                              released.  Lateral S/C
                                              motion control turned off
                                              - only vertical
                                              autonomous control used.
                                              Conflicts in operations
                                              script may not have
                                              allowed pellet firings.
                                              Shooting command given
                                              but ignition switch in
                                              safe mode. Fuel leak
                                              triggered s/c safe mode
                                              with many difficulties in
                                              recovering.


  SPACECRAFT RECOVERY OPERATIONS
  ------------------------------
  Mission Phase Start Time  : 2005-12-08
  Mission Phase Stop Time   : 2007-04-24

  --------------------------  ----------  ----------------------------
  Event                       Date        Description
  --------------------------  ----------  ----------------------------
  Radio contact lost          2005-12-08  Radio contact lost possibly
                                          due to sudden leak of
                                          attitude gas causing s/c
                                          to spin.

  Spacecraft in safe mode     2005-12-09

  Beacon signal received      2006-01-23

  Spacecraft responds         2006-01-26  Spacecraft anomaly functions
                                          begin responding

  Low bit rate com.           2006-02-25  8 bps data rate established

                              2006-03-04  32 bps data rate established
                                          Chemical fuel expended,
                                          batteries severely
                                          degraded

                              2006-03-16  256 bps data rate established

  Spacecraft stabilized       2006-05-08  Spacecraft stabilized and
                                          pointing properly


  CRUISE BACK TO EARTH
  --------------------
  Mission Phase Start Time  : 2007-04-25
  Mission Phase Stop Time   : 2010-06-12

  --------------------------  ----------  ----------------------------
  Event                       Date        Description
  --------------------------  ----------  ----------------------------
  Spacecraft departs          2007-04-25  Ion engines started;
                                          spacecraft begins return
                                          to Earth.


  SAMPLE CAPSULE AND HAYABUSA S/C ENTER EARTH'S ATMOSPHERE
  --------------------------------------------------------
  Mission Phase Start Time  : 2010-06-13
  Mission Phase Stop Time   : 2010-06-13
MISSION_OBJECTIVES_SUMMARY
Mission Objectives Overview
  ===========================

  MUSES-C Science Objectives  [FUJIWARAETAL2006]

  AMICA - Asteroid Multiband Imaging Camera [SAITOETAL2006],
          [ISHIGUROETAL2010]
   - Map surface morphology including surface features to 1-m resolution.
   - Determine spin state, colors, size, shape, volume, and rotation
       characteristics.
   - Search for possible asteroid satellites and dust rings.
   - Establish a global map of surface features and colors.
   - Reveal history of impacts from other asteroid and comet fragments.
   - Determine optical parameters of regolith particles using polarization
       degree vs. phase curve at large phase angles.
   - Map mineralogical composition of asteroid and identify rock types
       present.
   - Determine most likely meteorite analog for composition of asteroid.

  Near-IR Spectrometer [ABEETAL2006]
   - Map mineralogical composition of asteroid and provide main evidence
       for rock types present on surface at scales as small as 20 m.
   - Characterize surface heterogeneity.
   - Together with elemental composition measurements provided by (XRS)
         and color imagery from camera, IR spectrometer will provide
         link between this asteroid and a meteorite type.

  X-Ray Spectrometer (XRS)  [OKADAETAL2006]
   - Map the major elemental composition of the surface as the asteroid
       rotates under the spacecraft.
   - Determine the major elemental composition at localized areas during
       asteroid approach phases.
   - Measure surface composition accurately enough to establish
         relationship between asteroids and meteorites and identify type
         of meteorite to which asteroid is linked.
   - Provide elemental abundance maps to investigate inhomogeneity of
         regolith.

  Sample Return Analysis  [YANOETAL2006]
   - Samples returned to Earth will provide a detailed and definitive
         elemental composition analysis of the asteroid's surface
         materials and hence forge an unambiguous link between the
         asteroid's composition and a meteorite type.

  LIDAR  [MUKAIETAL2007]
   - Provide accurate shape and mass determinations for asteroid.
   - Map asteroid's surface with a maximum resolution of about 1-meter.

  MINERVA [YOSHIMITSUETAL1999]
   - View the surface at high resolution, including the sampling areas
   - Measure the surface gravity
   - Measure the surface temperature
REFERENCE_DESCRIPTION