Investigation Information
IDENTIFIER urn:nasa:pds:context:investigation:mission.2001_mars_odyssey::1.0
NAME 2001 MARS ODYSSEY
TYPE Mission
DESCRIPTION
Mission Overview
  ================
 
    The Mars Odyssey spacecraft was launched from the Cape
    Canaveral Air Station in Florida on 2001-04-07 aboard a Boeing
    Delta II 7925 launch vehicle.  At launch Odyssey weighed 729.7
    kilograms (1606.7 pounds), including the 331.8 kilogram (731.5
    pound) dry spacecraft with all of its subsystems, 353.4
    kilograms (779.1 pounds) of fuel and 44.5 kilograms (98.1
    pounds) of instruments.  The spacecraft traveled more than 460
    million kilometers over the course of a 200-day cruise period
    to reach Mars on 2001-10-24.
 
    Upon reaching Mars, Odyssey fired its main rocket engine for a
    19-minute Mars orbit insertion (MOI) burn.  This maneuver
    slowed the spacecraft and allowed the planet's gravity to
    capture it into orbit.  Initially, Odyssey whirled around the
    red planet in a highly elliptical orbit that took 45 hours to
    complete.
 
    After orbit insertion, Odyssey performed a series of orbit
    changes to drop the low point of its orbit into the upper
    fringes of the Martian atmosphere at an altitude of about 110
    kilometers.  During every atmospheric pass, the spacecraft
    slowed by a small amount because of air resistance.  This
    slowing caused the spacecraft to lose altitude on its next pass
    through the atmosphere.  Odyssey used this aerobraking
    technique over a period of three months to transition from an
    elliptical orbit into a 400 km nearly circular orbit for
    mapping.
 
    Mars Odyssey was intended to last for more than 2 full Mars
    years, or 1374 days.  The orbiter had its own science
    mission and also acted as a relay for landed Mars missions in
    2004.  The primary mapping mission began in
    February 2002 and lasted until August 2004 for a total of
    917 days.  An extended mission then took place through the end
    of September 2006. The inclination of the science orbit was 93.1
    degrees, resulting in a nearly Sun- synchronous orbit
    [JPLD-16303].  The orbit period was just under two hours.
 
    The spacecraft was three-axis stabilized and powered by solar
    cells.  It was built of lightweight composite materials and
    divided into two sub-assemblies: the equipment module and the
    propulsion module.  The equipment module consisted of two decks
    - the equipment deck, containing engineering equipment and one
    science instrument, the Martian Radiation Environment
    Experiment (MARIE), and the science deck, which housed the
    remainder of the science instruments and other engineering
    components.
 
    Mars Odyssey carried three on-board science instruments.  The
    Thermal Emission Imaging System (THEMIS) worked both in the
    visible and infrared spectral regions.  It took multi-spectral
    thermal-infrared images to determine the surface mineralogy at
    a global scale and also acquired visible images with a
    per-pixel resolution of 18 meters (59 feet).  The Gamma Ray
    Spectrometer (GRS) measured gamma rays emitted from the surface
    of Mars to determine the elemental composition of the surface,
    including mapping water deposits in water-ice form.  It also
    studied cosmic gamma ray bursts.  GRS was actually a suite of
    three instruments - the Gamma Ray Spectrometer, the Neuron
    Spectrometer (NS) and the High-Energy Neutron Detector (HEND).
    GRS and THEMIS could not operate at the same time due to
    conflicts in the parameters necessary for operation.
 
    The third instrument, the Martian Radiation Environment Experiment
    (MARIE), was intended to operate continuously throughout the
    science mission to collect data about the radiation environment of
    the planet. Flight commanders turned off MARIE on 2001-08-18
    because the instrument failed to reset after it did not respond
    during a downlink session the previous week. It was turned on
    again in early March 2002 after the mapping orbit had been
    established. MARIE operated from that time until it was disabled
    following an intense solar particle event on October 29, 2003.
    Before being disabled, the instrument showed abnormally high
    current draw and temperatures. Throughout November and early
    December of 2003, after the solar event subsided and after
    Odyssey recovered from entering safe mode, the Odyssey team
    attempted unsuccessfully to reestablish communication with MARIE.
 
    Two other instruments aboard Odyssey were, like MARIE,
    sensitive to energetic charged particles.  The first instrument
    was the gamma detector on GRS, which used a large germanium
    crystal to detects gamma rays coming from the Martian surface.
    The detection of gamma rays depended on the deposition of energy
    in the crystal by the incident photons. Charged particles also
    deposited energy in the crystal. The second non-MARIE instrument
    aboard Odyssey that was sensitive to charged particles was the
    scintillation block in the high energy neutron detector (HEND,
    an element of the GRS suite). The 'external' detector was a
    cesium-iodide (CsI) scintillator surrounding a stilbene crystal
    scintillator that was used for high-energy neutron detection.
    These two detectors were available to continue the monitoring of
    aspects of the radiation environment at Mars that was conducted
    by MARIE during Odyssey's cruise and prime mission phases.
 
    The local mean solar time (LMST) at the start of the Odyssey
    mission was approximately 4:00 p.m. and was later frozen by
    a maneuver to approximately 5:00 p.m. The local true solar time
    (LTST) oscillated about 45 minutes around the mean. During the
    Extended Mission, a small maneuver could be used to eliminate
    any further drift in LMST. The solar beta angle, which is
    closely related to the local solar time, had to be maintained
    at values less than -55 degrees to ensure that GRS radiative cooler
    was not exposed to the Sun. The Extended Mission orbit had several
    notable features. In late 2005, the LTST drifted to earlier
    values, which was favorable for THEMIS daytime infrared imaging.
    This period also coincided with a minimum in the Earth-Mars range,
    allowing high downlink data rates, also favorable for THEMIS.
    A similar favorable geometry occurs in late 2007.
 
 
  Mission Phases
  ==============
    Six mission phases were defined for significant spacecraft
    activity periods.  These were the Pre-Launch, Launch and
    Initialization, Cruise, Orbit Insertion, Aerobraking, and
    Mapping Phases.  The Cruise Phase included
    three sub-phases: near-Earth, Earth-Mars, and Mars approach.
 
    The final Mapping phase was intended to support the 2003
    twin Mars Exploration Rovers and the European Space Agency's
    Mars Express Beagle II Lander.  The rovers began surface operations
    in January 2004. Beagle II was lost following its landing attempt
    on December 25, 2003. The Extended Mission, which began in August
    2004, had the additional goals of supporting orbit insertion and
    aerobraking of the Mars Reconnaissance Orbiter in 2006 and landing
    site reconnaissance for the Phoenix Lander mission.
 
    PRELAUNCH
    ---------
      The Prelaunch Phase extended from the delivery of the
      spacecraft to the Eastern Test Range (ETR) until the
      beginning of the start of the launch countdown at the Kennedy
      Space Center.
 
      Mission Phase Start Time : 2001-01-04
      Mission Phase Stop Time  : 2001-04-07
 
 
    LAUNCH AND INITIALIZATION
    -------------------------
      The Launch Phase extended from the start of launch countdown
      until first contact with the Deep Space Network (DSN) 53
      minutes after launch.
 
      Mission Phase Start Time : 2001-04-07
      Mission Phase Stop Time  : 2001-04-07
 
 
    CRUISE
    ------
      The Cruise Phase began with initial DSN contact and lasted
      until 24 hours prior to Mars orbit insertion (MOI).  It
      included 4 trajectory control maneuvers (TCM).  The
      near-Earth subphase included checkout of the spacecraft
      engineering functions, instrument checkouts, THEMIS imaging
      of the Earth/Moon system, and TCM-1.
 
      Mission Phase Start Time : 2001-04-07
      Mission Phase Stop Time  : 2001-10-23
 
        Subphases             Dates
        ---------             -----
        Near-Earth            2001-04-07 to 2001-04-21
        Earth-Mars            2001-04-21 to 2001-09-04
        Mars Approach         2001-09-04 to 2001-10-17
 
 
    ORBIT INSERTION
    ---------------
      The orbit insertion phase began 24 hours before spacecraft
      arrival at Mars.  It included the Mars Orbit Insertion (MOI)
      burn, which achieved an orbit with a 18.6 hour period, making
      the planned Period Reduction Maneuver (PRM) unnecessary.  MOI
      was achieved through a 19 minute long bipropellant burn.
 
      Mission Phase Start Time : 2001-10-23
      Mission Phase Stop Time  : 2001-10-27
 
 
    AEROBRAKING
    -----------
      The Aerobraking phase began with the completion of the Orbit
      Insertion Phase and ended with the attainment of the 400 km
      science orbit.  It consisted of brushing through the Martian
      atmosphere, using the solar panels to create drag and slow
      down the spacecraft and thus reduce the orbit.  The phase also
      included the deployment of the GRS boom.  GRS acquired data
      throughout the aerobraking phase.  Aerobraking concluded with
      two weeks of transition into the Mapping Phase.
      The transition included the deployment of the high-gain
      antenna.
 
      Mission Phase Start Time : 2001-10-27
      Mission Phase Stop Time  : 2002-02-19
 
 
    MAPPING
    -------
      The Mapping Phase began once the 400 km science orbit with
      approximately 5 PM equator crossing was achieved, at
      19-Feb-2002 17:14:32 UTC. This time marked the beginning
      of orbit number 816. The intensive science portion lasted
      917 days, with at least one of the three science instruments
      operating at all times throughout that period.
 
      Mission Phase Start Time : 2002-02-19
      Mission Phase Stop Time  : 2004-08-24
 
 
    EXTENDED MISSION 1
    ------------------
      The first Extended Mission began when the Mapping Phase of the
      Primary Mission ended, in August 2004. It was to continue for
      slightly more than one Mars year, about two Earth years. The
      Extended Mission was designed to address NASA's Mars exploration
      goals by:
 
      - Significantly enhancing the scientific data sets already
        acquired, extending their temporal and spatial coverage,
      - Enabling new types of observations by operating the
        instruments and spacecraft in innovative ways,
      - Providing operational support for critical phases of future
        missions, such as communications relay, landing site
        characterization, and atmospheric monitoring for aerobraking,
      - Involving additional students and scientists in data
        collection and analysis, and
      - Establishing Odyssey's role as a long-term asset in the
        scientific and operational infrastructure at Mars.
 
      Mission Phase Start Time : 2004-08-24
      Mission Phase Stop Time  : 2006-09-30
START DATE 2001-01-04T12:00:00.000Z
STOP DATE N/A (ongoing)
REFERENCES Mars Surveyor 2001, Mission Plan, Revision B (MSP 722-201), JPL Document D-16303, Jet Propulsion Laboratory, Pasadena, CA, 2000.