Mission Information
MISSION_NAME MARS EXPRESS
MISSION_ALIAS MEX
MISSION_START_DATE 1997-10-31T12:00:00.000Z
MISSION_STOP_DATE 3000-01-01T12:00:00.000Z
MISSION_DESCRIPTION
Mission Overview
  ================
    Mars Express was the first flexible mission of the revised long-term
    ESA Science Programme Horizons 2000 and was launched to the planet
    Mars from Baikonur (Kazakhstan) on June 2nd 2003.  A Soyuz-Fregat
    launcher injected the Mars Express total mass of about 1200 kg into
    Mars transfer orbit. Details about the mission launch sequence and
    profile can be obtained from the Mission Plan [MEX-MMT-RP-0221] and
    from the Consolidated Report on Mission Analysis (CREMA)
    [MEX-ESC-RP-5500].
 
    The mission consisted of (i) a 3-axis stabilized orbiter with a fixed
    high-gain antenna and body-mounted instruments, and (ii) a lander
    named BEAGLE-2, and was dedicated to the orbital and in-situ study of
    the interior, subsurface, surface and atmosphere of the planet. After
    ejection of a small lander on 18 December 2003 and Mars orbit
    insertion (MOI) on 25 December 2003, the orbiter experiments began
    the acquisition of scientific data from Mars and its environment in a
    polar elliptical orbit.
 
    The nominal mission lifetime for the orbiter was 687 days following
    Mars orbit insertion, starting after a 5 months cruise. The nominal
    science phase was extended (tbc) for another Martian year in order to
    complement earlier observations and allow data relay communications
    for various potential Mars landers up to 2008, provided that the
    spacecraft resources permit it.
 
    The Mars Express spacecraft represented the core of the mission,
    being scientifically justified on its own by investigations such
    as high- resolution imaging and mineralogical mapping of the
    surface, radar sounding of the subsurface structure down to the
    permafrost, precise determination of the atmospheric circulation
    and composition, and study of the interaction of the atmosphere
    with the interplanetary medium. The broad scientific objectives of
    the orbiter payload are briefly listed thereafter and are given
    more extensively in the experiment publications contained in ESA's
    Special Publication Series. See [NEUKUM&JAUMANN2004],
    [BIBRINGETAL2004], [PICARDIETAL2004], [FORMISANOETAL2004],
    [BERTAUXETAL2004], [PAETZOLDETAL2004] and [PULLANETAL2004].
 
    The Mars Express lander Beagle-2 was ejected towards the Mars
    surface on 19 December 2003, six days before the orbiters capture
    manoeuvre. The probe mass was limited to about 70 kg by the
    mission constraints, which led to a landed mass of 32 kg. The
    complete experimental package was weighed in approximately at 9kg.
    The landers highly integrated scientific payload was supposed to
    focus on finding whether there is convincing evidence for past
    life on Mars or assessing if the conditions were ever suitable.
    Following safe landing on Mars, this lander mission would have
    conducted dedicated studies of the geology, mineralogy,
    geochemistry, meteorology and exobiology of the immediate landing
    site located in Isidis Planitia (90.74 deg E, 11.6 deg N), as well
    as studies of the chemistry of the Martian atmosphere. Surface
    operations were planned to last about 180 sols or Martian days (
    about 6 months on Earth), see [SIMSETAL1999]. As no communication
    could be established to the BEAGLE-2 lander, it was considered
    lost in February 2004 after an extensive 'search'.
 
    A nominal launch of Mars Express allowed the modify the orbit to a
    'G3-ubeq100' orbit. The 'G3-ubeq100' orbit is an elliptical orbit,
    starting with the sub-spacecraft point at pericentre at the equator
    and a sun elevation of 60 degrees.
    At the beginning of the mission, the pericentre moves southward with
    a shift of 0.54 degree per day. At the same time the pericentre steps
    towards the terminator which will be reached after about 4 months,
    giving the optical instruments optimal observing conditions during
    this initial period. Throughout this initial phase lasting until mid-
    May 2004, the downlink rate will decrease from 114 kbit/s to
    38 kbit/s.
    After an orbit change manoeuvre on 06 May 2004 the pericentre
    latitude motion is increased to guarantee a 50/50 balance between
    dayside and nightside operations. With this manoeuvre, the apocentre
    altitude is lowered from 14887 km to 13448 km, the orbital period
    lowered from ~7.6 hours to 6.645 hours, and the pericentre latitude
    drift slightly increased to 0.64 degree per day.
    After 150 days, at the beginning of June 2004, the South pole region
    was reached with the pericentre already behind the terminator.
    Following, the pericentre moves northward with the Sun elevation
    increasing. Thus, the optical instruments covered the Northern Mars
    hemisphere under good illumination conditions from mid-September 2004
    to March 2005.
    During the next mission phase, lasting until July 2005, the
    pericentre was again in the dark. It covered the North polar region
    and moves southward.
    Finally, throughout the last 4 months of the nominal mission, the
    pericentre was back to daylight and moves from the equator to the
    South pole, and the downlink rate reached its highest rate of 228
    kbit/s. The osculating orbit elements for the eq100 orbit are listed
    below:
 
    Epoch                                 2004:1:13 - 15:56:0.096
    Pericentre (rel. sphere of 3397.2 km) 279.29 km
    Apocentre (rel. sphere)               11634.48 km
    Semimajor axis                        9354.09 km
    Eccentricity                          0.60696
    Inclination                           86.583
    Right ascension of ascending node     228.774
    Argument of pericentre                357.981
    True anomaly                          -0.001
 
 
  Mission Phases
  ==============
    The mission phases are defined as:
 
    (i) Pre-launch, Launch and Early Operations activities, including
       (1) science observation planning;
       (2) payload assembly, integration and testing;
       (3) payload data processing software design, development and
           testing;
       (4) payload calibration;
       (5) data archive definition and planning;
       (6) launch campaign.
 
    (ii) Near-Earth verification (EV) phase, including
       (1) commissioning of the orbiter spacecraft;
       (2) verification of the payload status;
       (3) early commissioning of payload.
 
    (iii) Interplanetary cruise (IC) phase
       (1) payload checkouts
       (2) trajectory corrections
 
    (iv) Mars arrival and orbit insertion (MOI)
       (1) Mars arrival preparation;
       (2) lander ejection;
       (3) orbit insertion;
       (4) operational orbit reached and declared;
       (5) no payload activities.
 
    (v) Mars commissioning phase
       (1) final instrument  commissioning,
       (2) first science results,
       (3) change of orbital plane.
 
    (vi) Routine phase;
       Opportunities for dawn/dusk observations, mostly spectroscopy and
       photometry. This phase continued into a low data rate phase (night
       time; favorable for radar and spectrometers).
       Then daylight time, and went into a higher data rate period
       (medium illumination, zenith, then decreasing illumination
       conditions).
       Observational conditions were most favorable for the optical
       imaging instruments at the end of the routine phase, when both
       data downlink rate and Sun elevation are high.
 
    (vii) MARSIS Deployment
       The dates of the MARSIS antenna deployment is not known as of
       writing this catalogue file.
 
    (viii) Extended operations phase
       A mission extension will be proposed in early 2005 to the Science
       Programme Committee (SPC).
 
    (ix) Post-mission phase (final data archival).
 
 
  Science Subphases
  =================
    For the purpose of structuring further the payload operations
    planning, the mission phases are further divided into science
    subphases. The science subphases are defined according to operational
    restrictions, the main operational restrictions being the downlink
    rate and the Sun elevation.
 
    The Mars Commissioning Phase and the Mars Routine Phase are therefore
    divided into a number of science subphases using various combinations
    of Sun elevations and available downlink bit rates.
 
    The discrete downlink rates available throughout the nominal mission
    are:
     -  28 kbits/seconds
     -  38 kbits/seconds
     -  45 kbits/seconds
     -  57 kbits/seconds
     -  76 kbits/seconds
     -  91 kbits/seconds
     - 114 kbits/seconds
     - 152 kbits/seconds
     - 182 kbits/seconds
     - 228 kbits/seconds
 
    The adopted Sun elevation coding convention is as follows:
     - HSE for High Sun Elevation (> 60 degrees)
     - MSE for Medium Sun Elevation (between 20 and 60 degrees)
     - LSE for Low Sun Elevation (between -15 and 20 degrees)
     - NSE for Negative Sun Elevation (< -15 degrees)
 
    The science subphase naming convention is as follows:
      - Science Phase
      - Sun Elevation Code
      - Downlink Rate
      - Science Subphase Repetition Number
 
    The following tables gives the available Science Subphases:
 
      NAME       START        END          ORBITS     BIT  SUN
                                                     RATE  ELE
    ----------------------------------------------------------
    MC Phase 0  2003-12-30 - 2004-01-13    1  -   16
    MC Phase 1  2004-01-13 - 2004-01-28   17  -   58  114   59
    MC Phase 2  2004-01-28 - 2004-02-12   59  -  105   91   69
    MC Phase 3  2004-02-12 - 2004-03-15  106  -  208   76   71
    MC Phase 4  2004-03-15 - 2004-04-06  209  -  278   57   51
    MC Phase 5  2004-04-06 - 2004-04-20  279  -  320   45   33
    MC Phase 6  2004-04-20 - 2004-06-04  321  -  475   38   22
 
    MR Phase 1  2004-06-05 - 2004-08-16  476  -  733   28  -13
    MR Phase 2  2004-08-16 - 2004-10-16  734  -  951   28  -26
    MR Phase 3  2004-10-16 - 2005-01-07  952  - 1250   28   16
    MR Phase 4  2004-01-08 - 2005-03-05 1251  - 1454   45   63
    MR Phase 5  2004-03-05 - 2005-03-24 1455  - 1522   76   16
    MR Phase 6  2004-03-25 - 2005-07-15 1523  - 1915   91    0
 
    The data rate is given in kbit per seconds and represents
    the minimal data rate during the subphase.
    The sun elevation is given in degrees and represents the
    rate at the beginning of the subphase.
 
    Detailed information on the science subphases can be found in
    [MEX-EST-PL-13128].
MISSION_OBJECTIVES_SUMMARY
Mission Objectives Overview
  ===========================
    The Mars Express orbiter was equipped with the following selected
    payload complement, representing about 116 kg in mass, with the
    following associated broad scientific objectives:
 
    Energetic Neutral Atoms Imager   ASPERA
    - Study of interaction of the upper atmosphere with the
      interplanetary medium and solar wind.
    - Characterisation of the near-Mars plasma and neutral gas
      environment.
 
    High-Resolution Stereo Camera   HRSC
    - Characterisation of the surface structure and morphology at high
      spatial resolution
      (up to 10 m/pixel) and super resolution (up to 2 m/pixel).
    - Characterisation of the surface topography at high spatial and
      vertical resolution.
    - Terrain compositional classification.
 
    Radio Science Experiment   MaRS -
    - Characterisation of the atmospheric vertical density, pressure, and
      temperature profiles as a function of height.
    - Derivation of vertical ionospheric electron density profiles.
    - Determination of dielectric and scattering properties of the
      surface in specific target areas.
    - Study of gravity anomalies.
    - Study of the solar corona.
 
    Mars Advanced Radar for Subsurface and Ionosphere Sounding   MARSIS
    - Study of the subsurface structure at km scale down to the
      permafrost.
    - Mapping of the distribution of water detected in the upper portions
      of the crust.
    - Characterisation of the surface roughness and topography.
 
    Lander Communications Package   MELACOM
    - This telecommunications subsystem constitutes the data relay
      payload of Mars Express.
    - Its primary mission was to provide the data services for the
      Beagle-2 lander.
    - It was designed to relay at least 10 Mbits of information per day.
 
    IR Mineralogical Mapping Spectrometer   OMEGA
    - Global mineralogical mapping at 100-m resolution.
    - Identification and characterisation of specific mineral and
      molecular phases of the surface.
    - Identification and characterisation of photometric units.
    - Mapping of their spatial distribution and abundance.
    - Study of the time and space distribution of atmospheric particles.
 
    Planetary Fourier Spectrometer   PFS
    - Characterisation of the global atmospheric circulation.
    - Mapping of the atmospheric composition.
    - Study of the mineralogical composition and of surface atmosphere
      interactions.
 
    UV and IR Atmospheric Spectrometer   SPICAM
    - Study of the global structure and composition of the Martian
      atmosphere.
    - Study of surface-atmosphere interactions.
 
    Visual Monitoring Camera   VMC
    - Stand-alone digital camera to take colour snapshots of the Beagle
      lander.
    - Operation of this camera will occur during separation of the lander
 
    Geochemistry and Exobiology Lander  BEAGLE-2
 
    The top-level scientific objectives of the lander are:
      - Geological investigation of the local terrain and rocks (light
        element chemistry, composition, mineralogy, petrology, age).
      - Investigation of the oxidation state of the Martian surface.
      - Full characterisation of the atmospheric composition.
      - Search for criteria that demonstrated life processes appeared in
        the past.
      - Determination of trace atmospheric gases.
 
    When folded up Beagle 2 resembles a pocket watch. However, as soon as
    it comes to a halt on the Martian surface its outer casting will open
    to reveal the inner workings. Firstly the solar panels will unfold -
    catching sunlight the charge the batteries which will power the
    lander and its experiments throughout the mission. Next, a robotic
    arm will spring to life. Attached to the end of the arm is the PAW
    (Position Adjustable Workload) where most of the experiments are
    located. These include a pair of stereo cameras, a microscope, two
    types of spectrometer, and a torch to illuminate surfaces. The PAW
    also houses the corer/grinder and the mole, two devices for
    collecting rock and soil samples for analysis.
 
    Scientific Objectives
 
     Gas Analysis Package
      This is where investigations most relevant to detecting past or
      present life will be conducted. The instrument has twelve ovens in
      which rock and soil samples can be heated gradually in the presence
      of oxygen. The carbon dioxide generated at each temperature will be
      delivered to a mass spctrometer, which will measure its abundance
      and the ratio of carbon-12 to carbon-13. The mass spectrometer will
      also study other elements and look for methane in samples of
      atmosphere. The temperature at which the carbon dioxide is
      generated will reveal its nature, as different carbon bearing
      materials combust at different temperatures.
 
     Environmental sensors
       A variety of tiny sensors scattered about the Beagle 2 lander will
       measure different aspects of the Martian environment including
       atmospheric pressure ,air temperature and wind speed and
       direction; ultra-violet (UV radiation; dust fall out and the
       density and pressure of the upper atmosphere during Beagle 2's
       descent through the atmosphere.
 
     Two stereo cameras
       The cameras will provide digital pictures from which a 3D model of
       the area within the reach of the robotic arm may be constructed.
       As the PAW cannot be operated in real time from Earth, this 3D
       model will be used to guide the instruments into position
       alongside target rocks and soil and to provide information on the
       geological setting of the landing site.
 
     Microscope
      The microscope will pick out features a few thousandths of a
      millimetre across on rock surfaces exposed by the grinder. It will
      reveal the texture of the rock, which will help determine whether
      it is of sedimentary or volcanic origin.
 
     Mossbauer Spectrometer
      It will investigate the mineral composition of rocks by irradiating
      exposed rock surfaces and soil with gamma rays emitted by an
      isotopic source, cobalt-57, and then measuring the spectrum of the
      gamma-rays reflected back. In particular, the nature of the iron
      minerals in the pristine interior and weathered surface of the
      rocks will be compared to determine the oxidising nature of the
      present atmosphere.
 
     X-ray spectrometer
      This will measure the elemental composition of rocks by bombarding
      exposed rock surfaces with X-rays from four radioactive sources
      (two iron-55 and two cadmium-109). The rocks will emit lower energy
      X-rays characteristic of the elements present. Rock ages will be
      estimated using the property that the isotope potassium-40 decays
      to argon-40. The X-ray spectrometer will provide the potassium
      measure and the GAP will measure argon trapped in rocks.
 
     Mole
      The mole will be able to crawl up to several metres across the
      surface at a rate of 1cm every six seconds. Once it has reached a
      boulder, it will burrow underground to collect samples in a cavity
      in its tip. Alternatively, the PAW can be positioned such that the
      mole will burrow underground to collect samples possibly 1.5m below
      the surface.
 
     Corer/Grinder
       The corer/grinder consists of a drill bit which can either be
       moved over a surface to remove weathered material, or be
       positioned in one spot to drill a core of hopefully pristine
       samples.
REFERENCE_DESCRIPTION Bibring, J-P, et. al., OMEGA: Observatoire pour la Mineralogie, l'Eau, les Glaces et l'Activite, ESA SP-1240, September 2004

Deep Space Network / Flight Project Interface Design Book, Document 810-5, Jet Propulsion Laboratory, Pasadena, CA.

Formisano, V., et. al., The Planetary Fourier Spectrometer(PFS) for Mars Express, ESA SP-1240, September 2004

MEX-ESC-PL-5500, 'Mars Express Mission Implementation Plan', Issue 1.0, September 1999

MEX-ESC-RP-5500, 'Mars Express Consolidated Report on Mission Analysis (CREMA)', M. Hechler, Arturo Yanez, Issue 3.1, 6 May 2003.

MEX-EST-PL-13128, 'Mars Express, Master Science Plan', ESA Project Documentation, Patrick Martin, Version 1.5, July 2004

Mars Express, Spacecraft User Manual, Issue 4, Revision 0, 15 May 2003, Volume 1: Mission and Spacecraft Design

MEX-MMT-RP-0221, 'Mars Express Mission Plan', Issue 4.0, July 2000.

Neukum, G. and Jaumann, R., HRSC: the High Resolution Stereo Camera of Mars Express, ESA SP-1240, September 2004

Paetzold, M., F.M. Neubauer, L. Carone, A. Hagermann, C. Stanzel, B. Haeusler, S. Remus, J. Selle, D. Hagl, D.P. Hinson, R.A. Simpson, G.L. Tyler, S.W. Asmar, W.I. Axford, T. Hagfors, J.-P. Barriot, J.-C. Cerisier, T. Imamura, K.-I. Oyama, P. Janle, G. Kirchengast, and V. Dehant, MaRS: Mars Express Radio Science, in Mars Express: The Scientific Payload, European Space Agency SP-1240, 141-163, August 2004.

Picardi, G. et. al., MARSIS: Mars Advanced Radar for Subsurface and Ionosphere Sounding, ESA-SP-1240, September 2004

Pullan, D., et. al., Beagle 2: the Exobiological Lander of Mars Express, ESA SP-1240, September 2004