Mars Express

Mars Express

Künstlerische Darstellung der europäischen Mars Express Raumsonde Quelle: ESA

Künstlerische Darstellung der europäischen Mars Express Raumsonde
Quelle: ESA

Mars Express is the first European planet mission. In addition the Mars Express is the prototype for so called flexible (F) missions within the framework of the long-term scientific program “Horizon 2000 plus” of the European Space Agency (ESA).

Besides the member states of ESA also Poland and the USA are involved. Main agent for Mars Express is the company EADS Astrium, France. The responsible project group is an ESTEC team in Noordwijk, Netherlands. Starsem in Russia was responsible for the rocket, while Alenia Aerospazo, Italy, was responsible for the satellite integration. Germany is decisive involved with the High Resolution Stereo Camera HRSC and the Mars Radio Science Experiment (MaRS). Additionally Germany is partly concerned with the Planetary Fourier Spectrometer (PFS).

The planet Mars is an object of fascination already for hundreds of years. But the possibility  to investigate the planet with spacecrafts exists just since 40 years. The aim is to achieve statements about the differences between the planets in the Solar System and to understand their common origin. The first spacecrafts to Mars started in the sixties; the first global investigation was performed by mariner-9 in 1971. One of the most important missions was the Viking mission from 1976 to 1982 with two orbiters as well as two landers.

Mars-Express facts

Startrocket Soyuz – Fregat
Start position
Baikonur, Kazakhstan
Start time
2nd June 2003
Arrival on Mars
23th December 2003

Orbit data

Inclination 87°
Distance of pericenter
< 250 km
Distance of apocenter
11500 km
Orbital period
6.5 hours
Nadir observation phase 0.5 – 1.0 hours
Communication phase 6.5 – 7.0 hours
Duration of the mission
scheduled 4 Earth years

Scientific payload

The spacecraft mars Express contains seven scientific instruments. All measurement devices collect data about Mars’ surface and atmosphere. The orbit allows an approximately complete covering of Mars’ surface during the first mission period of about one Mars year which corresponds to approx one Earth year.

Instrument / Investigation Name Principal Investigator
ASPERA Energetic Neutral Atoms Analyser R. Lundin (S)
HRSC High Resolution Stereo Camera G. Neukum (D)
MaRS Mars Express Orbiter Radio Science M. Pätzold (D)
MARSIS Subsurface Sounding Radar/Altimeter G. Picardi (I)
PFS Atmospheric Fourier Spectrometer V. Formisano (I)
SPICAM UV Atmospheric Spectrometer J.-L. Bertaux (F)
OMEGA Visible and infrared mineralogical mapping spectrometer J.-P. Bibring (F)

Scientific aims of the orbiter

  • global high resolution photogeology (including topography, morphology, paleoclimatology, etc.) with a resolution of about 10 m
  • global spatial high resolution mineralogical mapping of the surface with a resolution of about 100 m
  • global atmospheric circulations and components of the atmosphere
  • underground structures down to  1 km depth
  • interaction between atmosphere and surface
  • interaction between atmosphere and interplanetary medium

MaRS – Radio-Science on Mars

MaRS uses the signals which transfer the data and the instructions between spacecraft and Earth in order to investigate the ionosphere, the neutral atmosphere, the surface and even the interior of Mars.
The information about the interior of the planet is provided by the precise determination of the gravity field. The velocity of the spacecraft changes due to the gravity field what can be detected in the radio signal.
Knowledge about the nature of the surface can be obtained by reflection of the radio waves on the surface  (“Bistatic Radar”).

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