content 16-January-2018 19:58:38

Fact Sheet

 Fast Facts

Mars Express 

Launch date: 02-Jun-2003 17:45 UT
Mission end: 31 December 2018 (subject to a mid-term review in 2016)
Launch vehicle: Soyuz-Fregat
Launch mass: 1223 kg
Mission phase: Operational
  • Orbital Inclination: 86.9°
  • Pericentre: 330 km
  • Apocentre: 10 530 km
  • Period: 7 h 00 m
  • Detection of hydrated minerals, including phyllosilicates
  • Possible detection of methane in the atmosphere
  • Identification of recent glacial landforms
  • Probing the polar regions
  • Investigation of recent and episodic volcanism
  • Estimation of the current rate of atmospheric escape
  • Discovery of localised auroras on Mars
  • Providing new views of the ionosphere
  • Phobos mapped in unprecedented detail
  • Unambiguous detection of CO2 clouds

Mars Express, so called because of the rapid and streamlined development time, represents ESA's first visit to another planet. Since launch in 2003, the mission has produced a range of significant results in its search for answers to fundamental questions about the geology, atmosphere, surface environment, history of water, and potential for life on Mars. The spacecraft built on previous work by borrowing technology from the Mars 96 mission (which had failed to reach Earth orbit) and from ESA's Rosetta mission (currently accompanying comet 67P/Churyumov-Gerasimenko in its orbit around the Sun). Mars Express also paves the way for future exploration as a part of a communications infrastructure for other missions.

Mission Name

Mars Express is so called because it was built more quickly than any other comparable planetary mission. The Beagle-2 lander was named after the ship in which Charles Darwin sailed when formulating his ideas about evolution.


Mass & Power Budget

Spacecraft Item Mass at Launch
Spacecraft Bus 439 kg
Lander 71 kg
Payload 116 kg
Propellant 427 kg
Launch Mass 1223 kg
Typical Mean Power Demand Observation Manoeuvre Communication
Spacecraft 270 W 310 W 445 W
Payload 140 W 50 W 55 W
Total 410 W 360 W 500 W


Spacecraft bus dimensions 1.5 × 1.8 × 1.4 m
Thrust of main spacecraft engine 400 N
Attitude thrusters 8 at 10 N each
Propellant tanks volume 2×270 = 540 litres
Pointing accuracy Better than 0.05°

Power Source

Solar array area 11.42 m²
Lithium batteries 3 at 22.5 Amp hour each (at launch)

Thermal Specification

Spacecraft bus 10-20 °C
PFS, OMEGA -180 °C
Thermal blanket Gold-plated AISn alloy



Mars Express was launched from the Fregat upper stage towards Mars with an absolute velocity of 116 800 km per hour  and a velocity relative to the Earth of 10 800 km per hour. On 19 December 2003, 5 days before orbit insertion, the Beagle-2 lander was successfully released towards the surface of the planet. However, no further contact was made with the lander and it was subsequently declared lost. (In January 2015, the UK space agency announced that the lander has been identified in images from NASA's Mars Reconnaissance Orbiter. The images appeared to show the lander partially deployed on the surface.) On 25 December 2003 the orbiter underwent a successful orbit insertion manoeuvre and after slow orbit adjustments it reached the operational orbit.

Nominal Operational Orbit Parameters

  • Orbital inclination - 86.9°
  • Apocentre - 10 530 km
  • Pericentre - 330 km
  • Period - 7 h 00 m
  • Observational phase at pericentre - about 1 hour
  • Communications phase - 6.5-7.0 hours minimum

Operations Centre

The European Space Operations Control Centre (ESOC) in Darmstadt communicates with the spacecraft via the ESA New Norcia ground station in Perth, Australia. The spacecraft sends housekeeping data on instrument temperatures, voltages and spacecraft orientation, for example, and science data. The ground station sends control commands to the spacecraft. Scientific data is stored onboard using the 12 Gbit solid state mass memory prior to the downlink to Earth.

Last Update: 04 October 2017

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