Mars

Europe has waited a long time for the opportunity to mount its own mission to Mars and that dream is now reality.  Mars Express, ESA's mission to the red planet launched June 2003, marks the opening of a new era for Europe in planetary exploration. The ESA project is also the start of an innovative way of organising the building blocks that form European space missions. The spacecraft was built and launched in record time and at a much lower cost than previous, similar missions into outer space.

A scientific water diviner

Artist's impression of the Mars Express orbiter

Mars Express is the first 'flexible' mission of ESA's long-term science exploration programme. The journey to the red planet began on 2 June 2003 with the launch from the Baikonur Cosmodrome on a Soyuz-Fregat rocket. It ended on 25 December 2003 with the successful orbit insertion. Mars Express comprises a number of essential components - the spacecraft and its instruments, the lander, a network of ground and data processing stations, and the launcher itself. These are supported by an experienced team of engineers in ESA and industry and hundreds of international scientists.

The mission's main objective is to search for sub-surface water from orbit and deploy a lander onto the Martian surface. Seven scientific instruments onboard the orbiting spacecraft will perform a series of remote sensing experiments designed to shed new light on the Martian atmosphere, the planet's structure, geology and composition.

Beagle 2 lander leaving Mars Express following the Cruise Phase

The lander, called Beagle 2 after the ship in which Charles Darwin set sail to explore unchartered areas of the Earth in 1831, represents an exciting opportunity for Europe to contribute to the search for life on Mars.

While addressing its science objectives, Mars Express will also provide relay communication services between the Earth and various landers deployed on the surface by other nations, thus forming a centre piece of the international effort in Mars exploration.

Searching for the elixir of life

Scientists hope that the instruments onboard Mars Express will detect the presence of water below the surface. This could exist in the form of underground rivers, pools, aquifers or permafrost. Overall, the main goals of the instruments to be carried by the Mars Express orbiter are:

• Sharp-eyed, 3D photography to discover more about the surface and geology of Mars.
• Looking at the 'invisible' beneath the surface by using radar beams to penetrate below ground. Different materials or structures will send back different radar echoes allowing scientists to produce an accurate 3D survey.
• Precise determination of atmospheric circulation and composition to build up an accurate picture of Martian meteorology and climate.
• Study of the interaction of the atmosphere with outer space.

Gathering such information on the history and present day circumstances of Mars may also improve our understanding of phenomena that influence our own environment. For example, if we can determine why Martian water disappeared in the past we may learn more about whether a similar fate one day awaits the oceans of Earth. The Mars Express spacecraft and its instruments represent a truly international endeavour - a stereoscopic camera from Germany, a mineralogical mapping device from France and an atmospheric sounder from Italy. The radar instrument, to probe for water at depths of a few kilometres below the surface, has been built jointly between Italy and the Jet Propulsion Laboratory in California. The Beagle 2 landing craft has been designed and built in the UK. As well as the remote observation payload, the orbiter carries a lander communications package to support international Mars lander missions from 2003 to 2007.

Postcards from the surface

The Beagle 2 lander showing its solar panels outspread and its robotic arm and instruments being deployed.

If the deployment is successful, the Mars Express Beagle 2 lander will have to survive temperatures down to as low as -100^oC. It carries a variety of scientific experiments powered by solar cells and a rechargeable battery.

Like any self-respecting tourist visiting a new destination for the first time, Beagle 2 will take photographs. Panoramic and wide-field cameras will be used for pictures of the landing site to guide further exploration as the mission progresses.

A microscope will look closely at the rocks and soil with a high degree of magnification. Fragments of rocks within reach of Beagle 2's small robotic arm will be analysed for the existence of organic matter, water and aqueously-deposited minerals.

The busy lander will also deploy a mole capable of crawling short distances across the surface at one cm every six seconds (the relative equivalent of six metres an hour) and burrowing beneath large boulders to collect soil samples for a gas analysis system. The primary aim of these experiments will be to see if any evidence of past life processes near the landing site remains.

Unmanned Soyuz on launch pad (Image courtesy Starsem)

How Europe got to Mars

The selection of a Soyuz/Fregat launcher to put Mars Express on its course towards Mars was linked to the flexible approach adopted by ESA. The launcher was procured through Starsem, a Russian/European company. As a relatively low-cost launcher it helped keep the overall cost of the Mars Express mission within a total initial budget of 150 million Euros.