If you live in Europe, there's almost certainly a research institute or industrial company near you that is contributing materials or expertise to Mars Express, Europe's first mission to the Red Planet. Under the umbrella of the European Space Agency, at least 25 companies from 15 European countries are building hardware or software for the spacecraft, or otherwise contributing their expertise; and more than 200 scientists from research institutes in all ESA member states and beyond are contributing towards the scientific payload. "The Mars Express project is providing about 1000 jobs throughout Europe," estimates Rudi Schmidt, Mars Express Project Manager at ESTEC, the European Space Agency's technical centre in the Netherlands.

An artist's concept of Mars Express in orbit around the Red Planet. Photo: ESA

Preparations are well under way and on schedule for a May/June 2003 launch sending the spacecraft on its six-month voyage. The structure is taking shape under the guidance of the prime contractor Astrium, Toulouse (France), and the scientific teams are on target with scientific instrument development.

ESA's Mars Express mission consists of an orbiter, carrying seven scientific experiments, and a lander element, Beagle 2. The two vehicles will play key roles in an international Mars exploration programme spanning the next two decades.

The instruments on board the orbiter will provide remote sensing of the atmosphere, the surface and up to 5 km below the surface, to a degree of accuracy never before achieved. The information gleaned will help answer many questions outstanding about Mars. One concerns the fate of water that once flowed freely on the planet's surface; another is whether life ever evolved on Mars.

Illustration of Beagle 2 lander on surface of Mars. ESA

Beagle 2 will be the first lander since NASA's two Viking probes in the 1970s to look specifically for evidence of past or present life on Mars. No other Mars probe planned so far is making exobiology so central to its mission.

When the spacecraft arrive at the Red Planet around Christmas 2003, the Mars Express orbiter will jettison Beagle 2 and then move into a near-polar orbit from which it will observe the whole planet over the next Martian year (equivalent to two Earth years). The lander will make its own way to a carefully selected site on Isidis Planitia, a plain just north of the equator near where the ancient, cratered southern highlands meet the younger, smooth northern lowlands. Beagle 2 will complete its mission in about six months.

The Mars Express orbiter instruments will:

• Image the entire surface at high resolution (10 m/pixel) and selected areas at super resolution (2 m/pixel) (HRSC instrument)
  
  
• Produce a map of the mineral composition of the surface at 100 m resolution (OMEGA instrument)
  
  
• Map the composition of the atmosphere and determine its global circulation (PFS instrument)
  
  
• Determine the structure of the sub-surface to a depth of a few kilometres (MARSIS instrument)
  
  
• Determine the water vapour and ozone in the atmosphere (SPICAM instrument)
  
  
• Determine the interaction of the atmosphere with the solar wind (ASPERA instrument and MaRS experiment)
  
  

The Beagle 2 lander will:

• Determine the geology and the mineral and chemical composition of the landing site
  
  
• Search for life signatures (exobiology)
  
  
• Study the weather and climate
  
  

Mars Express will provide unique investigations that will contribute to an understanding of many of the unknowns about Mars. Here are a few:

• If Mars really was warm and wet during its early history, where did the water go? Some may have been lost to space and some may be buried underground. ASPERA will measure water loss to space and MARSIS is the only instrument planned for any mission with the capability of looking for water or ice down to a depth of a few kilometres. The presence of underground water would have a considerable impact on the prospects for future manned missions to the planet.
  
  
• If there was water could there have been, or still be, life? Beagle 2 will scoop up soil and rock samples and analyse them there and then for some of the key chemical signatures of life. The results will be far more telling than anything yet found in Martian meteorites on Earth, as the chances of contamination by biological specimens from Earth will be virtually eliminated.
  
  
• What is the surface of Mars made of and what can the composition tell us about the history of the planet, in particular about the history of water there? OMEGA will map surface mineral composition more accurately than ever before. In particular, it will look for carbonates, which no previous mission has found, but which should be present if water was once abundant on Mars.
  
  
• The thin Martian atmosphere is thought to be very oxidising - it turns the plentiful iron in the surface rocks and dust into rust, hence the planet's red colour. SPICAM will help to determine precisely how the atmosphere has this effect. Such understanding will ultimately have implications for designing space suits and life support system for visiting astronauts!
  
  
• Was there an ancient ocean over the northern plains of Mars? The evidence revealed by previous missions has been ambiguous. The HRSC's contiguous 3D imaging in full colour has the best chance yet of revealing an ancient shoreline, if one exists.
  

Over the next few months, the European Space Agency in collaboration with national organisations will be holding press conferences about Mars Express at different locations across Europe. Further information will follow as soon as it is available.