Tim Furniss/LONDON Julian Moxon/PARIS

France is to become a partner in the NASA programme to mount a mission to Mars to bring the first samples of planetary material back to earth.

The surprise French involvement was announced on 30 November by education, research and technology minister Claude Allègre. Speaking to the Senate, the minister said that France would contribute some Fr2.5 billion ($420 million) of the overall $1.9 billion cost of the programme, after the successful conclusion of negotiations between French space agency CNES and NASA's Jet Propulsion Laboratory.

The five-year mission is scheduled to begin in 2003 with the launch of a Delta III rocket carrying a Mars lander and surface rover, along with a Mars Ascent vehicle. This will carry samples of Martian soil into orbit, to await the second mission, due to be launched two years later aboard an Ariane 5 and with a similar Mars payload, plus an orbiter. This will undertake the same mission on the Martian surface and, in a complex exercise, will collect the first samples from orbit and return to earth with the combined payload.

"These missions will enable a far better analysis than possible actually on the planet," says Allègre, "particularly in terms of dating the samples. It will also provide the best possible evidence of whether there has ever been life on Mars."

While the USA and France work out the detail of the mission, the latest assault on the planet is due to begin on 10 December, when the first of two Lockheed Martin-built NASA spacecraft is launched by a Boeing Delta II from Cape Canaveral, Florida. The Mars Climate Orbiter (MCO) will be followed on 3 January by the Mars Polar Lander (MPL), also aboard a Delta II.

The MCO will enter Mars orbit in September 1999 and will use an atmospheric aerobraking technique to place it into its final circular orbit over the Martian poles at an altitude of 421km. The orbiter is equipped with an atmospheric sounder - a copy of the one which was lost aboard the fated Mars Observer in 1993 .

The sounder will measure temperatures, dust, water vapour and clouds up to an altitude of 80km, while the imager will be able to return 40m-resolution pictures of the Martian surface. The MCO will first act as a data relay satellite for the MPL, due to make landfall in December 1999 on the edge of the largely frozen carbon-dioxide polar cap about 1,000km from the south pole - using a retro-rocket, rather than airbags similar to those deployed by the successful Mars Pathfinder in 1997.

A robotic arm will be used by the MPL to deliver samples to an on-board thermal and evolved gas analyser. A weather station will monitor the surface environment continuously, while a small microphone will record the first sounds from the planet, and an imager will scan the surface.

Before landing, the MPL will deploy two microprobe penetrators, flying as the Deep Space 2 New Millennium programme mission. The probes will impact on Mars at a velocity of 200m/s and it is hoped that they will return data from under the surface, drawing a small sample for analysis.

Matra Marconi Space has been recommended by the ESA Industrial Policy Committee as prime contractor for the European Space Agency Mars Express orbiter, to be launched in June 2003.

Source: Flight International