Leo Enright reports on the Beagle 2 lander

On the Origin of the Species, the book he wrote following the voyage, laid down the theory of evolution, the basis of our study of life's development.

Now a team of predominantly British scientists hopes to do justice to that heritage by going someway towards answering that fundamental question: Are we alone?

Following Darwin's legacy: Beagle 2

If all goes to plan, Beagle 2 will be launched in 2003 aboad the European Space Agency's Mars Express, a probe that will map Mars' landscape, mineral deposits and even its weather systems.

The tiny lander will then be dropped onto the surface of the red planet to pick up where others have left off in attempting to establish whether or not life has ever existed, or continues to exist on Mars.

Professor Colin Pillinger, lead scientist for Beagle 2 and head of the Planetary Science Research Institute at the Open University, said the results could be quite amazing.

Colin Pillinger: "Mars is suitable for life"

"The study of rocks that have been thrown to us by impacts on Mars tells us that water, and warm water something between 0 and 100 degrees, percolated through the surface of Mars in comparatively recent times," said Prof Pillinger.

"That means that conditions on Mars were very suitable for life to have developed."

The team behind Beagle 2 are facing an October 30 deadline to find £25m for the European Space Agency to accept the lander.

Professor Colin Pillinger: "Beagle 2 will bring us closer to discovering life is universal"

ESA's £2.4bn budget comes from member countries, with the UK currently the fourth largest donor with a little over £120m this financial year.

Launches are paid for through the general budget but on-board instruments must be financially self-supporting.

The UK's space agency, the British National Space Centre, has already committed all its current funds this year.

Gathering samples: Beagle 2 mole will collect samples

A spokesman said: "We believe Colin Pillinger has come up with an exciting project which would really add to our understanding of Mars.

"But the Mars Express mission is a late entry into the European Space Agency's science programme.

"It came along after the UK had committed funds to other missions, such as next year's X-ray astronomy mission, XMM, and the comet lander Rosetta."

Beagle 2's team have turned elsewhere for their funding and have enlisted some of the leading names in British technology.

Professor Colin Pillinger: "Conditions on Mars could be suitable for life"

Leicester University's Space Research Centre, partners in the project, are designing the lander with Matra Marconi Space in Bristol.

The Martin Baker Aircraft Company in Uxbridge, Middlesex, will construct the all-important entry descent and landing system and the Rutherford-Appleton Laboratory will be responsible for ensuring Beagle 2 can withstand wild swings in Mars' surface temperature.

Living rock?

Interest in extra-terrestrial life will always be strong, but the Beagle 2 team are working on the crest of a wave formed by Nasa's 1996 announcement that a Martian meteorite contained fossilised evidence of life.

They argued that the catchily named ALH84001 included evidence of Martian carbonates, indicators of life.

ALH84001: More interesting than its name

It may not have been as dramatic as a great dinosaur footprint, but it caused an even bigger impact.

"The thing that is much more controversial about the Martian samples is whether or not they contain the real evidence of life," said Prof Pillinger.

"People claim to have seen fossils, others have argued that organic matter is there.

"There is a question that this material got into rocks on earth and what I am trying to do is go to Mars and avoid these questions of contamination."

Beagle 2 will be constructed to strict sterilisation standards to ensure that it does not carry these earth organisms to Mars.

Once it has landed, the tiny craft will open its petal-like solar panels to power instruments.

Checking the evidence: Beagle 2 carries an on-board laboratory

A robot arm will be able to swing out to nearby rocks and prepare samples.

But the key piece of technology will be a robot mole.

It will scurry to nearby rocks and then burrow underground to take samples of Martian earth protected for millennia from the harsh atmosphere.

The earth will be entered into a mass spectrometer, an instrument that uses magnetic and electrical fields to determine the isotopes, molecules and composition of a sample.

These experiments may then point to chemical or organic compounds suggestive of life long since dead - or life still existing.

Beagle 2 is also designed to carry out a host of other valuable experiments.

"What I am convinced about is that the conditions on Mars are appropriate for life," said Prof Pillinger.

"It does not mean that life is there or that it was there.

"If we could make these first tentative steps to show that life forms are not unique, it brings closer the eventual discovery that life is universal.

"And I believe that should be the case because the elements of life, carbon, hydrogen, oxygen and nitrogen are four of the five most abundant elements that make up everything around us."