/ 22 May 2003

Britain joins the hunt for life on Mars

It’s a space lander the size of a portable barbecue, stapled to a mothership not much bigger than a household refrigerator, and it’s about to make history. On June 2 — the date could slip, but not by much — Beagle 2 will leave Kazakhstan aboard a Russian Soyuz rocket and begin a journey of 400m km.

Mars Express will be the first European mission to reach another planet and Beagle 2 will be the first British lander to unfold under extraterrestrial skies. The first carries ground-penetrating radar that will ”feel” deep below the surface of a freezing, arid, hostile planet and the second a little mole that will explore the surface and even burrow a metre below it. Between them, they might answer one of the great questions of the past 300 years: is there, or was there, life on Mars?

There is the Mars of the imagination, and the Mars of cold reality, and they intersect. Three hundred years ago, the giants of the Enlightenment speculated about life on the other planets.

Victorian astronomers were convinced that they could see canals on Mars, and even a seasonal change as vegetation flourished in the Martian spring and summer. HG Wells imagined technologically-advanced invaders from Mars, Edgar Rice Burroughs fantasised about a Princess of Mars.

By 1976, the little green men had been abandoned but researchers thought wistfully about some kind of slow-growing, cold-adapted Martian: Nasa even prepared an artist’s impressions of Martian lifeforms based not on carbon but silicon. After the Viking lander in 1976, however, Mars was pronounced sterile, a dead planet.

Twenty years later, the discovery of highly-debated little structures inside a meteorite from Mars found in Antarctica reopened the debate, but it was reopening anyway, just because of the consistent discovery of living things in improbable places on Earth — in soda lakes and acid baths, down volcanic vents and under the polar ice, in the clouds and deep in the crustal rocks.

”If all places to which we have access are filled with living creatures, why should all those immense spaces of the heavens above the clouds be incapable of inhabitants?” Isaac Newton asked 300 years ago, and the question remains a good one. Astrobiology is now a university discipline, and Mars is, in theory, capable of producing life.

Mars has the solar system’s largest volcano and the biggest known canyon. It has what looks exactly like a dried-up ocean bed, with a pronounced shoreline. It is scoured by what on earth would be unequivocally identified as river beds, flood plains, fossil lakes and gullies left by flash floods.

It also has an atmosphere based on carbon dioxide, much like that of Earth before any life formed. But it now has hardly any atmosphere, and no liquid water at all. If it once had an ocean, it must also have had a much denser atmosphere. Where did they go? Are they still somewhere on the planet? Were they stripped away in some catastrophic cosmic collision? Or did a magnetic field that must once have protected the planet fade, leaving it at the mercy of pitiless solar and stellar radiation that gradually dismantled molecules and stripped the atmosphere and seas a little at a time?

And where are all the organic molecules — carbon-based and linked to life, if not necessarily made by life — that rain down on Earth from space, and presumably do so on Mars? Scientists would like all these questions answered — hence the continued and very serious interest in the red planet.

The Mars Express mission is made possible only by the merry-go-round of the planetary orbits. Both planets have roughly the same day length, but Mars takes 687 Earth days, or nearly two Earth years, to go round the sun. So space scientists have to time journeys to Mars at intervals of about 26 months, when the distance between the two planets is at its shortest. Every 17 years or so, the distance gets even shorter — a mere 55-million km — which means that researchers can save on fuel and pack more on board. And so on June 2, a launch from the Russian Baikonur cosmodrome will put the Fregat upper stage rocket with its Mars-bound cargo into a 200km-high circular orbit around Earth. At the right moment engineers will press the trigger again. The next burn should send Fregat on to a long sweep around the Sun, calculated to veer steadily outwards, in the direction of the orbit of Mars. Then Fregat will separate, and Mars Express, bearing Beagle 2 like a shield, will head across space and away from Earth at 10 800 km/hr.

On December 19, or thereabouts, as it nears the red planet, a command from the European Space Agency mission control in Germany will tilt Mars Express so that it points towards a place on Mars called the Isidis basin, a flattish, boulder-strewn stretch 10 degrees north of the martian equator. Mars Express itself will change direction to go into a hugely elliptical orbit around the planet.

Beagle 2 will coast for five days until it hits the thin Martian atmosphere. The friction will slow it down to a speed at which it will be safe to release a parachute, which will slow it further. Then, 1km above the martian surface, three airbags will inflate to cocoon the tiny package of instruments as it bounces to rest. When it finally comes to a full stop, the airbags will separate, inflate further and roll away in three directions, dropping their little cargo on to the surface. If Beagle 2 lands the wrong way up, it will open its lid to flip itself over to face the distant sun. If it lands the right way up, it will simply open its lid, unfold solar panels and gather electronic strength to send a simple call sign: the Beagle has landed.

It will be 100 years and eight days since the Americans Wilbur and Orville Wright first flew a heavier-than-air machine at Kitty Hawk. It will also be Christmas Day. That’s the plan, anyway.

All big science is teamwork — the lander team has partners from Cologne, Leicester, Mainz, Neuchatel, London, Hong Kong and British industry — but Beagle 2 is incontestably the baby of Colin Pillinger, who leads the planetary science research group at the Open University in Milton Keynes.

He thought of the mission six years ago during a scientific meeting about the unearthing of some puzzling discoveries fossilised inside a meteorite known to have come from Mars. He then began a skilful campaign of pushing and persuading, backed up by masterly use of the media, to get satellite-makers, scientists, engineers and the British and European bureaucracies at first sympathetic, then interested, and then involved and finally committed as partners.

Professor Pillinger also played the British card, before a Britain that had, until then, invested relatively little in space. He named the lander after the ship that took Charles Darwin into the history books. With help from Alex James of the Britpop band Blur, he commissioned a signature call sign for Beagle 2. When he learned that James also knew the Britart star Damien Hirst, he commissioned a tiny spot painting to serve as a colour calibration chart for the lander’s cameras.

”When we started this I bet there were a lot of people who guessed we wouldn’t get very far,” says Pillinger. ”We are on the launch pad. We stand on the verge of the expedition. It all sounds very much like a fairy story. I sometimes have to pinch myself.”

All being well, Beagle 2, up close and personal, will photograph, measure, sniff, analyse and report on the chemistry of the Martian dust and rocks, while from on high Mars Express begins a series of dramatic swoops over the planet’s terrain, to deliver some of the highest-resolution photography yet, as well as the furthest reach into depths to search for ice, or even liquid water. Beagle 2 could survive for months, Mars Express for two years.

The whole project’s a bargain — in space mission terms — at a budget of â,¬150-million (£106-million). And just for once, a space mission has time on its side. ”2003 is particularly good,” says Agustin Chicarro, of the European Space Agency, and project scientist. ”You can launch the most mass of all the foreseeable launch windows. 2005 would be particularly bad. If we were to launch in 2005 we could not take the Beagle lander on board, we could only take the orbiter. So we would lose about 30% of the scientific payload mass. That’s the difference.”

Of course something could go hideously wrong. Some of the hardware for Beagle 2 and Mars Express is tested on other sorties into space, some of it is brand new. And Mars is the jinx planet: of 30 missions in 40 years, only 14 have had any degree of success. Once the Soyuz rocket begins to rumble on June 2, knuckles will whiten. Fingers are likely to stay crossed not just until 2.45am on Christmas Day, when Beagle will hopefully bounce to a standstill on the surface, but for another two hours, until an American orbiter comes over the Martian horizon and Beagle 2 can relay its call sign back to Earth.

Beagle 2 and Mars Express are merely the leaders of a flotilla of spacecraft aimed at the red planet. Two Nasa landers, each bearing a robot rover, will follow within days and start poking about the surface. A Japanese mission called Planet B/Nozomi, lost in space years ago, has extricated itself from the gravitational bramble bush and is to arrive next year.

There is already one Nasa orbiter sweeping the planet’s surface, measuring and taking photographs, and more are being designed. There could be missions every 26 months from now on, delivering ever-more sophisticated hardware, and much of it, indirectly at least, will be addressing the question of whether there is life on Mars.

Fourth rock from the sun

1896: Astronomer Percival Lowell proposes that Mars is an arid, dying planet criss-crossed by canals dug by intelligent life

1938: Orson Welles inadvertently causes panic in the US by presenting HG Wells’ 1898 novel War of the Worlds – which began the tradition of the alien invader with vastly superior technology -as a dramatised news report

1962: Soviet Union launches Mars-1, with a mass of almost 900kg, aimed at the red planet. Radio contact is lost 106m km from Earth

1976: Nasa Viking lander mission pronounces Mars lifeless – but the orbiter photographs the notorious ”face” on Mars, an illusion that fuels fantasies for two more decades

1996: Nasa team examine a meteorite known to have come from Mars, and publish highly contested evidence of microbial fossils locked inside three-billion-year-old rock

1999: Mars Climate Orbiter crashes on the Martian surface, because one team of Nasa engineers used imperial units, another metric measurements

Further reading

Mapping Mars, Oliver Morton, 2002 (Fourth Estate) ISBN: 184115668X

The Case for Mars: the plan to settle the red planet and why we must, Robert Zubrin with Richard Wagner, 1996 (Free Press) ISBN: 0684827573

The Quest For Mars: Nasa scientists and their search for life beyond earth, Laurence Bergreen, 2000 (Harper Collins) ISBN: 0002570300

Mars: the Inside Story of the Red Planet, Heather Couper and Nigel Henbest, 2001 (Headline) ISBN: 0747235430 – Guardian Unlimited Â