Man with a mission

It may look like a garden barbecue, or a giant pocket watch. But it is, in fact, a space probe - on Christmas Day it will land on Mars and start exploring. Here, Colin Pillinger, the British scientist behind this shoestring project, tells the story of the Beagle 2
Beagle: From Darwin's Epic Voyage to the British Expedition to Mars by Colin Pillinger

The Beagle 2 probe was launched from the Baikonur Cosmodrome in Kazakhstan at 11.45pm local time on June 2, 2003. The Soyuz rocket soaring off the launch pad created a spectacular, star-like image against the night sky, before being lost from view. Landing on Mars is scheduled for 2.54am GMT on December 25, Christmas morning.

After a journey of nearly seven months, and a few days before reaching Mars, the probe, with lander inside, will be detached from the orbiter using an eject mechanism that will send it unpowered, but spinning for stability, towards the planet's surface. Then Beagle 2 will be an autonomous spacecraft for the first time; its coast to Mars will begin; the final descent to the planet surface will take a matter of minutes.

Slowed down by a heatshield and parachutes, and cocooned in gas-filled bags, the lander will bounce to rest on the surface of Mars at its destination in the depression known as Isidis Planitia. Alone at last, Beagle 2 will open its lid, the solar arrays will fold out and a precious cargo of instruments and sample-handling tools will begin a six-month study of the environment. The probe's search for life on Mars will begin.

While Beagle 2 - commemorating Charles Darwin's voyage on HMS Beagle that led to the publication of On the Origin of Species - will be the first space mission to carry the name, two other missions used it. One was fictional and the other came to nought. The science fiction writer AE van Vogt titled his 1950 Star Trek-style novel, The Voyage of the Space Beagle. Travelling from galaxy to galaxy, its crew visited a number of planets and encountered the remains of past civilisations. They found that life forms existed in space itself.

Then, in 1963, Nasa initiated a study by the General Electric Company of a mission to land on Mars to search for life; it was intended to be a continuation of the Voyager programme using Saturn V rockets. To avoid confusion with projects already in development, the codename Beagle was suggested, derived from the ship which took Charles Darwin around the world on his groundbreaking inquiry into the evolution of life on earth.

All resemblance to Beagle 2 ends there. Nasa's Project Beagle was to have two landers, each 9,500kg. Entry was to be behind an aeroshell six metres in diameter and, when deployed, the petals would measure 10m across. Its projected cost, more than $1bn at 1964 prices, made it a massive enterprise. For comparison, the Beagle 2 probe weighs 68kg, with the lander weighing just 33kg, its diameter is the size of a bicycle wheel and its cost at the outset was estimated as £25m.

Not surprisingly, the Nasa Beagle never got off the ground. Five years ago, you might not have given much for our chances either.

The first model of Beagle 2 was made of cardboard. But it performed a vital function: it launched the dream. The cardboard mock-up saw action on many occasions, including television appearances on Blue Peter and the Big Breakfast. More models swiftly followed. A space mission is all about making models to test all aspects such as mass, centre of gravity and electrical interfaces, demonstrating that all components work at all stages during design and development. In an ideal world, Beagle 2 would have been built in a logical sequence with test programmes completed before moving on to the final assembly of the lander and probe which would be sent to Mars. Unfortunately, there was no time before early 2003, when Beagle 2 joined Mars Express for its journey to Baikonur - so a parallel programme of working had to be arranged. Versions (models) of Beagle 2 had to be made available with the various functions needed. Different sections of the team were then able to proceed flat out with their own aspect of the work.

Some would not be recognisable as anything like the full-size model of the lander used for public exhibitions. For electrical tests, it would be a box of circuit boards wired together; sometimes the box was left out. Other models looked more representative, but all had their purpose.

One might think that the idea of adding a lander to Mars Express to search for life would be instantly acclaimed. But, like Darwin's request, when it was first proposed, the idea of Britain providing the landing spacecraft and the instruments to look for life on Mars was dismissed out of hand. The sceptics had plenty of reasons ready: "It's been done before and the results were negative"; "It will jeopardise the Mars Express orbiter"; "It's a gimmick, a stunt"; "It will wreck plans for other space missions"; "Nasa is going to do it when they bring back samples"; "The Russians have tried to land and failed, why should Britain think it can succeed?" At that stage, the doubters not only included the European Space Agency (ESA), but the British government itself.

In fairness, the ESA had every cause to be worried about British commitment. The UK did not have a good record of supporting its space missions. For Beagle 2, the turning point was not the intervention of one man but a group - or to be precise, a band - Blur, and with them they brought the artist Damien Hirst.

Alex James, the bassist, and Dave Rowntree, Blur's drummer, joined the Beagle 2 team to help with PR in the summer of 1998. The band's unique contribution is writing the Beagle 2 signature tune, a call sign to be beamed back from Mars to announce the lander's arrival. The refrain was composed in 1999 and released on a CD along with No Distance Left To Run, the third single from Blur's album, 13.

Hirst, meanwhile, has produced one of his trademark spot paintings to act as the calibration target for Beagle 2's cameras and spectrometers. The target is fitted to a place on one of the ribs of the lander so that the instruments can focus on it to check their readings.

The biggest problem was money. Beagle 2 had none. The attraction of looking for life on Mars was, however, irresistible and the Beagle 2 team began work without any visible means of financial support. A new term was coined by those who gave up their own time to Beagle 2 - "Marslighting". The lobbying to get the project technically selected and properly funded took several years.

Unlike Darwin's experience, the powers-that-be eventually agreed to help finance this great adventure. The announcement that the ESA had agreed to take our tiny spacecraft led to the release of a tranche of £8m of government money for the industrial partners in the lander and the university groups building the instruments. Then, after a review of the project by an independent Nasa panel, the ESA was also persuaded to contribute. Even this was not enough, however, and the balance of the £25m budget had to be borrowed on the strength of a business plan that predicted that Beagle 2 would attract sponsorship and advertising revenue. Unfortunately for me, Beagle 2 was never going to be big enough to carry a member of the space project team, so stowing away to avoid repaying the loan was not an option.

Size and weight were indeed two of the major technical challenges for our design.The ESA announced it could spare only 60kg for a lander. Since no one had at that stage proposed to build a lander so small, Mars Express was designated as an orbiter mission only. But the ESA reckoned without the resourcefulness of the Beagle 2 team.

Within weeks of learning the drastic payload limit, the team had come up with a lander that met the criteria without sacrificing a single element of scientific study. Beagle 2 (the puppy version) was essentially a miniature of the bigger original. The robotic arm was stowed for launch by wrapping itself around the lander body inside fold-out solar panels. We were still in business.

When the probe was weighed just before delivery to Mars Express, it was within 100g of the mass estimated more than two years earlier - no small feat for a spacecraft that, literally, started life sketched on the back of a beer mat.

The final design of Beagle 2 turned out to be clam-shaped; other descriptions have likened it to a large pocket watch, a garden barbecue, and a bagel. Some modifications were necessary along the way. For example, the pop-up telecommunication aerial, which originally looked like the coathanger favoured by Ford Cortina owners, was abandoned for a more conservative version incorporated into the lander lid.

Once landed in the Isidis Planitia basin, a 1,000km-wide crater believed to be filled with sediment washed down from the southern highlands, Beagle 2 will raise its robotic arm to full height and rotate it through 360 degrees taking a series of pictures which can be stitched into a panorama of the landing site. As the mission progresses, the cameras will perform their own scientific functions, making astronomical observations and investigating the dust burden in the Martian atmosphere.

To address its most important scientific objectives, Beagle 2 needs to collect soil. Several such samples will be analysed for organic matter, mineral components and isotopic ratios to seek evidence of extinct life on the planet. These will be gathered with the "mole", a self-penetrating mechanism shaped like a pencil which is deployed somewhat like a dog on a leash for sorties away from the lander.

Nasa's 1976 Viking lander discovered that many of the mineral building blocks of life were present on the surface of Mars, but a crucial experiment failed to find any evidence of the organic compounds that would imply a Martian biology. More recent studies of Martian meteorites have offered encourage-ment. Two meteorites in particular, known as EETA79001 and ALH84001, provided samples of carbonates showing the presence both of water - the universal solvent necessary for life - and organic matter. Controversially, it was also claimed that ALH84001 contained a microscopic fossil of a martian "worm".

Studying meteorites that have landed on Earth, however, is not as conclusive as finding the evidence on the surface of Mars. Unfortunately, Nasa's 1997 Pathfinder mission was hampered in its exploration because it had no provision for eliminating the red dust which covered all the boulders, so frustrating chemical analysis and detailed photography. So it is imperative for Beagle 2 that the weathered outer surfaces of rocks are removed. To combat the problem of the dust and an obscuring outer rind, Beagle 2 is equipped with a corer-grinder - designed and built by a dentist - to obtain samples of rock for analysis. As the launch date approached, the Beagle 2 team were confident that our lander had all the scientific tools necessary to determine once and for all whether there is - or was - life on Mars.

The Baikonur Cosmodrome is not in Baikonur at all but more than 100km away, a relic of disinformation from the cold war. The last part of the journey to the launch pad was on top of the Soyuz Fregat module on a slow-moving railway. The launch schedule changed several times. It was a tense time: Beagle 2 had to be off by June 28 at the latest or the wait would be for 26 months. The final decision to launch the rocket was taken just two and a half hours before the event.

It is a journey that lasts seven months. The final few days will be the most fraught. Several days out from the planet, Beagle 2 will be ejected from Mars Express by a spring. Thereafter it will be on its own - still travelling at a velocity of Mach 31.5 (12,000mph relative to Mars) and gently spinning, like a ball thrown by a rugby player, into the atmosphere of the red planet. After being slowed down, protected behind a heat shield, by the resistance of the atmosphere to Mach 1.5 (1,000mph), a mortar will deploy a pilot parachute to further brake Beagle 2 and stabilise the lander as it passes through the velocity of sound (Mach 1, roughly the same on Mars as it is on Earth).

When the lander is falling at 230mph, the drogue pulls the Beagle 2 probe into two halves dropping the heat shield and removing the back cover. This action pulls the main parachute out of its bag.

The job of the main chute is to reduce the velocity to less than 40mph. On contact with Mars, the lander in its protective cocoon of inflatable bags, will bounce out from under the parachute until it comes to rest. If it lands upside down, the hinge which opens the lid is able to turn Beagle 2 over.

A journey of 250m miles will be over, but the real work will just begin. Unlike Darwin's Beagle, ours will not be coming back - but it will be transmitting invaluable information about whether Mars has ever supported life. If this mission succeeds where Nasa has failed, it will be an astonishing tribute to British scientific endeavour. It just goes to show: never knock an idea that started out on the back of a beer mat.

· This is an extract taken from Beagle: From Darwin's Epic Voyage to the British Mission to Mars, by Colin Pillinger, published by Faber and Faber on November 20. To order a copy for £12.99 plus p&p (rrp £14.99), call 0870 066 7979.