Europe plans robotic quest for life on Mars

A roving robot that can search for signs of extraterrestrial life could be sent to Mars within six years. Although the launch is due in 2011, it will not arrive at the Red Planet until the middle of 2013, when it could become the first scientific instrument to show we are not alone in the universe.

A roving robot that can search for signs of extraterrestrial life could be sent to Mars within six years. Although the launch is due in 2011, it will not arrive at the Red Planet until the middle of 2013, when it could become the first scientific instrument to show we are not alone in the universe.

Scientists announced the plan yesterday as part of the ambitious programme of European space exploration that could eventually see samples of Martian rock being returned to Earth in 2016. But if the missions are to happen, the space scientists must convince their political masters that the project is worthwhile.

Success in the second part of the programme could lead to an even more extraordinary manned mission to our neighbouring planet in the 2030s, according the European Space Agency (ESA). "The long-term goal of the programme was and still is to put humans on Mars in the 2030s," said Jean-Pierre Swings, the chairman of the ESA's advisory committee on exploration.

ESA scientists announced they have formulated three possible options for the Aurora mission to land a robotic roving laboratory on the surface of Mars in June 2011, after a two-year, circuitous journey through the solar system. The cost is estimated to be £350m but before any money is spent it will need the approval of ESA's council of ministers, who will discuss the proposal at the end of this year.

Although fine details have yet to be finalised, the scientists said they would require a robotic laboratory on wheels that can search for signs of past or present life in the rocks and atmosphere of Mars.

Since the ill-fated attempt to search for life on Mars with the Beagle-2 probe ­ which was lost on Christmas Day 2003 ­ European scientists have tried to devise a successor to rival the big-budget Mars missions of Nasa. More than 100 scientists from Europe and Canada ­ a member of ESA ­ met in Birmingham this week to hammer out what was needed for a return to Mars.

In the past five years ESA and Nasa scientists have confirmed there were once huge bodies of water on Mars where life could have evolved, and that there may still be water underground. Still more intriguing was the more recent discovery of methane gas in the atmosphere which could be produced only by volcanic activity or as a by-product of living organisms.

Mark Sims, of Leicester University, who chairs the Aurora advisory committee, said the presence of methane on Mars was one of the most exciting areas for the rover to investigate. "It's still too early to say where the landing site will be. It would be nice to go for one of the methane hot spots. It is the exciting hot topic because it's related to life," Dr Sims said.

Nasa is planning to put twin robotic rovers on Mars during the same period, continuing the work begun by its rovers Spirit and Opportunity, which have been exploring the planet for the past year.

Bruno Gardini, the Aurora programme manager at ESA, said a more ambitious programme to send spacecraft to Mars that can return samples of rock to Earth will require close collaboration with Nasa.

Such a mission is estimated to cost between £3bn and £10bn and will almost certainly require a nuclear-powered spacecraft which could generate the energy needed for the return journey. A manned mission is also too big a project for Europe alone. "It will require a tremendous effort and it needs to be a global enterprise," Dr Gardini said."

The Aurora rover is likely to include a drill that can take soil and rock samples at a depth of two metres under the Martian surface, which should be deep enough to escape the harsh, oxidising nature of the planet's atmosphere. It will also have geological instruments that can measure seismic or volcanic activity on Mars as well measuring hydrothermal movements caused by underground water.

But perhaps the most important instruments will be Beagle-2's array of equipment for measuring the chemical signatures of life, such as the gas analysis package capable of studying stable isotopes in the atmosphere, rocks and soil.

MISSIONS TO THE RED PLANET

* 1976: Viking probes land on Mars. They show a dry, desolate terrain colder than Antarctica and drier than the Sahara. Life thought to be impossible.

* 1996: Nasa scientists analyse Martian meteorite ALH84001 which was recovered from the Antarctic ice cap. They conclude that it shows fossilised signs of life that may have existed on Mars 3.6 billion years ago. Other scientists dispute the interpretation.

* 2003: Beagle-2, a British-built probe, arrives on Mars but disappears during its descent to the planet's surface. It contained a package of instruments that could have searched for chemical evidence of life.

* 2004: Nasa's twin rovers, Spirit and Opportunity, land on Mars. ESA scientists confirm that abundant bodies of water once existed on the planet. They also find traces of methane gas, which could be a by-product of living organisms, or the result of volcanic activity.

* 2011: Aurora mission launched which will land a robotic rover on Mars in 2013. Nasa also plans two additional rovers to look for signs of life.

* 2016: An ambitious mission to return rock samples of Mars to Earth is due to be launched. This could confirm whether or not simple life forms have ever existed on Mars.

* 2030s: The first manned missions to Mars could take place as a joint project between the major developed countries of the world. It would be the first time that humans set foot on another planet.