The triumphant landing of the Phoenix craft on Mars is a tribute to the team of engineers at the Jet Propulsion Laboratory in California - one of whom, Peter Smith, was a colleague of mine on the Beagle 2 mission to the planet in 2003. Using the Mars reconnaissance orbiter, they selected an excellent place to land, and were able to use thrusters to hit the spot safely and softly.
But it's also a tribute to the perseverance of Nasa, which has launched missions to the planet every 26 months. They have built at least 23 orbiting spacecraft, and have now had three successful landings. They've had a policy of following the water, the essential element of life. We have known for 200 years that Mars has polar caps, which could have contained a mixture of water and carbon dioxide. Nasa has seen, from orbit, where the most likely places are for water to be found; they have also identified minerals that appear to have been deposited from water. But though the orbiters can suggest water is present - from radar signals and an abundance of hydrogen - they haven't been able to identify water unambiguously. That's why Nasa has had to send a lander.
It is, though, very difficult to steer a craft towards the poles - orbiting around the equator is far easier - so the Phoenix mission has landed at a site which is, in relative terms, as far north as Greenland. The pictures beamed back so far show no obvious signs of snow or ice, but the craft's robotic arm can reach up to two metres, and dig a trench, in the hope that there is permafrost to be found below the surface.
I'm 99% certain they will find water. And, if so, they will also be able to identify the salts within it, and whether they are suitable for micro-organisms to live on. They'll be able to clearly answer whether this place could be suitable for life to evolve. They are also going to check for organic molecules. I really hope they find them. Though we have found carbon on meteorites on earth, nobody has ever discovered a single atom of carbon on Mars - other than the carbon dioxide in the atmosphere.
And this is where the mission's limitations could set in. The measuring equipment they have on board won't be able to tell if any carbon is biological (ie, living carbon) or simply the debris of meteorites that may have crashed on the planet.
I can't help feeling frustrated, because the Beagle 2 mission would have been able to make this distinction. The Phoenix design is based on a craft that crash-landed in 1999, and building Beagle technology into this mission simply wasn't feasible in the planning time they had. After the 1999 loss, Nasa simply shrugged their shoulders, learned their lessons, and got on with the next mission. With Beagle, the British government and the European Space Agency sighed a collective "oh dear," and stopped there. There was no reason why another Beagle mission couldn't have worked, but they seemed to lose the will to go on.
As it is, the next European mission will not be until 2015, by which time it may feel out of date (and there's a chance it may not happen). It will cost €1.5bn, six times more than the current Nasa mission. That's why I get frustrated, because it proves this is not a question of money: a Beagle mission would have been even cheaper than Nasa's, so the ESA could easily have tried again.
We had enough time to have launched another mission last year, ahead of Nasa, and with instruments capable of identifying every carbon atom in all its forms - to detect whether life exists, or has ever existed.
We could have solved the question all humanity really wants answered: are we alone? If we could show that life on Earth was not unique, the discovery would be on a par with Copernicus saying the Earth went round the sun. It would bring a fundamental shift in the way we all think about ourselves.
Nasa have another spacecraft, set to launch in 2009, that will be carrying a much more sophisticated instrument on a car-sized, roving module. With their findings from Phoenix, they will be able to choose a suitable landing spot and give themselves a much better chance of answering whether there is, or was, life on Mars. These are big stakes. If a British mission had made this breakthrough, it would have inspired our whole country: we'd have kids wanting to take up science, which is what so many people want; and we would have sent a message to the world that Britain, once the dominant power over the seas, is now a space-faring nation.
As it is, Britain and Europe chose shortsightedness over scientific endeavour. Their inaction must go down as a huge missed opportunity.
· Colin Pillinger is the principle investigator for the Beagle 2 Mars project, part of the European Space Agency's 2003 Mars Express mission; he was talking to a Guardian journalist c.t.pillinger@open.ac.uk
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