When the spacecraft’s view of the sun was obscured by Mars during a solar eclipse, a lithium-ion battery (67.5 amp hours), previously charged up by the solar panels, took over the power supply.
Five of the instruments on Mars Express (HRSC, OMEGA, PFS, ASPERA and SPICAM) were descendants of instruments originally built for the Russian Mars ’96 mission. Each of the seven orbiter instrument teams on Mars Express had Russian coinvestigators who contributed their intellectual expertise to the project.
The Japanese spacecraft Nozomi was intended to go into near equatorial orbit around Mars shortly after Mars Express entered polar orbit. Nozomi had been due to reach the Red Planet in October 1999, but was delayed by a problem with the propulsion system, so the two missions took the opportunity to collaborate.
They shared a common interest in the Martian atmosphere – Nozomi even carried a close relative of ASPERA, the instrument on Mars Express to study interactions between the upper atmosphere and the solar wind.
Measurements recorded simultaneously by both spacecraft from their different vantage points would provide an unprecedented opportunity to study such interactions, so the two missions agreed to a programme of joint investigations and to the exchange of coinvestigators between the instrument teams.
ESA’s Beagle 2 landed on Mars at about thesametime as NASA’s Mars Rover mission. The two space agencies made arrangements to use each other’s orbiters as back-up for relaying data and other communications from the landers to Earth.
Mars Express also intended to use NASA’s Deep Space Network for communications with Earth during parts of the mission. US scientists played a major role in one of Mars Express’s payload instruments, MARSIS, and participated as co-investigators in most other instruments.
Mars Express and Beagle 2 marked the beginning of a major European involvement in an international programme to explore Mars over the next two decades. Europe, the US and Japan are planning to send missions, but many more countries will be contributing experiments, hardware and expertise.
The Beagle 2 lander was built by a British team. Being small and light it did not have a propulsion system of its own, and had to be “carried” precisely to its destination. On 19 December 2003 Mars Express was on a collision course with Mars, at which point Beagle 2 separated from it. Mars Express then veered away to avoid crashing onto the planet by firing its thrusters to get away from the collision course and enter into orbit around Mars. This was the first time that an orbiter delivered a lander without its own propulsion onto a planet, and attempted orbit insertion immediately afterwards.
Unfortunately no signal from Beagle 2 was ever received although Mars Express sent back significant pictures and information from orbit. It is thought that the atmospheric conditions at the time Beagle 2 attempted to land resulted in it being destroyed upon impact.
On 24 January 2004 Dr John Murray of the Mars Express team stated:
Scientists are on the threshold of the most exciting discovery about humanity’s place in the Universe since Galileo and Copernicus proved that the Earth goes round the Sun.
The European Mars Express spacecraft has determined beyond reasonable doubt that water, the prerequisite for all forms of terrestrial life, still exists on the Red Planet, and that it once flowed in torrents across its surface.
These remarkable revelations about our celestial neighbour provide the most tantalising evidence yet that the miracle of life on earth may not be unique, even within the confines of the solar system.
Wherever water is found on the Blue Planet – from the tundra of Antarctica to the depths of the ocean floor – we know there is life. For life as we know it, we need water. Now we can be certain that this vital commodity is present, and may once have been abundant, on the surface of Mars.
It seems more probable than ever that the planet so long considered barren and inert, may once have supported life.
It would be no exageration to compare such a discovery to the Copernican revolution, which put paid to the notion that the Earth stood at the centre of the Universe, or the voyages of Columbus and Magellan, proving the world to be round. It would mean that life has arisen twice on planets separated by as little as 35 million miles. And if that is so, it is probably common throughout the Universe.
We are not quite there yet. Neither Mars Express, nor NASA’s Spirit and Opportunity rovers, are designed to test the soil and rock for the chemical evidence that would provide definitive proof. Indeed, the European Probe’s results make it more frustrating than ever that Beagle 2, the British lander that was sent to Mars specifically to search for life, remains incommunicado.
The evidence of water, in the form of ice, makes it yet more important that we refuse to give up and dispatch Beagles 3, 4 and 5 to the Red Planet to resume the search.
We should not hold our breath for intelligent Martian life. Anything we find there will be extremely primitive, hardy microorganisms that can cope with extreme cold and harmful ultraviolet rays. These can live under the most unlikely of conditions: the Apollo moon landings turned up microorganisms carried years before as passengers on an unmanned probe.
Martian life could be found in the form of fossils that died out long ago. Or it could survive in certain suitable zones. The search will be a little like opening a window on the Earth billions of years ago.
There are times when science is more like hearing a Beethoven quartet than poring over reams of numbers. Yesterday was one of those occasions.
To look at the pictures from Mars Express’s high-resolution stereo camera was to see something so supremely beautiful that I had to remind myself it was science, not art. These images would not have looked out of place at the Royal Academy’s Summer Exhibition.
Yet they tell us so much. There can be little doubt that the vast channel of Reull Vallis was carved by flowing water. It has water deposition and erosion: there is no way it could be anything else. When we look at Valles Marineris, it is as if we are gazing on the canyons and mesas that are so familiar to us from the American South West. It is a landscape of desolation and grandeur, but one that might possibly have harboured life.
This voyage of discovery encompasses so many great aspects of human endeavour. Important scientific advances are being made. But it is also advancing the achievement of the human race.
On 27 January 2004 Professor Colin Pillinger, the chief scientist of Beagle 2, was interviewed in The Times. When the loss of Beagle 2 was described as a heroic failure, he said:
“I don’t want to be a heroic failure. We would still like to be a heroic success, and we’ve done enough – if we don’t find it this time – to merit a second chance.”
Mars Express had found direct evidence of water on Mars. When he was asked about it he said:
“None of us thought there wasn’t water on Mars. I’ve seen it in my own Martian meteorites. But this is not a discovery of water. It was a very elegant demonstration of it.”
Professor Pillinger became interested in space years before Sputnik went into orbit in 1957, his mind catapulted starwards by the BBC radio programme Journey into Space.
Professor Pillinger compared the ESA and NASA missions: