Mars Express works in shadows

While NASA's twin rovers, Spirit and Opportunity, garner all the headlines, the European Space Agency's satellite, Mars Express, is poised to deliver just as much science, including important clues in the hunt for Martian life, at a far lower price. NASA spent more than $800 million on its project, while Mars Express cost a mere €150 million, or about $190 million.Despite the relatively small price tag, Mars Express is well equipped. It is using its cameras, spectrometers, and radar to get a more thorough global picture of Mars. “The attention span has gone on to other things,” Agustin Chicarro, the lead project scientist on the Mars Express mission, told The Scientist. “But we'll be up there for at least 2 Earth years. That's going to provide a lot of data.”There are already two camera satellites floating above Mars: Mars Global Surveyor and Odyssey. Mars Express' camera, while more powerful, is still only a minor improvement over those on the other satellites. Its high-resolution stereo camera, by far the most powerful camera used in Martian science, according to Chicarro, can take a global photograph and discern individual objects on the surface that are 10 meters or larger. When focused on a smaller spot, its resolution can go as high as 2 meters. “The high-resolution images produced by the Express have given us some never-before seen views of the Martian landscape—that's very significant,” Indiana University geochemist Edward M. Ripley told The Scientist. Mars Express' arrays of spectrometers are also technological advances over the spectrometers and magnetometers on board the other satellites.For 2 brief moments in late December and early January, the Mars Express team did have a flirtation with the media hordes. First came the bad news: its foster brother Beagle II, a detachable lander, was lost on impact on the Martian surface on Christmas Day. Then, 2 weeks later, jubilant Mars Express scientists held a press conference that provided preliminary data that proved that large stores of water and carbon dioxide ice existed on the south pole of the planet. “The report of water ice at the poles was not new,” said Jack Farmer, director of the astrobiology program at Arizona State University. “But it did show the promise of the mission.”That promise must wait at least 6 months to begin to bear fruit. That's because all Mars Express data belong to the principal investigators who built the instruments it carries for half a year before being released publicly—presumably enough time for them to publish papers, according to Chicarro. The polar water news was too hot to keep bottled up, he said. The rest of the data will begin to be released in June.The instrument that could significantly alter the understanding of Mars hasn't been unfurled yet. It's a subsurface radar called MARSIS. In late April, as the satellite begins its tour of the southern half of the planet and the days grow shorter, Mars Express will open up two 40-meter long radio antennae designed to reveal what lies deep beneath the surface—in some instances as much as 5 kilometers down. “We've never peered underneath the surface of any planet besides our own before,” Chicarro told The Scientist.It could even solve one of the raging debates about Mars: whether there are underground water aquifers that might sustain microbial life. “Any underground water or ice will reflect the radar waves very strongly,” said Roger Buick, an astrobiologist at the University of Washington. “If there's any geothermal heat in those areas, there's a good chance for life forms.”Meanwhile, Spirit and Opportunity look at individual rocks on the surface. Flying high above them, Mars Express is collecting data that might be even more significant. “I expect the impact of this mission will be substantial over the long haul,” said Arizona State's Farmer. “It is just a question of letting the discoveries build over time and then opening up the dialogue on an international basis.”

Mars Express works in shadows

NASA rovers are media darlings, but European Space Agency satellite will give big picture

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