"You pushed people too hard," he continued. "If you work with a limbo bar that's going down, you really have to take a look beforehand to see that the guy who has got to go under the limbo bar is physically capable of it. You can't simply declare: You will save such and such.
"Building a spacecraft is not building a spacecraft; it's building and testing and testing a spacecraft, because you can't go up and fix it. You can always ask: Can you do the tests more efficiently? But what you mustn't do is just tell some guy who's got a set of procedures, 'OK, reduce the procedures by 10 percent.' If you don't analyze how you're going to do it—that's what I mean by 'smarter'—clearly there's a high risk."
ESA was under even more pressure than NASA to be cheap when it finally decided, in late 1996, to go to Mars. Marcello Coradini, a short, bespectacled, and good-humored Italian who is ESA's solar system mission coordinator, was instrumental in the decision. Earlier that year, the agency's Space Science Advisory Committee had vetoed yet another proposal of his for a mission to Mars, preferring to spend money on orbiting telescopes and on relaunching Cluster. Coradini's constituents, the planetary scientists of Europe, were upset. The agency had never funded a mission to another planet. Some scientists, as a result, were participating in a Russian mission called Mars 96. In addition to its homegrown payload, it carried several hundred million dollars' worth of instruments built in France and Germany. On November 16, 1996, Mars 96 was launched on a Proton rocket from Baikonur. It disappeared downrange in a satisfying way, and the scientists headed for the airport. Then the fourth stage of the rocket failed to fire, and Mars 96 fell into the Pacific.
At a meeting of the SSAC that December, with the gloom still deep, Coradini seized the day. He knew the scientists who had built instruments for Mars 96 had spares; that's standard procedure in space science. "I said, 'Look, gentlemen, Mars 96 is lost. Why don't we put together a fast mission, with a simple spacecraft and all these spare instruments, and launch it to Mars?' I said it almost as a provocation.
"There was a moment of silence. And in about 25 seconds, the committee said, 'This is a great idea, we should do it!'" Coradini laughs gleefully at the memory. "I stared at them and said, 'What? Are you serious?'"
The constraints certainly were serious. The instruments were mostly ready and paid for, but given ESA's other commitments, the spacecraft would have to be built, launched, and operated for $150 million. And it had to be done fast, because the best launch opportunity in decades is this month, as Earth passes Mars at perihelion, when the two planets are closest to the sun and to each other. That gave them only six years, whereas the usual gestation period for a scientific spacecraft is more than a decade.
"So I went to John Credland," says Coradini, "who is responsible for spacecraft construction at ESA, and I said, 'John, you got to do some magic here.' And he had this brilliant idea." If much of the payload of Mars Express was being recycled from Mars 96, much of the spacecraft itself could be recycled from the comet-chaser Rosetta, which also had a launch date of 2003 and was already under construction. Just as space scientists always build spares of their instruments, the makers of the spacecraft itself build spares of subsystems—propulsion, attitude control, electric power, communication, and data handling. Credland realized those spares could be taken off the shelf, modified, assembled into a box, and flung at Mars. Suddenly, six years seemed feasible.
Next ESA cut out layers of bureaucracy, giving far more responsibility than it had before to the prime contractor—in this case Astrium, the aerospace giant based in Toulouse—and limiting Rudi Schmidt's staff to a dozen or so engineers. "The design period was fast and short and crisp—that saves money," says Schmidt. "But then we do so much testing that we're sure we still have a good spacecraft." ESA has another guarantee, he adds. Astrium gets its last payment only when the spacecraft achieves orbit around Mars.
Astrium has another incentive to get it right: It is already at work on Venus Express, which will be assembled mostly from spare components of Mars Express and is scheduled for launch in 2005. Southwood has taken the idea Credland had for Mars Express and pushed it to the hilt. His whole program is now organized into production groups, in which each expensive flagship mission, such as Rosetta—which cost $750 million—has at least one cheaper spin-off. The Mars mission is the first test of this fundamental strategy. "It's fast, it's cheap; that's why it's called Mars Express," says Coradini. "And it's beautiful—if everything goes well." He crosses his fingers and laughs.
If everything goes well, Mars Express will tell us where all the planet's water has gone. Like Earth, Mars must have received a lot of water at birth; some researchers think the plains that cover most of its northern hemisphere were once the bed of a vast, shallow ocean, filled by cataclysmic floods of water cascading out of the southern highlands. As Mars Express flies in polar orbit, dipping to within 155 miles of the planet spinning beneath it, instruments made in Sweden, France, and Italy will map the composition of the atmosphere, looking in part for evidence that vestiges of that water are still escaping into space. An infrared spectrometer built by Jean-Pierre Bibring of the Institute of Space Astrophysics in Orsay, France, will make a mineralogical map of the planet's surface, looking in part for the carbonate sediments that should have been deposited in Martian lakes or oceans. Finally, ground-penetrating radar designed by Giovanni Picardi of La Sapienza University in Rome will attempt to probe the frozen Martian crust to depths of two to three miles, looking for water ice or even liquid aquifers. Last year scientists operating a gamma-ray spectrometer on Mars Odyssey, the NASA spacecraft launched in 2001, reported indirect evidence of large amounts of hydrogen, presumably in the form of water, in the upper few feet of Martian soil. Picardi's instrument may greatly expand on that evidence.
It is the two remaining instruments, however—the stereo camera and Beagle 2, the British lander—that are most likely to enchant the layman. Sitting at an outdoor café in Toulouse, Gerhard Neukum, a bald, stocky planetary scientist from the Free University of Berlin, explained the many virtues of the camera he built—starting with its sex appeal. "You can't sell particles-and-fields measurements to the public," he said. "With a camera, you see a landscape on Mars and you can say, 'This is it.' It doesn't matter what it means. You see dunes, volcanoes, dry riverbeds, ice—people understand that."
Neukum started working on his camera in 1988, and before Mars 96 came along, he was hoping it would fly on Mars Observer. NASA instead chose a camera built by Michael Malin, now of Malin Space Science Systems. After Mars Observer failed, Malin's camera went into space in 1997 on Mars Global Surveyor, and it is still sending back spectacularly detailed pictures. In 2000, for instance, Malin published pictures of small gullies that, judging from the absence of meteorite craters in them, seem to have been formed by running water within the past few million years. People used to think Mars had dried up billions of years ago; Malin's camera has rejuvenated Mars.
Malin delivered the sharpest pictures of Mars ever: Each image covers roughly a square mile; each pixel—at maximum resolution—an area five feet across. But Mars Global Surveyor is surveying less than 1 percent of Mars in such detail. The images are like scattered postage stamps on the Martian map, Neukum says, and because the global photographic coverage is so crude, Malin's gullies and other fine features can be situated to within only five miles or so. Neukum's camera is designed to fill that gap. During the two-year mission of Mars Express, it will survey more than half the planet at a resolution of 30 to 50 feet; if the mission is extended to four years, he says, he can do the whole thing.
Neukum's pictures will be in stereo and in full color—whereas the detail shots from Mars Global Surveyor are flat and black-and-white. In Neukum's camera, the CCD light sensors are arrayed in nine parallel lines, each one 5,184 pixels long by a single pixel wide and all of them perpendicular to the direction of flight. The center line will look straight down, while the back line will be angled slightly forward and the front line slightly backward. Thus, as Mars Express streaks over Mars at two-and-a-half miles per second, the three lines will record a given point on the surface from three different viewing angles—"it's as if you had three eyes, not just two," Neukum says—and those records will then be melded into a 3-D image that will reveal the precise height and shape of the land below. Meanwhile, the other six lines of sensors will record the brightness and full color of the scene, with one line each for red, green, blue, and infrared. Right now there are almost no true color pictures of Mars, Neukum says: Because of the spectral limitations of previous cameras, nearly all the color images you've seen have involved some degree of fakery or interpretation.
What the public can imagine doing in a few years, if Neukum's camera works, is donning a pair of 3-D glasses in a movie theater to go on an aerial tour of Mars. What Neukum imagines doing is unraveling the geologic history of the planet—including the history of its water and the question of whether it ever had enough, long enough, for life to evolve. Some top American Mars experts, he notes with pleasure, have joined the team that will analyze his images. "Malin's camera was good, but I want to beat him," Neukum says. "This will be the best experiment ever for Mars, or for any planet. I'm not exaggerating."
One person who might argue the point is Colin Pillinger. Pillinger, a chemist at the Open University in Milton Keynes, England, is the man behind Beagle 2. Recent photographs show him bent over his contraption, with a big, devilish grin. A year from now he may have more to grin about. If Beagle 2 finds evidence of life on Mars, no other result from Mars Express, or from any other planetary mission, will compare with it.