The Quest for Mars: NASA scientists and Their Search for Life Beyond Earth. Laurence Bergreen. Читать онлайн. Newlib. NEWLIB.NET

Автор: Laurence Bergreen
Издательство: HarperCollins
Серия:
Жанр произведения: Прочая образовательная литература
Год издания: 0
isbn: 9780007440986
Скачать книгу
cameras? Why not make Pathfinder a science mission as well as an engineering mission? “Wait a minute,” he told anyone who’d listen, “we can actually do science.” Perhaps the mission would need a Project Scientist, after all. Matt saw his chance to push against the system and work with the engineers to make room for science. For Pathfinder to accomplish anything significant, it would have to land in a place with attention-grabbing rocks – rocks that would speak volumes about Martian geological history, especially the presence of water, rocks that were big, but not too big. He didn’t want boulders, for instance, and he didn’t want pebbles, either. He wanted, so he said, a “rock mission.” He wanted a “grab bag, a smorgasbord, a potpourri of rocks.” He wanted sermons in stone.

      Everyone at JPL recognized that Matt was a very good scientist. Now he demonstrated that he was a very good scientific operator, as well. His gift for caustic repartee concealed considerable shrewdness; depending on his purposes, he could be engagingly cynical, or firm and cool. He was persuasive with his colleagues, lacing his remarks with irony, imparting to all those around him the intoxicating sense that they were being drawn into some grand cosmic joke. Nothing intimidated him, least of all NASA’s bureaucracy. NASA was a bunch of civil servants – c’mon, people, don’t you see the joke in this situation? It was a racket. Caltech was another racket, as was JPL. Then there was the science racket, the engineering racket, the budget racket, and of course, the Mars racket, and they were all susceptible to lobbying and influence if you knew where to apply pressure, which came down to motivating people to do something different. “The hardest part of going to Mars,” Matt once told me, “was getting everyone working on Pathfinder to march in the same direction.”

      Unlike most scientists, he was good with the engineers; he appreciated the difficulties they faced. Scientists and engineers often develop adversarial relationships: scientists usually display scant patience for the difficulties of building and operating the instruments, and engineers tend to regard scientists as impractical, arrogant, impossible to please. Stepping into the midst of the fray, Matt pushed back on the scientists, knocking down the number of experiments, and he convinced engineers they could do things they wouldn’t have thought possible. That was a formula for a very successful manager of space science. “You almost have to turn yourself into an engineer,” he said, “because you have to understand what your spacecraft’s doing. Your dominant job as a Project Scientist is to make sure they don’t engineer the science off the mission. It’s not that engineers are dumb, they’re doing the best they can, but they don’t necessarily think about science. And so you sit through interminable meetings waiting for the one silly thing that will pop up and threaten the science. I mean, it’s crazy! The other aspect, once you get the mission going, is that you have to lead the science team. You have to show them where you’re going. What’s really important? How do you allocate resources? How do you keep people’s egos from getting in the way? That’s very tricky.”

      He became adept at building a consensus around the selection of a site. He led a site selection workshop at the Johnson Space Center in Houston, fielding ideas from the entire Mars community. They whittled the choices down to about ten, which Matt put on a large, complicated diagram called “The Chart from Hell.” After much study, Matt, working with another geologist, Hank Moore, concentrated on a Martian basin named Chryse Planitia – Chryse Plain. Within Chryse there is an outflow channel called Ares Vallis, the geological legacy of a huge, ancient flood that deposited interesting and varied rocks on the surface. The diverse rocks were the greatest attraction, as far as he was concerned. The area’s sheer size made it very appealing. Pathfinder, in addition to all its other uncertainties, could not make a carefully predetermined landing; if all went well, it would land somewhere within an ellipse 60 miles wide and twice as long. Matt fretted over the temperature range of Ares Vallis, over the distribution of rocks, and especially over the amount of dust blowing around. If you’ve ever come into contact with terrestrial lava dust, you immediately understand the problem. It’s gritty and irritating and clings to the fingers. Martian dust, made from powdered lava, is similarly fine and gritty. It relentlessly clogs machinery and obscures solar panels.

      To get a better idea of what Pathfinder might encounter if it landed in Ares Vallis, Matt used an Earth analogue – not Iceland, in this case, but the Channeled Scabland in the state of Washington. This desolate region was formed during a huge flood about 13,000 years ago; the turbulent water redeposited rocks across a flat plain, just as Matt believed had once occurred in Ares Vallis on Mars. The Channeled Scabland is much smaller than the Martian site he was considering, and tufts of grass spring from the soil, but geologically, it is remarkably similar to Ares Vallis. He took several field trips to the Channeled Scabland, and even brought along the rover to see how it would fare on the rock-strewn terrain. It ably negotiated the varied surface, and he figured he had finally found his landing site. Ares Vallis was safe, it was geologically interesting, and it was, he hoped, not too dusty.

      NASA’s review panel considered his choice. “You’re going to go back there and kill the spacecraft – and kill your career,” they said, but Matt would not be intimidated. He had seen the results of Pathfinder tests in even worse conditions than it would encounter on Mars, and the spacecraft had survived. “We ended up making the most robust lander that’s ever been designed to land on a planet. Pathfinder could land anywhere,” he told the panel. In the end, Matt got his way, and his landing site on Ares Vallis, but his career would ride on Pathfinder’s fortunes.

       4 FROM OUTER SPACE TO CYBERSPACE

      The Kennedy Space Center in Florida employs sixteen thousand people and covers over a hundred thousand acres. It includes a wildlife refuge; herons, egrets, condors, crocodiles, horses, and cattle roam its expanses. From the road, you can see a six-foot-wide bald eagle’s nest suspended in the branches of a tree. If you drive in the general direction of the launch pads, away from the animals, you will see the outsized Vehicle Assembly Building, a giant hangar for rocket ships, shimmering through the haze. You can pick out the odd Shuttle transporter here and there; they resemble huge, primitive locomotives with giant cleats. Many of the transporters are rusting in the humidity. In recent years, NASA has built the center into a tourist attraction featuring life-size mockups of the Space Shuttle, a few garish exhibits, and a souvenir emporium. On the outskirts of Titusville, the nearest town, discarded rockets litter front yards like so many abandoned cars, looking nothing like the towers of power that I remember from my youth. A heavy nostalgia for the future lingers over the place like the scent of magnolia on a humid evening, and the marquee in front of the local high school always reads, “Countdown to Graduation – Six Weeks.”

      This was where Pathfinder, weighing nearly a ton, arrived on a rainy day in August of 1996. There was a lot of work to do. Things were just beginning to get serious at this point. First thing, engineers wiped down the spacecraft with alcohol to prevent bacteria from Earth contaminating the surface of Mars. Then, electrical technicians wearing bunny suits to prevent dust or hair falling into the delicate machinery, took the spacecraft into a large clean room and tested every circuit. They corrected software problems and installed the rover’s heaters, which contained a tiny amount of plutonium. NASA wasn’t eager to advertise the fact, for the use of nuclear materials in space, even for purely scientific purposes, rouses environmentalists to fury. It was also a giant bureaucratic pain, because NASA had to prepare exhaustive environmental impact statements. The plutonium was deemed necessary because of Mars’ great distance from the Sun. On Mars, sunlight is only a quarter of the strength that it is on Earth, and small solar cells alone could not generate enough power to operate even a small spacecraft and rover.

      After the initial preparation, Pathfinder underwent months of additional testing at Kennedy. Often, the tests were more complicated than the actual mission would be. For a test to work correctly, the ground team had to simulate the positioning of the stars and the Sun, the amount of light, and the temperature for Pathfinder, and then program Pathfinder to respond. Nothing went exactly as planned; everything required extra effort. Work became so intense that the young engineers involved with the project didn’t know what to do when they weren’t testing Pathfinder;