The Quest for Mars: NASA scientists and Their Search for Life Beyond Earth
- -
- 100%
- +
Goldin didn’t give up on the idea of sending people to Mars. He directed scientists at NASA to make plans for an eventual human mission. Although the project was unfunded and unofficial, it was real enough, and the scientists and engineers went at it with the zeal of true believers. Their enterprise went under vague names, such as Beyond Earth Orbit (BEO) and Human Exploration and Development of Space (HEDS), names that meant different things to different people, and wouldn’t upset Congress. But to those within NASA, the names meant one thing: sending people to Mars. So a lot was riding on the success of the little Pathfinder mission; the implications went far beyond the success or failure of its experiments. It was, potentially, the first step in the most ambitious exploration in history, but few outside of NASA realized that.
The loss of Mars Observer meant Pathfinder’s site selection team was forced to rely on twenty-year-old Viking data. Since Pathfinder was designed to plummet to the Martian surface, it would not be able pick and choose a landing site as Viking had. The site would have to be selected in advance, and it had better be good. A lot of the responsibility for selecting a site fell to Matt Golombek, a young geologist. If you can recall the kid in the seventh grade who always seemed a couple of steps ahead of the teacher, let alone the class, and who was wiry and agile and had a way of laughing off anything that bothered him, you have a sense of Matt Golombek. He came to the agency from Rutgers and the University of Massachusetts as one of the new generation of planetary geologists that included Maria Zuber and Jim Garvin. “You only do this because you love it. It’s not like you’re going to get rich or famous. You’re especially not going to get rich,” he says. Although he reports to work at JPL, which is a government facility, he is, like everyone else there, technically employed by Caltech. It’s a peculiar arrangement, which he facetiously likens to a “money-laundering scheme to lower the number of civil servants.” Matt maintains a certain skepticism concerning government work. “You know what they say about civil servants, don’t you? They’re like rusty old guns. They don’t work, and you can’t fire them.”
Despite his youth, Matt brought with him long experience in Mars exploration. “I was the pre-Project Scientist on all the Mars missions before Pathfinder for ten years, and there was a whole string of them. I was brought in originally with something called the Mars Rover Sample Return, which was actually a politically motivated study to work with the Russians, which didn’t go anywhere.” This was followed by assignments on other luckless missions, including Mars Observer. “I think one of the reasons they assigned me to Pathfinder as the Project Scientist was that I was young. Part of their thinking was, ‘Well, it doesn’t matter who we appoint. It’s not going to mean anything.’ I wasn’t sure I even wanted the job, because the mission was an entry, descent, and landing demonstration that would have little or no science of benefit to anyone. What the hell do you need a Project Scientist for? There’s no science, right? I mean, Pathfinder’s main goal was to land safely, period.”
To achieve even that limited goal, he spent two years mastering every detail of the choices before making his recommendation. The pixels in the old Viking images concealed many potential hazards. “Imagine if you looked at an image to select a potential landing site, and the smallest you see is the size of a football stadium, and you are worried about things that are the size of a meter,” Matt said. “All we had was very coarse, low resolution remote sensing information about Mars, yet we had to guesstimate that the place we would come to rest would be safe, and that the rover could travel out on it. That’s a very difficult job. It was a two-and-a-half year process. We did an exhaustive study of the options, of cost, and of the kind of science you could get at different places.” He had to factor many subtle requirements into his choice. He looked for a spot where Pathfinder’s solar cells would supply power, and where the antennae could communicate with Earth as often as possible. He wanted an area free of mesas, which would confuse Pathfinder’s navigational system. Those and other constraints eliminated ninety percent of the surface of the planet. Geological factors eliminated a number of other tempting targets; if an area was too dusty, too cavernous, or too rocky, it was eliminated from consideration.
There was something else on his mind. What was the point in going all the way to Mars only to land in a dried-up, featureless lake bed and watch the rover go round and round? Why not use the tools they were bringing, the Alpha Proton X-ray spectrometer and the 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; they sought any distraction available in greater Titusville. They screamed themselves hoarse in a Karaoke bar, they played in mud volleyball tournaments, they surfed, they picnicked in the rain – anything to take their minds off the obstacles they faced to ready Pathfinder for space. At four o’clock one morning, they attended a Shuttle launch. The rocket’s glare turned night into day, and the sound of its engines was powerful enough to make observers’ clothes tremble. Pathfinder’s launch vehicle, a Delta II built by Boeing, was nowhere near as big as the Shuttle’s powerful solid state boosters, but the Shuttle simply attains low Earth orbit, about 350 miles high. It circles the Earth for a few days, and then lands on a nice smooth airstrip. If you happen to be a planetary exploration zealot, Shuttle missions, for all their sound and fury, can be a trifle dull. Pathfinder, in contrast, would travel 309 million miles to reach Mars, following the broad ellipse of its trajectory, and would arrive in a new world.
Whenever they could find a few minutes to spare, Pathfinder’s youthful team members posted their field journals on the Internet. These were casual, subjective reflections on their lives and work, with more questions than answers. The mere act of writing made everyone self-aware. It was weird: they were doing their jobs, and simultaneously, they were watching themselves do their jobs. They were doing their jobs on Pathfinder, and they were watching themselves at the same time. Anyone with access to the Internet could log on and check up on the team members’ psyches. As with so much else on this mission, the plan was very cool, and very un-NASA. Taken together, the team’s written observations sounded like an all-night college dormitory bull session about the meaning of God and life and truth and beauty, and that was their charm. The team members, especially the younger ones, unashamedly asked, Who am I? Where am I going? The field journals became confessional, a form of therapy. The more enthusiastic correspondents realized something unusual was going on here, something that extended beyond the boundaries of the Pathfinder mission, something that the words “faster, better, cheaper” didn’t begin to convey: a transformation of consciousness. They weren’t just devising a new way to reach Mars, although that was surely foremost in their minds. They were collaborating on a new way to solve problems, to create, to communicate, to imagine.
In late October, the engineers at KSC mated the spacecraft with the cruise stage of the Delta rocket, and loaded fuel into the spacecraft’s propulsion system. It was powered by hydrazine, nasty stuff that requires careful handling. If you touch hydrazine, it can burn your skin. If you spill it, it can start a fire. The engineers wore protective suits very much like an astronaut’s while they worked. In this instance, the fueling process proceeded safely. Soon after, technicians tested the Deep Space Network, the system for communicating with Pathfinder. The DSN consists of three ground stations – one in Goldstone, California, another in Madrid, Spain, and a third in Canberra, Australia. Exquisitely sensitive, the DSN can pick up exceptionally faint signals from spacecraft as far away as Jupiter, and possibly beyond the boundaries of the Solar System. In November, the team started holding practice countdowns. The launch was approaching rapidly; now it was days, not weeks away. Back at JPL in Pasadena, a sign read, “OBJECTS ON THE CALENDAR ARE CLOSER THAN THEY APPEAR.” It was a message that everyone on the Pathfinder team had learned to heed.
The closing of the spacecraft, supposedly a modest episode in the life of Pathfinder, inflated into a media event. Dan Goldin, the NASA Administrator, showed up at the Kennedy Space Center and gave a rousing speech. Crowds turned out to watch Pathfinder’s four petals fold shut around the rover. As everyone applauded, the engineers glimpsed a sliver of daylight between the petals. This was not a good omen: to close a spacecraft in preparation for launch, only to find that the pieces don’t fit. The event had been scheduled for television broadcast, but the engineers waved away the cameras so they could study the problem. This was the first time the spacecraft had been fully loaded, and the increased weight created structural sagging, which kept the petals from sealing as designed. During the next several days, engineers worked desperately to repair the problem, and couriers bearing modified parts flew in from JPL. “objects on the calendar are closer than they appear.” One by one the new parts were mated, and the entire assembly was stacked on to the launch vehicle, and trucked over to Launch Pad 17A at Cape Canaveral Air Station.
The launch was scheduled for December 2, and it proved to be an exercise in frustration. “The weather was so bad they decided to cancel the attempt for the day,” Donna Shirley wrote in her field journal. “On December 3, many of us went out to the launch pad to watch the gantry roll back. This was supposed to happen at 5 PM but didn’t actually occur until 7:30 PM. It got colder and colder, and there was a prelaunch party scheduled. A few diehards, including me, were all that were left to see the rocket standing free of the supporting structure. It was worth waiting for, shining in the spotlights, gleaming blue and white.” For a few hours that night, the countdown proceeded smoothly, but problems started to mount. “First, the winds aloft looked bad,” Donna recorded. “The range sent up balloon after balloon to see what the winds were like, and gradually they began to improve. By the fourth balloon they looked acceptable, and we all began to get excited. But there was another problem. One of the ground computers was having problems. After much discussion, the launch vehicle team decided to change to a backup computer. But about two minutes before launch time, that computer also had trouble, and the launch was scrubbed. Everyone sagged. We’d been running on adrenalin, not a bit sleepy, but once there was no launch everyone went home to bed.” Bridget Landry, a Pathfinder software engineer who’d been following the tortured countdown from Pasadena, also turned to her journal for consolation: “We were all so disappointed when they said we had to scrub! All that anticipation! In some ways, it’s funny, all that buildup, and then nothing happens. But it’s also scary: the Russian mission, Mars ’96, was unable to escape Earth’s gravity just a few weeks ago. Somehow, that makes us worry more about our launch. Guess scientists and engineers can be a little superstitious, just like anyone else.”
On December 4, with all conditions favorable, Pathfinder finally launched from Cape Canaveral at 1:58 AM, local time. Although the blast was visible in the night sky for miles, there were no throngs along the beach. The event was the merest blip on the news radar; the public remained mostly oblivious to the fact that we were returning to Mars. Pathfinder was just another planetary mission, for the time being.
After launch, the engineers at JPL had a rough idea where Pathfinder was located in space, but now they needed to know precisely where it was. To get a better fix on the spacecraft, they planned to establish contact with it through the Deep Space Network. But before they could do that, the spacecraft was supposed to orient itself with a device called a sun sensor, a small disc covered with photoelectric cells. The event was supposed to occur about ninety minutes after the launch, with the spacecraft traveling at 17,000 miles an hour, but the sensor wasn’t working properly, and if it failed, they would soon lose the spacecraft entirely. As everyone involved with the mission knew, if Pathfinder failed, the future of the entire Mars program, including a human mission, would be in grave doubt.
After extensive searches, the Goldstone, California, antenna of the Deep Space Network finally acquired a signal from Pathfinder, which confirmed that something was seriously wrong with the spacecraft: the sun sensor wasn’t returning data. The best guess was that the sensor’s photoelectric cells had been nearly blinded by exhaust from one of the launch rockets, and Pathfinder refused to pay attention to it. The fix was simple, in theory: send three new software files to command Pathfinder to tune into the sensor. The engineers transmitted the files again and again, but each time they were only partially received, and no one could say why. The situation, already very serious, deteriorated when the spacecraft began to ignore all commands. Eventually, one of the engineers realized that Pathfinder was revolving slowly and came in position to receive commands for only five seconds at a time. Now Pathfinder had two problems – the dirty sensor and the uncontrollable spinning. The double fault was likely to be fatal to the entire mission.
Working around the clock, the Pathfinder engineers compensated for the rotation, and transmitted a complete set of commands to the spacecraft. Once they did, Pathfinder paid attention to the sun sensor, oriented itself properly, and both problems disappeared. The process of resolving them, collaborative and critical, proved to be a rite of passage for the Pathfinder team. Although they were relieved to have fixed a problem that could have killed the mission, they knew that more could appear at any time. Pathfinder was single-string all the way; if a component failed, there was no backup.
In the ensuing days, a weird sense of calm descended on JPL. There wasn’t much anyone could do for the next ten months besides monitor the spacecraft, whose instruments were powered down for the long cruise. “I’ve always known that the spirit on Pathfinder was special,” Bridget Landry noted in her journal, “but when the people who worked on Apollo 11 and 13 say this project has more sense of identity and team spirit than even those two missions, you know you’re involved with something extraordinary. But the feeling here, at least for me, is bittersweet, too. Now that we’ve launched, some people are being laid off, and even though most of us are staying, the scope of the mission means that in less than a year, all this will be over.”
In the spring of 1997, as the spacecraft approached Mars, the Pathfinder team began a new series of tests to prepare for its prime mission – the weeks Pathfinder would spend on the Red Planet, roving and returning data. “Think of it as a rehearsal,” Bridget Landry’s journal explained. “We have a computer that simulates the spacecraft, as well as a model of the lander and a duplicate rover. We put the last two in our sandbox (a room full of sand and rocks used to simulate the surface of Mars), then close the curtains so that no one can see in, and a few people go in and rearrange the rocks. Then the operations team has to take pictures with the lander camera, determine where the rocks are, and generally do all the tasks we’ll do on the first two days on Mars.”