The Quest for Mars: NASA scientists and Their Search for Life Beyond Earth

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Meteorites have held a special fascination as relics from the heavens, mute messengers from parts unknown. In the Middle Ages, meteors falling to Earth generated superstition and concern. Where did they come from? What did they mean? The faithful brought them to the authorities, and in time, the Catholic Church acquired a large repository of these curiosities. In 1969, the study of meteorites underwent a quiet revolution when Japanese researchers found high concentrations of them preserved in arctic ice. Since 1977, NASA, a technological Vatican, has been collecting meteorites from Antarctica and housing them at the Johnson Space Center in Houston. Each year, there are hundreds of new arrivals, and when there’s a promising delivery, scientists clamor to get a piece to study. There are now nearly 10,000 rocks under lock and key in Building 31 at Johnson, many of them preserved in nitrogen. By measuring the radiation absorbed by the meteor during its space travels, scientists can determine approximately when the rock arrived on the Earth, and even how long it spent in space before it arrived on our planet.

In December 1984, Roberta Score was hunting for meteorites in Antarctica. At the time, she was employed by Lockheed Martin and working at the Johnson Space Center. Around Johnson, a meteorite collecting mission is not exactly choice duty; join one, and you were said to have become part of the “Houston weight loss program.” Walking across an apparently endless sheet of ice, Robbie Score came across a greenish stone about the size of a potato. Once she removed her sunglasses, she saw the meteorite was not greenish, after all; it was gray and brown, but she knew it looked different from the ordinary meteorites she found in the field. Along with other samples, it was kept in a freezer aboard the ship that brought it from Antarctica to Point Magu, California, where it was packed in dry ice and sent to Johnson, where it was stored in cabinets that once held moon rocks. The meteor curators, including Robbie Score, designated it ALH 84001 – their way of saying this was the most interesting meteorite collected in 1984 in the Allan Hills of Antarctica. But after being delivered to Johnson, ALH 84001 was misidentified as an asteroid fragment, a diogenite, rather than a piece of Mars, and stored in Building 31. It was not ignored, however; small sections were allocated to the scientific community for further study over the years; in all, almost a hundred “investigators” examined it, and everyone continued to misclassify it as a diogenite – with one exception.

In late 1993, David Mittlefehldt, a veteran Lockheed Martin scientist also working at Johnson, reexamined ALH 84001. Mittlefehldt was an expert on diogenites, and this particular rock didn’t look like one to him. It seemed to have more oxidized minerals in it than your normal diogenite, for one thing. Using new technology in the form of high-resolution laser spectrometry, two other scientists, Donald Bogard and Pratt Johnson, extracted gases trapped inside the strange meteorite and discovered that their very idiosyncratic characteristics exactly matched gases on Mars as measured by the Viking spacecraft in 1976. Mittlefehldt published his findings in 1994 in a scientific journal, and attracted the notice of the science community. Although this wasn’t the first meteorite from Mars to have been discovered, the reclassification created a stir. Of the thousands of meteorites that have been cataloged, only fourteen are believed to have come from Mars; the overwhelming majority come from asteroids, and a few from the moon. Meteorites are named for the places where they have fallen to Earth, so the Martian meteorites have some fairly exotic names – Shergotty (India), Nakhla (Egypt), and Chassigny (France), among them – and are known collectively as SNC or “snick” meteorites. “SNC meteorites” is an elaborate way of saying “meteorites from Mars.”

Carefully considering his find, Mittlefehldt noticed minuscule reddish-brownish areas deep within ALH 84001; they looked a lot like carbonates, and on Earth, carbonates such as limestone tend to form close to water. What made this all so curious was that no one had detected carbonates – and their suggestion of water – in the other Martian meteorites. They were billions of years newer; they probably came from a more recent era in the geologic history of Mars, after the water that once flowed freely across its surface had disappeared. This one, however, apparently harkened back to that warm and wet golden age on Mars. Dating confirmed that the meteorite was indeed very old: 4.5 billion years old, much older than other known Martian meteorites, and it contained carbonates that were 3.9 billion years old. Mittlefehldt wanted to get some idea of the temperature range in which the carbonates had formed billions of years ago, so he went to yet another NASA scientist, Everett Gibson, who examined the very curious meteorite with Chris Romanek; they published a paper in the December issue of Nature in which they said the carbonates had formed at temperatures below 100° C, in other words, at moderate, Earthlike temperatures – “well in the range for life processes to operate,” as Gibson puts it.

By now a line of reasoning was beginning to take shape. The team had their meteorite; it was from Mars. Almost no one disputed that singular fact. And it was very old, when water was thought to exist on the Red Planet. And it had carbonates, suggestive of water, formed at moderate, Earthlike temperatures. With each new discovery, the stakes became exponentially higher. ALH 84001 had gone from being a curiosity to an interesting and instructive case study to a potential harbinger of a scientific revolution. Each new link had been more difficult to fashion than those that had preceded it, and the final link – to life on Mars – would be the most difficult of all to fashion.

Other scientists soon began angling for a piece of the curious, potato-shaped Martian meteorite, among them David McKay. Over the years at Johnson, he’d become known as a solid and reliable scientist, not the type to go out on a limb. Carl Sagan he was not. If you asked around about McKay, you often heard words like “cautious” and “self-effacing,” yet he had a distinct air of authority; he’d published hundreds of scientific papers, and he knew his way around Johnson and around NASA. Over the decades, he’d learned about science and about maneuvering in the world of scientists. He knew about the pitfalls, how quick others were to leap on “discoveries” and tear them to bits. Yet with all his experience, he seemed destined to retire in honorable obscurity, until ALH 84001 came to his attention.

“I’m going to get a piece of that meteorite and look for signs of life in it,” he told his wife.

“Sure you are,” she said.

McKay had a vast storehouse of information and impressions about rocks on which to draw. In his long career, he had looked at perhaps 50,000 of them, and he spent many hours studying the most intriguing he’d ever seen, ALH 84001, with a scanning electron microscope capable of magnifying objects 30,000 times. With this instrument, McKay identified a bunch of – well, they looked a little like miniature subterranean carrots, or worms, or tubes. Whatever they were, they didn’t look like something you’d expect to find in a meteorite.

Again, he turned to another scientist for assistance. Kathie Thomas-Keprta was a biologist who had spent almost a decade studying extraterrestrial particles – space dust – before she focused her attention on the meteorite from Mars. She was accustomed to making do with very little. A specially modified B-57, flying at high altitude for an hour, might collect just one extraterrestrial particle from an asteroid, a particle too small to see but big enough for her to examine under a powerful microscope. When McKay invited her to study a Martian meteorite, she was delighted to have something as big as one millimeter by one millimeter to work on after all those years of studying specks. Even better, she was an expert with a new type of electron microscope that could reveal the mineral composition of the carbonates locked in the meteorite. McKay and Gibson showed her the photos taken by the scanning electron microscope, and they proposed that she examine those peculiar, worm-like structures to see if they were fossils. She listened respectfully to their proposal, and when she got home that night, Kathie told her husband, “These guys are nuts!”

A team of researchers based at Stanford subjected chips of the meteorite to further laser tests, which yielded polycylic aromatic hydrocarbons – PAHs, for short – which are often associated with life. That finding raised more questions than it answered, for PAHs are also associated with inorganic material such as pollution and exhaust. If that were the case, the carbon in the meteorite could be the result of very recent contamination on Earth, not evidence of ancient life on Mars. Additional tests showed that the PAHs were buried inside the meteorite and probably quite old, lessening the likelihood that they were the result of exhaust. It looked like the PAHs came from Mars, after all.

The team felt confident enough to announce some initial findings at the 1995 Lunar and Planetary Science Conference, held at the Johnson Space Center. In the planetary science community, the LPSC is a very big deal, a sort of scientific Super Bowl. If you don’t show up for this event, scientists say, everyone assumes you’ve died, and when you do show up, you come to make news, if you can. On behalf of the meteorite team, Kathie Thomas-Keprta presented a paper about the unusual and provocative features of ALH 84001 observed by the team. The paper stopped short of declaring they had found evidence of life on Mars, even very ancient, very tiny life. In fact, she adamantly denied it to a reporter from the Houston Chronicle who suspected she was hinting at it.

She knew other scientists would soon challenge her findings, no matter how cautiously expressed. Faulty science or clumsy handling of the situation could mar several carefully-tended careers. So McKay and his colleagues ran still more tests on the meteorite with an even more powerful scanning electron microscope designed to inspect rockets for minuscule fissures; this instrument was capable of magnifying objects up to 150,000 times. McKay put a four billion year-old piece of Mars under the microscope, and on his monitor there appeared a bunch of worm-like forms. He printed an image, and gave it to his teenage daughter.

“What does it look like to you?” she asked her father.

“Bacteria,” he answered.

Kathie Thomas-Keprta eventually decided the guys on her team weren’t nuts, after all. Her conversion occurred in Building 31 at the Johnson Space Center one night when she was working late. As she examined the shapes of the nano-fossils in the meteorite, she knew from experience they were of biological origin. “It was gregite, an iron sulfite present in the carbonate. It had a certain morphology known to be produced by bacteria. It was actually a biomarker, a thumbprint left by biological activity. I thought, ‘That’s it. There’s life on Mars.’

“I walked out the door to the parking lot, half-expecting to see flags waving and bands playing, but there was nothing at all out there, just a dark, empty parking lot at night.”

The chain of reasoning was more or less complete. The meteorite was old enough to contain of a record of Mars’ early days, when water was plentiful. It had carbonaceous material; it probably had Martian rather than terrestrial PAHs; and it had gregite, a universally accepted sign of biological activity. Although each distinct link could not be taken as proof, they all added up to a fairly strong argument for ancient life on Mars.

The team, now grown to nine, approached Science magazine. They realized that getting the prestigious journal to accept their paper would be difficult and delicate; they might have to withstand as many as four or five anonymous critiques of their work. Science was tempted by the paper but reluctant to support invalid conclusions, so the publication sent out the manuscript to nine readers. The resulting article relied solely on sober observations and rigorous science, and its title reeked of compromise: “Search for Past Life on Mars: Possible Relic of Biogenic Activity in Martian Meteorite ALH 84001.” The most important sentence was the summary: “Although there are alternative explanations for each of these phenomena when taken individually, when they are considered collectively … we conclude that they are evidence of primitive life on Mars.” In other words, the meteorite offered the first scientific evidence that ours is not the only planet in the Solar System where life emerged. Publication of the issue of Science containing the article was set for August 16, 1996.

When Jim Garvin heard about the impending Science paper, he felt the skin on the back of his neck prickle. “I was dumbstruck,” he said. In 1990, he had looked at another meteorite, Shergotty. At the time, no one realized that particular rock had come from Mars. He borrowed a piece of it from the Smithsonian, where it is stored. “I took it up to our lab and made the measurements I’d wanted to make for impact metamorphism” – looking for evidence of shock waves, that is. “This was a passive measurement, by the way, like bouncing a laser pointer off a rock; we weren’t destroying it.” There he was, examining a piece of Mars without realizing it.

The force of the new paradigm – that life on other planets was probably tiny – spun Jim’s thinking in a new direction. “We were still a few months before the launch of Pathfinder and Mars Global Surveyor, and the question was asked, ‘What could be done with these ready-to-go spacecraft to look for more signs of life?’ ” Suddenly, Jim’s Mars mission had a new reason for being. He had always believed it presumptuous to assume that life existed only on Earth, and he was sympathetic to the meteorite team’s conclusions about ALH 84001. Their research science was rigorous, it was cautious, and it was consistent with the latest findings concerning extremophile life. There was something in that meteorite that could not be explained away by conventional arguments. Jim agreed with the team that the burden of proof had now shifted to those who insisted there was no life on Mars. If that was the case, he said, “an interesting explanation as to why life failed to make at least a tenuous foothold would have to be crafted.”

The midsummer Martian madness started in earnest a couple of weeks before publication of the article, when Dan Goldin, the mercurial, publicity-loving head of NASA, heard that Science had accepted the article for publication. Next, the White House wanted to make a grand occasion out of the discovery of possible life on Mars. In preparation for the announcement, Goldin summoned David McKay and Everett Gibson to Washington. “We had thirty minutes scheduled with Dan to talk about the meteorite,” Everett told me. “After an hour and a half, Dan said, ‘You guys take a break, I’ve got some things to do, and then we’ll continue.’ During the break, he dictated a commencement address he was going to deliver at UCLA and handled a few other things, and then we continued for another hour and a half. I felt like I was giving an oral defense of a Ph.D. thesis. I mean, Dan went back to first principles, and he took twenty-eight pages of notes.” At the end of the ordeal, Dan Goldin had one last question for the two scientists: “Can I give you a hug?” The gesture was pure Goldin. In general, NASA is not a touchy-feely place – but Goldin is a man of enthusiasms.

After that, the story began to leak everywhere. Space News, a weekly trade journal, hinted at the forthcoming Science paper about ALH 84001, and the buzz preceding an important Washington story started; then things suddenly went awry. At the stylish Jefferson Hotel in Washington, Dick Morris, an advisor to President Clinton, told a prostitute named Sherry Rowlands about the discovery, in the vain hope of impressing her. “Is it a bean?” she asked. Well, no, not really, he replied. It was, uh, more like … a “vegetable in a rock.” When Rowlands got home and opened her diary to write about her day with Dick, she noted, “He said they found proof of life on Pluto.” Scientists dread being misunderstood by the public, but who could have imagined the magnitude of misunderstanding generated by this discovery? The situation deteriorated even further when the befuddled hooker tried to peddle the story to the tabloids, which turned out to be more interested in extraterrestrial life in the form of little green men than vegetables in rocks, thank you. And her inability to recall just what planet Dick said they’d found life on – Saturn, maybe? – didn’t help her credibility, either. There was no sale.

The life-on-Mars story quickly took on a life of its own. The CBS Evening News was making disturbing noises that it might break the news even before confirmation, according to an account that appeared in Texas Monthly. Other networks sensed news in the making and assigned reporters. Science tried to halt misunderstandings by posting the article on the Internet shortly before publication. On the first day alone, the website received over a million hits. Giving substance to an age-old dream, and terror, the article’s findings excited worldwide attention. The announcement gave new impetus to America’s expensive, beleaguered space program, especially its investigations of Mars. Goldin was delighted to confront a challenge of this magnitude, and the mood surrounding it recalled the great days of the space race, when Americans had an emotional investment in NASA and the nation’s fortunes seemed to rise and fall with the agency. But the issue of life on Mars was more complicated to explain to the public and sell to Congress than sending people to the moon had been. There was no life-on-Mars race for politicians to exploit. National security and national pride were not at stake. Only the science really mattered. The discovery involved concepts difficult for most people, even scientists, to understand, including a meteor of unimaginable age that had traveled to Earth from an unimaginable distance, containing evidence of life that was unimaginably tiny.

NASA finally made the announcement at a flashy press conference, at which an exuberant Dan Goldin proclaimed, “What a time to be alive!” (And the head of NASA, he might have added.) Bill Clinton, campaigning for reelection, appeared on the South Lawn of the White House to hail the discovery as if it were another triumph for his administration, but he actually sounded a note of caution that went largely ignored: “If this discovery is confirmed, it will surely be one of the most stunning insights into our universe that science has ever uncovered.” That was still a big if. And his declaration that the American space program would now “put its full intellectual power and technological prowess behind the search for further evidence of life on Mars” did not necessarily mean additional money for a beleaguered NASA. His words amounted to a mere presidential pat on the back.

The summer of Mars was underway. For a while, the names of the several NASA scientists on the meteorite team – McKay, in particular – were known to journalists and the general public. The sudden popularity threw the scientists for a loop. They naturally desired professional recognition, but not celebrity. In their line of work, being famous meant being considered suspect, a semi-charlatan, a talking head rather than a working research scientist. None of them aspired to become the next Carl Sagan, bridging the gaps among the media, the scientific community, and the public. Although their thinking was revolutionary, they weren’t visionaries; they just wanted their funding, and they wanted to pursue their scientific interests. The announcement concerning ALH 84001 made it harder for them do that, as publicity insinuated itself into the normally orderly process of disseminating scientific information. Instead of addressing specialists at conferences and publishing in specialized journals, science teams proclaimed their findings in press releases, in advance of publication. Freed of the constraints imposed in a refereed publication such as Science, the releases tended to make larger claims than the articles that inspired them. Conducting science by press release troubled many, including those engaged in the practice.

The announcement concerning ALH 84001 transformed NASA. For the first time, many people realized that NASA supports scientists, not just astronauts and engineers and the crews that send them into space. In its youth, NASA had accomplished one spectacular engineering feat after another: putting an astronaut in orbit, sending astronauts to the moon, keeping astronauts in orbit for months on end. These missions included science, but science was rarely the point. Flags and footprints on the moon were the point. Astronauts did collect a few hundred pounds of moon rocks for scientists to analyze, but the public had scant interest in lunar geology. Now, with the announcement of possible nanofossils in ALH 84001, NASA scientists were no longer overlooked. And with the end of the cold war, they could participate in missions that were primarily scientific rather than political, missions that might become more significant than sending people to the moon. They suddenly had an opportunity to devise experiments exploring fundamental questions about the nature of the universe and the origins of life. Their results of their search, a NASA report concluded, “may become a turning point in the history of civilization.”

The message in a bottle had arrived, but who would decipher it correctly?

Throughout the summer of 1996, David McKay expected a backlash concerning his discovery, but it was slow in coming. At first, members of the public, some of them deeply suspicious of all federal agencies, NASA included, sent him angry e-mails, most of which echoed the theme, “What kind of fools do you take us for?” One said, “Your life on Mars story is a good example of your mistaken belief that the general public is comprised of a bunch of total idiots.”

Eventually, scientists joined the clamor. Some insisted that ALH 84001 proved absolutely nothing. The wormlike structures, said critics, were far too small to be bacteria; in fact, they were many times smaller than the smallest bacteria ever seen on Earth. Others insisted that if the meteorite contained evidence of biological activity, it was the result of contamination. Still others challenged the team’s analysis of the PAHs. Some scientists stated flatly that McKay and his team had unfairly manipulated the evidence to support a flawed hypothesis. Everett Shock at Washington University invoked the Murchison meteorite, believed to have come from the asteroid belt, to invalidate the discovery. “It has carbonate minerals in it,” he said, “and real solid evidence of water – yet there isn’t anybody saying that there is life in the asteroid belt.” True, no one was saying it at the time, but that situation is beginning to change as scientists have come to think of life as widely distributed throughout the Solar System. Finally, the scientists attacked the reputations of McKay and his team, a tactic that took cooler heads by surprise. “It’s kind of strange when scientists, who are thought to be rational, become emotional,” said Marilyn Lindstrom, a curator of meteorites at the Johnson Space Center. “What bothers me most is that so many people have made up their minds before the data come in. I mean, sometimes I’m amazed by McKay and Gibson’s almost true-believer attitude.”

Carl Sagan was seriously ill at the time of the announcement, with only a few months to live. During his decades with NASA, he had become familiar with both the science and the passions involved in the search for life beyond Earth, and his pronouncement on the subject was enlightening yet equivocal. “For years I’ve been stressing with regard to UFOs that extraordinary claims require extraordinary evidence. The evidence for life on Mars is not yet extraordinary enough. But it’s a start.” Although he was deeply intrigued by the meteorite team’s findings, Sagan insisted that more study was required. Yet other scientists were convinced by McKay’s rigorous approach. “If this is not biology,” said Joseph Kirschvink of Caltech, “I am at a loss to explain what the hell is going on. I don’t know of anything else that can make crystals like that.”

Because McKay, Gibson, and company were cautious, even cunning, in the way they stated their findings, they made it difficult for their critics to disprove their argument. The meteorite team held that the fossils were merely possible evidence of relic life; they were not the only explanation for what they’d found, merely the best explanation. To disprove or dismiss these findings, their critics would have to understand ALH 84001 even better than the original investigators did. They would have to refute four separate, interrelated lines of argument. They would have to be familiar with geochemistry and physics and geology and of course biology. No one person knew enough about all these fields as they applied to the meteorite; it would take a team, a bigger and better team, to show McKay and his colleagues the error of their ways.

The significance of the debate transcended the meteorite itself. Even if it contained crystals that mimicked biological morphology, or contamination, the search for extraterrestrial life had undergone a sea change. Even scientists who thought ALH 84001 contained no life signs at all now found themselves thinking that if we were going to find evidence of extraterrestrial life, it would probably be tiny and ancient and carried throughout the Solar System in a meteorite. McKay, Gibson, and Thomas-Keprta’s real discovery was a new paradigm. Even if their conclusions turned out to be incorrect, their thinking was too sophisticated to dismiss. From now on, they would define the terms in the search for extraterrestrial life. Their credibility rested not so much on what they found as on how they found it: their precise, rigorous methodology.

Two years after the announcement, I found Kathie Thomas-Keprta in the featureless Building 31 at the Johnson Space Center, where many of the crucial discoveries concerning the meteorite had occurred. She is tall and slender, with long blond hair swept up in back. Despite the intense debate concerning her work, she didn’t look embattled; she was poised, with a certain swagger and the smooth delivery of a television talk show host, at least in one-on-one conversation. We were standing beside another Martian meteorite, EETA 79001, a cousin of the more famous ALH 84001. EETA 79001 resembles a black ice cube, about two inches by two inches. I peered carefully at this Martian specimen. There wasn’t much to see except for a little hole in one side drilled by a laser to extract gases trapped within.

Her team expected a lot of debate after their discovery, she told me, although the vehemence came as a surprise. “Still, all the criticism and attacks on our findings don’t bother me because I’m from Green Bay Wisconsin, and I’ve been a Packers fan for thirty years, and I know what it’s like to hang in there from one losing season to the next.” She thought it would take five to ten years for their findings to be fully vindicated, and she couldn’t wait for that day. Her case now was stronger than ever, she said. The recent discovery of microorganisms far below the Columbia River, in Washington State, gave her a lot of corroborating evidence for nano-life on Mars. No one expected to find nanobacteria a mile or more below the surface of the Earth, and no one knows how they started growing. Like their ancient Martian cousins, they live in basalt. More important, they are almost as small as the Martian nanofossils. Critics of the meteorite team insisted that the presumed nanofossils in ALH 84001 were much smaller than any organisms found on Earth – too small to be considered micro-organisms. Since the Columbia River discovery, that objection lost much of its force.

I wondered what kind of energy source for life could be found in rock a mile or two underground, where there is no sunlight, no lightning, no real heat from the Earth’s core. Some scientists think the source could be as simple as water passing over the basalt, which might cause a chemical reaction. If this is the case, the answer to the Genesis Question becomes simpler all the time; it appears that the rock bottom (so it might be said) requirements for life are even more minimal than scientists believed only a few years earlier. All you need is water and an energy source for life to emerge. Water might be running through subsurface basalt everywhere; the same thing might have happened on other planets, or even on asteroids; it might be happening now. There might be more ways for life to emerge than we now imagine – enough to suggest that life really is an inevitable outcome of chemistry and an inevitable part of the universe, predestined, as it were, but so simple that we hardly acknowledge the phenomenon for what it is.

David McKay is tall, slender, silver-haired, professorial, imposing. As the leader of the meteorite team, he is suspicious of outsiders and chooses his words with care. His office, where we met, is capacious, even by the standards of the sprawling Johnson Space Center, and the walls are lined to the ceiling with plaques, awards, degrees, citations, and a child’s squiggly drawing of a small Martian meteorite beside a large man labeled, “Dad.”

“We are still getting new data,” he said, as he snacked on a small bag of pretzels, eying me warily. He wasn’t exactly thrilled that I’d appeared in his lair; he was sensitive to criticism and assumed I was about to add my voice to the chorus of those who angrily criticized his findings. He was about to dismiss me – or so it seemed – but he thought again, and decided to test his case with me. “We are very excited about the data from the meteorite called Nakhla that fell in Egypt in 1971,” he said. “The British Museum had a piece the size of a potato, covered with fusion crust, which protects it from contamination. The problem with the Allan Hills meteorite, ALH 84001, is that it may have been contaminated with carbon or terrestrial bacteria. A chunk of the Nakhla meteorite came in here, to our lab, and we had permission to break it up and pass it out to various investigators. We requested six grams. We think it’s likely to have the least contamination of any Martian meteorite.” I sensed he knew more, but this partial revelation was all he would risk revealing at the time.

He also wanted me to know he hadn’t given up on ALH 84001 as the prime suspect in the search for life on Mars. He didn’t want me to think for one second that Nakhla was a substitute for ALH 84001; rather, it offered supporting evidence. As he talked, it became apparent that he felt that all the criticisms leveled at his findings, and there had been a lot of them, more than most scientists encounter in a lifetime, had only strengthened the arguments he originally advanced. To illustrate what he meant, he invited me to sit with him before a large monitor. “Here’s a new picture from the Allan Hills meteorite. We really suspect these are fossilized bacteria. They have better characteristics than what we have already seen; they are curved, segmented. If you gave this to a biologist, he’d say, ‘Of course it’s bacteria,’ but we have to prove beyond a shadow of a doubt it’s of Martian origin and fossilized. Fossilization is very common with bacteria; the organic components are replaced by mineral components such as iron oxide or silica. This can happen quickly, in a couple of weeks, and it happens when you bury the material in water. They are one hundred to two hundred nanometers long and forty to fifty nanometers wide, smaller than the big worms in the published pictures, which were five hundred nanometers long. My guess is that life is still on Mars, but it’s underground, in the water system. That’s where the underground organisms are living, a couple of kilometers underground. On Earth,” he reminded me, “there are microbes growing four kilometers underground.”

As we parted, David McKay insisted, “Our critics have proved nothing. Our research has defeated each and every one of their arguments, and the case for ancient life on Mars is now stronger than ever.”

Nine months after our meeting, McKay made his latest findings public at the 1999 Lunar and Planetary Science Conference in Houston; his announcement added to the controversy and ensured that the debate surrounding fossilized Martian bacteria would continue for years. To his way of thinking, there were now two meteorites from Mars bearing evidence of fossilized bacteria, ALH 84001 and the newcomer, from Nakhla, Egypt. His detractors claimed his analysis of the newer meteorite, Nakhla, compounded the errors he had made in his analysis of the first, but his supporters insisted it offered compelling confirmation of extraterrestrial life.

3 GROUND TRUTH (#ulink_9dd2d5f6-be70-531c-a359-c187ff70c38d)

To reach the Jet Propulsion Laboratory, you take the freeway to Pasadena and get off at the Oak Grove Exit, then follow Oak Grove as it winds gently toward the mountains through the luxuriant landscape. You feel the smog settle on your chest as you go. There’s no suggestion of high technology in the area, just a somnolent Southern California suburb, lush, green, and slightly sullen. As you sense the end of the road approaching, you assess the looming mountains, but there’s still no sign of JPL, and you begin to wonder what gives. JPL isn’t exactly off-limits, but it’s not easily accessible, either. It will be found only by those who put some thought into looking for it. You think you’re finally there when several large white modern structures appear on the left, but as you drive up to them, you realize it’s a local high school, and then, just ahead, there’s a gate and a guardhouse, and that, at last, is JPL.

People arrive for work early. By 7:30 AM, the parking lot is filled with Hondas and Fords and Nissans and Tauruses – nothing fancy, except the odd Corvette. Employees quietly fan out across the campus and go to work. The buildings at JPL are boxy, functional, crisp. Within its offices, there are the same horrible green plants you see everywhere at NASA, at headquarters or the Johnson Space Center in Houston. Once you’re indoors, you can forget all about Southern California; you might as well be in Washington or Florida; it’s NASA-land.

Despite its innocuous location, JPL is among the world’s leading centers for spacecraft engineering and development. Started in 1936 as the Guggenheim Aeronautical Laboratory at the California Institute of Technology, JPL is now run jointly by NASA and Caltech. In the early days, there were just a few people on hand, including Frank Malina, a rocket enthusiast, and Theodore von Kármán, an influential Caltech professor. The lab barely survived the Depression, but it got a boost during World War II for experiments in rocketry. During the fifties, JPL developed a satellite that, according to legend, could have beaten Sputnik into orbit by a few months and irrevocably changed the space race – if it had been launched. Throughout the sixties, JPL solidified its reputation as the place for robotics – unmanned spacecraft destined for the moon and the planets – but it lacked the high profile of the Johnson Space Center in Houston or the Kennedy Space Center in Florida.

All that changed with the advent of the new Mars program in 1992, when a new generation of employees began streaming into JPL, reinvigorating the place. Unlike many of the old timers, they hadn’t come out of the military or the aerospace industry, they were just out of grad school, and had grown up watching the space program on television. They were young, and they weren’t burdened by the past. The men wore earrings and pony tails instead of military buzz cuts, and tie-dyed t-shirts replaced white polyester short-sleeve button-down shirts and narrow black ties. But that was just the men. Many of the new recruits were women, and among them was Jennifer Harris.

Growing up on her family’s farm in Fostoria, Ohio, Jennifer never expected to explore Mars or to become a flight manager for a Mars mission. She wanted to be a concert pianist. She played the piano, the saxophone, marimbas, bassoon, trumpet, tuba; she was a one-woman band. On the other hand, she loved math and competed successfully in county-wide math competitions. Astrophysics excited her imagination, especially black holes; she loved just thinking about them. In the summer before her senior year in high school, she went to music camp, where she realized that her survival as a concert pianist would depend on her ability to practice every waking moment, and she wasn’t sure that was what she wanted to do with her life. She also wanted to travel, to meet people; she was even thinking of becoming a missionary. When MIT accepted her, she went into a mild state of shock. Eventually, she chose to major in Aerospace Engineering – partly because it sounded like the coolest thing she could do and partly because her father had tested missiles for NASA when he was younger, and she had come of age hearing his tales of countdowns, halts, and explosions. Or maybe the picture of a rocket on a wall in the den of her home influenced her decision. After graduation, she went to work for the Jet Propulsion Laboratory.

Even after she arrived at JPL, Jennifer was restless. They were designing spacecraft on spec, hoping to get funding from Congress, and most projects never did. If a project actually received a green light, the lead time was awfully long. As she toiled away at her subsystems, she couldn’t see where her little cog fit into the machine, or if there even was a machine. She began to ask herself, “Is this all there is?”

She was single and didn’t have any serious ties to Pasadena or JPL. She chose to take a leave of absence, without assurance that a job would be waiting for her when she returned, if she returned. She still wanted to see the world and meet people, so she decided to do missionary work in Russia. She was assigned to Sevastapol, in the Crimea, near the Black Sea, where the conditions were unbelievably grim. There was no hot water, and they lived in cement buildings that were always cold and damp. A lot of the population were flat-out atheists. The economic situation was horrendous. She was paid about $30 a week, which made her among the wealthiest citizens of the town. Everyone around her was subsisting in a barter economy, using coupons instead of cash; one Snickers bar, for instance, cost 2,000 coupons. She and her friends based everything on the cost of a Snickers bar, but that didn’t help keep track of finances, because the inflation was incredible. Pretty soon that Snickers bar cost 8,000 coupons, then 16,000. People who had saved throughout their entire lives lost their fortunes overnight when the ruble crashed.

At times she wondered what kind of space program the Russians could possibly mount under these conditions. She had to wonder how they got anything done. As if the Russians’ pervasive fatalism wasn’t enough, there was the corruption, another thing she hadn’t been exposed to back at MIT and JPL and the family farm. She knew evil when she saw it, though, and it seemed to her that Russia, or at least her speck of it, was basically run by the Mafia, the politicians, and the church, all in bed together. After a while, she wondered if she was meant to be doing missionary work, if it was really the best use of her abilities. Was this what God wanted her to do? Was this what she wanted to do? She had to say honestly that the answer was no, her education was going to waste here. When her tour of duty was over, she left Russia to wander around Europe.

One day, she sent a postcard to a friend at JPL to say she would be back in a few months. “Do you have any jobs?” she asked, knowing the answer was very much in doubt. The day she arrived back in Ohio, JPL called to say they had a job for her, a good job, if she wanted it, but she would have to make a decision that day or the next. The job opening was on the new Pathfinder project, the next spacecraft to go to Mars. She said she’d take it. Jennifer was fairly skeptical about Pathfinder, but so was JPL. “A lot of people thought it would never work. There were so many things that could go wrong, especially with the Mars environment.” Her new job didn’t seem to have official status at JPL. Even the official Mars program people kept their distance. The development of Pathfinder struck her as a skunkworks, basically. She knew what that meant: if it wasn’t working, they could take it out and shoot it and bury it and no one would be the wiser.

The nature of her job changed as the mission went along. She began by working on software, “but the neat thing about Pathfinder was that once you took a job, it was sort of a ‘where-do-you-fit-in?’ type of thing. People didn’t say, ‘That’s not your job, stay out of there.’ They allowed you to move around, so I ended up doing more integration and testing in the early stages than operations. People were always given the opportunity to move over the borders and learn more and do more.” This open-ended, go-wherever-you-fit-in approach was something very new at NASA, and at JPL, which functioned along rigid, bureaucratic lines of command. The problem with the traditional structure was that if one element was delayed, or failed, or went awry, it brought the entire system to a halt. It became accepted practice for missions to slip several years. People were confined to narrowly defined jobs, and many of their talents and interests went untapped, because they had only a single task to perform. That paradigm didn’t apply to Pathfinder. Things were more flexible. It actually was faster and better and cheaper. This was all new, and very un-NASA.

Not everyone at JPL took to this open-ended approach, but Jennifer did. She became more confident in her various roles, accustomed to change. After her experiences in Russia, she knew not to overreact to situations and to plug along until she found a solution or failed miserably. In time she developed an informal network of specialists and advisors she could trust, her go-to people. The Pathfinder cradle-to-grave approach helped a lot. People came on board at the beginning, when the hardware was delivered, and they stayed all the way through to the end of operations. On the typical NASA mission, the person responsible for delivering the hardware would say, “I’ve delivered my hardware on time,” and walk away. If the hardware happened to be a camera, and it took pictures, they felt they had achieved their goal. They didn’t care if it was impossible to operate, or if it didn’t get the right pictures. But if you worked on Pathfinder, you had to undergo a mental shift. If you designed your component incorrectly, if it was difficult to test or to operate, it was still your problem.

It was difficult to explain the new thinking, Jennifer realized. You had to experience it for yourself, and then it could make a huge impact. You would become committed to the ultimate goal, whatever it was. In Pathfinder, the goal was to get to Mars quickly and cheaply, and to get a rover to function on the Martian terrain. Things worked in a sort of non-systematic way because people attacked problems where they saw them. Eventually, they generated procedures, and she wrote the documentation, but this was not a document-heavy mission, like most NASA missions. She sat down with a couple of other people, and they asked, “What are the most likely contingencies? What’s our nominal plan at the big-picture level?” She realized this could be a wonderful opportunity to participate in the exploration of space, and that idea pleased her greatly. “I feel like God has blessed me in my career,” she once wrote, “and I would like to glorify Him by exploring His incredible creation.” So the missionary had a new mission, but even as a scientist, especially as a scientist, she still devoted herself to God.

The Pathfinder mission originated in a speech given by President George Bush in 1989 to commemorate the twentieth anniversary of men – American men! – landing on the moon. NASA was in the doldrums at the time; and the occasion of the speech seemed to point up how little it had done since the halcyon days of Apollo. The Challenger disaster, which occurred more than three years before the anniversary, still loomed; when people thought of NASA, they didn’t visualize Neil Armstrong jumping onto the surface of the moon, they thought of the faces of the parents of Christa McAuliffe, the school teacher who rode aboard the Space Shuttle, looking in disbelief at the Y trail left in the sky by the catastrophic explosion.

Along came George Bush, discussing the future of space exploration. The demoralized NASA contingent could scarcely believe what they heard. Did the President mention “the permanent settlement of space”? Yes, he did. Did he also say it was time to travel “back to the moon, back to the future, and this time back to stay”? Indeed, he said that, as well. But surely he could not have said, “And then, a journey into tomorrow, a journey to another planet: a manned mission to Mars.” Yes! The President said that, too. Mars. The NASA bureaucrats began to ask themselves: how much was all this going to cost? No one thought you could go back to the moon and on to Mars for under 400 billion dollars; the tasks might require twice that amount. NASA’s annual budget at the time was around 13 billion. Where would the money come from? Interestingly, few doubted that the technology existed to send people to Mars, or that it could be developed quickly; if NASA had the money, they could get the job done.

George Bush’s remarks evoked John Kennedy’s famous speech in which he charged NASA with the duty of sending men to the moon. Without realizing it, Bush tapped into the agency’s other obsession, reaching Mars, an obsession that had begun in the mind of its ace rocket engineer, Wernher von Braun, during World War II. Von Braun, a member of the Nazi party, and a favorite of Hitler’s, had helped to design the V-2 missile. When he became disillusioned with the Nazi war machine, the Gestapo arrested him and sent him to jail. In his cell, he turned his attention to interplanetary travel, and Mars in particular. And it was in these strange and harsh circumstances that the kernel of what would become the American effort to explore Mars was born. In May 1945, von Braun and over a hundred other German rocket scientists surrendered to the Allies. They were swiftly transplanted to New Mexico to continue their work on rockets, this time for the United States. The German V-2 became the prototype of a new generation of American missiles, and on the strength of his engineering accomplishments for the Nazis, von Braun quickly established himself as the chief architect of the American space program’s booster rockets during the 1950s and 1960s; his designs were responsible for getting American men to the moon.

Throughout his career, von Braun was mesmerized by Mars. He published his plan to send people to Mars, the one he had conceived in jail, as a long magazine article titled “Das Marsprojekt,” which was translated into English. In 1953, it appeared as a book in the United States: The Mars Project. It became a classic, but this was not science fiction; The Mars Project contained no inspiring rhetoric about humankind’s greatest adventure. It was a how-to manual, a master plan for getting people to Mars. He used a simple slide rule to make his calculations, and its pages contained his blueprint for the actual mission, using available technology. “The logistic requirements for a large elaborate expedition to Mars are no greater than for those for a minor military operation extending over a limited theater of war,” he wrote. The key to reaching Mars, he believed, was sending a flotilla of spacecraft. “I believe it is time to explode once and for all the theory of the solitary space rocket and its little band of bold interplanetary travelers. No such lonesome, extra-orbital thermos bottle will ever escape Earth’s gravity and drift toward Mars.” Instead, in von Braun’s vision, “Each ship of the flotilla will be assembled in a two-hour orbital path around the earth, to which three-stage ferry rockets will deliver all the necessary components. Once the vessels are assembled, fueled, and ‘in all respects ready for space,’ they will leave this ‘orbit of departure’ and begin a voyage which will take them out of the earth’s field of gravity and set them into an elliptical orbit around the sun … Three of the vessels will be equipped with ‘landing boats’ for descent to Mars’s surface. Of these three boats, two will return to the circum-Martian orbit after shedding the wings which enabled them to use the Martian atmosphere for a glider landing. The landing party will be trans-shipped to the seven interplanetary vessels, together with the crews of the three which bore the landing boats and whatever Martian materials have been gathered. The two boats and the three ships which bore them will be abandoned in the circum-Martian orbit, and the entire personnel will return to Earth orbit in the seven remaining planetary ships. From this orbit, the men will return to the earth’s surface by the upper stages of the same three-stage ferry vessels which served to build and equip the space ships.” It was a grand scheme, and it became the template for NASA’s plans to send people to Mars, a goal von Braun thought could be accomplished by the late 1970s.

Bush’s speech endowed von Braun’s dormant plan with new life, but the prospect of returning to Mars raised new questions, as well. If NASA planned to send people to Mars safely, scientists needed to know much more about the Red Planet. If there was life on Mars, what form did it take? Was it dangerous to humans? Could it devastate the Earth if astronauts brought samples home? How severe were the effects of radiation? And, most important, was there water on Mars? The presence of water would dramatically enhance the prospects for finding life, but more than that, water meant it would be possible to manufacture rocket fuel, oxygen, and other human essentials on Mars.

Three years after Bush’s speech, in 1992, NASA announced plans to send between twelve and twenty small landers to Mars. They would fly frequently, and they would take advantage of new equipment, especially computer technology, to explore more effectively. The new program went by the name of Mars Environmental Survey – MESUR, in NASA-speak. The agency then announced another planetary program, Discovery, with similar goals; it was a nice instance of the right hand not knowing what the left was doing. Eventually, the two programs merged into one trial program: Pathfinder. It was going to be fast, it was going to be cheap, but no one knew if it would be better than previous planetary missions. Unlike most NASA missions, which are built and often operated by a private aerospace contractor such as Lockheed Martin, Pathfinder was an in-house project, designed, built, and operated by JPL. It was meant to embody JPL’s prowess as NASA’s robotics center, and that posed an embarrassing problem.

It had been a generation since Americans had landed a spacecraft on Mars. The old guard was gone, and few around JPL or NASA remembered exactly how that trick worked. Some scientific data had been preserved, though not completely, along with thousands of Viking images, but there was little documentation of the mission’s engineering accomplishments. Rob Manning, the young leader of Pathfinder’s Entry, Descent, and Landing team, sought veterans who could tell him what they had done on Viking, but many had died, and others had retired. JPL pulled a few of the old grizzlies out of retirement to help assemble a unit capable of developing a lander, and they went to work under Manning.

The idea behind Pathfinder, to develop and build a new spacecraft on a drastically reduced schedule and budget to land on the surface of Mars, sounded like a losing proposition to many at JPL, given the risks involved in getting there. Just setting their ship safely onto the surface posed difficult engineering problems. The spacecraft travels at about 17,000 miles an hour as it reaches Mars. Then it must slow to nearly zero miles an hour so that it does not vaporize in the Martian atmosphere or crash into the surface like a meteorite. The Viking solution to this problem, an expensive and cumbersome one, employed powerful, heavy thrusters capable of guiding the spacecraft gently to the surface. There was no money for that kind of extravagance with Pathfinder. Instead, Pathfinder’s engineers planned to wrap the lander in a protective bubble, place the bubble inside an aerodynamic cone, and parachute it through Mars’ thin atmosphere to the surface, letting the cone peel off in sections. Then Pathfinder would bounce around the surface like a big hi-tech beach ball. If all these cushioning devices worked properly, Pathfinder would still be in once piece when it came to a stop. This follow-the-bouncing spacecraft approach was profoundly troubling to conservative NASA engineers, but Manning casually accepted the risks. “Pathfinder is just a rotating bullet with nothing controlling it. This cone shape produces some unstable results – not so unstable that it’s devastating, but you live with that.” When he presented his landing scheme to NASA’s review board, they were, he said, “skeptical – borderline hostile, as they should be. They were paid to challenge everything. So it was a big deal when we deviated from the Viking heritage.”

Even if it landed safely, Pathfinder wouldn’t sit still on the surface of Mars, taking measurements, as the Viking landers had. It would carry a rover designed to roam across the surface, functioning as a twelve-inch-tall geologist. This was not a new idea; for decades, NASA had explored the possibility of sending a rover to investigate Mars. “My most persistent emotion in working with the Viking lander pictures was frustration at our immobility,” Carl Sagan recalled in 1980. “I found myself unconsciously urging the spacecraft at least to stand on its tiptoes, as if this laboratory, designed for immobility, were perversely refusing to manage even a little hop. How we longed to poke that dune with the sample arm, look for life beneath the rock, see if that distant ridge was a crater rampart … I know a hundred places on Mars which are far more interesting than our landing sites. The ideal tool is a roving vehicle carrying on advanced experiments, particularly in imaging, chemistry and biology.” He outlined, with his usual visionary fervor, a rover-based mission very much like Pathfinder. “It is within our capability to land a rover on Mars that could scan its surroundings, see the most interesting place in its field of view and, by the same time tomorrow, be there … Public interest in such a mission would be sizable. Every day a set of new vistas would arrive on our home television screens. We could trace the route, ponder the findings, suggest new destinations … A billion people could participate in the exploration of another world.” At the time he wrote those words, they sounded like the vaguest hyperbole, but Pathfinder and the Internet would make his outlandish prediction a reality.

Although a rover seemed like a nifty idea, it was untried. The later flights in the Apollo program had taken along a dune buggy to traverse the powdery surface of the moon. The astronauts could steer and stop the rickety lunar flivver at will. The difficulties involved in guiding Pathfinder’s rover across the surface of Mars by remote control seemed insurmountable. What if the rover didn’t emerge from the beach ball after all that bouncing? What if it got stuck on a rock or a crevice or sank into the talcum-powder-fine Martian soil? What if the beach ball landed in inhospitable terrain? What if it landed on the wrong part of Mars, where it couldn’t receive signals from Earth? And yet, if it avoided all these pitfalls and worked, the rover would provide a whole new paradigm for exploring the surface of Mars, because JPL had visions of building bigger and better rovers in years to come, until they reached the size of small trucks. But most people guessed a small rover would never work, not with the two million dollars allotted for its development.

A debate sprang up over the best way to control the rover, and, given the personalities involved, it quickly escalated into a dispute over technological theology. Tony Spear, a veteran engineer at JPL, believed the most reliable and cheapest way was to tether it to the mother ship. The other approach, advocated by Donna Shirley, was to control the rover remotely, but that meant designing or finding a new radio system, one that could tolerate the extreme fluctuations in the Martian environment, including fluctuations in temperature between the rover and the lander.

Donna Shirley was a controversial figure around JPL. When her name was announced as the Pathfinder mission director, a few cheers went up, but only a few; there was also consternation. Tony Spear, the Pathfinder project manager, was nowhere to be seen during the announcement, and Donna took his absence to indicate his lack of support. She could live with that. She thought the apparent indifference had to do with the fact that she was a woman, but she was accustomed to handling that problem. Donna had been with JPL since 1966, when very few women filled responsible posts there; during her years there, she married, raised a daughter, and got a divorce. At work, she was relentlessly cheerful, almost, but not quite, to the point of bullying, and she was a world-class talker. Many bureaucrats and scientists at NASA were camera shy, but when a television crew appeared at JPL, there was Donna Shirley in her bright red dress, flashing her assertive smile, prepared to discuss in her folksy Oklahoma twang just about anything. Her appearance was perfect for television. TV producers were delighted to interview the ebullient Donna Shirley instead of a pale male attired in the gray suit, gold-rimmed glasses, and neat mustache favored by the upper echelons at NASA. But, while being interviewed, she occasionally appeared to take credit for the work of a great many NASA scientists and engineers toiling anonymously, and that did not work to her advantage.

Her detractors said she really didn’t know her science well, but she made her lack of expertise into an asset because she had no scientific agenda, nothing to prove. She was content to bang heads together cheerfully and say, “Look, guys, now we are going to do it this way.” To the increasing number of women coming out of graduate school to work for NASA, she became a symbol. These younger women liked to tell a story about the time Donna Shirley attended a launch party at Cape Canaveral. As usual in those days, she was the only woman present. A guitarist singing a bawdy song, accompanying himself on the guitar, stopped dead when he saw her. She took his guitar and completed the song herself, delighting everyone. That was great, as far things went, but she didn’t realize there was a tradition at these launch parties that a woman – a hooker, basically – was paid to show up and pull a stunt like that. One of the men assumed Donna had been hired for the occasion, maneuvered her into an alcove, and grabbed her. “I didn’t exactly deck him,” she said, “I just hit him on the nose.”

Working on Pathfinder, she saw her team of engineers and scientists as a large family, her family. To her credit, she encouraged everyone to talk to everyone else, if only in self-defense, and she always smiled and radiated optimism. Most found it impossible to bear a grudge for long in the face of such cheerfulness; it was too exhausting to oppose her. Still, she wanted her radio-controlled rover for Pathfinder, and Tony Spear, the project manager, did not. “In his position, I wouldn’t either,” she said, “because he had the impossible job of landing on Mars for a fraction of what it cost the last time we landed. He had no idea how to do it, and here’s this parasite coming along, giving him nothing but trouble. What I did was to convince the scientists that we really could do useful work with the rover. That was number one. Number two was to convince Tony that we really could fly without damaging his mission.” When Donna presented her case to NASA’s review board, one member, Jim Martin, the former Viking project manager, insisted a Mars landing could not cost less than Viking had. As for the rover, “he thought it was terrible.” Donna and the rover team persisted, building better iterations of the rover and demonstrating they worked as advertised. “It became a very powerful selling tool,” she realized, and eventually, to everyone’s surprise, it turned into the mission’s raison d’être.

If Pathfinder’s engineering was, ultimately, carefully weighed, the mission’s science component tended to be rushed, improvised, an afterthought. Plenty of scientists were eager to participate in the new Mars mission, but they needed time and money to formulate, conduct, and analyze experiments. Pathfinder didn’t work that way. At the last minute, for instance NASA stuck a couple of stereographic cameras on the lander and another camera on the rover. These weren’t your standard television cameras; they used a technology known as a Charge Couple Device. The CCD reproduces light very accurately and is especially useful for spectroscopy, which reveals more than the naked eye can see by measuring which wavelengths of light are absorbed, and which reflected, from an object. They were useful, but they were not capable of sending back the sparkling, gorgeous images returned by Viking twenty years earlier. Pathfinder also carried an Alpha Proton X-ray spectrometer to detect the composition of Martian rocks, and a weather mast to measure the Martian temperature and atmospheric conditions. Every so often, Pathfinder would collect the weather mast’s data and return it to Earth, so for the first time it would be possible to obtain accurate weather reports from the surface of Mars. Everyone agreed the weather mast would be a terrific experiment, if it worked. It looked like Pathfinder had a chance to become a real mission, after all.

Manning’s team conducted early Pathfinder landing tests at a NASA facility in Cleveland, Ohio, which featured a large vacuum chamber. Within, girders, lava rocks, and wood simulated the Martian surface. They dropped Pathfinder in its protective bubble onto the sharp objects and observed the result.

R-r-r-r-r-r-rip!

“The first time we did it, we had a tear the size of a human being,” Manning said. They took it back to the lab, fixed it up, and dropped it again.

R-r-r-r-r-r-rip!

They tweaked it and tried again. R-r-r-r-r-r-rip! … R-r-r-r-r-r-rip! … R-r-r-r-r-r-rip!

The trials went on like that for months; they were “total disasters,” said Manning, and NASA nearly canceled the mission. Late in 1995, the Pathfinder team redoubled its efforts. The engineers adjusted the spacecraft’s small guidance rockets. They modified the shape of the sphere contained inside the protective beach ball. They had been imitating the Russian model, which was spherical and consequently difficult to manufacture; now they adopted a tetrahedron, which was easier to manufacture. They toyed with the air bags protecting the tetrahedron, trying one deflation strategy after another, getting incremental improvements. Gradually, they came to feel more confident about Pathfinder. They did have one advantage: because the gravity of Mars is less than half of Earth’s, the spacecraft would endure less wear and tear. “We always worked in terms of the mass, and the mass kept getting bigger and bigger,” Donna said. “That meant the mechanical parts had to be heavier because they were supporting all of this additional structure. The mission design people came to the rescue. They said, ‘Okay, if we’re going to fly into the atmosphere of Mars, there’s a corridor we have to hit. If we go in too shallow, we’ll just skip out of the atmosphere and keep on going. If we go in too deep, we’ll burn up on entry, or we won’t have enough atmosphere to slow down before we hit the surface.’ So there’s a narrow range of angles at which you can enter the atmosphere, and that takes some really accurate shooting by the navigators. So the navigators heard this and said, ‘Okay, if we can shoot more accurately and give up some of our margin for error, we can let the spacecraft have more mass.’” Now the engineers were able to add small thrusters that would slow Pathfinder during its descent to the surface.

The mission was still alive, but the development of a decent, affordable rover still posed engineering problems. JPL had to devise a nimble mechanical creature that could scale small barriers and climb over rocks, like a little tank. To complicate matters, it would take twelve or fifteen minutes for a radio signal to travel from the Earth to Mars, which eliminated spontaneous, real time commands. “If you’re looking through the rover’s eyes, and you see a cliff coming, and you say, ‘Stop!’ it’s too late – it will be over the cliff, so it has to be smart enough to stay out of trouble,” Shirley said. In addition to negotiating the Martian terrain, which was in many details unknown, the rover had to keep its solar panels in position to receive sunlight, or it would lose power and die.

Attempting to meet these requirements, JPL devised variations on a theme. They built a rover the size of a small truck, and they built one just eight inches long, nicknamed “Tooth.” They built a mid-sized rover called Rocky, which, when tested in the desert, actually did things required on Mars, such as scooping up soil. Rocky went through various iterations until it weighed just fifteen pounds, yet negotiated the kind of obstacles and terrain that geologists expected to find on the surface of Mars. It could perform simple experiments, and it appeared sturdy enough to withstand the rigors of landing on the Martian surface and bouncing around inside a beach ball.

The development of Pathfinder’s components took place in a knowledge vacuum, because the engineers and scientists didn’t know exactly where they were going on Mars or what to expect when they got there. From a spacecraft’s point of view, Mars presents a landscape of treachery. The team expected to receive finely detailed studies of the surface from Mars Observer, the billion-dollar spacecraft launched on September 25, 1992. It was supposed to reach Mars the following August, when its cameras would send back pictures of the Martian surface with much higher resolution than Viking had captured in the seventies, and those pictures were supposed to give JPL a well-informed notion of where to land their bouncing beach ball. Just when Mars Observer was to begin orbiting around the Red Planet, JPL lost the signal, and the spacecraft was never heard from again. There was speculation that a fuel line had frozen and ruptured, and the spacecraft went out of control, but nobody could say for sure – nobody, that is, but fringe elements, who concocted some fairly creative theories. There was the “Hey! That was no accident” scenario: NASA deliberately destroyed the spacecraft because it had detected signs of intelligent life on Mars. And there was the “Mad Martian” scenario: Mars Observer had been destroyed by sophisticated Martian weapons whose existence NASA conspired to conceal from the American public.

Within NASA, scientists feared they had lost their chance to return to Mars. Shortly after Mars Observer disappeared, Dan Goldin journeyed to the Goddard Space Flight Center in Greenbelt, Maryland, to rally the troops. Although Goddard is only a short commute from NASA headquarters in Washington, D.C., the head of NASA is not in the habit of dropping in, so his presence signaled a major announcement. For many scientists, it was their first close-up look at the man whom George Bush had appointed in 1992 to run the agency. At Goddard, he reminded the scientists that NASA attempts to do difficult things, risky things, and the possibility of losing a spacecraft was an ever-present hazard, but the risk didn’t mean the mission wasn’t worth doing. They would continue to explore Mars. Conditioned to regard managers as antagonists, the scientists were impressed.

Under Goldin’s leadership, the loss of Mars Observer provoked NASA to hone and intensify its Martian agenda. The agency decided to launch a pair of missions to the Red Planet approximately every two years, whenever the orbits of the two planets brought them into a favorable alignment, beginning in 1998. Each mission would have a distinct identity and purpose, but, taken as a whole, they would culminate in sending humans to the Red Planet. What sounded like a rather vague statement of intent acquired sudden conviction in August 1996, with the announcement of possible fossilized life in ALH 84001. Goldin suddenly began pressing JPL and the scientists to make specific plans to bring a sample of Martian soil back to Earth to continue the search for life. Donna Shirley and the other managers said they couldn’t do that much on their subsistence budget.

Returning a sample of Mars to Earth is a complex, costly, and hazardous undertaking. You send two spacecraft – a lander and orbiter – to Mars. The lander scoops up enough soil to fill a can of Coke, and then it must launch itself from the surface of the Red Planet and guide itself to a rendezvous with the orbiter. NASA has never done that before – launched a spacecraft from a distant planet. If that part of the mission succeeded, the orbiter would bring the sample to Earth, where new hazards would arise – for instance, the sample might be dangerous or even lethal to terrestrial life. The safe handling, testing, and decontamination of the sample would amount to a large project in itself. NASA confronted a similar problem with samples of the moon in the sixties, and set up an elaborate, isolated lunar laboratory at the Johnson Space Center, where moon rocks were analyzed with great care by technicians wearing long rubber sleeves and working behind glass until the rocks were found to be harmless. There is much greater concern about possible harmful effects of Martian soil because of the greater likelihood of life on Mars. The quarantine will likely be extreme and long-lasting. When you talk about a sample return, you’re talking about spending billions of dollars and placing the lives of everyone on the planet in some degree of jeopardy. You’re talking about a mission almost as complicated as a human mission to Mars.

NASA expanded its string of Mars missions into a more formal, and better-funded, program of exploration. “The Human Exploration people at the Johnson Space Center came along and said, ‘Okay, we want to fly humans to Mars.’ Dan Goldin set 2018 as a date, but the Johnson Space Center said, ‘Well, we think it should be earlier than that. We’d like to do it by 2011,’” Donna Shirley said. “To decide whether to send humans to Mars by 2011, you need to make a decision by about 2005 that you are going to invest in doing that, and you need to have the information necessary to make the decision. The only way to get the answers by 2005 is to fly by 2001.” Just when it looked as though Mars might get a lot more money, Congress realized that the International Space Station was generating huge cost overruns, and it sucked up money that might have gone to human Mars exploration.

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 (#ulink_e41eb43a-6b46-502c-a96f-58888afa1c0c)

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.”