Lunine listed the benefits and negatives of exploring Europa, Enceladus, and Titan. Europa’s ice shell and computer-melting, thermonuclear-war-level radiation were, in his view, pretty big minuses. Titan’s singular negative? Well, we hadn’t yet planned a mission to get there—but we could. “We have no baggage or anything that’s weighing us down in terms of thinking about what we might do.”285
Jonathan wasn’t oblivious to the crowd’s reaction. He was a professor—lectured for a living—had been doing so for a very long time. And as he spoke, he noticed the talk was . . . not going well. Standing room only gradually gave way to standing room and a few chairs in the back . . . and along the aisles. People were leaving, just walking right out. He finished his talk to silence. During the question-and-answer period, he noticed entire rows in the rear opening up, and then the front: a crowd, dissolving before his eyes.
After the talk, he emerged unmolested from the ballroom—he didn’t need a police escort or anything—and crossing the hallway threshold, he smacked face-to-face with lapel after lapel of these Europa buttons or stickers worn now by his colleagues. They (i.e., the paraphernalia) had proliferated, apparently, during his talk. And while he was happy to continue the discussion, he had a flight to make to Rome, where he was working with Italian colleagues on a project, and he slipped to his car and hit Beltway North for IAH.
Lunine was right about one thing, later conceded those who listened. Because NASA had not maintained a careful cadence of exploration, the outer planets, lighted for three decades by one spacecraft after another, would almost certainly go dark after Cassini. The worst-case scenario was upon us, and it was unlikely that a spacecraft could even begin construction before Cassini plunged permanently into Saturn. During the decade of darkness that would follow, planetary scientists would slip away from the field and into the arms of industry. The longer NASA took in getting behind an outer planets flagship, the fewer graduate students would focus their studies beyond the asteroid belt. What would be the point? Better to be an employed Mars researcher than a starving Europa scholar.
But the Titan community, grumbled scientists, had no real mission concept.286 Its science wasn’t mature—it wasn’t even complete! It wasn’t like they were wanting for new material: Cassini was still there and would be for years to come, transmitting tantalizing Titan data practically daily. It took years to formulate the correct questions to ask of a world you wish to explore, let alone develop a way to answer them. By the time a Titan study reached the project phase, we could have a spacecraft at Europa, or at least flying there.
ON CHRISTMAS DAY 2004, two years before the Masursky Lecture and Jonathan’s act of sedition, Cassini, its orbital position just so around Saturn, released the lander Huygens.287 It would take twenty days for Huygens to arrive at Titan, and in the runup, its science team gathered at the European Space Operations Centre in Darmstadt, Germany—Europe’s equivalent to the Center of the Universe at JPL—to prepare for the first spacecraft landing on an outer planetary body. As Huygens descended to Titan’s surface, it would beam back to Cassini—which was within range and recording relentlessly—everything it saw, sniffed, scanned, and struck. Once the probe alighted on Titan’s topsoil or ocean (the probe floated . . . just in case!), it would live for maybe three or four minutes before passing through nature to eternity. The data upload complete, Cassini would swing around and point its dish toward Earth and transmit the complete collection of Huygens’s Greatest Hits.288
Lunine was an interdisciplinary scientist—basically a free agent—on Huygens and, like everyone else, really wanted to be there for the probe’s initial images as it drifted down to titanus firma. Nobody had ever seen the surface of Titan before—not with telescopes, space observatories—not even from orbit, Cassini’s camera stymied by Titan’s opaque atmosphere shrouded in hydrocarbons. And if you were a Titan scientist, vexed by its flaxen veil—oh, you developed models, analyzed the data, saw a surface with your mind’s eye as clearly as deaf Beethoven heard Opus 125 on the page—but you just didn’t know for sure—and you wanted to be the first to see it.
It was freezing that day in Darmstadt, a city south of Frankfurt, renowned as the beating heart of German science, with research centers, universities, technical institutes, and, on a hill to the south, Castle Frankenstein—that one, yes—which, if nothing else, loomed as a menacing scientific totem to ward away hubris. The Huygens imaging team members were holed up in a tiny trailer adjacent to the operations building. They needed to work undisturbed, analyze incoming data in an isolated setting, didn’t need managers, dignitaries, and press peering over shoulders, smudging monitors with greasy fingers and asking questions as though speaking to tour guides. Jonathan wasn’t on the camera team, but he scored an invite by its principal investigator to join them in the trailer and bear witness to the horizon to which he had dedicated his life.
Though the Huygens antenna was oriented and powerful enough only to reach Cassini, radio astronomers back on Earth did the math and realized they could track its carrier signal—that is, they could tell when Huygens was talking to Cassini, though not what it was saying. If nothing else, they would know if it was working and for how long. That was exciting in itself. So on the morning of zero hour, as Huygens plunged from the tip-top of Titan’s atmosphere to touch down on solid surface, the Titan team gathered to watch the signal of its able emissary. Descent took just over two and a half hours, and slowdown involved a heat shield and three parachutes—the last chute smaller than the second, designed to speed things along lest the lander ran out of battery before actually touching the surface. In all, Huygens slowed from fourteen thousand miles per hour to ten miles per hour and, on gentle touchdown, zero.289
Engineers expected Huygens to survive three or four minutes after touching Titan’s surface, and there were cheers all around when zero altitude was reached and the signal survived. What a plucky little lander they had fashioned! And three minutes elapsed, and it was just great—marvelous!—and then four, and that was even better. Every second on the ground would yield extraordinary data. And then five minutes elapsed, and could you believe how well we built this thing? And then six and seven and then thirty minutes elapsed, and still, there’s Huygens chatting happily with Cassini, and this went on for an hour, and then two hours, and everyone’s looking now for Rod Serling, cigarette in hand, submitting for our approval one Huygens probe, weight: seven hundred pounds, with a delicate payload of six scientific tools designed to decipher a murky, mysterious world.290 Engineers expected its battery life to last no longer than three hours, almost all of that dedicated to the descent. It was now approaching hour five.
After three hours and fourteen minutes sitting on the surface, Huygens at last transmitted its final packet of data.291 Cassini had long stopped listening; it had crossed Saturn’s horizon hours earlier and, as planned, swung round and phoned home. It takes more than an hour for a signal sailing from Saturn at lightspeed to arrive at our planet. At midafternoon, it reached the Deep Space Network on Earth. The “recording” played. And there was nothing. Silence. Dead air. And at that moment, the Titan team weathered the woes of the crews of the Mars Polar Lander, Mars Climate Orbiter, and Mars Observer. The moment of betrayal by a promised signal.
Or maybe not. After five minutes of terror, data began to arrive from the second channel of the probe’s communications device.292 Huygens, time limited (Rod Serling notwithstanding), spoke to Cassini on twin channels. For whatever reason, one of Cassini’s two channels did not play properly, and the science team would thus receive data from only one of them. Which was OK—the channels were redundant! That was the whole point of redundancy.
But members of the imaging team, congregated together, arms folded, gazing downward, would look up, lock eyes, exchange glum, knowing glances, their insides now melted, turned to goo. The camera system was not redundant. It used both channels. The idea was to get twice the data during descent. Now they would have half.
Th
e cold, convivial dawn in Darmstadt became a raw, dolorous evening. It took time for the Huygens data to be split off and sent to the various science teams: the atmospheric structure group, the surface science team, the mass spectrometer section, &c. It came from space as a single, eight-hundred-million-mile beam, the data, and the imaging team trudged to its trailer, a brief walk through a piercing German January chill, to wait. When it was time, their parcel downloaded, they huddled around the computer, and one-by-one, one image per second, they became the first human beings to gaze beneath the Titanian haze. They were blurry at first, the images, fuzzy from the murky sky, but slowly a world resolved below. The images weren’t in order—you’d get ground and sky and haze and hillside at incongruous intervals—but suddenly a shot filled the screen that caused Jonathan to gasp and scream, and the entire imaging team recognized what they were seeing, and hooted, hollered, and hurrahed. They were staring at a set of braided river channels. Liquid flowed on Titan. Maybe now, maybe long ago, but it flowed. There were hills. A stream. It was—these were features you could recognize. And there were features that you could not—in the plains, there was this thing that looked like the tail of a dragon. And as deeply and distressingly as it had set in, evening gloom dissipated, gave way to the unfettered joy, the frontier excitement of science, discovery, and exploration. No human eyes had ever seen what they saw. No human eyes might ever again see it in such detail. The wider Huygens team, the press, and the public all needed to know now what the camera group knew, what they had witnessed, so at ten o’clock at night, the imaging team began building a mosaic to go out to the world. They pieced together Titan from different heights, eyes unblinking, the team running on reserves, the coffeemakers mainlining caffeine into their systems. This world they were building was so recognizable and yet so alien, exotic, unnatural. Mountains and lake beds, floodplains and channels where rivers flowed—it looked both like Earth and not. Titan was a world not of water but of hydrocarbons, and its haze, its sepia skies, the low light levels, the enigmatic chemistry—it was all the same, like here, but made of different stuff. Where Huygens settled on the surface were these rounded stones made of . . . ice? . . . perhaps, from Titan’s interior. The scientists were doing analysis on the fly here. It all reminded Jonathan of the lowest level of Dante’s hell: a place not of eternal, inextinguishable flame but of blistering cold, and the pit above shaped by landslides, earthquakes, and erosion.293, 294 Titan was so familiar—Jonathan couldn’t look away—and yet so bizarre: Earth through a mirror darkly. Titan felt like a place that was somehow wrong to see.
AFTER A DECADE of leading strategic science committees, sitting on prominent panels, and just being an agency go-to guy, Jonathan Lunine, post–TITAN WANTS US! was suddenly persona non grata’d, a troublemaker, and for more than a year, his phone simply stopped ringing. But his reputation at Jet Propulsion Laboratory remained quite good. He knew how to do mission science, which is why, when JPL inherited leadership of the shootout studies in 2008, Curt Niebur asked him to lead the American half of the Titan science definition team.
Ralph Lorenz of the Applied Physics Laboratory had led the initial Titan proposal for the Quad Studies. An engineer and planetary scientist, Lorenz had worked on the Huygens lander and, by the time of the Titan study, had written a half dozen books on the Saturnian moon, physics, spaceflight, and planetary missions of exploration. Never dry tomes, either, but imaginative works with literary flair. Accordingly, what he and his co-lead came up with was extraordinary: the Apollo program if Jules Verne had been in charge.295 An orbiter that would map Titan from space, scan its surface composition and atmosphere (by doing so returning four times the Titan data that Cassini could hope to achieve); a lander that would drift to the surface by parachute, touch down, and collect close-up data and take seismic measurements; and a Montgolfière—a hot-air balloon—that would drift across Titanian skies, passively studying its atmosphere, imaging its surface at a meter scale, and going whither the wind would take it (and thus returning meteorological measurements as well). It could float across the lakes, capture waves and tides, and amble aloft and across Titan’s gentle mountaintops and valley bases.
Even the arrival was ambitious. You could use Titan’s atmosphere to enter orbit by way of something called aerocapture, which involved arriving at a target body, dipping into its atmosphere, and letting the resultant aerodynamic drag slow the spacecraft to a suitable speed.296 Once decelerated, the vessel could again exit the atmosphere and enter a suitable orbit around the moon itself. This was critical for the Titan mission because of the astounding speeds at which spacecraft traveled through space: in this case, four miles per second. Historically, to enter a body’s orbit, a spacecraft would fire thrusters to slow down. The problem was that such propulsive braking required you to bring boatloads of fuel because those thrusters were going to be blasting like crazy to slow this thing to some reasonable velocity. But by using aerocapture, the Titan mission wouldn’t need all that fuel and could use the thus-available mass for other things. It wasn’t some harebrained scheme: aerocapture was proven, rated even for human spaceflight in a little program called . . . Apollo.297 Alas, when Alan Stern narrowed the studies from quad to duo, an inexplicable decision filtered from headquarters forbidding Titan from using aerocapture, which really annoyed Ralph because it meant the spacecraft wouldn’t be able to carry as many instruments, and would therefore do less science. Moreover, Jet Propulsion Laboratory would build the orbiter, but the European Space Agency would build the Titan lander, as it had done for Huygens. The Montgolfière would go to the French for reasons perhaps poetic: the brothers Joseph-Michel and Jacques-Étienne Montgolfier invented the hot-air balloon in the late eighteenth century.
Well, right away, Ralph figured, that was that. All the sexy stuff on his mission was going to the Europeans! Ralph himself was born, raised, and educated in the United Kingdom and was stridently Scottish, so it was nothing personal. But in this arrangement, he worried, Jet Propulsion Laboratory would be far less invested in making the Titan mission a success versus that of the Jupiter Europa Orbiter, which would be built almost entirely at the lab. So he expressed pointed disinterest in leading the next step. He had done a fine job the first time, thank you—why reassess the mission with excessive constraints that could only frustrate everyone involved? He would still take part but would not take point. Thus the appointment of the apostate Jonathan Lunine.
In a sense, Lunine was born on Titan. He had a tough childhood. His father was an alcoholic, and the disease would prove fatal, though it didn’t happen all at once. There was a long decline first into dysfunction and then to divorce, and in the meantime, to support her family, Jonathan’s mother went back to work as a dancer—a Rockette—at Radio City Music Hall in Manhattan, a job as grueling as it was glamorous.298 At the rehearsal hall, you stepped on a scale sometimes daily and had to weigh just so. Had to smile just so. Had to kick, tap, pirouette, jeté just so. You rehearsed this rigid, Swiss-watch choreography all the time, and when you didn’t get it right, or—and this was too horrible to fathom, but it happened—if someone made a mistake during a performance, you repeated rehearsals between shows. And you’re doing this while still wearing the luminous Rockettes smile. (Not too broad, not too narrow. Just so.) The money wasn’t great, and the work was seasonal, but you were a celebrity. She loved it, and because she was now a single mom with two children, each of those thousand daily breadwinning kicks counted, kept her family fed, under a roof, in clean clothes, and warm on winter nights.
Then came the toe problem (she was a dancer; it was just part of the job), and she was on painkillers for that, and it sure didn’t help her overall health, and then one day she was walking the family dog and she slipped and broke her shoulder, and a gloomy situation got grim, and fast. A dancer with a broken shoulder cannot dance, is not even a dancer, is—what is she? A Rockette with a broken shoulder cannot be a Rockette. There were ten thousand women waiting in the wings to weigh just so and
smile just so and kick and tap and pirouette just so, and Jonathan’s mom was soon on disability and then unemployment.
Jonathan, fourteen years old, escaped a dreary life in the pages of Sky & Telescope magazine. Every month, he waded through issues of galactic import—the goings-on of spacecraft launched and in development—major moments in astronomic history—the transits and occultations of planets circling the sun—observatories now open and what they’ve seen—notes from such recent meetings as the Lunar Science Conference in Houston—serious science: the early evolution of stars, the activities of comets at perihelion—astrophotography—a celestial calendar for the month ahead. He saw mention of a book by this astronomer at Cornell named Carl Sagan, titled The Cosmic Connection: An Extraterrestrial Perspective, and he rushed to the bookstore to buy it, money crumpled in his hand. The store didn’t have it, so he had to wait for it to be specially ordered, shipped, and delivered, and when he received it, he’d bent the spine in seconds.
This book was everything. The words were so eloquent that, unprompted, he would read passages aloud to his mother. Jonathan loved science fiction, but this was just so much more than a moment’s entertainment. He saw a glimpse of his life that might be, of studying and exploring the cosmos.
His mother encouraged Jonathan to write this Carl Sagan fellow a letter, but Jonathan felt that he couldn’t do that—I mean, you didn’t just write to guys like Carl Sagan, people who could write books like this, but she really pressed the point, and because deep down he knew he wanted to write it, to reach out, to somehow connect to this person (she knew it, too), he relented. Jonathan poured himself into the letter, explained his love of astronomy, of the book, and he asked, simply: How do I do this? How do I become an astronomer? I’m not rich. How do you even pay for something like college? He found the right address, folded the letter, stuffed the envelope, stamped it, and sent it.
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