Which icy moons in the outer solar system were the consensus community targets for exploration?
There was Titan at Saturn.
Enceladus, also at Saturn.
And, yes, Europa at Jupiter. (I mean, we can’t ignore the Decadal.)
Curt proposed forming full teams to develop, over the course of one year, competing missions to each of those worlds. Then—unlike any such early-stage flagship concept study that had ever come before—NASA would run those missions through complete, independent reviews of their technical, management, and cost feasibilities, as well as their science rationales and implementations—everything. The agency would treat each prospective mission as though it were going to fly. Once the independent review results came in, the leaders at headquarters could take a look, and they could choose the best mission to launch, the best moon to explore. Maybe it would be Europa. Maybe it wouldn’t. But at least something in the outer solar system would see a flagship.
It was the only thing he could think of to shift some of the attention away from Mars.
This kind of contest had never before been considered, let alone attempted. That’s just not How Things Worked Around Here. NASA didn’t decide flagship destinations by competition. Multibillion-dollar missions were directed from above and developed down below (i.e., Hear ye, scientists and engineers: Send us your spacecraft concepts, for as you have long pined, we are going to Saturn. NASA has spoken). Sure, the smaller, focused missions competed for flight—the five-hundred-million-dollar jobs—but never the flagship targets. Headquarters gave guidelines—place and price, science sought—and an institution such as Jet Propulsion Laboratory would take it from there, develop a nominal mission profile—more of a vision, really, though coincidentally, I mean, since you happen to ask, we’ve been working on this problem for quite a while! And the institution would go to headquarters, drop a three-inch stack of full-color-printed pages on the associate administrator’s desk, wind up, and pitch:
“This spacecraft is a steal. You fly this thing off the launch pad and it’s going to appreciate in value. I don’t—look, I like you, but if you take this deal, I’m pretty sure you don’t like me! [slaps desk, laughter] You seem like the kind of person who knows a good price when you see it, so I’m OK with you taking the money out of my pocket here, only . . . [sotto voce] don’t tell my manager. Look, this orbiter, it’s an investment, really. I can—OK, let me ask you this. You have scientists on this mission, yes? And what do scientists like to do? I bet they like to use ion and neutral mass spectrometers. They do, don’t they? I could tell the minute I said it. See this spacecraft? See this spot right here? Perfect place for an ion and neutral mass spectrometer. Right? Look, I’d never speak ill of another NASA center, and we could make a lot more by selling you a spacecraft just like the ones they make, but [leans in closer, almost a whisper] you really don’t want their thrusters on your spacecraft. I’m not saying they’re bad—I’m not—saying—they’re—bad. But they don’t thrust. [raises hands, eyebrows] That’s what I heard, honest to Charlie. And let me ask you this: You look at their spacecraft—go on, I encourage it!—and you know what you won’t see? Space for an ion and neutral mass spectrometer. Not this one, anyway. Not comfortably, at least. But you drive a hard bargain! I’ll be right back. [stands, absconds to breakroom for full three minutes] I’m sorry about that. My manager wanted to talk to me about the price. Look I’ll be frank: she’s not happy about this price I’ve put on the table. I knew better, but this is between friends and I can take a little dressing down if it means helping out a friend. So what do you say? [dangles keys] You want these? You want these. You do, don’t you. I know you do. [extends hand] So do we have a deal? [lets outstretched hand hang, says nothing] We have a deal! Whoa, firm handshake you have there. I’m going to need to get my wrist checked out later! OK, sign here, and I’ll have our people draw up the paperwork. You’ll be sending me Christmas cards for the next twenty years for this one, mark my words.”
The other reason no one had ever tried putting flagship destinations into competition was the consequence of failure. By putting the outer planets in opposition, Curt wasn’t risking only Europa; he was risking the entire outer planets program. If every target came back over budget, headquarters could write off everything beyond the asteroid belt as needing technology development and delay exploration indefinitely. Mars was easier, a launch window opening every two years, and astronauts would one day walk there. It took six, seven, eight years or longer to reach Jupiter and beyond—and that’s after the eight, sometimes ten years spent designing and building the thing. Which meant most of a manager’s career, literally, might be spent fighting for the flagship, defending its funding across multiple Congresses with different parties in power, different White Houses, and new NASA overseers, who might be scientists but who might be political attachés. And that lowly, beleaguered manager would be fighting alone because the dominant human spaceflight half of the agency certainly wasn’t going to pony up coin to explore Titan, three hundred degrees below zero—so cold a human’s skin would burn off, just slough away if unprotected. Curt knew that if the three full-fledged flagship studies came back with three impractical, overpriced proposals, three unworkable schemes, agency administrators could take hold of the lovingly prepared plans, each in a binder three inches thick, and bludgeon him with them for the next ten years.
Complicating Curt’s plan was that he wanted Jet Propulsion Laboratory to lead the Europa study. Headquarters leadership had zero faith that the lab could keep Europa in the cost box, and wouldn’t want to give it yet more money to fritter away on yet another study. But of the three moons, Curt was adamant that Europa had to go to JPL. The lab had the best engineers in the world—women and men so smart that when you set foot on campus, you risked developing a nosebleed from all the brainwaves. Yes, as NASA leadership noted pointedly and in colorful metaphors, those very engineers had been working headquarters-funded Europa concepts for eight years now, starting with the Europa Orbiter in 1998 (which asked: What is the smallest Europa mission we can do?) and ending with the recently departed JIMO (which asked: What is the biggest possible Europa mission imaginable?). In both cases, the answer was something very, very expensive. Still, Curt knew that those dollars spent and lessons learned had yielded solutions to technical obstacles and sharpened the science objectives of an expedition there. And if the Europa people returned another battlestar? Then we’d go somewhere else—go with the winning proposal—Titan or Enceladus. Europa might have to enter stasis, but the outer planets would go on.
So Curt presented his competed flagship proposal to NASA leadership and received, generously speaking, a Not No. Emboldened, he pressed the issue again and again, suggesting study structures and timelines and—look, Curt, this isn’t working—OK, Curt . . . OK . . . OK . . . again with this?—and conversations could come just short of name calling, and more than once Curt walked out of a meeting wondering if he would be told to pack his desk at the end of the day. But this was his job! And if we weren’t going to follow the Decadal, then what were we even doing here?
And then the federal budget made the decision for everyone: NASA was simply tapped out. It would have died right there, Curt’s gambit, were it not for the hiring in August 2006 of Jim Green, who was 1. the new head of planetary science and 2. Curt’s new boss.
Jim was an outsider not only in the division but also in the entire field. He was a scientist, but he wasn’t a planetary scientist per se. He was a space physicist, and consequently came to headquarters carrying none of the baggage that a partisan of a particular planet (e.g., of Mars) might pack. Green was a pragmatist, saw the value of a balanced exploration portfolio, and understood immediately the allure of the outer planets and what Curt was attempting to do with the studies. Green even suggested adding a fourth moon to the mix: Jupiter’s Ganymede, the largest moon in the solar system and the only one in possession of a powerful magnetosphere. This made what had then been a trio of studies
quad, and collectively, the mission investigations would become known informally at headquarters as the Quad Studies.
The four flagships would be spread across the agency: two at Jet Propulsion Laboratory, one at the Applied Physics Laboratory, and one at Goddard Space Flight Center. Each would have a study lead and science team co-leads. Curt got his wish, and the Europa study would be conducted by JPL. An engineer named Karla Clark, who had been running Europa studies since 1997, would take lead, with Bob Pappalardo and Ron Greeley running science.
The Ganymede study, similarly, would be helmed by veterans of JIMO and Galileo: Louise Prockter at APL and Dave Senske at JPL, with the latter lab leading the overall effort. If successful, the mission, with the broader aim of studying the entire Jovian system, would also get a good glimpse of Callisto—the largest moon in the solar system that was not differentiated (i.e., it had no crust-mantle-core makeup; it was just this big ball in space).
Titan would be run from the Applied Physics Laboratory at Johns Hopkins University. Whereas Jet Propulsion Laboratory (its rival of sorts) was a master of the Big Expensive Missions, the So Crazies It Might Work, the Applied Physics Laboratory was famed for cost control and smart design. APL had recently launched the spacecraft New Horizons to Pluto—the smaller lab’s first outer planets mission—and Titan would be another good opportunity to take a swing at the solar system beyond Mars. Ralph Lorenz and Hunter Waite, both of the orbiter Cassini’s Titan probe, Huygens, would lead the science.
If Europa had the advantage in terms of mission refinement and well-honed science goals, Titan was by far the beguiling new thing. Cassini, now two years into its mission, found something new with every Titan flyby: standing liquid lakes of methane! Gullies and riverbeds! Weather, rain, a cool breeze in a dense atmosphere. (Denser, even, than that of Earth. When Cassini released Huygens, it took two and a half hours for the probe to touch Titan’s surface. The lander had to switch to a smaller parachute halfway down to speed things up and get on with it.)145
Huygens, indeed, had discovered a primordial Earth. Titan’s tantalizing atmosphere and winsome weather meant you could explore it as pioneers once explored our world: on wheels, wing, and watercraft (well, liquid-methanecraft). And unlike Europa, there was no belt of blistering radiation for a spacecraft to endure, no miles and miles of granite-hard ice to penetrate. Its liquid was easily accessible, and if it had life . . . well, it would be like nothing encountered ever before. It wouldn’t be based on water, as on Earth. It would be exotic, truly alien: methane-based biology.
The Enceladus study, based out of Goddard, was a long shot because so little was known about the Saturnian moon. Before Cassini arrived at Saturn, its team had allotted three tepid orbits to observe the drab, airless ice ball. Enceladus was too far from the sun for an active surface and too small to retain a warm interior. It was a checkbox moon, interesting because it orbited inside of Saturn’s hazy E-ring—a sort of ring around the rings—and that maybe something about that would make a fine footnote to a more interesting paper.
Then Cassini arrived, encountered Enceladus, and it was as though Gaspard Marsy himself had carved the white marble moon with hammer and chisel.146 Its southern surface was mystifyingly young and, though veiled in darkness, was warmer somehow than its sunlit equator. Cassini found four stunning stripes on that pole, like some great galactic beast had slashed its claws in anger across its surface, leaving gashes parallel and preternatural. And finally, the impossible: from those claw marks—tiger stripes, they were dubbed—blades of water vapor were being blasted hundreds of kilometers into space. The moon wasn’t dead—it wasn’t even an ice ball—there was liquid water down there! Enceladus, this teeny, tiny ball circling Saturn, was venting a subsurface ocean into space, and despite the heat and velocity of the water being blindly blasted into the ether, some of that water came back down to the Enceladan surface as snow!147, 148 Which was an arresting idea, but wasn’t even the exciting part. The majority of water vapor that managed to escape was going to Saturn, where it formed the E-ring. It was all so phenomenal, so preposterously magical—and it rewrote the scientific understanding of active, geologically living ocean worlds. For much of the history of planetary science, the consensus was that everything in the solar system bar Earth was dead: a scattered cluster of spinning rocks circling a giant fusion reactor. That was especially true of the outer moons, formed and frozen for billions of years, and orbiting where it was simply too cold for anything interesting to happen.
But there was Enceladus! It soon seemed clear to planetary scientists that beneath its icy crust, below its liquid, interior ocean, was ongoing hydrothermal activity. Areas around such hydrothermal vents on Earth—our planet’s plumbing system—invariably teemed with life. (Earth scientists had observed it directly in our oceans, along the midocean ridges where tectonic plates were spreading apart.) Moreover, because water touched rock on the Enceladan ocean floor, the ocean was conducive to chemistry. If Earth was any indication, an energy source plus chemistry meant the possibility of genesis around Saturn, too.
And unlike Europa, at Enceladus, you didn’t have to drill through miles and miles of ice to get to the ocean: the ocean was coming to you. This was like a wheat thresher rolling across an entire field of science! Even if a focused Enceladus mission study didn’t prevail, it would certainly sharpen the objectives of some future expedition. The brain power behind the study, Amy Simon-Miller of the spacecraft Cassini and John Spencer of New Horizons to Pluto, promised something special . . . and you never knew.
Green found four million dollars to make this thing happen—one million per corner of the quad—and that wasn’t easy. The planetary science budget was eviscerated by twenty-two percent between 2005 and 2007—the Iraq war wouldn’t pay for itself, after all—and for an agency already living paycheck to paycheck, the threat was mortal. Jim searched sofa cushions and spreadsheet cells to find funds.149
Curt had watched worriedly, meanwhile, as flagging funding for research reduced the roster of scientists and engineers able to sustain careers—especially those who worked in the outer planets. When Galileo plunged into Jupiter years earlier, never to return, research resources receded and withered away. Most of the scientists working with the data collected by Galileo weren’t NASA employees—some survived only on soft money (i.e., they lived off grants). They had mortgages to pay, children to support. So Niebur pushed for an Outer Planets Research Program—a NASA funding line for research grants—and a Cassini Data Analysis Program (same).
Which is one reason NASA needed to get another flagship mission going: because big missions meant money for grants, the lifeblood of many a scientist’s career. Feed a starving scientist. The oil business (Earth was a planet, too) paid royally for genius geologists. You lose a first-rate Titan scientist to Exxon Mobil, and she will quickly come to count on those extra zeros on a paycheck—a paycheck guaranteed to deposit every two weeks—to say nothing of the generous health plan, four weeks of vacation, and the 401(k) that Big Oil could promise. To do soft-money science was to have googled the nearest homeless shelter at least once . . . just in case. So every chance that Curt could get, he sent money their way. It would do no good to get an outer planets mission off the ground if there were no scientists left to study the data returned.
Engineers needed scratch as well. Enter headhunters for the defense contractors. If a woman could land a rover on Mars, she could probably land a missile on some nebulous enemy in some as yet undeclared war. So when NASA needed an engineering study conducted on, say, flinging a brick beyond the asteroid belt, Curt would look at his list and assemble a team of engineers who could then feed their families for a few months more. (And to double his investment, Curt would tell them to blast that brick to, oh, I don’t know, Europa.) He wasn’t some space saint saving scientists, and it wasn’t welfare. He was a program scientist at NASA headquarters who was just doing his job, impeding a repeat of Europa Orbiter’s catastrophic, study-canceling cost estimat
e. He was building a foundation of knowledge and eliminating uncertainties, buying down risk on future mission studies.
During this time, Congress came to the notion that “flagship-adjacent” outer planets missions could be launched for less than one billion dollars. Curt knew this wasn’t possible, but as a matter of due diligence, he announced the “Billion Dollar Box” studies: Everyone, please plan a mission, if you would, to, oh, I don’t know, Titan, and another to Enceladus, and keep it within a billion-dollar cost cap.150 How much science can you do for the money? (The answer eventually returned: not enough!)
During all this, the years spent working to keep an outer planets program alive at NASA, Niebur saw daily just how highly organized and thus highly effective the Mars community was in comparison. They marched in lockstep. When they disagreed among themselves, they settled it among themselves, and when they emerged from meetings, they had a plan: something to rally around and, more important, something to show NASA headquarters that they had rallied around. Orbiter, orbiter, orbiter, orbiter, or: lander! lander! lander! lander! or: twin rovers, twin rovers, twin rovers, twin rovers. They spoke in a single shout, the volume of which surmounted the din of discussion by scientists recommending the rest of the solar system. They were like the U.S. Army in Panama, blaring Van Halen outside of Manuel Noriega’s hideout until he surrendered from sheer auditory exhaustion. Mars roared. NASA listened. None of this just happened. It was made to happen. The community of scientists studying the Red Planet was organized by the Mars Exploration Program Analysis Group, a cross-discipline science committee chartered by NASA to help set Martian exploration priorities.
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