by Alan Stern
Weiler decided enough was enough. He was sick and tired of Pluto studies that never got off the drawing board because they kept blowing up on cost. So in mid-September of 2000, he announced that NASA was canceling the instrument proposal competition—stillborn—meaning that there was to be no winner at all. Everybody lost.
And not only was the instrument competition canceled, but Weiler issued a “stop-work order” on all further Pluto mission work.
As the head of all NASA science missions, Weiler’s letter had the force of a legal document saying that no further NASA money could be spent on studying any Pluto mission. Alan recalls:
It was stunning. After five separate efforts, endorsements from who knows how many NASA advisory committees, after a Science Definition Team and a call for instrument proposals, after spending probably $300 million on studies over ten years, Weiler’s action threw it all in the can and offered no hope of reversal.
In response, JPL just put everything in filing cabinets, and disbanded Staehle’s team. The whole thing evaporated.
Those of us who’d been working on it felt like we had been through a decade of hell running errands, with endless study variations for NASA Headquarters. How many iterations of this, how many committees had we been in front of, how many different planetary directors had we had at NASA, how many different everythings had we put up with? Big missions, little missions, micro-missions, Russian missions, German missions, nonnuclear missions, Pluto-only missions, Pluto-plus-Kuiper-Belt missions, and more; Weiler’s move just threw it all away.
It was the end. He’d killed it. It felt like we’d survived the Bataan Death March across the 1990s, and then just when we got to the finish line, when there was a promise of being released to build the instruments and start the mission, they beheaded you.
Weiler’s cancellation directive just took people’s breath away, and it left us as if we were back in 1989 trying to start something from scratch.
And if that wasn’t enough, Weiler also declared that NASA would not even consider another Pluto mission study for a decade—until the 2020s. He publicly called Pluto mission studies and any efforts to make a mission new start “Dead. Dead. Dead.”
That was it: After a dizzying decade of false hopes, reversals, new renewals, and after persevering longer than might have been healthy, the Plutophiles had finally reached the end of the line. Goldin backed Weiler. There was no appeal.
It was over.
4
THE UNDEAD
KICKING THE FOOTBALL
With all of the work on Pluto missions since 1989 now swept off the table, the defeat of Weiler’s once-and-for-all cancellation was breathtaking. Even more than any of the previous delays and setbacks, this one was utterly profound. NASA had declared itself out of the Pluto exploration business.
To Alan, this simply could not pass: too much was at stake, and too many people had invested too much. So he and the Pluto Underground did what they had always done: they dusted themselves off again and got to work. They began behind the scenes, but soon opened a second front and moved their efforts to front stage. They wanted to share their shock and indignation with both the public and their professional community and wanted to put the need for and excitement of Pluto exploration in the press at every turn. They generated letters to editors and newspaper op-eds (this was well before blogs existed), making their argument clear: don’t throw this all away just because JPL made the mission too expensive.
And they also enlisted others to agitate on behalf of resuscitating a Pluto mission. Their rabble-rousing was effective: the press and the public widely decried the cancellation. An article in Space Daily reported, “This move infuriated many planetary scientists, because … Pluto is virtually unique in being a scientific subject that won’t wait.” And it quoted Lou Friedman, then the director of The Planetary Society, saying that the deciding factor in a resurrection could be that “NASA is surprised to see how popular Pluto really is.”
Yet time was running out, because various terrestrial and celestial factors were lining up in ways that meant it could be “now or never” for Pluto exploration.
First, there was the launch window dictated by the relative motions of Earth, Jupiter, and Pluto. Just as Voyager’s grand tour mission had been constrained to launch when the giant planets were in rare alignment, so, too, any trip to Pluto requiring a Jupiter Gravity Assist (JGA) to speed it on its way could only be made when Jupiter, on its twelve-year orbit, came around to be in line with Pluto. To reach Pluto before the 2020s, the upcoming 2002–2006 Jupiter launch window was a must-make.
Additionally, two different aspects of Pluto’s motion in its 248-year orbit added further deadline pressure. First, in 1989, Pluto had reached its perihelion—its closest point to the Sun in its orbit—and ever since then it had begun slowly receding, making it a slightly harder target to reach with each passing year. Second, as Pluto receded from the Sun, it was cooling, and that held a potentially ominous threat for studying its atmosphere.
By the early 1990s it had been known that Pluto’s atmosphere was primarily composed of molecular nitrogen, the same gas that makes up most of the Earth’s atmosphere. But unlike Earth, Pluto’s nitrogen atmosphere is created by the sublimation1 of its snowy surface. In this process, the atmospheric pressure is very strongly, in fact exponentially, dependent on the surface temperature. As a result, each few degrees of surface cooling cuts the atmospheric pressure in half. So as Pluto traveled outward in its orbit, and the Sun’s warming of Pluto’s surface naturally decreased, the atmospheric temperature was expected to decrease, and as a result the atmospheric pressure would begin to fall, steeply, perhaps to levels hundreds or thousands of times lower than its perihelion pressure. If that happened, the atmosphere would, in effect, cease to exist and couldn’t be studied by any mission sent there once the atmospheric freeze-out occurred.
Atmospheric models were predicting that this pressure collapse might well happen sometime between 2010 and 2020, but almost certainly soon thereafter. For the Plutophiles, this placed a deadline on getting a flyby of Pluto. If a mission was going to observe the atmosphere, it had better get under way—now.
And if that wasn’t enough, there was still more reason to hurry: Pluto’s sharply tilted spin axis, angled 122 degrees from the plane of its orbit (Earth’s tilt is just 23.5 degrees), creates drastic seasonal lighting changes across its globe. Think of how, on Earth, places that are North of the Arctic Circle and South of the Antarctic Circle enjoy both a midnight Sun and then perpetual night for months each year. Something similar but much more extreme happens on Pluto because its axis is so much more extremely tilted than Earth’s.
As the 1990s wore on and Pluto followed its slow orbital arc around the Sun, a steadily larger portion of its southern hemisphere was entering into a decades-long season of perpetual darkness. As a result, any spacecraft that reached Pluto in 2015 would be able to observe only about 75 percent of the surface, with the other 25 percent enshrouded in a polar winter night. But by the early 2020s, only 60 percent would be visible, with more of the planet drifting into darkness with each successive year, and by the 2030s, only 50 percent would be visible. Translation: the longer a mission was delayed, the less of the surface of Pluto (and for that matter, of Charon, too) could be studied when the spacecraft arrived.
These factors—the need for a Jupiter gravity assist, the possibility that Pluto’s atmosphere would freeze out, and the shrinking amount of Pluto and Charon that could be mapped—were all reasons to get the mission started as soon as possible.
An old and powerful ally in this battle was the SSES. In their meeting on the auspicious day of Halloween of 2000—barely a month after Weiler’s PKE cancellation—the Pluto situation was at the top of the agenda.
The community of planetary scientists the SSES was charged to represent did not take kindly to the seemingly cavalier cancellation of a mission that had, through a painfully long process, risen to the top. They had seen their collea
gues at universities and labs around the country working their tails off to create the science case and then competing to design the best possible set of scientific instruments to explore Pluto. Weiler’s cancellation felt like more than just a setback to the Pluto crowd: The entire planetary science community was being jerked around by it, and finally started feeling what the Pluto crowd had been experiencing all those years.
Alan and Jonathan Lunine spoke to the SSES that Halloween, making the case to go to Pluto, presenting a hard-nosed scientific rationale to do the mission now, and forcefully defending a quick restart of Pluto exploration. They also described how the exploration of Pluto could be done much more simply and inexpensively than JPL had planned with PKE.
The problem for PKE was that the JPL estimated cost of the entire outer planets program, which now included missions to both Pluto and Europa, had exploded to almost $4 billion in today’s dollars, and the Pluto mission alone had ballooned to $1.5 billion, possibly more. But as the SSES learned more, they became ever more skeptical of the way in which these costs had been calculated.
One member of the SSES who played a pivotal role was a venerable and senior Greek-American space scientist named Stamatios “Tom” Krimigis. Tom is tall, thin, and genteel. Speaking with a deep voice and thick Greek accent, he could easily play the role of a handsome Greek stranger in a classic Hollywood film.
Tom had been involved in planetary exploration from nearly the beginning and had built instruments for spacecraft that had traveled to every planet but Pluto, as well as to a number of asteroids and comets, and he had been one of NASA’s first mission PIs back in the 1980s (creating artificial auroras to understand the origin of that phenomena). In the 1990s, Tom had also been instrumental in helping NASA develop the then-new competition structure for interplanetary missions. In this new paradigm, not just the scientific instruments, but everything—the design and construction of the entire spacecraft, the ground operations, and the scientific investigations—all of that would be competed for and then awarded to the one team with the best proposal led by a scientist: the principal investigator (PI).
Largely a response to the ballooning mission costs and extreme budget pressures of the late 1990s, which threatened to derail America’s planetary exploration program, this new PI-led model represented a departure from NASA’s usual procedure of assigning planetary missions to a big lab (usually JPL), running competitions only for the scientific instruments that would go aboard, and placing the entire project under the helm of a professional project manager.
Suffice to say, Krimigis had as much credibility as anyone in the business. But Tom had one more piece of relevant experience: he was also the head of the Space Science Department at the Johns Hopkins Applied Physics Laboratory (APL), which was emerging as a smaller, leaner competitor to JPL, able to produce less expensive planetary missions.
Tom remembers one moment at that crucial October 2000 SSES:
[JPL Project Manager] John McNamee came to the committee to tell us why the Pluto mission budget had gone from $600 million to $1.5 billion, and why the Pluto spacecraft was also so heavy and couldn’t be built for less, and so on. He made the mistake of passing around a circuit board part that had about an inch of aluminum on top of it, and he said, “Take a look at this. Look how heavy it is. We are going to fly by Jupiter on the way to Pluto, and so it needs all this shielding to protect it from the radiation. That’s why we are doing this.”
That circuit board was circulated around the table, and when it came to me I said, “Now, wait a minute. This Pluto spacecraft will fly by much farther out from Jupiter than Voyager did, which didn’t need any shielding. This is ridiculous.”
As it turned out, JPL, following a dictum from NASA Headquarters, had put expensive Europa-mission Jupiter radiation-protection design requirements on PKE, like a boat anchor, and that anchor had sunk Pluto by driving its cost skyward.
Once the SSES discovered this, they saw that the Pluto mission could be done much less expensively. So, led by chairman Mike Drake, then head of the Lunar and Planetary Laboratory at the University of Arizona—the largest planetary research institution in the United States—the SSES wrote a letter telling Weiler they did not approve of the cancellation and saw it in a larger context: as a bad sign for the health and future of American planetary exploration. The SSES then recommended that Weiler resurrect the Pluto mission, but to control costs, do it in the style of a competed mission, rather than giving it directly to JPL, as NASA had done so many times before. They further recommended that the Europa mission be delayed, if necessary, to insure adequate funding for a Pluto mission, reiterating all of the reasons why Pluto could not wait, none of which applied to Europa.
At the same time, two other significant events were taking shape to resurrect the mission. First, with Alan’s cajoling, The Planetary Society organized another old-school letter-writing campaign among their members, who were fanatical about planetary exploration and who had long been excited for Pluto exploration. The Society flooded NASA Headquarters with thousands of letters protesting the cancellation. At the same time, unbeknownst to Alan, a high school student named Ted Nichols appeared on the scene. Possessing an intense passion for exploring Pluto—as well as some great PR skills—Ted attracted much attention both with his “Save-the-Pluto-mission” website and some other ambitious PR. Alan remembers:
Ted was a seventeen-year-old, and a really kind of cute-looking kid, and he just couldn’t stand that the effort to explore Pluto had been canceled. Ted lived in Pennsylvania, which isn’t all that far from DC, so he went on his own to NASA Headquarters in Washington and pleaded for Pluto exploration, and he brought the press with him. He was a brilliant tactician, because he made himself the poster child for, and the face of, public disappointment about NASA’s cancellation of PKE. And somehow he got all the way up to Weiler’s office. I don’t know how he talked his way in there. NASA actually thought I put him up to it or that The Planetary Society did, but he did it entirely on his own. I didn’t even know him then. And what did Weiler’s folks do when the kid arrived there? They put the seventeen-year-old in a room with six adults, six NASA bureaucrats, and they began questioning him: “Who put you up to this? Why are you coming here out of nowhere? Who’s backing you? Who paid for your trip?” And the kid responded saying something like, “It’s just me. I want to see Pluto explored, and you have dashed my dream. How could you?”
Nichols himself and that dream of his became a media story that personalized the cancellation, embodying the disappointment of youth. And in addition, by the late fall of 2000, The Planetary Society had generated more than ten thousand letters to NASA and Capitol Hill from citizens concerned about the cancellation. Lou Friedman, then The Planetary Society’s executive director, who had cofounded the society with Carl Sagan, bundled them all up, got on a plane from California, and delivered them ceremoniously to Capitol Hill … with the press in tow, of course. The news release read: “The American people are pleading for Pluto!”
And the barrage continued. The DPS, the largest and most influential professional group of planetary scientists in the world, at the urging of members like Stern and Lunine, issued a press release pointing out that if a Pluto mission was not started soon, the crucial Jupiter launch window would be missed, and that if that happened, there would likely be no atmosphere to study when some future probe arrived in the then crazy, far-off 2020s.
* * *
The press was beginning to pick up on these messages, creating magazine, newspaper, and even television news stories, further pressuring NASA. Weiler was getting criticized from all sides. Once, while on a quiet cigarette break outside his NASA building, he encountered people on the street pestering him to restart the mission to Pluto.
By early November, the pressure caused Weiler to begin looking for a way out. In his search for a solution, he turned to Tom Krimigis at APL.
APL had not done many planetary missions—only one, in fact—but it had an impres
sive, decades-long track record of building and launching Earth observation and military satellites that performed well and were inexpensive. Moreover, their first and only interplanetary mission had been a resounding success. That mission had been born when Krimigis had helped spearhead NASA’s development of the Discovery Program of small, competed, PI-led planetary missions. APL’s Discovery mission was called NEAR, for “Near Earth Asteroid Rendezvous.” The craft launched in 1996 and became the first spacecraft to orbit an asteroid, circling for a year around the asteroid Eros. Later, it would even land on Eros, a bonus achievement that was not even conceived of in the original mission proposal. And to top that, the APL team had completed the spacecraft ahead of schedule, and ended up doing the mission for $30 million under budget, giving the money back to NASA.
NEAR had been a triumph by every measure. How did APL manage to perform so well? One big part of it was a management philosophy of not having more managers than was absolutely necessary, since layers and layers of managers drove costs up. Instead, they put more responsibility at the level where the knowledge was—with their engineers. APL also kept their missions small through a fundamental desire to remain a lean organization. APL preferred to grow in prominence rather than head count.
All this had established APL, and its space department head, Tom Krimigis, as a team well known for being capable of delivering successful spacecraft missions on a tight budget. So Weiler asked Krimigis in mid-November if he could find a way to do the Pluto mission in a much less expensive way. Tom told him he could. “I can probably do this for a third of the cost of JPL. It’s how APL works.”
So with Weiler’s encouragement, Krimigis got a small team to work intensely on the problem for a lightning-fast, ten-day prototype design and costing study. The team worked straight through the Thanksgiving holiday, and on November 29, 2000, Tom met with Weiler to give him the study results and cost estimate. Tom recalls: