Few impediments could have been more severe. For a spacecraft to reach the Jovian system with enough speed to eventually achieve orbit around Europa, it had to either launch from a powerful rocket (which NASA lacked, limiting spacecraft to a space shuttle deployment) or be absurdly light (which the required radiation armor rendered impossible). JPL engineers dashed out hastily written equations in chalk before driving fists against blackboards in fits of despair.
Nothing for NASA was ever free… except for gravity assists. Ordinarily, the agency could compensate for the meager speeds of heavy spacecraft by taking indirect flight paths and using planets encountered along the way to yank and shove the robotic pilgrim outward, inward, or onward. The laws of physics being immutable, and the salient numbers known, NASA’s orbital dynamicists could do this all day, running the numbers to sling spacecraft precisely, one planet to the next: free propulsion from Isaac Newton. It was incomparably the best bargain in space exploration.
But then television tabloid journalism got involved, and everything became complicated.
In 1997, while waiting at Cape Canaveral for liftoff, the Cassini mission was beset suddenly by political protest. Cassini carried three radioisotope thermoelectric generators, which were powered by the decay of plutonium 238. The plutonium wasn’t of the Back to the Future variety—a disquieting drop of Scary Substance Indeed into a homemade flux capacitor—but rather was stored in a ceramic form, wrapped in iridium, and caked in graphite. It could not corrode, or be obliterated by heat, or vaporize, or disintegrate as an aerosol, or dissolve in water. It was made to withstand not only the explosion of the rocket carrying it, but even a catastrophic reentry into Earth’s atmosphere. Because it couldn’t vaporize, in a disaster situation, no one would inadvertently breathe it in and develop superpowers or extra appendages. In fact, it was designed so that you could even eat the stuff. The human body could not absorb it.
But 10 days before three and a half million pounds of rocket thrust put inches between Cassini and Earth, a much smaller number—60, as in 60 Minutes—nearly nailed NASA to the ground. The CBS TV newsmagazine aired a feature on the soon-set-for-Saturn spacecraft, Steve Kroft starring in the segment. The correspondent’s opening line: “On October thirteenth, a Titan IV rocket is scheduled to lift off from Cape Canaveral carrying seventy-two pounds of deadly plutonium; enough plutonium, in theory anyway, to administer a fatal dose to every man, woman and child on the face of the Earth several times over.”
And it got only worse from there. Cassini was an afterthought in the story, and interviews from experts were interspersed with comments from… nonexperts, to be kind, but very well-spoken nonexperts, whose contributions—the generous ones! —included lines such as, “What gives anybody, including the federal government, the right to risk the population’s death or—or injury just for space exploration?”
The segment featured a plutonium expert from the Department of Energy stating flatly that even if the rocket, spacecraft, and graphite-sealed, iridium-wrapped, ceramic plutonium blew up on the launch pad, it was literally impossible for the debris to do what protesters said it would. But just to be balanced, Kroft’s menagerie of doomsayers described in lurid detail what plutonium—not in the form used by NASA, which you could safely sprinkle on your breakfast cereal, because, again, you could eat it—could do to the human body. Among the highlights: “it can produce pulmonary cancer” and “you could have numbers like 100,000 or more people who develop lung cancer” and “if there is such an explosion, you can kiss Florida good-bye.”
Kroft even found a former NASA employee (“He’s neither a scientist nor an engineer,” admitted Kroft, “but…”) to lament publicly his role in endangering lives for such frivolities as space exploration. “I feel guilty, quite frankly,” bewailed the penitent insider.
To seal the deal, Kroft intercut the story with snippets of an interview with Wes Huntress, head of NASA’s planetary program, who had presided over the successful landing of Mars Pathfinder only months earlier.
“This is from your own environmental impact statement,” said Kroft to Huntress—the tone of the host solid but affable, his countenance hard but eyes somehow benevolent. “I want to read you a couple of things from it.”
Huntress was a pioneer in the study of interstellar clouds and one of the world’s foremost experts in planetary exploration, but he was not exactly tabloid-TV material, and after the cavalcade of activists arguing compellingly and without interruption, he seemed less than confident in his responses.
Quoted Kroft: “If there’s an accident it talks about, quote, ‘removing and disposing of all vegetation in contaminated areas, demolishing some or all structures and relocating the affected population permanently.’”
“If there should be any such accident,” said Huntress, accurately but unhelpfully.
Replied Kroft, “I mean, that sounds fairly drastic…” and Kroft waited patiently for Huntress, in possession of rope necessary to hang himself, to fill the silence, which 60 Minutes interview subjects always did, and he did, and did.
“Well, the—what they’re probably talking about mostly is—is the damage on site, near the—near—near the launch pad because there’s clearly, when one of these things goes, a lot of damage near the launch pad.”
And after Huntress tap-danced and staggered—this guy didn’t even know what his own official Armageddon report said!—and at last swung gracefully from the gallows, well-honed doomsayers followed up, explaining precisely how Life as We Know It was drawing to a close, and kiss your babies tonight because our foolhardy quest to conquer the cosmos—Saturn! This pointless mission to a gas giant, whatever that meant—will leave mutated survivors fighting for the last canned goods on ransacked store shelves.
Worse yet, Cassini would take a second swing at the peaceful people of planet Earth! If it didn’t blow up on launch, it was set to follow a VVEJGA trajectory to boost its way toward Saturn: that is, two swings by Venus (V, V), and then it would play chicken with the Earth, and if something went wrong... (but if all went well, from Earth [E] to Jupiter [J] for a gravity assist [GA]).
The Clinton administration really did not have time for this but dutifully absorbed the panicked letters and optics of protesters grasping concertina-topped chain-link fences on Cape Canaveral’s perimeter, while on the inside, police lined up in body armor and carrying riot shields stared silently, just waiting to—what? Open fire? Brandish batons?
Nevertheless, NASA went forward with its reckless rocket launch likely to leave only cockroaches crawling the Earth (or whatever some future species would call this planet), and things were fine, as they had been for previous launches dozens of times over. But the message from headquarters to those filing future space missions: if you must launch radioactive material, do not plan trajectories taking the spacecraft back to Earth for a gravity assist. Nobody needs the headache.
Which meant, for Karla and company, years-long discussions on potential trade-offs for the Europa Orbiter mission, as it came to be called. They analyzed other trajectories, other launch vehicles—anything to get more mass for a suitable science return. What hardware do you make “rad-hard”—impervious to radiation (but expensive) —versus simply wrap in “dumb mass,” i.e., big blocks of cheap protective shielding? What was the absolute smallest science payload possible? Ultimately, they found a relatively happy medium: a spacecraft that could launch direct and achieve the minimum science required to make a Europa expedition worthwhile, and NASA loved it, and then the cost doubled, and in 1999 Ed Weiler shot it dead. Just like that.
From THE MISSION, or: How a Disciple of Carl Sagan, an Ex-Motocross Racer, a Texas Tea Party Congressman, the World's Worst Typewriter Saleswoman, California Mountain People, and an Anonymous NASA Functionary Went to War with Mars, Survived an Insurgency at Saturn, Traded Blows with Washington, and Stole a Ride on an Alabama Moon Rocket to Send a Space Robot to Jupiter in Search of the Second Garden of Eden at the Bottom of an Alien Ocean Inside of an Ice World Called Europa (A True Story) by David W. Brown. Copyright © 2021 by David W. Brown. From Custom House, a line of books from William Morrow/HarperCollins Publishers. Reprinted by permission.