Voyager: Exploration, Space, and the Third Great Age of Discovery

by Stephen J. Pyne

  More experienced in the temptations, and so tempered against their ugly seductions, Stanley offered an explanation without apology. The men had, he believed, been changed by their “circumstances.” “At home these men had no cause to show their natural savagery,” but suddenly transplanted “to Africa & its miseries,” they became “deprived of butcher’s meat & bread & wine, books, newspapers, the society & the influence of their friends.” Fever “seized them, wrecked minds and bodies,” while “anxiety” banished their “good nature.” The breakdown was relentless. “Pleasantness was eliminated by toil. Cheerfulness yielded to internal anguish . . . until they became but shadows, morally & physically of what they had been in English society.” As exploration segued into empire, the same dark unravelings threatened their sustaining society as well. 181

  Yet there was no alternative. If exploration was to happen, someone had to go, and that someone would be as affected as those he met, and would become a carrier of a cultural virus, whether malign or benevolent, back to the society to which he returned. The sustaining culture dispatched explorers to discover what it wanted—wealth, souls, allies, trade goods, beetles and butterflies, knowledge that would expand the existing cosmology of religion and science, but all ultimately an ordering of the world that was at heart moral.

  Yet what the explorer often acquired—what the sensitive observer could not help but get, whether pinning it like a beetle to a collection box or getting it into his blood like malaria—was an empathy for alternative cosmologies, for understanding and often admiring the perspectives and codes of his native companions even though that appreciation might be profoundly unsettling of his own culture’s existing order. The very nature of contact made such an exchange inescapable. If the discovered peoples had not wanted to be discovered, neither did the discovering peoples wish to see their own beliefs frayed and unwound. Yet that is what, inevitably, exploration did.

  POST-ENCOUNTER: MODERNISM AS EXPLORER

  The nature of the encountered geography and the character of its purposes as science and national prestige pushed the Third Age more and more toward machines. Remote sensing acquired its own motive power. Antarctica had robots descending into the caldera of Mount Erebus, and robotic snowmobiles traversing crevasse fields and empty ice sheets. The deep ocean had a flotilla of unmanned craft, some capable of autonomous voyaging for weeks or months. And interplanetary space had its spacecraft. The first contact with the outer planets, the first traverse through the solar system, came with robots.182

  This went beyond naming expeditions by their transport vessels, which already had a long pedigree. The voyage of the Beagle; the Challenger expedition; the Discovery, Nimrod, and Terra Nova expeditions to Antarctica—these were signature labels that summarized the complex societies and stories they carried. So it was with spacecraft. Mariner 4 or Viking distilled an institution, a population of engineers, technicians, scientists, and bureaucrats, and a culture. A trek as long as Voyager’s spanned generations. It was an easy step to go from encapsulating to anthropomorphizing, just as mariners had long invested their ships with personalities.

  The culture at JPL openly disdained anthropomorphism. Engineers treated the spacecraft as they would a glitchy computer or a cantankerous vacuum cleaner. Edward Stone characterized Voyager as only “a tool,” like “using a telescope; it’s the same,” and refused “to personalize” the spacecraft. Preparing for the first of the planetary encounters, Mariner 2 to Venus, Oran Nicks dismissed the spacecraft as “a machine that had no real consciousness.” It didn’t “ ‘know’ ” what it was doing or why. “At the time,” Nicks observed, “few of us thought about the similarities of the spacecraft to ourselves or to other living creatures.”183

  But of course anthropomorphism crept in. Voyager was not simply a prosthesis, but a projection of the personalities of its creators. They saw themselves in its history: its conduct was theirs, its triumphs and flaws their own. The Voyager mission took on a life of its own, as a work of art might: a Moby Dick, a Mona Lisa, a Ninth Symphony, distinctive of its author (in this case its complex society of authors), but somehow possessing an existence of its own. Inevitably, “Voyager” as a label went beyond the traditional shorthand of characterizing crews and support institutions by the name of the vessel.

  Particularly as commentators sought to explain its trek and purpose, they did so in traditional tropes, genres, and narrative styles that had evolved out of centuries of human explorers. Whether or not Voyager was a person, it behaved like one. Voyager became a character. Carl Sagan explained its encounter at Jupiter as another in the long legacy of “travelers’ tales.” Oran Nicks, speaking for those who worked on Mariner 2, “conscious of the precariousness of the enterprise and the unpredictable behavior of that historic spacecraft,” concluded that it became “not so much a rudimentary automaton” as “a beloved partner, feverish and slightly confused at times, not entirely obedient, but always endearing.” So, similarly, did Voyager appear to Bruce Murray: “I certainly think it has a personality.” That’s “perceptual,” he confessed, and “in the mind of the beholder,” and something that scientists, ever reaching for analogies to help explain, were more disposed to adopt as figures of speech than were engineers, whose numbers had to measure against empirical designs. It was also a tendency of those who had to interpret the mission to the public. Still, he believed that Voyager did have a “personality,” a “very nasty” one for a while, “then lost it,” and behaved itself.184

  As the saga grew, so did the tendency to attribute to Voyager the character traits of its designers, operators, and interpreters. As it pushed on to newer, outer worlds, it acquired such epithets as “plucky,” “valiant,” “indomitable,” and “enduring.” It became the Little Spacecraft That Could.

  The grand gestures of the three ages had each embodied what Cherry-Garrard called the intellectual passion, each attuned to its times. The voyage of the Victoria was to discovery as the Renaissance was to learning and the Reformation to religion. The travels of Humboldt to the New World were of a piece with European Enlightenment and imperialism. So the Voyagers were, in peculiar ways, emissaries of a Greater Modernism and its postmodern progeny. That was a second reason why people didn’t need to go.

  Without an Other, exploration became about the self. Encounter turned inward; dialogues simplified into soliloquies; discovery slid into self-disclosure. All this was not peculiar to exploration. It was an essential trait of modernism, which thrived on paradoxes of self-reference and self-scrutiny. Russell’s paradox, Heisenberg’s principle, Gödel’s proof, Bohr’s concept of complementarity, all built on the apparent contradictions and topological riddles that made the self into a Möbius strip. Does the set of all things include itself? Can a set be both consistent and complete? Can you know both the location and velocity of a particle with equal precision, or does the act of measuring, the presence of an observer, introduce irreducible uncertainties? Efforts to study the self yielded odd distortions of logic and meaning. And when the self had no Other, the boundary conditions dissolved into the circularity of a Klein bottle, whose inside and outside surface are the same.

  Yet this is precisely what the geographies of ice, abyss, and space created. In previous ages, an explorer might stare thunderstruck, like Defoe’s Robinson Crusoe, at the footprint of another man in the sand. In the Third Age, the explorer was more likely to photograph, as Apollo astronauts did, their own footprints on the lunar dust. The protocol went a step further when the Viking lander sent, as its initial image of Mars to Earth, a photo of its mechanical foot on the red sands. The constant discovery of new peoples had forced scholarship beyond its inherited taxonomies. New tribes and customs overwhelmed ethnography as new mountains did geology and new flora did biology. It demanded a distinctive scholarship, and got it with anthropology; and when the flow of exotic cultures ceased, that scholarship turned inward and shriveled. The anthropology of the Third Age is the psychology of the explorers themselves, or their
virtual facsimile.

  Perhaps nothing so conveys the paradox, however, as that canonical photo from Apollo 11 taken as men first walked on the Moon. The image is a portrait of astronaut Buzz Aldrin staring at a camera held by Neil Armstrong. Here, it would seem, was at least a vestige of a classic encounter, if only of one member of the party with another. Yet with the reflective visor of Aldrin’s helmet lowered, the image conveyed of his face is of the photographer taking the photo. The Möbius loop is complete.

  No Voyager took a photo of its twin, and no one photographed Voyager on its flybys. But Voyager took images for Earth and of Earth, and its decades-long communication might well stand as a conversation with ourselves. The Third Age was different not only because of its weird terrains, but also because of the cultural syndrome that determined what it saw and how it spoke. Without an Other, there was no reason to send a human self. That paradox any good modernist would have understood instinctively.

  Even as euphoria alloyed with exhaustion and as the Voyagers’ triumphs sharpened the contrast with Challenger’s tragedy, they indefatigably continued their journey. Voyager 1 rose unveeringly upward toward the remote heliopause, routinely sampling the interplanetary medium. Voyager 2 still had plenty of observations to complete, and they remained squarely within the realm of geophysics, not metaphysics, even as another jolt of gravity-assisted acceleration flung it away from Uranus.

  Its post-encounter phase lasted from January 26 to February 25. There was new data to gather and course corrections to make. Passage outward, after all, complemented passage inward. For the first three days Voyager 2 crossed bow shock seven times. It tracked the rotation of Uranus’s magnetosphere. Its instruments sampled the dark side of Uranus. It reported more occultations. It attempted a ring movie, though the images proved too dark to discern. Its interminable record of fields and particles continued. Yaws and rolls and other maneuvers recalibrated instruments. Most critically, Voyager executed two playbacks of its near-encounter data—twice, to ensure a successful transmission; briskly, before the tapes were overwritten by further activity and because the European Space Agency’s Giotto spacecraft was scheduled to rendezvous with Comet Halley within a week after Voyager’s near-encounter and the DSN had to redirect its antennas. For four months Voyager 2 had enjoyed priority: Uranus was unique, and the prospects for another visit, remote. But now the other fledglings in the space science nest squawked for attention. 185

  On February 16 Voyager 2 executed a trajectory correction that propelled it to Neptune. It was a slow burn, the longest in the lengthening history of its interplanetary traverse—some three hours. When it ended, the spacecraft was sprinting toward an encounter with the outermost planet, scheduled for August 1989. The Voyager twins returned to a state of quasi-hibernation.186

  DAY 2,636 - 3, 829

  17. Cruise

  For the next forty-two months Voyager 2 cruised at 70,000 kilometers per hour toward a cold, dark planet far beyond the realm of what the naked eye could see from Earth, a world first intuited only mathematically by the quirky perturbations its gravitational presence caused in the motions of Uranus and whose first sighting was confused with a comet. It was an abstract world, posited by astronomers, outside the realm of ancient mythology, beyond Newton’s classic model of the solar system. Of Neptune’s particulars very little was known. It had a moon, Triton; it had some kind of ring; it was gaseous and experienced a variety of weather conditions. Much of this information came from intensive observations amassed after Voyager had launched (and conducted to better inform Voyager 2’s encounter). Neptune was as little known as the abyss that its namesake ruled. At the time of encounter, Pluto’s skewed path would bring it closer to the Sun than Neptune, which left the murky blue giant as the outermost planet of the solar system .187

  Both spacecraft were well beyond their specifications and warranties. Ellis Miner likened them to a “vintage automobile” whose accumulating eccentricities its owner understood and could tweak to advantage. Yet while its mechanical aches never lessened, while its power supply relentlessly faded, and while distance magnified communication needs geometrically, the capacity of its computers for reprogramming meant Voyager 2 was in some respects a better spacecraft at Uranus than at Saturn, and would be better still at Neptune—and so were its human handlers. Without competing projects—the Challenger disaster had shut down all the others—the Voyager mission kept more of its experienced staff, and JPL understood better the demands for preparing, the procedures for crafting a master sequence for encounter, and the protocol for rehearsing. Between them the Voyager team had experienced five planetary encounters.188

  Now they prepared for Neptune. It would be, its handlers liked to say, Voyager 2’s “last picture show.” It would, in effect, perform an occultation on the entire mission. 189

  OCCULTATION OF THE GRAND TOUR

  Once again, readying Voyager meant managing a complex staging by which science objectives evolved, trajectories were tweaked, communications upgraded, and new software uploaded. A change in one meant a change in the others. The process of establishing guidelines for the final uplink of commands consumed over three years. But doing it previously was not the same as doing it at Neptune.

  Too little was known, the planet was impossibly far, and while Voyager 2 could receive new software, it could not rebuild its aging hardware. Its power output was particularly troubling. It would broadcast at “a billionth of a billionth of a watt.” At Jupiter, Voyager could transmit a maximum of 115,000 kilobits per second; at Uranus, even with clever compression coding, 21,600 kps; and at Neptune, perhaps 14,400 kps. Some new algorithms helped, but the only option was to improve Earth’s capacity to hear Voyager’s whisper against the background static.190

  Fortunately, the Canberra DSN station would once more serve as primary antenna. So, again, the DSN arranged to contract for the Parkes radio telescope, and NASA agreed to allow the Voyager team to delay the spacecraft’s anticipated arrival by five hours in order to maximize the time of Canberra reception. So vast were the distances, and so attenuated the signal, however, that effective communication would need much more, a virtual array the size of the Pacific Basin. The DSN thus reached northward to Japan’s Usuda 64-meter tracking antenna on the island of Honshu, and to western North America as well, first to the Goldstone complex, which now included one 74-meter and two 24-meter antennas, and then to the very large array of radio telescopes at Socorro, New Mexico, operated by the National Radio Astronomy Observatory, which added the equivalent of two 70-meter antennas. The actual synthesis of data would have to occur after the flyby rather than in real time, but Earth could now hear what Voyager had to say.191

  The other worry was identifying the roster of targets and the means to navigate to them, particularly since so little was known. Planners made their best guess, and then hedged by actually building into the scenario places for the acquisition of new data and recoding on the fly. The scientific working groups had already begun identifying targets even as they planned for Uranus, since the route past Uranus had to include a path to Neptune. And in one sense, the spectrum of interests was already hardwired into Voyager 2’s instrument package, a medley of hard- and soft-geography scans. Specifically, Voyager 2 would interrogate the Neptunian atmosphere, notably its composition, energy budget, structure, and aurorae; it would map, delineate, and identify the constituent parts of the planetary rings and ring arcs; it would search out and characterize satellites, especially the planet’s largest moon, Triton; it would survey the magnetosphere and its dynamics; and it would conduct an experiment close to the science working group’s heart, four occultations and a close passage over the north pole that would deflect Voyager into a course as near as possible to Triton. Along the way it would record such fundamentals as the planet’s rotation period, the orientation of its axis, and its precise mass along with those of its moons. And the spacecraft’s master sequence would not only allow for fresh input but even anticipate it. 192

&
nbsp; The Neptune groups held a series of meetings between August 1986 and July 1987 to agree on a roster of wishes and to establish priorities. It submitted its final recommendations, pending further discoveries, on July 15, 1987. The process would continue up to encounter, a total of three years.193

  Of all the Voyager encounters, Charles Kohlhase concluded, the planning for Neptune’s was the “most challenging,” and he likened the task to guiding the spacecraft “through an imaginary needle’s eye about 100 km wide, while the spacecraft is going a blistering 27 km/ sec—and they expect to predict when this will happen to within one second!” The final trajectory was the outcome of nearly eight years of planning, editing, refining, tinkering, a ceaseless juggling between what scientists wanted, what engineers could provide, and what the spacecraft could bear.194

  The one ameliorating factor was that Neptune ended the Grand Tour. Voyager 2 would not have to tweak its trajectory in order to continue to another planet, so its passage around Neptune could be maximized for the values that planet offered. But the only hope for anything like the precision demanded was a good sequence of course corrections, constant refinements of trajectory based on improving data about Neptune’s hard geography and its gravitational effects, and a stream of successfully uploaded commands to tell Voyager 2 how to perform its acrobatics.

  Nothing in the Grand Tour, perhaps, was more daring than the hope—the planned expectation, really—that the spacecraft could in fact acquire the additional data it needed for precision guidance. The engineering term “critical late activities” disguised the audacity behind the ambition. The particular issue was that the spacecraft’s navigational system could not work reliably from Canopus alone; it needed other bodies, preferably Neptunian moons, objects that were not, at the time, known to exist but whose identities were programmed blankly into Voyager’s computers. If—when—such satellites were discovered and their orbital parameters measured, the additional information would be uploaded into the code. Voyager 2 needed at least one such moon; it found six. It then needed to tweak its trajectory to thread the Neptunian needle. It planned for six corrections, the first coming on February 14, 1986, a scant three weeks after the Uranus encounter. It needed only four.195