Voyager - Exploration, Space, And The Third Great Age Of Discovery

by Stephen J. Pyne

  Cape Canaveral, Florida, followed the latter pattern as a place developed specifically to fire rockets. Rocketry’s hazards, and to some extent its secrecy under military sponsorship, argued for remote sites, typically deserts such as White Sands or Edwards Air Force Base or Baikonur, Kazakhstan, until their heft demanded greater domains of emptiness. By 1949 the range of the V-2’s successors had lengthened sufficiently that President Harry S. Truman established a Joint Long Range Proving Ground on what was then a largely uninhabited belt of Florida shoreline.

  The site had plenty of attractions. The surrounding countryside was lightly developed; missiles could be readied, and even fail in violent fireballs, without threatening communities. Launches would arc over the Atlantic, and if missiles wobbled off course, blew up, or had to be destroyed, they again posed no danger to people. The weather allowed for continual operations, save for fleeting thunderstorms and the occasional hurricane. Islands trending southeast, from the Grand Bahamas to Ascension, themselves famous as sites for past discovery, could service tracking stations. There was ample land for future development.

  In 1950 the army moved its facilities from White Sands to Cape Canaveral, while the air force acquired a nearby naval air station (Banana River) to convert into its Air Force Missile Test Center. In 1955 the navy relocated its Vanguard missile program to Canaveral. In December 1959 the army transferred its facilities to NASA. When the expanding program demanded still more land, nearby Merritt Island was acquired for development into a major “spaceport,” the John F. Kennedy Space Center and Eastern Space and Missile Center.78

  The site had its quirks, as all ports do, which is why historically pilots were first and foremost versed in local lore. Canaveral’s shoals and tidal bores were its weather—its thunderstorms, its frosts. Having an electrostatic match striking randomly around a tower of distilled combustibles could kindle catastrophe, and a cold snap could turn pliable O rings into brittle plastic. These were local lessons, learned over time, and they would take many decades to codify into pilotage for the Cape.

  Yet in one respect it did resemble so many of its predecessor ports from which explorers had embarked: Cape Canaveral was an island, or effectively so, cut off from mainland Florida by estuaries and the Banana River. Its development stands to space voyaging as the colonization of Atlantic isles does for the Great Age of Discovery. Those isles permitted a final fitting and provisioning, and then positioned a vessel within the geography of wind and currents that would carry it to the New World or around Africa, which is what also happened at the Cape. Today’s equivalent to the Canaries, astride the trade winds, is a locale closer to the equator, which can contribute more rotational velocity from the Earth to a rocket moving east (Canaveral adds 1,666 kilometers an hour). For deep-space ventures, the ideal would be a port of call beyond Earth’s gravitational shackles altogether, something like an orbiting space station or a lunar base. Since neither exists, the compromise is a pause in orbit before the final stage ignites.

  The Voyagers’ launches were the climax to a dozen years of meticulous planning, and liftoff was almost ritualistic in its tight choreography. The larger factors were many, and rarely aligned, among them the immutable geometry of the planets, the rocket’s capacity for thrust, the size of the payload, the ability to navigate, and the ambitions of the mission. Every consideration varied, and each changed with changes in the others. There could be no singular solution.

  Every planet had its unique launch window based on the minimum energy trajectories first elaborated by Walter Hohmann in 1925. For Venus these came every nineteen months; for Mars, every twenty-six; for Jupiter, every thirteen. The thrust available determined velocity, which then set launch opportunities, but as payload varied, so did velocity, and as velocity changed, so did potential routes and hence launch dates. Where one launch was to lead to another through gravity assistance, the options multiplied, and a planning calendar became maddeningly complex. For the Grand Tour, a suitable collective geometry would reappear only every 176 years. Yet at each planet along the way there were sites to visit, so the prospects for routes were almost unbounded. Planners began with 10,000 potential trajectories, which they then whittled down to 100 possibilities.

  Voyagers’ window was tight. To preserve the Grand Tour option, launch had to occur between 1976 and 1978; to capture Jupiter’s gravity, it had to obey a thirteen-month cycle; to reconcile Jupiter’s and Earth’s orbits, it had to happen within a month of consecutive dates within that recurring near-annual cycle, and for each day within that month, within an hour-long window. There was, as well, a cultural window, for five years earlier a Grand Tour would not have been technically possible, and five years later not politically feasible.

  As in the past, ceremonies of departure had emerged. There were bleachers for dignitaries and associates, cameras to record and broadcast to the public, rites of political blessing. It had ever been so. Traditionally, ship launches were a bedlam of last-minute provisioning, the testing of anchors and ropes, the bustle of late-arriving crew-men. There were observers, whether family, dockworkers, the curious, or the emissaries of sponsors. There would be a Mass said, a service recited, a political proclamation, a poem. The expedition’s orders and rules of conduct might be read.

  There would also be a search heavenward for signs and portents. When Sir John Franklin departed to plot out the Northwest Passage, a white dove settled on a mast, and became for many well-wishers (including Franklin’s daughter, Eleanor) “an omen of peace and harmony.” As Voyager 2 rested at its gantry the day before launch, black thunderheads and lightning approached threateningly within a mile of the combustible rocket before veering off to sea. In both these cases, the portents misread subsequent events entirely.79

  Since they had different trajectories, the Voyager twins launched separately. Their names reflected the sequence of arrival at Jupiter, not the sequencing of launch. Voyager 2 went first. Voyager 1 followed sixteen days later. They had met their launch dates and sailed with the cosmic tides.

  For expeditions, time can be more powerful than place. It is always possible to reposition ships (or keel boats or entradas) for secondary departures, and this was normal; but it is tricky and often fatal to ignore the seasonal geographies of wind and wave. The need for timing could further argue for staggered embarkations. Always exploration has had its launch sequences.

  These could span from hours to years. Spanish fleets from the Caribbean had to sail outside hurricane season; Russian promyshlenniki relied on frozen rivers in winter and flowing streams in summer, and shunned the mires of spring breakup. Voyages to the Spice Isles had to obey the ebb and flow of the monsoons, first from Africa to India, and then to the East Indies. Vasco da Gama caught those winds for 23 days from Mombasa to Calicut, and when he tried to defy them on his return, he nearly lost his crews to scurvy in fighting their contrary flow for 132 days. Expeditions up the Missouri River left early in the spring to reach the mountains before the snows, or else they found a valley to winter over until the following spring. In Australia, the Burke and Wills expedition managed to undertake its trek across the interior with exquisite (and fatal) mistiming, fighting brutal summer heat to Cooper’s Creek, and then breasting the rainy season to the Gulf of Carpentaria. In extreme cases it might take a year or more to relocate to a site from which further exploration could proceed. The Franklin expedition to the Northwest Passage expected to winter over in the frozen Arctic before summer melt would allow further progress. Ship-borne Antarctic exploration would likewise break through the enveloping pack ice late in the summer, only to winter over in preparation for late-spring treks. Russian forays to the Pacific might demand a year’s travel just to reach the coast, and another year to return, with exploration limited to fleeting opportunities in between.

  But apart from seasonal or secular rhythms, there were always local considerations of tide and wind, over which the explorers had often little knowledge and less control. Many a bold expedition toasted the t
ide, and then sat while contrary winds kept them in port, or took to sea and had to beat against the winds for a week or more until they could properly launch. (The equivalent for rockets are technical glitches that pause or close countdowns.) Tide and winds could make for cruel embarkations, and even crueler returns. These were the launch delays of the past, when the countdown stopped, the expedition slid from élan to ennui, and the drama stalled while the stagehands replaced the faulty curtains and broken limelights. This mattered less when communications were not instantaneous and when the vagaries of earthly weather offered more flexibility than the foreordained orbits of celestial mechanics.

  LIFTOFF

  On August 20, 1977, at 10:29:45 a.m. EDT, Voyager 2 lifted off from Cape Canaveral. On September 5, at 8:56:01 a.m. EDT, Voyager 1 followed.

  They rose atop a boiling column—a controlled explosion—of flame. If their ultimate thrust derived from a cultural combustion that mixed ambition, curiosity, greed, political posturing, and utopianism, the proximate cause was a violent collision of liquid hydrogen and liquid oxygen into a distilled, full-throated burn. It was a magnificently Promethean gesture, in its audacity—the first satellite had broken into earthly orbit only a scant twenty years before, yet here was a launch intended to traverse the solar system. But it was Promethean, too, in its choice of means, for fire is humanity’s signature technology and a chemistry that has no natural presence outside Earth. Once beyond Earth’s gravitational tug, the Voyagers would be beyond the realm of life, which is also the realm of fire. That reach beyond was the essence of their mission. But it seemed altogether right that they should begin those journeys to lifeless worlds and a near-eternity of vacuum upon the pillars of the fire its makers had long ago seized from the heavens.

  part 2

  BEYOND THE SUNSET: JOURNEY ACROSS THE SOLAR SYSTEM

  Push off, and sitting well in order smite

  The sounding furrows; for my purpose holds

  To sail beyond the sunset, and the baths

  Of all the western stars, until I die.

  —Alfred Tennyson, “Ulysses”

  But the way is dangerous, the passage doubtful, the voyage not thoroughly known.

  —Richard Hakluyt, The Principal Navigations

  Beyond Earth

  DAY 1-28

  6. New Moon

  Two escape velocities frame the Voyager mission. The first, the escape from the gravitational pull of Earth, allowed the twin spacecraft to begin their quest through the solar system by getting them to Jupiter. The second, the escape from the gravitational pull of the Sun, happened at Jupiter and allowed them to complete the Grand Tour. That second momentum would also define the end of their quest by propelling them beyond the solar system altogether.

  Those dual moments of propulsion help to bookend the mission’s narrative as well, by segregating the geography of places visited from that of places shunned. Simply departing Earth’s gravity was not enough, for there were two other bodies from whose psychological orbits the Voyagers also had to escape. The first was the Moon, whose tidal pull had turned minds heavenward since ancient times and whose political phases had filled the night sky of the space race. The second was Mars, the most Earth-like of planets and the obsession of a culture of colonization. Both the Moon and Mars were the scenes, either actual or imagined, for human space travel, and thus for all the rest of what the segue from exploring to colonizing implied, not least some bond to a national military. A critical fact is that Voyager bypassed both bodies with hardly a wobble. In less than a day the Voyagers blew past the sublunary realms and began the first of their long cruises between encounters.

  OUT OF ORBIT

  Passage from Earth to the Moon was, for both Voyagers, little more than a heartbeat in a long marathon. When they completed their final firings, Voyager 1 and 2 had velocities in excess of 143,000 kilometers per hour and 140,000 kilometers per hour, respectively. They passed the average orbit of the Moon, roughly 384,403 kilometers from Earth, some ten hours after launch.

  There were a few launch glitches, some serious, some merely annoying. The most critical occurred when Voyager 1 nearly failed to attain its mandatory velocity, which would have still sent the spacecraft to Jupiter and Saturn but would have scrubbed the Grand Tour. By contrast, Voyager 2’s launch crisis involved more of an anxiety attack. This began when onboard computers detected accelerations greater than expected and overly “self-corrected”; then dust particles set in motion by vibrations sparkled and misoriented the spacecraft’s tracking system. Together these events left the antenna misdirected, and hence oblivious to ground commands. For a heart-stopping moment, it seemed that the spacecraft might be lost altogether. In fact, it was working as programmed, but its programs had been written for a different set of expectations; the shaking incurred at launch exceeded those forecast conditions, and had jarred overly sensitive fault-protection algorithms into sending the spacecraft into a fetal crouch. The scare passed. When the etiology of the affliction had been diagnosed and cured, one analyst described the episode as an “anxiety attack”; another, as a kind of “vertigo,” or perhaps seasickness, part of Voyager getting its sea legs. Bruce Murray observed that the “new, superautonomous robot” lacked the “repertoire of human judgment and experience,” and it had “mistrusted itself” before finally being “righted by its own logic.” Voyager had already begun to surprise its creators, and it had begun to learn.1

  The anxiety attack continued in other manifestations, felt more intensely by its human controllers than by Voyaget 2. Signals indicated that the science boom had failed to deploy fully; but this was deemed a failure of the sensor, not the boom. Weirdly, a hydrazine thruster pointed wrongly at the spacecraft itself, which caused the vessel to drift off trajectory, which required more precious hydrazine, until the problem was recognized and repaired and course corrections made. Sensors began to fail (some seventy-two out of several hundred throughout the mission), all pertinent but none fatal. Then the infrared sensors deteriorated when bonding materials crystallized and distorted their mirrors after the protective sheath was removed, until a flash heater corrected the problem. There were odd pitches and yaws, never explained. As a result, several days of testing commenced before Voyager 2 could acquire its navigational guide star, Canopus. For their first two weeks both spacecraft underwent shakedown cruises in which they extended booms, tested instruments, and learned to communicate with a fast-receding Earth.2

  Similar breakdowns continued throughout the mission and not all were mechanical; some of the worse stemmed from the failures of human controllers. The Grand Tour meant a constant negotiation between robot and human, with each learning from the other and at times compensating for the other’s lapses. Voyager 2 overcame its makers’ errors in failing to program for a jarring launch, and its makers overlooked the malfunction of its boom sensor and fixed its faulty thruster. Over the years that exchange deepened, though their mutual reliance, begun at launch, never disappeared.

  WAXING MOON

  The Moon mattered. After IGY had field-tested the technologies of the Third Age, Earth and its Moon were the place where it took its ambitions. The Earth-Moon system was to the new geography of discovery what the Atlantic isles were to the First Age, and what a resurvey of Europe’s interior by naturalists was to the Second.

  Proximity was an obvious explanation. The Moon was the closest as well as the dominant object in the night sky, and space travelers advanced upon it step by step. The first Earth-launched satellites were identified as “new moons.” The earliest spacecraft targeted near-Earth realms and the Moon. The primary rival to (and disturber of) planetary exploration, the Apollo program, aimed at the Moon. Colonizers imagined the Moon as a port of call for the solar system akin to that enjoyed earlier by Madeira and the Canaries to the Indies and Americas. Planetary spacecraft evolved from lunar Ranger to inner-planets Mariner to outer-planets Voyager. In 1969, in the months prior to the Apollo 11 lunar landing, Mariner 6 and 7 completed magnifi
cent flybys of Mars, and while for true believers Mars mattered as much as the Moon, public attention and politics remained riveted on a lunar landing.

  So it was a waxing Moon, not Earth’s planetary siblings, that dominated the political sky. For planetary discovery to thrive, spacecraft, and mission planners, had to see the satellites of far planets, and couldn’t do so if their eyes were flooded with the reflected light of Earth’s. Then the Apollo program, its cold war mission completed, sank into near-parody as astronaut Alan Shepard hit two golf balls down the gray-powder fairways of Fra Mauro. The glittering vision of humans leaping beyond their home planet imploded into Skylab and Soyuz, the shuttle, and a hypothetical space station. Yet even as the shuttle began to drain NASA in a slow-death hemorrhage of money and talent, the planetary program blasted into its glory years.

  As the Voyagers quickly rushed beyond the orbit of the Moon, they passed by the first planetary marker on their grand traverse. When the Third Age began, the Earth-Moon nexus was its Pillars of Hercules, the limits of humanity’s practical powers and its blinkered imagination.

  That setting served the Third Age as Europe’s bounding seas had the First Age, and as the scientific rediscovery of its internal geography did for the Second when the grand tour shifted from art and classical literature to natural history. The botanical excursions of Linnaeus replaced a pilgrimage to the ruins of Rome, and the geological collecting of Christian Leopold von Buch amid the Alps superseded oils and watercolors of Mount Etna in eruption. In effect, the eyes of discovery turned to Europe, not to witness new scenes but to see old ones with new insight. The emergence of modern biology, geology, and ethnology revived the tired geography of Ptolemy into something fresh and vibrant. That experience was the essence of the Second Age, much of which had been known in some fashion to formal learning, and only a tiny fraction of which did not have indigenous inhabitants.