Bruce Murray
1992 was the 500th anniversary of Columbus' opening of the New World to European colonization. It played to mixed reviews in today's multi-cultural America where anxiety about our collective future overshadows interest in the longer historical process of which we all are a part. Space exploration is the contemporary manifestation of the human process of exploration reaching back to the Ice Ages when Homo Sapiens colonized new lands by adapting to challenging environments. Today, we travel in space vicariously through televised astronauts and cosmonauts. As we sit safely here on Earth, robotic space probes are an extension of ourselves to the remotest places of our Solar System.
However, the Columbus anniversary has not stimulated the renewed enthusiasm for today's space exploration some space enthusiasts expected. In fact, our civil space program is in shambles -- demoralized, bogged-down, and overly expensive. Like the sleeping Gulliver being bound up by the Lilliputians, NASA has become ensnared in special interest relationships that various congressional, scientific, and industrial factions nourished over the two decades since the ending of the Apollo flights to the Moon, the high point of NASA's life. This obsolete political dinosaur suddenly is being challenged by the prospect of declining budgets in the post-Cold War era. NASA's low point may have been reached in mid-1991 when NASA, the White House and Congress decided in concert to proceed with a full-blown Space Station Freedom, nominally to operate in the year 2000 as a symbol of American "leadership in space." Rejecting simpler, more practical, and more affordable alternatives, our national leadership chose symbolism over substance. A hugely expensive dreadnought circling in low Earth orbit three decades after America sent astronauts to the moon would be a remarkable symbol of not exploring. An uncertain America now seems to be wishing that the frontier of space could be redefined back to convenient low Earth orbit. However, in our youth as a space faring nation we boldly rocketed astronauts safely across the deep ocean of space to the moon and back and changed forever human expectations.
What is the future of space exploration? That's a fair question. Deep and enduring American and international interest in space exploration has been a very powerful public force for the last three decades. Where will such hopes and visions focus in the coming decades?
Explorers have always explored for three reasons: gold, glory, and curiosity. And finally, there is a genuine curiosity about places unknown.
Five hundred years ago colonization of new lands and utilization of raw materials were dominant motivations for exploration, driven by the material needs and personal vanities of kings, queens and nations. But Columbus sought personal recognition as much as his royal sponsors wanted their own recognition and rewards. Two hundred and fifty years go the focus began to shift to the search for mysterious peoples at the furthermost ends of the Earth -- Tahiti, central Africa, the search for Prester John; Captain Cook pursued knowledge as much as recognition. Then gradually the focus shifted to nearly-uninhabited parts of the Earth -- the search for the Northwest Passage, the race to the North Pole, the first probing of the Antarctic continent, and finally the race for the South Pole. Until the World War 2, private endeavors still co-existed with military expeditions representing governments. Exploration has more and more been in search for glory and curiosity than for gold. In our times, organized scientific curiosity, aggregated into Big Science, has become a dominant element in robotic space exploration.
World War 2 spawned in its aftermath the modern exploration of Antarctica. Starting in 1957-58, underutilized ships and airplanes left over from the great global conflict became available that could operate in that most difficult terrestrial environment. Thence began the sustained scientific exploration of Antarctica within binding international agreements -- quite different from the private initiatives of Shackelton and Amundsen half a century earlier -- and a welcome contrast in a century otherwise dominated by ethnic and national egocentrism.
But, away from the silent ice of Antarctica, the strident Cold War has dominated exploration until the last several years. Space travel by humans and robots became the supreme symbol of technological achievement, particularly for the Soviet Union. For the Soviet Union to be first in space, and therefore seeming to be first in other modern endeavors, constituted a tremendous reinforcement of Soviet domestic self-esteem. As a consequence, the U.S.S.R. made a maximum effort and had extraordinary successes early -- Sputnik, Lunik 3, Gagarin. The response of the U.S. with Kennedy in 1961 was to challenge the Soviets to a technological race only we could win - to go to the moon with humans.
The Apollo program succeeded brilliantly with Neil Armstrong's first step onto the austere lunar landscape on July 20, 1969. Lustrous space spin-offs of many kinds were happy by-products, including the early U.S. planetary program which was supported politically mainly for national prestige.
In 1965, the first Mars pictures radioed back by Mariner 4 warranted special viewing at the Senate and the House. I happened to be the one who presented those Mariner 4 imaging results to the Senate. Senator Stennis was in the chair. I went through my little song and dance, talking about Mars with (by current standards) very mediocre pictures.
Afterwards, he said, "Son, Ah didn't unduhstand a woud you said, but it was great!" And the reason it was great for him was because he saw the U.S. doing something of great international distinction in a competitive posture.
Televised images in 1972 of the last U.S. astronaut standing on the moon aided the authorization of funds to develop the Voyager mission to explore the mysterious outer planets. Launched in 1977, the twin Voyager spacecraft accomplished spectacular reconnaissance of Jupiter and Saturn in 1979, 1980, and 1981. In January 1986, at Uranus nearly two billion miles from Earth, Voyager 2 returned stunning close-up pictures of the enigmatic, tiny, icy moon Miranda. Miranda was only discovered in 1948! Voyager magnified 50,000 times what had been just a faint point on a photographic plate. Voyager 2 was an extraordinary electronic zoom lens linked via mass communication to the eyes and brains -- and curiosity -- of billions of people on Earth. Finally, in August 1989, as if to counterpoint the collapse of the Soviet empire, Voyager 2 raced past planet Neptune, the outermost world of our Solar System. It arrived there barely three decades after the launching of the first artificial Earth satellite by the U.S.S.R. and less than three centuries after the invention of the telescope.
Voyagers 1 and 2, and their smaller precursors Pioneer 10 and 11, continue obediently to radio their findings from the very edge of our star back to an unimaginably changed America. Truly, their signals are a faint, distant echo of John Kennedy's May 1961 Apollo speech -- a last hurrah for that fantastic burst of American technological capacity in service of human imagination...and Cold War competition.
In the coming decade or two, most likely there will be a slowing, perhaps even a hiatus. The reason is that the whole thing started anomalously. If Franklin Delano Roosevelt had not survived as President for four terms, the United States would not have changed its Constitution to provide for a two-term limitation to the Presidency. I think that, in turn, would have meant that the very popular Dwight D. Eisenhower would have had little choice but to run and be elected for a third term as President. However, Eisenhower was opposed to Big Space. He called it "pie in the sky." When JPL launched the first Explorer satellite in the dark days following the early Russian Sputnik successes, one of his aides was out at the Goldstone Tracking Station. He called up and said in effect, "Hey, Boss, good news. We received the radio signal at Goldstone, proving that Explorer's in orbit." Eisenhower's response was, "That's great, but don't make too much of it." He did not want a space race. His farewell address as President was to caution the nation against the military industrial complex which he felt, correctly, would grow much stronger under a Big Space government.
So by that little difference, humanity went along the Big Space track with Kruschev and Kennedy and on to the extraordinary events which have left such a great scientific and exploratory legacy -- and all of us with grand expectations. If it hadn't been for John Kennedy's bold Apollo address to Congress on May ____, 1961, George Bush on July 20, 1989 at the National Air and Space Museum might have called for the first human flight to the moon, rather than the first human flight to Mars!
We have lived through an extraordinary escalation of history. Humanity's first few steps into space happened prematurely and at an accelerated pace. Now we're living in the aftermath -- after the Cold War has ended and, to some extent, in a period of "End of Empire" for the U.S., no longer the supreme cultural, political and economic force in the world as it was following World War 2. In my professional life I work hard to help create valuable scientific and exploratory robotic space endeavors at modest cost. And I try to articulate an interesting future role for humans in space worth pursuing for all of us. But we shouldn't think something is fundamentally wrong if the frenzied tempo of the '60s, or the naive projections of 1970s and 1980s, can't be continued into the demanding new era of the '90s. It is proper that there be a post-Cold War downsizing of space efforts to "cheaper, smaller, quicker" -- and most importantly to "better."
The deeper and much more serious American problem is that we as a society no longer have a confident vision of ourselves leading anywhere. Like Lot's wife in the Old Testament, we are too strongly tempted to look backward, and like the biblical account, are in danger of being immobilized as a consequence. NASA looked backward to Cold War motivations in placing symbolism over substance with Space Station Freedom. As a consequence, our whole civil space effort is immobilized. Fortunately, NASA now has a new post-Cold War administrator, Dan Goldin. He is starting to steer the agency in a new direction, toward high achievement at affordable cost. But profound conflict lies ahead as the new fiscal reality forces wrenching choices between hopes for new exploration and high achievement in space, and continuing costly and bureaucratic programs inherited from the 1970's and 1980's. Finally, after two decades of post-Apollo drifting, we shall have to deal effectively and realistically with the questions "Where shall we go and why?" Otherwise, we shall become increasingly irrelevant to both the Present and the world's Future. I'm hopeful that my children will witness the first close-up images from Pluto, from the unexplored half of Mercury and from the tarry surface of Saturn's cloud-enshrouded moon Titan. Perhaps they will even see Venus' surface close-up through the robotic eyes of some novel submersible, periodically diving down through the scalding hot envelope of carbon dioxide gas surrounding that planet, exploring briefly, and promptly ascending back up to more tolerable environs. And surely, the fascinating landscape of Mars will become more familiar to everyone as robotic rovers, probably from several nations, crawl about its vast surface, looking, touching, feeling, tasting.
Hopefully, there also will be exciting milestones reached on the grand human road to Mars. The new space agreement between Russia and the U.S. opens the door for affordable joint biomedical tests using the proven and versatile Russian space station MIR. On board MIR, and supported by the vast U.S. capability in biomedical research, astronauts and cosmonauts can together search for effective means to combat the debilitating effects of weightlessness in preparation for the year-long flight to Mars. Robotic missions beyond the protective influence of Earth's magnetic field will be needed also to delineate the hazard to future Mars crew members posed by cosmic radiation in space . What counts is to be journeying to Mars, not about arriving there by some arbitrary date. Apollo was preceded by nearly two dozen robotic scouts. The first human visit to Mars will need at least as many -- a task best accomplished by pooling the considerable capabilities of both the U.S. and Russia aided by Europe and Japan. The international exploration of Mars beckons as a major theme of post-Cold War exploration.
What will the next 100 years bring in terms of space exploration? Humans will go to Mars. The journey is technically feasible. Mars is inevitably the next place to go after the moon. And adventurous societies will also send adventurous individuals on expeditions to asteroids, comets, the icy moons around Saturn and other exotic destinations.
But Mars may be the only place for humans to go to stay because Mars offers the only potentially habitable surface in the Solar System besides Earth. Oxygen, carbon, nitrogen, and hydrogen, the critical elements for biological systems, are all available on Mars' harsh but survivable surface environment. Probably, some kind of limited outpost will be emplaced there during the next century. There might even be a permanent base by the end of the 21st century, similar to the base the U.S. has operated at the South Pole for many decades, where all supplies and personnel are flown in and out. I hope the Mars base will be a international one, truly representing Planet Earth. That would be a grand escalation into the 21st century of the 20th century Antarctic experience.
Beyond that, there are speculations about terraforming. Terraforming means the artificial modification of an alien planet's surface and atmosphere (such as Mars or Venus) in order to make it habitable for humans. But humanity's problem for the next century on its home planet is that we relentlessly, if unintentionally, modify Earth's atmosphere and surface to making it less habitable. Indeed we are reverse terraforming Earth. The overriding challenge of the next century will be to bring humanity and the Earth's biosphere into a sustainable balance. Thus, serious consideration about how to satisfactorily modify another planet seems to me not very timely. Centuries will pass before the necessary environmental knowledge is likely to be available. Even then, the moral issue will arise, "We screwed this one up -- what gives us the right to screw up another one?" So terraforming from my perspective, if it is in human destiny at all, is a long, long way down the road.
Where will future bursts of humanity's energy lead restless homo sapiens? Has Voyager put us on the pathway to the stars? We live in unprecedented times and have come to accept mind-bending changes as the hallmark of our present and future. The sustained success of such films as 2001, Star Wars, Alien, Close Encounters of the Third Kind, and E.T. testify to the widespread popular acceptance of interstellar travel in the tangible future. Remember, however, the stars are very far apart. Our nearest stellar neighbor is so distant that its light is more than four years old by the time it reaches us. For humans to travel to even the nearest star would be a one-way journey requiring many generations. Who would want to be locked up, to live, breed, and die in a giant sealed space cannister? The icy plateaus of central Greenland and the Antarctic by comparison offer far more attractive locales for colonization, still bathed from time to time with blue sky, moonlight and breathable fresh air. So unless there are wormholes and parallel universes or some other kind of unimagined new physical possibilities, star travel by humans is simply not going to happen on any timescale. Maybe that's why we aren't being visited by aliens (despite reports in the tabloids one sees in the supermarket checkout line!).
How will humankind probe stellar environments? Successful exploration usually involves novel adaptation to difficult environments. Captain Cook overcame scurvy through nutrition and hygiene in order to succeed on his unprecedented transoceanic journeys. Amundsen learned from the Eskimos of the north how to travel light and fast in the lifeless south, and defeated Scott and smug Edwardian pride in the race to the South Pole. In the 20th century, when new means of transportation -- airplanes, submersibles, and finally, rockets -- enabled access to uninhabitable environments, habitable conditions are carried along artificially in sealed canisters to permit human access to hitherto forbidden locales. Most recently, we have developed robots that are adapted to the vacuum and radiation of space. Our adaptation will be increasingly robotic in the future, with the corporal intelligence and feeling remaining on Earth while ever more intelligent and adaptive robotic sensors race out as far as we can send them, communicating back through invisible neurons of radio or light beams.
Indeed, I have wondered if micro-miniaturized Voyagers could be sent streaking swiftly enough beyond the reach of the Sun's gravity to travel deep into the Galaxy. However, even for robots the stars are very far apart. If an automated probe is to send back results, say, thirty years after launch, a considerable length of time to expect contemporary societies to wait for results, that space ship must reach a speed at least one-fifth that of light itself. At such speeds, collision with but a tiny grain of interstellar dust becomes a miniature atomic explosion. And there will also have to be some kind of new super-propellant. Even the wildest rocket concepts proposed, today's visionaries could never make star travel practical. Perhaps human ingenuity eventually may extend our robotic reach to touch the envelopes of nearby stellar neighbors. But I doubt that even the next century's most advanced robots and exotic propulsion systems are likely to bring the bulk of our stellar neighborhood into direct examination.
Thus, I foresee the possibility that our descendants will encounter real limits to physical exploration. Perhaps, over the next several centuries, aggressive and expansive Homo sapiens will finally come to a benign, sustainable equilibrium with its surroundings after so many millennia of relentless geographic and demographic expansion. Indeed, our distant descendants very well may look back upon centuries of reckless growth and technological change as the adolescence of Homo sapiens. I don't believe humanity is doomed to the eternal Hellfire of technologically-generated instability, a half-savage with a pistol in his hand, never able to overcome quietest location of all.
By the end of the Century we should be able to detect alien beaconing generally, not just those radio signals "spoon fed" to us in this particular stellar location. I will be disappointed (in spirit!) if signals of extraterrestrial origin are not detected by the end of the next century. I firmly believe that my grandchildren -- or their children -- will have proof about the existence of a galactic community out there -- and wonder if it accepts new members. They can be justifiably puzzled if the Cosmos still seems devoid of signals after systematic searches for beaconsfully its animal origins. We are free to grow up -- or to fail -- as a species. Someday, our descendants will exhibit a true planetary consciousness -- one people, living relatively harmoniously on one planet, with shared dreams.
However, physical limits to going out in space don't mean there isn't a way to keep exploring. We will continue to probe the cosmos ever more deeply and more finely through telescopes on the ground, in Earth orbit, and probably on the Moon. Most importantly, we are already beginning to listen for artificial radio signals emanating from the vicinity of other stars. By far the most interesting thing to strive for in outer space is evidence of alien intelligence -- proof that we are not alone. It is hard for me and many other scientists to accept the proposition that intelligent life originated only in the vicinity of this rather undistinguished star we call "Sun" when there are billions of comparable locales in our galaxy. Serious continuing efforts to listen for alien beacons are under way in the U.S. An elegant and inexpensive one, sponsored by non-profit The Planetary Society is to be supplemented by a comprehensive new NASA effort starting this month (despite renewed Congressional threats to the funds). And there are smaller efforts in the U.S. and other countries. Such imaginative searches could bear fruit soon if something out there is trying very hard to communicate with us by radio. Over the next century, Earth's efforts to detect intentional signals from other stars can grow enormously more effective and complete by exploiting all the new sensor and computational technologies that are likely to become available. And we will locate some listening stations in space, above the ionosphere and away from the "din" of our own electronic transmissions. The remote back side of the Moon may come to occupy a special place in our destiny as the radio.
Few will remember the thousandth anniversary of Columbus' voyage in 2492 A.D., I think. By then, the emotional, intellectual, and moral potential of Homo may be flowering, having been obscured for a time by the sound and fury of electricity, rockets, and atoms splitting in the hands of adolescent Homo sapiens. Then Earthlings may be ready to join the Galactic Community.