space travel

Human ingenuity seldom fails to improve on the fruits of human invention. Whatever may have dazzled everyone on its debut is almost guaranteed to be superseded and, someday, to look quaint.

In 2000 B.C. a pair of ice skates made of polished animal bone and leather thongs was a transportation breakthrough. In 1610 Galileo's eight-power telescope was an astonishing tool of detection, capable of giving the senators of Venice a sneak peek at hostile ships before they could enter the lagoon. In 1887 the one-horsepower Benz Patent Motorwagen was the first commercially produced car powered by an internal combustion engine. In 1946 the thirty-ton, showroom-size ENIAC, with its 18,000 vacuum tubes and 6,000 manual switches, pioneered electronic computing. Today you can glide across roadways on in-line skates, gaze at images of faraway galaxies brought to you by the Hubble Space Telescope, cruise the autobahn in a 600-horsepower roadster, and carry your three-pound laptop to an outdoor cafe.

Of course, such advances don't just fall from the sky. Clever people think them up. Problem is, to turn a clever idea into reality, somebody has to write the check. And when market forces shift, those somebodies may lose interest and the checks may stop coming. If computer companies had stopped innovating in 1978, your desk might still sport a hundred-pound IBM 5110. If communications companies had stopped innovating in 1973, you might still be schlepping a two-pound, nine-inch-long cell phone. And if in 1968 the U.S. space industry had stopped developing bigger and better rockets to launch humans beyond the Moon, we'd never have surpassed the Saturn V rocket.

Oops!

Sorry about that. We haven't surpassed the Saturn V. The largest, most powerful rocket ever flown by anybody, ever, the thirty-six-story-tall Saturn V was the first and only rocket to launch people from Earth to someplace else in the universe. It enabled every Apollo mission to the Moon from 1969 through 1972, as well as the 1973 launch of Skylab 1, the first U.S. space station.

Inspired in part by the successes of the Saturn V and the momentum of the Apollo program, visionaries of the day foretold a future that never came to be: space habitats, Moon bases, and Mars colonies up and running by the 1990s. But funding for the Saturn V evaporated as the Moon missions wound down. Additional production runs were canceled, the manufacturers' specialized machine tools were destroyed, and skilled personnel had to find work on other projects. Today U.S. engineers can't even build a Saturn V clone.

What cultural forces froze the Saturn V rocket in time and space? What misconceptions led to the gap between expectation and reality?

Soothsaying tends to come in two flavors: doubt and delirium. It was doubt that led skeptics to declare that the atom would never be split, the sound barrier would never be broken, and people would never want or need computers in their homes. But in the case of the Saturn V rocket, it was delirium that misled futurists into assuming the Saturn V was an auspicious beginning—never considering that it could, instead, be an end.

On December 30, 1900, for its last Sunday paper of the nineteenth century, the Brooklyn Daily Eagle published a sixteen-page supplement headlined THINGS WILL BE SO DIFFERENT A HUNDRED YEARS HENCE. The contributors—business leaders, military men, pastors, politicians, and experts of every persuasion—imagined what housework, poverty, religion, sanitation, and war would be like in the year 2000. They enthused about the potential of electricity and the automobile. There was even a map of the world-to-be, showing an American Federation comprising most of the Western Hemisphere from the lands above the Arctic Circle down to the archipelago of Tierra del Fuego—plus sub-Saharan Africa, the southern half of Australia, and all of New Zealand.

Most of the writers portrayed an expansive future. But not George H. Daniels, a man of authority at the New York Central and Hudson River Railroad, who peered into his crystal ball and boneheadedly predicted:

It is scarcely possible that the twentieth century will witness improvements in transportation that will be as great as were those of the nineteenth century.

Elsewhere in his article, Daniels envisioned affordable global tourism and the diffusion of white bread to China and Japan. Yet he simply couldn't imagine what might replace steam as the power source for ground transportation, let alone a vehicle moving through the air. Even though he stood on the doorstep of the twentieth century, this manager of the world's biggest railroad system could not see beyond the automobile, the locomotive, and the steamship.

Three years later, almost to the day, Wilbur and Orville Wright made the first-ever series of powered, controlled, heavier-than-air flights. By 1957 the U.S.S.R. launched the first satellite into Earth orbit. And in 1969 two Americans became the first human beings to walk on the Moon.

Daniels is hardly the only person to have misread the technological future. Even experts who aren't totally deluded can have tunnel vision. On page 13 of the Eagle's Sunday supplement, the principal examiner at the U.S. Patent Office, W. W. Townsend, wrote, The automobile may be the vehicle of the decade, but the air ship is the conveyance of the century. Sounds visionary, until you read further. What he was talking about were blimps and zeppelins. Both Daniels and Townsend, otherwise well-informed citizens of a changing world, were clueless about what tomorrow's technology would bring.

Even the Wrights were guilty of doubt about the future of aviation. In 1901, discouraged by a summer's worth of unsuccessful tests with a glider, Wilbur told Orville it would take another fifty years for someone to fly. Nope: the birth of aviation was just two years away. On the windy, chilly morning of December 17, 1903, starting from a North Carolina sand dune called Kill Devil Hill, Orville was the first to fly the brothers' 600-pound plane through the air. His epochal journey lasted twelve seconds and covered 120 feet—a distance just shy of the wingspan of a Boeing 757.

Judging by what the mathematician, astronomer, and Royal Society gold medalist Simon Newcomb had published just two months earlier, the flights from Kill Devil Hill should never have taken place when they did:

Quite likely the twentieth century is destined to see the natural forces which will enable us to fly from continent to continent with a speed far exceeding that of the bird.

But when we inquire whether aerial flight is possible in the present state of our knowledge; whether, with such materials as we possess, a combination of steel, cloth and wire can be made which, moved by the power of electricity or steam, shall form a successful flying machine, the outlook may be altogether different.

Some representatives of informed public opinion went even further. The New York Times was steeped in doubt just one week before the Wright brothers went aloft in the original Wright Flyer. Writing on December 10, 1903—not about the Wrights but about their illustrious and publicly funded competitor, Samuel P. Langley, an astronomer, physicist, and chief administrator of the Smithsonian Institution—the Times declared:

We hope that Professor Langley will not put his substantial greatness as a scientist in further peril by continuing to waste his time, and the money involved, in further airship experiments. Life is short, and he is capable of services to humanity incomparably greater than can be expected to result from trying to fly.

You might think attitudes would have changed as soon as people from several countries had made their first flights. But no. Wilbur Wright wrote in 1909 that no flying machine would ever make the journey from New York to Paris. Richard Burdon Haldane, the British secretary of war, told Parliament in 1909 that even though the airplane might one day be capable of great things, from the war point of view, it is not so at present. Ferdinand Foch, a highly regarded French military strategist and the supreme commander of the Allied forces near the end of the First World War, opined in 1911 that airplanes were interesting toys but had no military value. Late that same year, near Tripoli, an Italian plane became the first to drop a bomb.

Early attitudes about flight beyond Earth's atmosphere followed a similar trajectory. True, plenty of philosophers, scientists, and sci-fi writers had thought long and hard about outer space. The sixteenth-century philosopher-friar Giordano Bruno proposed that intelligent beings in habited an infinitude of worlds. The seventeenth-century soldier-writer Savinien de Cyrano de Bergerac portrayed the Moon as a world with forests, violets, and people.

But those writings were fantasies, not blueprints for action. By the early twentieth century, electricity, telephones, automobiles, radios, airplanes, and countless other engineering marvels were all becoming basic features of modern life. So couldn't earthlings build machines capable of space travel? Many people who should have known better said it couldn't be done, even after the successful 1942 test launch of the world's first long-range ballistic missile: Germany's deadly V-2 rocket. Capable of punching through Earth's atmosphere, it was a crucial step toward reaching the Moon.

Richard van der Riet Woolley, the eleventh British Astronomer Royal, is the source of a particularly woolly remark. When he landed in London after a thirty-six-hour flight from Australia, some reporters asked him about space travel. It's utter bilge, he answered. That was in early 1956. In early 1957 Lee De Forest, a prolific American inventor who helped birth the age of electronics, declared, Man will never reach the moon, regardless of all future scientific advances. Remember what happened in late 1957? Not just one but two Soviet Sputniks entered Earth orbit. The space race had begun.

Whenever someone says an idea is bilge (which, I suppose, is British for baloney), you must first ask whether it violates any well-tested laws of physics. If so, the idea is likely to be bilge. If not, the only challenge is to find a clever engineer—and, of course, a committed source of funding.

The day the Soviet Union launched Sputnik 1, a chapter of science fiction became science fact, and the future became the present. All of a sudden, futurists went overboard with their enthusiasm. The delerium that technology would advance at lightning speed replaced the delusion that it would barely advance at all. Experts went from having much too little confidence in the pace of technology to having much too much. And the guiltiest people of all were the space enthusiasts.

Commentators became fond of twenty-year intervals, within which some previously inconceivable goal would supposedly be accomplished. On January 6, 1967, in a front-page story, The Wall Street Journal announced: The most ambitious U.S. space endeavor in the years ahead will be the campaign to land men on neighboring Mars. Most experts estimate the task can be accomplished by 1985. The very next month, in its debut issue, The Futurist magazine announced that according to long-range forecasts by the RAND Corporation, a pioneer think-tank, there was a 60 percent probability that a manned lunar base would exist by 1986. In The Book of Predictions, published in 1980, the rocket pioneer Robert C. Truax forecast that 50,000 people would be living and working in space by the year 2000. When that benchmark year arrived, people were indeed living and working in space. But the tally was not 50,000. It was three. The first crew of the International Space Station.

All those visionaries (and countless others) never really grasped the forces that drive technological progress. In Wilbur and Orville's day, you could tinker your way into major engineering advances. Their first airplane did not require a grant from the National Science Foundation: they funded it through their bicycle business. The brothers constructed the wings and fuselage themselves, with tools they already owned, and got their resourceful bicycle mechanic, Charles E. Taylor, to design and hand-build the engine. The operation was basically two guys and a garage.

Space exploration unfolds on an entirely different scale. The first moonwalkers were two guys, too—Neil Armstrong and Buzz Aldrin—but behind them loomed the force of a mandate from an assassinated president, 10,000 engineers, $100 billion, and a Saturn V rocket.

Notwithstanding the sanitized memories so many of us have of the Apollo era, Americans were not first on the Moon because we're explorers by nature or because our country is committed to the pursuit of knowledge. We got to the Moon first because the United States was out to beat the Soviet Union, to win the Cold War any way we could. John F. Kennedy made that clear when he complained to top NASA officials in November 1962:

I'm not that interested in space. I think it's good, I think we ought to know about it, we're ready to spend reasonable amounts of money. But we're talking about these fantastic expenditures which wreck our budget and all these other domestic programs and the only justification for it in my opinion to do it in this time or fashion is because we hope to beat them [the Soviet Union] and demonstrate that starting behind, as we did by a couple of years, by God, we passed them.

Like it or not, war (cold or hot) is the most powerful funding driver in the public arsenal. When a country wages war, money flows like floodwaters. Lofty goals—such as curiosity, discovery, exploration, and science—can get you money for modest-size projects, provided they resonate with the political and cultural views of the moment. But big, expensive activities are inherently long term, and require sustained investment that must survive economic fluctuations and changes in the political winds.

In all eras, across time and culture, only three drivers have fulfilled that funding requirement: war, greed, and the celebration of royal or religious power. The Great Wall of China; the pyramids of Egypt; the Gothic cathedrals of Europe; the U.S. interstate highway system; the voyages of Columbus and Cook—nearly every major undertaking owes its existence to one or more of those three drivers. Today, as the power of kings is supplanted by elected governments, and the power of religion is often expressed in non-architectural undertakings, that third driver has lost much of its sway, leaving war and greed to run the show. Sometimes those two drivers work hand in hand, as in the art of profiteering from the art of war. But war itself remains the ultimate and most compelling rationale.

Having been born the same week NASA was founded, I was eleven years old during the voyage of Apollo 11, and had already identified the universe as my life's passion. Unlike so many other people who watched Neil Armstrong's first steps on the Moon, I wasn't jubilant. I was simply relieved that someone was finally exploring another world. To me, Apollo 11 was clearly the beginning of an era.

But I, too, was delirious. The lunar landings continued for three and a half years. Then they stopped. The Apollo program became the end of an era, not the beginning. And as the Moon voyages receded in time and memory, they seemed ever more unreal in the history of human projects.

Unlike the first ice skates or the first airplane or the first desktop computer—artifacts that make us all chuckle when we see them today—the first rocket to the Moon, the 364-foot-tall Saturn V, elicits awe, even reverence. Three Saturn V relics lie in state at the Johnson Space Center in Texas, the Kennedy Space Center in Florida, and the U.S. Space and Rocket Center in Alabama. Streams of worshippers walk the length of each rocket. They touch the mighty rocket nozzles at the base, like the apes who touched the Monolith in the 1968 film 2001: A Space Oddysey, and wonder how something so large could ever have bested Earth's gravity. To transform their awe into chuckles, our country will have to resume the effort to boldly go where no man has gone before. Only then will the Saturn V look as quaint as every other invention that human ingenuity has paid the compliment of improving upon.

The time has come. The New Year is upon us and there'll be no escape from the relentless comparisons between the space-faring future world of Stanley Kubrick's 2001: A Space Odyssey, and our measly earthbound life in the real year 2001. I take a different view. Even though we've got no lunar bases and we haven't sent hibernating astronauts to Jupiter in outsized space ships, I think we have done quite well for ourselves.

People sometimes wax nostalgic over the Golden Age of space exploration: the Mercury, Gemini, and Apollo programs led to the first moon landing in 1969. No doubt those were special times and special moments, but are they more special than the events of today? The greatest obstacle to the human exploration of space, apart from funding and other earthly political factors, is surviving biologically hostile environments. We need to engineer a version of ourselves, an emissary who can somehow withstand the extremes of temperature, the high-energy radiation, and the meager air supply, yet still conduct a full round of scientific experiments.

We've already invented such things.

They are called robots, and they conduct all of our interplanetary exploration. You don't have to feed robots. They don't need life support. And they won't get upset if you don't bring them back. Our current ensemble of space robots includes probes that are, at this moment, monitoring the Sun, orbiting Mars, intercepting a comet's tail, orbiting an asteroid, orbiting Jupiter, and on their way to Saturn. Four of our earlier space probes were launched with enough energy and with the right trajectory to escape the solar system altogether, each one carrying encoded information about humans for the intelligent aliens who might recover the hardware. And NASA is now soliciting proposals from the scientific community for the first robotic mission to Pluto.

We have compelling evidence for the existence of barely frozen water on Mars and of liquid water deep within Jupiter's moon Europa. These worlds hold tantalizing prospects for the past or present existence of non-Earth-based life. This news was, of course, beamed to us by semi-intelligent, robotic probes endowed by humans with the capacity to ask and answer many of the questions that humans would ask were we the ones making the trip. We also maintain, at any moment, hundreds of communication satellites as well as a dozen space-based telescopes that see the universe in bands of light from infrared through gamma rays. One of these pass bands, the microwaves, allows us to see evidence for the Big Bang, coming from the edge of the observable universe.

Just because we have no interplanetary colonies, or other unrealized dreamscapes, it doesn't mean that our presence in space has not in fact grown exponentially. We should not measure our space-faring era by where footprints have been laid. Nor should we measure it by how many people deify our astronauts or follow the progress of our launches. We should measure our era by how many people take no notice at all. A legacy rises to become culture only when its elements are so common that they no longer attract comment-not because people have lost interest, but because people cannot imagine a world without them.

As for the real year 2001: apart from our flocks of robotic probes, we have a silent ballet of hardware in the heavens. The International Space Station is under construction, just like the one portrayed in 2001 the movie, and it will never know a day without an astronaut on board-our human presence in space is now permanent. The Space Station is being assembled with parts delivered by reusable, docking space shuttles, each of which say NASA on the side panels instead of Pan Am. Further similarities include zero-G flush toilets with complicated instructions, and the platters of unappealing astronaut food.

As far as I can tell, the only thing Kubrick's movie has that we don't have is Johann Strauss's Blue Danube Waltz filling the vacuum of space and a homicidal mainframe named HAL.

For most of the 20th century, the United States was the envy of the world in nearly every economic sector driven by science and engineering, especially aerospace. As we coast today on investments made by generations that came before us, the technological and economic strength we take for granted is in grave jeopardy.

It's time for the United States to shape a bold vision for the industry. A vision that will excite generations to come. A vision of space exploration that views the solar system as our backyard, the Milky Way galaxy as our neighborhood, and the universe as our hometown.

Unfortuanely, discovery and exploration have never driven the funding of expensive projects, even if our sanitized memories tell us so, and even if the people doing the discoveries are themselves, discoverers. Instead, we need to do this as a vital investment in our economic strength and ultimately in our capacity to defend ourselves against enemies known and unforeseen.

Just weeks after the Soviet Union's Yuri Gagarin became the first person to orbit Earth in 1961, President Kennedy addressed a joint session of Congress and uttered words that still resonate today:

I believe that this nation should commit itself to achieving the goal, before the decade is out, of landing a man on the moon and returning him safely to the Earth.

But few people remember the sentence that followed, which was a powerful appeal to defeat communism:

If we are to win the battle that is now going on around the world between freedom and tyranny, the dramatic achievements in space which occurred in recent weeks should have made clear to us all, as did Sputnik in 1957, the impact of this adventure on the minds of men everywhere.

This was not, of course, the first time that significant monies were spent on military programs. But a review of projects that garner an uncommonly large fraction of a nation's gross domestic product demonstrates that only three drivers have been sufficient to create them: defense (e.g. Great Wall of China, Manhattan Project, Apollo Project), the promise of economic return (e.g. Columbus Voyages, Magellan Voyages, Tennessee Valley Authority), and praise of power (e.g. Pyramids, Cathedrals, Versailles).

Kennedy knew that while bravery may win battles, science and technology provide security. Science and technology win wars. What's clear today is that without such investments, the United States will fade in prosperity and our descendents will reflect fondly on a time passed when America shined in the timeline of civilization.

As a scientist and educator, I cannot inspire a classroom of 8th graders to become aerospace engineers if all I can promise them is a job designing airplanes or rockets that are slightly faster or slightly more fuel efficient than the ones of their parents' generation.

We need a mission plan where our curiosity guides our destinations. We need to share dreams worthy of a nation's commitment yet worthy of a child’s capacity to imagine. And we know of no subject with greater power to achieve these goals than the prospect of reaching for the stars.

Only in space is the sky not the limit. It's America’s choice.

In ancient days two aviators procured to themselves wings. Daedalus flew safely through the middle air, and was duly honoured in his landing. Icarus soared upwards to the sun till the wax melted which bound his wings and his flight ended in a fiasco. In weighing their achievements perhaps there is something to be said for Icarus. The classic authorities tell us, of course, that he was only 'doing a stunt'; but I prefer to think of him as the man who brought to light a serious constructional defect in the flying-machines of his day [and] we may at least hope to learn from his journey some hints to build a better machine.

Sir Arthur Eddington, astrophysicist
Stars & Atoms (1927)

For millennia the idea of being able to fly preoccupied human dreams and fantasies. Waddling around on Earth's surface as majestic birds flew overhead, perhaps we developed a form of wing-envy. One might even call it wing worship. You needn't look far. The United States adopted a flying predator as a symbol of its strength—the bald eagle appears on the back of the dollar bill, the quarter, the Kennedy half dollar, the Susan B. Anthony dollar, and the Eisenhower dollar. There's also one on the floor of the Oval Office in the White House. Our most famous superhero, Superman, can fly, upon donning blue panty hose and a red cape. When you die, if you qualify, you might just become an angel—and everybody knows that angels (at least those with wings) can fly. Then there is Peter Pan and his fairy sidekick Tinkerbell, the winged horse Pegasus, the wing-footed Mercury, and the aerodynamically unlikely Cupid. And for most of the history of broadcast television in America, when a station signed off for the night, it didn't show somebody walking erect and bidding farewell, it instead would play the Star Spangled Banner and show things that fly, like soaring bald eagles or some Air Force jets whooshing by.

In textbook comparisons of human biological features to those of other species in the animal kingdom, our inability to fly often goes unmentioned, although we are quick to use the word flightless as a synonym for hapless. Birds such as the ostrich, the kiwi, and the penguin tend to find themselves at the wrong end of evolutionary jokes told by humans. In our own defense, we ultimately learned to fly due to the technological ingenuity of our human brains. And of course, while birds can fly, they are stuck with bird brains. But this self-aggrandizing line of reasoning is somewhat flawed because it ignores the thousands of years that preceded the twentieth century, when we had not yet figured out how to fly and thus could not have make such a comparison.

I remember as a student in junior high school reading an essay, published near the turn of the nineteenth century, that argued the impossibility of flight by any device that was heavier than air. This was clearly a myopic prediction, but one didn't have waited for the first airplanes to be invented to refute premise of the essay. One only needed to look at birds, which have no trouble flying and, last I checked, are all heavier than air. If something is not forbidden by the laws of physics then it is, in principle, technologically possible, regardless of the limits of your foresight. The speed of sound though air falls anywhere from 700 to 800 miles per hour, depending on the atmospheric temperature. There's no law of physics that prevents objects from going faster than Mach 1, the speed of sound. But before the sound barrier was broken in 1947 by the Major Charles E. (Chuck) Yeager piloting the Bell XS-1 (a U.S. Army rocket plane) there was much claptrap written about the impossibility of objects moving faster than the speed of sound. Meanwhile, bullets fired by high-powered rifles had been breaking the sound barrier for over a century. And the crack of a whip, or the sound of snapping somebody's rear end with a wet towel in the locker room is the mini sonic boom created by the tiny tips moving though the air faster than the speed of sound. Any limits to breaking the sound barrier were purely psychological and technological.

The fastest winged aircraft is incontestably the Space Shuttle, which, when emerging from orbit, slows down from speeds in excess of Mach 20. When I now tell you that you can never travel faster than the speed of light, I speak not from a naiveté about technology's future. I speak from a platform built from the universal laws of physics. The Apollo astronauts who went to the Moon are credited attaining with the fastest speeds at which humans have ever flown: about seven miles per second at the end of the rocket burn that lifted their craft beyond Earth's orbit. This is a paltry 1/250th of one percent of the speed of light. Actually, the real problem is not the moat that separates these two speeds but the laws of physics that prevent any physical object from ever achieving the speed of light, no matter how inventive your technology. The sound barrier and the light barrier are not equivalent limits on invention.

The Wright Brothers of Ohio are, of course, generally credited with being first in flight, as North Carolina's automobile license plate slogan is quick to remind you. But this claim needs to be further delineated. Wilbur and Orville Wright were the first to fly a heavier-than-air, engine-powered vehicle that carried a human being—Orville, in this case—and that did not land at a lower elevation than its takeoff point. Previously, people had flown in balloon gondolas, in gliders, and had executed controlled descents from cliffsides, but none of these efforts would make a bird jealous. Actually, Wilbur and Orville's first trip would not have turned bird-heads either. At 10:35 AM eastern time, on December 17, 1903, the first of their four flights on that historic day lasted 12 seconds, at an average ground speed of 6.8 miles per hour, against an air speed of 30 miles per hour.

The Wright Flyer, as it was called, had traveled 120 feet, a little more than length of one wing on a Boeing 747 jumbo jet. Surprisingly, even after the Wright brother's achievement was widely known, the media took little notice of this and other aviation firsts. As late at 1933, H. Gordon Garbedian ignored airplanes in the otherwise-prescient introduction to his book Major Mysteries of Science:

Present day life is dominated by science as never before. You pick up a telephone and within a few minutes you are talking with a friend in Paris. You can travel under sea in a submarine, or circumnavigate the globe by air in a Zeppelin. The radio carries your voice to all parts of the earth with the speed of light. Soon, television will enable you to see the world's greatest spectacles as you sit in the comfort of your living room.

But some journalists did pay attention to the way flight might change civilization. After the Frenchman Louis Bleriot crossed the English Channel from Calais to Dover on July 25, 1909, an article on page three of the New York Times, was headlined Frenchman Proves Aeroplane No Toy. The article went on to observe England's reaction to the event:

Editorials in the London Newspapers buzzed about the new world where Great Britain's insular strength is no longer unchallenged; that the aeroplane is not a toy but a possible instrument of warfare, which must be taken into account by soldiers and statesmen, and that it was the one thing needed to wake up the English people to the importance of the science of aviation.

The guy was right. Thirty-five years later, not only had airplanes been used as fighters and bombers in warfare, the Germans took the concept a notch further and invented the V2 which wreaked havoc on London in 1943. This vehicle was significant in many ways. First, it was not an airplane, it was an unprecedentedly large missile. Second, it was launched like a rocket from five hundred miles away in Germany. Third, its modern-looking, pointy, bullet-shaped body with large fins at the base influenced an entire generation of images in science fiction stories of space travel. And lastly, for its entire airborne journey after launch, it moved under the influence of gravity alone. In other words, it was a sub-orbital ballistic missile, the fastest way to deliver a bomb from one location on Earth to another. Cold War advances on the design of ballistic missiles enabled cities halfway around the world to be targeted. The flight time? About a half an hour.

Colloquial usage of the term notwithstanding, if something goes ballistic, its trajectory is simply no longer controlled by rockets or fins or wings. Where it goes (and where it lands) is controlled by the laws of gravity alone, although fins can add stability to its flight. All falling objects, all satellites (including the Hubble Space Telescope), and all interplanetary spacecraft go ballistic after they are launched.

While we can say they're traveling ballistically, do we have the right to declare missiles to be flying? Are falling objects in flight? Is Earth flying in orbit around the Sun? By Wright Brothers' rules, a person must be on board the craft and it must move under its own power. But there is no rule that says we cannot change the rules. If flight includes space travel, then the sky is the limit. Knowing that orbital technology was within reach with the V2 rocket, people were getting impatient. An article dated 22 March 1952, and titled What Are We Waiting For? was written by the editors of Collier's Magazine, a popular, family-oriented magazine that especially flourished in the post war period. The article was conceived and written after two Collier's journalists had visited New York City's Hayden Planetarium on Columbus Day of 1951 for a seminal Space Travel Symposium, attended by engineers, scientists, and visionaries. The Collier's editors commented on the need and value of a space station serving as a watchful eye over a divided world:

In the hands of the West a space station, permanently established beyond the atmosphere, would be the greatest hope for peace the world has ever known. No nation could undertake preparations for war without the certain knowledge that it was being observed by the ever-watching eyes aboard the sentinel in space. It would be the end of the Iron Curtains wherever they might be.

We didn't build a space station, but we went to the Moon. In this effort, human bird-worship continued. Never mind that on the Moon, where there is no air and where wings are completely useless, our astronauts landed in a spacecraft named after a bird. A mere 65 years, 7 months, 3 days, 5 hours, and 43 minutes after Orville left the ground, Neil Armstrong gave his first statement from the Moon's surface, Houston, Tranquillity Base here. The Eagle has landed.

The human record for altitude does not go to anybody for having walked on the Moon. It goes to the astronauts of the ill-fated Apollo 13. Knowing they could not land on the Moon after the explosion in their oxygen tank, knowing that they did not have enough fuel to just stop, turn around, and head back, they executed a single figure '8' ballistic trajectory around the Moon, which swung them back towards Earth. But the Moon just happened to be near apogee, its farthest point from Earth in its oval-shaped elliptical orbit. No other Apollo mission (before or after) went to the Moon during apogee, which granted the Apollo 13 astronauts the human altitude record. When I calculated that they must have reached about 245,000 miles above Earth's surface, including the orbital distance from the Moon's surface, I asked Apollo 13 commander Jim Lovell, when he was visiting the Museum recently, Who was on the far side of the command module as it rounded the Moon? That single person would hold the altitude record. He refused to tell.

In my opinion, the crowning achievement of flight was not Wilbur and Orville's airplane, nor Chuck Yeager's breaking of the sound barrier, nor the Apollo 11 lunar landing. For me, it was the launch of Voyager 2 , which ballistically toured the solar system's outer planets. During the flybys, its slingshot trajectories stole some of Jupiter and Saturn's orbital energy for its rapid exit from the solar system. Upon passing Jupiter in 1979, Voyager's speed exceeded 40,000 miles per hour, sufficient to escape the gravitational attraction of the Sun. Voyager passed the orbit of Pluto in 1993, entering the realm of interstellar space. Nobody happens to be on board the craft, but it does contain a gold phonograph record attached to its side and etched with the earthly sounds of, among many things, the human heartbeat. So with our heart, if not our souls, we continue to fly farther and faster than ever before.

From listening to space enthusiasts talk about space travel, or from watching blockbuster science fiction movies, you might think that sending people to the stars is inevitable and will happen soon. Reality check: It's not and it won't —the fantasy far outstrips the facts.

A line of reasoning among those who are unwittingly wishful might be, We invented flight when nobody thought it was possible. A mere sixty-five years later, we went to the Moon. It's high time we journeyed among the stars. The people who say it isn't possible are ignoring history.

My rebuttal is borrowed from a legal disclaimer of the investment industry: Past performance is not an indicator of future returns. Analysis of the problem leads to a crucial question: What does it take to pry money and labor from a population to pay for major initiatives? A study of the world's famously funded projects across time and place reveals three common drivers: praise of person or deity, economics, and war. Some expensive investments in praise include the Great Pyramids, the Taj Mahal, and plush cathedrals. Some expensive projects launched in the hope of economic return include Columbus's voyage to the new world, Magellan's round-the-world voyage, and Marco Polo's voyage to the Far East. Expensive projects with military or defense incentives include the Great Wall of China, which helped to keep the Mongols out of China, the Manhattan Project, which designed and built the first atomic bomb, and the Apollo Project, which vaulted the United States past our Soviet enemies in the race for superiority in space.

During the 1960s, the prevailing rationale for space travel presented to children was that we were going to the Moon because humans are innate explorers—and that space was America's next frontier. When President Kennedy's addressed a joint session of Congress on 25 May 1961, in what many consider to be his second inaugural address, he waxed eloquently about the need for Americans to explore the Moon, including the famous lines:

I believe that this nation should commit itself to achieving the goal, before the decade is out, of landing a man on the moon and returning him safely to the earth. No single space project in this period will be more impressive to mankind, or more important for the long-range exploration of space; and none will be so difficult or expensive to accomplish.

This statement alone confused me (when I grew old enough to care about politics and be confused by it) because I knew that nearly every astronaut in the space program was drawn from the military, yet our voyage to the Moon was hardly ever mentioned in the same breath as the Soviet Union or the Cold War. Only later in Kennedy's speech do you hear him take a military posture, triggered by the successful launch of Cosmonaut Yuri Gagarin into Earth orbit, but this portion is hardly ever replayed:

If we are to win the battle that is now going on around the world between freedom and tyranny, the dramatic achievements in space which occurred in recent weeks should have made clear to us all, as did Sputnik in 1957, the impact of this adventure on the minds of men everywhere who are attempting to make a determination of which road they should take.

Had the political landscape been different, Americans (Congress in particular) would have been loath to part with the two-hundred billion dollars that accomplished the task. In spite of such rhetoric, the debates that followed on the floor of Congress certainly demonstrated that funding for Apollo was not a foregone conclusion.

Still, once liquid fuel rockets had been invented by Robert Goddard in 1926, enabling flight without the lift provided by air moving over a wing, a trip through the vacuum of space to the Moon was in sight even if the idea was technologically distant—it was just a matter of time. Goddard, himself, realized that a trip to the Moon was finally possible but that it might be prohibitively expensive; It might cost a million dollars he mused naively.

Calculations that were possible the day after Isaac Newton introduced his universal law of gravitation show that the most efficient trip to the Moon would be in a craft escaping Earth's atmosphere at a speed of seven miles per second and coasting all the way. Such a trip takes about a day and a half. Such a trip has been taken only nine times—between 1968 and 1972. Otherwise, when NASA sends astronauts into space they launch a crew into orbit a few hundred miles above our 8,000-mile-diameter Earth. Space travel this isn't. If you had told John Glenn after his historic three orbits and successful splashdown in 1962, that in 37 years NASA was going to send him into space once again, you can bet the last place he would have imagined going is back into Earth orbit.

What seems to be the trouble with space travel?

Let's start with money. If we can send somebody to Mars for less than a hundred billion dollars then I say let's go for it. But I have a friendly bet with Louis Friedman, a fellow Board member and the Executive Director of The Planetary Society (a membership funded-organization founded by the late Carl Sagan and others to promote the peaceful exploration of space) that we are not going to Mars any time soon. More specifically, I bet him that there will be no funded plan in place by any government to send one or more people to Mars before the year 2005. I hope I am wrong. But I will only be wrong if the cost of modern missions is brought down considerably compared with those of the past. Below is a note on NASA's legendary spending habits forwarded to me from a Russian colleague.

The Astronaut Pen

During the heat of the space race in the 1960s, the U.S. National Aeronautics and Space Administration [NASA] decided it needed a ball point pen to write in the zero gravity confines of its space capsules. After considerable research and development, the Astronaut Pen was developed at a cost of approximately $1 million U.S. The pen worked and also enjoyed some modest success as a novelty item back here on earth. The Soviet Union, faced with the same problem, used a pencil.

Unless we have a reprise of the socio-political circumstances that dislodged two hundred billion dollars for space travel from taxpayers' wallets in the 1960s, my reading of history leaves me unconvinced that we will ever send Homo sapiens anywhere outside of Earth orbit. I quote a Princeton colleague J. Richard Gott, from a panel discussion held few years ago at the Hayden Planetarium that touched upon the health of the manned space program: In 1969, [space flight pioneer] Werner von Braun had a plan to send astronauts to Mars by 1982. It didn't happen. In 1989, President Bush promised that we would send astronauts to Mars by the year 2019. This is not a good sign. It looks like Mars is getting farther away! To this I add that as we approach the millennium, the only correct prediction from the 1968 sci-fi classic 2001: A Space Odyssey is that things can go wrong.

Space is vast and empty beyond all earthly measure. When Hollywood shows a starship cruising through the galaxy, they typically indicate this fact with points of light (stars) drifting past at a rate of one or two per second. The distance between stars in the galaxy is so vast, that for these ships to move as indicated would require speeds up to five-hundred-million times faster than the speed of light.

The Moon is far when compared with where you might go in a jet airplane, but it sits at the tip of our noses compared with anything else in the universe. If the Earth were the size of a basketball, the Moon would be the size of a softball some ten paces away—the farthest we have ever sent people into space. On this scale, Mars (at its closest) is a mile away. Pluto is 100 miles away. And the nearest star to the Sun is a half million miles away.

Let's assume money is no object. In this pretend-future, our noble quest to discover new places and uncover scientific truths has become as effective as war at drumming up funds. If a spaceship managed to sustain Earth's escape speed of seven miles per second, a trip to the nearest star would last a long-and-boring 100,000 years. Too long, you say? Energy increases as the square of your speed, if you want to double your speed you must invest four times as much energy. A tripling of your speed requires nine times as much energy. No problem. Let's just assemble some clever engineers who will build us a space ship that can summon as much energy as we want.

How about a spaceship that travels as fast as Helios B, the U.S.-German solar probe that was the fastest-ever unmanned space probe. Launched in 1976, it was clocked at nearly 42 miles per second (150,000 miles per hour) as it accelerated toward the Sun. (Note that this is only one-fiftieth of one percent of the speed of light.) This craft would cut the travel time to the nearest star down to a mere 15,000 years—three times the length of human recorded history.

What we really want is a spaceship that can travel near the speed of light. How, about ninety-nine percent the speed of light? All you would need is seven hundred million times the energy that thrust the Apollo astronauts on their way to the Moon. Actually, that's what you would need if the universe were not described by Einstein's special theory of relativity. As predicted by Einstein, however, while your speed increases, so too does your mass, which forces you to spend even more energy than previously figured to accelerate your space ship near the speed of light. A back-of-the-envelope calculation shows that you would need at least ten billion times as much energy used for our Moon voyages.

No problem. These are very clever engineers. But now we learn that the nearest star that is known to have planets is not Proxima Centauri, the nearest star, but one that is about fifteen light-years away. While traveling ninety-nine percent of the speed of light, Einstein's special relativity shows that you will age at only ten percent the pace of everybody back on Earth, so the round trip for you will last not thirty years, but about three. On Earth, however, thirty years actually does pass by and everybody has forgotten about you.

The distance to the Moon is ten-million times farther than the distance flown by the original Wright Flyer of the Wright brothers. But the Wright Brothers were two guys with a garage. Apollo 11, the first moon landing, was two guys with two hundred billion dollars and ten thousand scientists and engineers and the mandate of a beloved, assassinated president. These are not comparable achievements. The cost and effort of space travel is a consequence of the fact that space is supremely hostile to life. You might think that the early explorers had it bad too. Consider the Gonzalo Pizarro's 1540 expedition from Quito east across Peru in search of the fabled land of Oriental Spices. In the William H. Prescott account of this ill-fated adventure in the classic History of the Conquest of Peru, the oppressive terrain and the hostile natives ultimately led to the death of half his expedition party of more than 4,000. Prescott describes the state of the expedition party a year into the journey:

At every step of their way, they were obliged to hew open a passage with their axes, while their garments, rotting from the effects of the drenching rains to which they had been exposed, caught in every bush and bramble, and hung about them in shreds. Their provisions spoiled by the weather, had long since failed, and the live stock which they had taken with them had either been consumed or made their escape in the woods and mountain passes. They had set out with nearly a thousand dogs, many of them of the ferocious breed used in hunting down the unfortunate natives. These they now gladly killed, but their miserable carcasses burnished a lean banquet for the famished travelers.

What happens next has no meaningful counterpart in space travel. On the brink of abandoning all hope, Pizarro and his men build from scratch a boat large enough to take half the remaining men, the weakest half, along the Napo river in search of food and supplies. Prescott describes the construction:

The forests furnished him with timber; the shoes of the horses which had died on the road or had been slaughtered for food, were converted into nails; gum distilled from the trees took the place of pitch; and the tattered garments of the soldiers supplied a substitute for oakum...At the end of two months, a brigantine was completed, rudely put together, but strong and of sufficient burden to carry half the company.

Pizarro transferred command of the makeshift boat to Francisco de Orellana, a cavalier from Truxillo while he stayed behind to wait. After weeks of no return, Pizarro gives up on Orellana and returns to the town of Quito, taking yet another year for the journey. Pizarro later learns that Orellana successfully navigated his boat down the Napo River to the Amazon, and with no intent on returning for Pizarro, continued along the Amazon until he emerged in the Atlantic. Orellana and his men then sail their way to Cuba, where they subsequently find safe transport back to Spain.

There is a profound lesson in this story, first called to my attention by Steve Napear, Deputy Director of the San Diego Supercomputing Center. When nearly all hope was lost, the members of the expedition built a boat, exited the continent along the Amazon, and traveled back to Spain via Cuba. Suppose one of our spacecraft with a ship-load of astronauts crash-lands on a distant hostile planet—the astronauts survive, but the spacecraft is totaled. Hostile planets tend to be considerably more oppressive than hostile natives. The planet might not have air. And if it does have air, the air may be poisonous. And if the air is not poisonous, then the atmospheric pressure may be one hundred times higher than on Earth. If the air is fine, then the planet may be at 200 degrees below zero. Or 500 degrees above zero. None of these conditions bode well for our astronaut explorers, but perhaps they can survive for a while on their reserve life-support system. In the spirit of our sixteenth-century Spanish explorers, all they would need to do is mine the planet for raw materials and build another spacecraft from scratch, along with its controlling computers (using whatever spare parts are musterable from the crash site.) They would also need to build a factory that manufactures rocket fuel. When finished, they would simply launch themselves back into space and fly back home.

I needn't dwell on the absurdity of this scenario.

Perhaps what we really need is a genetically engineered life form that can survive the stress of space and still conduct scientific experiments. Actually, such life forms have already been engineered. They are called robots. You don't have to feed them . They don't need life support. And most important, they won't get upset if you don't bring them back. People, however, generally want to breathe, eat, and eventually come home.

It's probably true that no city has ever held a ticker-tape parade for a robot. But it's probably also true that no city has ever held a ticker-tape parade for an astronaut who was not the first to do something or go somewhere. Can you name the two Apollo 16 astronauts who walked on the Moon? Probably not. It was the second-to-last moon mission. But I'd bet you have a favorite picture of the cosmos taken by the orbiting robot known as the Hubble Space Telescope. I'd bet you remember the images from the Mars robotic lander Pathfinder and its deployed rover Sojourner, which went six-wheeling across the Martian terrain. I'd further bet that you remember the Voyager images of the Jovian planets and their zoo of moons from the early 1980s.

In the absence of a few hundred billion dollars in travel money, and in the presence of the hostile cosmic conditions, what we need is not wishful thinking and science-fiction rhetoric inspired by a shallow reading of the history of exploration. What we need, and must wait for, is a breakthrough in our scientific understanding of the structure of the universe so that we might exploit such shortcuts through the space-time continuum as worm holes that connect one part of the cosmos to another. Then, once again, reality will become stranger than fiction.