America’s human spaceflight program is adrift. The space shuttle has made its final flight, and the Obama administration has no coherent plan what to do next. Instead, it has proposed that the United States waste the next decade spending $100 billion to support a goalless human spaceflight effort that goes nowhere and accomplishes nothing. In the face of a mounting imperative to find ways to cut the federal deficit, this has set up the nation’s space program for the ax.

In order for NASA’s human-exploration effort to be defensible, it needs a concrete goal and one that is truly worth pursuing. That goal should be sending humans to Mars.

As a result of a string of successful probes sent to the Red Planet over the past 15 years, we know for certain that Mars was once a warm and wet planet and continued to have an active hydrosphere for a period on the order of a billion years – a span five times as long as the time it took for life to appear on Earth after there was liquid water here. Findings released by NASA last week indicate that underground water seeps are reaching the surface of the Red Planet periodically. Thus, if the theory is correct that life is a natural phenomenon emerging from chemistry wherever there is liquid water, various minerals and a sufficient period of time, life must have appeared on Mars and may still be there.

If we go to Mars and find fossils of past life on its surface, we will have good reason to believe we are not alone in the universe. If we send human explorers, who can erect drilling rigs that can reach underground water where Martian life may well persist, we will be able to examine it. By doing so, we will be able to determine whether life on Earth is the pattern for all life everywhere or, alternatively, whether we are simply one esoteric example of a far vaster and more interesting tapestry. These things truly are worth finding out.

Furthermore, Mars is a bracing positive challenge that our society needs. Nations, like people, thrive on challenge and decay without it. A humans-to-Mars program would be an invitation to adventure to every young person in the country, sending out the powerful clarion call: “Learn your science, and you can take part in pioneering a new world.” In return for such a challenge, we would get millions of young scientists, engineers, inventors and medical researchers, making technological innovations that create new industries, find new cures, strengthen national defense and increase national income to an extent that utterly dwarfs the expenditures of the Mars program.

But the most important reason to go to Mars is the doorway it opens to the future. Uniquely among the extraterrestrial bodies of the inner solar system, Mars is endowed with all the resources needed to support not only life, but the development of a technological civilization. For our generation and those that will follow, Mars is the New World. We should not shun its challenge.

We’re ready. Despite its greater distance, we are much better prepared today to send humans to Mars than we were to send men to the moon in 1961, when President Kennedy started the Apollo program – and we were there eight years later. Contrary to those seeking indefinite delay of any commitment, future-fantasy spaceships are not needed to send humans to Mars. The primary real requirement is a heavy-lift booster with a capability similar to that of the Saturn V launch vehicle employed in the 1960s. This is something we fully understand how to create.

The issue is not money. The issue is leadership. NASA’s average Apollo-era (1961-73) budget, adjusted for inflation, was about $19 billion a year in today’s dollars, just 5 percent more than the agency’s current budget. Yet the NASA of the ‘60s accomplished 100 times more because it had a mission with a deadline and was forced to develop an efficient plan to achieve that mission. If NASA were given that kind of direction, we could have humans on Mars within a decade. If not, as the rudderless agency continues to drift into the coming fiscal tsunami, we may soon end up with no human spaceflight program.

Some may say, why not just let it sink? Aren’t there more vital things to salvage from the budget shipwreck? Such thoughts, however, would be wrong. The government fiscal catastrophe was not caused by NASA but by an administration with no interest in it. Acceptance of the destruction of the space program simply amounts to acceptance of American decline. For all its flaws, NASA is one of the ornaments of our age. The United States comprises 4 percent of the world’s population yet has been responsible for 100 percent of the people who have walked on the moon, 100 percent of the rovers that have wheeled on Mars and 100 percent of the probes that have visited Jupiter, Saturn, Uranus or Neptune. Our time will be remembered because this is when humankind first set sail for other worlds. Our nation should be remembered as the people who opened the way.

With the final space shuttle mission scheduled to end this morning when Atlantis glides to earth, and with only uncertainty to follow for NASA’s manned spaceflight program, this may seem like the moment to weep for the lost promise of the space age.

It is not. I have shed tears of wonder and awe at the scale and achievement of NASA’s manned spaceflight program, but not for its inexorable end. The close of this phase of space exploration is long overdue. And what appears to be an epic conclusion is, like much of NASA’s history, an elegant mirage.

In 2005 and 2006, I regularly took a long, slow bus ride from the National Air and Space Museum in Washington, D.C., where I was a research fellow, to the warehouse where the Smithsonian stores its Apollo spacesuits. Dry-cleaned by NASA after their return to earth and meticulously preserved since, the suits remain stained, indelibly, with gray-black moon dust. Their surface, a wrinkled study in chiaroscuro, seems alive.

One day, as I rode back to Washington, I saw the full moon rise into view. Preoccupied with earthly concerns, I was startled to tears by the vertigo of having spent the day with those moon-stained spacesuits, objects in human shape that had touched heaven and returned.

Mine were not the shining tears of Walter Cronkite, unforgettably captured on television on July 20, 1969, as Neil Armstrong and Buzz Aldrin landed on the moon. But he and I must have felt that same marvelous mixture of delight and awe, terror and relief, at the scale of human achievement and the shift in history that hinged on a footstep.

We easily forget, however, that the heroic venture had one essential justification: life-and-death geopolitics. In the hot center of the cold war, statecraft was also space-borne stagecraft. After the Soviet Union launched Yuri Gagarin into outer space in 1961, President John F. Kennedy asked Vice President Lyndon B. Johnson: “Is there any other space program which promises dramatic results in which we could win?” Johnson’s advisers in recommending a moon landing included not only scientists but also Frank Stanton, the president of CBS.

Props and costumes mattered in this theater of war. That NASA’s equipment should be painted white, and feature no military shields or corporate brands but only “USA,” “NASA” and the flag, was a deliberate decision by President Dwight D. Eisenhower. Yet American rockets were nevertheless cobbled together from instruments of war, their craftsmen drawn from the same network of systems engineers that was devised to manage the arms race and its doomsday scenarios. Our first astronauts went to space hunched into an improvised capsule atop ICBM’s, squatting in place of warheads. The brilliance with which the resulting achievements shone was — like a diamond’s — the result of terrible pressure. We should be glad that this era is past.

But if the dazzling image of midcentury spaceflight obscures its dark origins, close scrutiny of the Apollo spacesuit reveals a different and more robust approach to innovation — one that should inspire us at this uncertain moment in space exploration.

Early in the Apollo program, the conventional wisdom was that the spacesuits would be like the rockets: adamantine, metallic, armored and smooth. But repeatedly, prototypes of such suits failed under pressure. In the end, the Apollo spacesuit was made in a more unassuming fashion: needle-sewn by seamstresses taken from the shop floor of Playtex, the bra and girdle company.

The suit was stitched together from 21 layers of different materials as varied as Teflon and Lycra. Each solved a specific problem — from durability (the white fiberglass exterior) to restraining the balloonlike pressure bladder against the astronaut’s body (brassiere-grade nylon). The suit was a literal patchwork of improvisations and adaptations, the kind of invention that typically takes place in the garage, not the lab. Indeed, the suit’s head engineer, Leonard Sheperd, was a former television repairman from Queens who was recruited to Playtex after he artfully fixed the television set of the company’s founder, Abram Spanel.

The success of this “soft” approach — ad hoc, individualistic, pragmatic — should be a lesson to us. The institutional culture and mismanaged expectations of the space shuttle program have contributed, not once but twice, to the destruction of craft and crew. It was not a mere faulty O-ring or insulation fragment that threatened the Challenger and Columbia; it was, as the presidential commission that investigated the Challenger disaster concluded, a tragic disconnect between NASA’s bureaucracy and the real-world complexities of engineering for space. “For a successful technology,” the physicist Richard Feynman wrote in his appendix to the commission’s report, “reality must take precedence over public relations, for nature cannot be fooled.”

Despite the shuttle’s extraordinary achievements, it came to illustrate how ill-suited the military-industrial enterprise is to the only enduring rationales for manned spaceflight: heroism, pure delight and the essential expansion of human possibility.

As entrepreneurial endeavors like SpaceX and Virgin Galactic arise to fill our new gap in manned spacecraft, we have reason to be optimistic. In the same farewell address in which he cautioned against the undue influence of “the military-industrial complex,” Eisenhower also issued a second, less-remembered warning, against the related prospect of a world in which a “government contract becomes virtually a substitute for intellectual curiosity.”

Such curiosity and its astonishing consequences, as exemplified by the Apollo spacesuit, is likely to flourish more richly outside the organizational constraints and corporate shell of post-Apollo NASA. And so will continue to inspire us all.

Fifty years ago Tuesday, an obscure Soviet Air Force lieutenant named Yuri Gagarin climbed onboard an eminently conventional form of transport — a converted city bus — and headed toward another order of vehicle altogether: a towering rocket, on top of which was mounted a gleaming spherical Vostok capsule encased in a pointed fairing.

According to Soviet media, upon exiting at the launch pad Gagarin made a spontaneous speech stuffed with patriotic fervor. Except it didn’t happen: His ghost-written oration had been taped in Moscow weeks earlier and only broadcast later that day. What he really did was order the driver to stop on its way to the pad, exit, and relieve himself on the rear tire. This action has since been repeated by most of the hundreds of crews launched from the Baikonur Cosmodrome. In fact it’s considered bad luck — even bad manners — not to.

Two decades before Tom Wolfe coined the phrase, Gagarin clearly had an irrevocable case of Right Stuff. Ensconced in his cramped capsule, he was informed, only 20 minutes before launch, that his pulse rate was a calm 64. “Roger. That means my heart’s beating,” he responded.

His sense of humor weathered the thunderous ride to orbit as well, when up to five G’s of pressure shoved him deep into his seat, distorting his face into a sagging mask. Asked anxiously by the chief designer of the spacecraft, Sergei Korolev, how he felt, Gagarin laconically replied, “I feel fine. How about you?”

In fact pre-launch jitters had caused Korolev to swallow a dose of tranquilizers, which reportedly failed to prevent him from shaking visibly during much of Gagarin’s ride. Korolev’s agitation was understandable — half of the early R-7 rocket had failed during unmanned test flights, making Russian roulette a far safer activity.

But if Korolev’s pills didn’t work, his rocket did, and a euphoric Gagarin became the first person ever to witness the ravishing sight of the Earth from space: “It’s beautiful! What beauty!”

The Gagarin anniversary, and the retirement of the U.S. Space Shuttle this year after three decades spent reconnoitering low Earth orbit, bring the first great chapter of space flight to an end. So where do we stand a half century after Gagarin’s rocket ride? Are things “beautiful”?

The short answer is no — even if on the face of it, there are good reasons for satisfaction.

The space race triggered by early Soviet successes quickly led to the U.S. Apollo program and six triumphant Moon landings by American astronauts. Subsequent U.S. and Soviet space stations, most notably the giant American Skylab station and the Soviet Mir station, were ultimately replaced by the single most complex collective space engineering project ever attempted: the International Space Station.

Scheduled for completion this year, staffed by rotating mixed crews of American, Russian, European and Japanese astronauts, it’s also among the most expensive such project, clocking in at roughly $150 billion — a figure comparable to that of Apollo, only without a destination or truly convincing rationale.

And therein lies the rub. No matter how courageously, vigorously and skillfully human beings have worked in low Earth orbit since the return of the last Moon mission in 1972, through no fault of their own they’ve simply not been mandated to go anywhere new. The shuttle and the International Space Station, after all, both fly at altitudes lower than those achieved by the comparatively primitive two-man Gemini capsules of the mid-60’s. Let alone the Moon.

It’s hard to characterize such missions as exploration. In fact, most reasons for satisfaction in our progress in space lie in the achievements of a different kind of pioneer. Real space exploration since 1972 has been blazed by successive generations of spindly, elegantly machined, cost-efficient robotic spacecraft.

Possessing a different kind of stuff than Yuri Gagarin or Neil Armstrong, they’ve fanned out across the dazzlingly variegated archipelago of worlds that orbit the sun. With astronauts consigned to the outermost fringes of Earth’s atmosphere, it has been the unmanned spacecraft that have been opening the solar system to our eyes.

Robotic missions have landed on Venus, Mars, Saturn’s moon Titan, and the asteroid Eros. They’ve deployed balloons to explore the dense Venusian atmosphere, rovers to crawl across the ochre desert landscapes of Mars, and atmospheric probes to dive into Jupiter’s kinetic storm systems.

They’ve discovered the solar system’s largest canyon, its highest mountain and its deepest sea. In the last few years, they’ve observed giant plumes of water venting from Saturn’s moon Enceladus; standing lakes of liquid ethane on Saturn’s foggy satellite Titan; fallen meteorites and whirling dust-devils on the surface of Mars; and volcanoes erupting perennially from the pock-marked surface of Jupiter’s moon Io.

In the late 1990s NASA’s Galileo Orbiter provided stunning evidence that Jupiter’s enigmatic satellite Europa is in fact a giant pearlescent drop of sea-water with a comparatively thin ice crust and a deep rocky core. Europa’s vast global ocean may in fact possess up to three times as much water as all the oceans of Earth combined — an astonishing prospect, and one that should have created far more excitement than it has.

Many planetary scientists consider Europa the most likely potential home of extraterrestrial life inside our solar system. It seems to possess all the conditions known to have fostered life on Earth, and has probably had them for billions of years.

All these revelations have been gotten at a fraction of the cost of human space flight. NASA’s Science Mission Directorate, which runs all of the U.S. unmanned missions — including revolutionary space-based observatories such as the Hubble Space Telescope — receives less than half of the funds allocated to crewed missions.

Despite this, space probes have steadily increased in their reach and capabilities, to the point where the engineering wizards of NASA’s Jet Propulsion Laboratory in Pasadena, California, can take a budget so comparatively miniscule that those in charge of human space flight might consider it a rounding error, and whip up such immaculately machined robots as the two exceptionally peripatetic and hardy Mars rovers, Spirit and Opportunity.

One is still fully operational and one finally failed last March, a whopping eight years after landing on what were originally conceived to be three-month surface missions. To date they’ve cost about $924 million dollars in total — only two thirds the cost of a single shuttle mission.

Despite this record of successes, and even with the retirement of the shuttle and the termination of NASA’s Constellation Program — a congenitally under-funded Bush-era effort to return astronauts to the Moon — the Science Mission Directorate is facing significant budget cuts for 2012.

For example, with NASA likely facing a decrease in funding of $6 billion, a mission dedicated to Europa is in imminent danger of being canceled — for the third time in just over a decade. This is not just deplorable, it’s contrary to our deepest innate drives as a species. Since when have we discovered an ocean and turned our backs on it?

None of this is to argue for phasing out human space flight in favor of the robotic kind. On the contrary, excellent reasons exist for a vigorous expansion of human activities beyond low Earth orbit and across the Solar System.

But in many ways the construction of the International Space Station has locked human space flight into a holding pattern for the near term, simply because it makes no sense to complete such an expensive project and then immediately abandon it. In that light, the recent Obama administration decisions to cancel the Constellation Moon program, retire the Space Shuttle and seek lower-cost ways of sending crews to the station are understandable.

But given their record of success with automated exploration, our first priority should be to use the savings thus achieved — and if necessary additional funds — to insure that NASA’s Science Mission Directorate remains fully funded.

Robotic space flight has revealed the Solar System to be a cornucopia of wonders, producing an unprecedented explosion in our understanding of our place in the universe.

It has provided stunning evidence of innumerable planets elsewhere in our galaxy, and even delivered pictures of embryonic solar systems forming. And it has done all this on less than one third of the budget of an agency that itself only consumes about 0.6 percent of the annual budget of the federal government.

In the late 1930’s H.G. Wells observed that the human race faces a choice between “the universe or nothing.” Given our planet’s ever-growing population, diminishing natural resources and the ominous specter of climate change, the same stark choice applies to our generation — only with interest. The decision should be obvious.

Soviet sculpture renders all its subjects larger than life, but few more so than Yuri Gagarin, who became the first man in space on April 12, 1961, nearly 50 years ago. A gleaming, 125-foot-tall titanium statue of the world’s most famous cosmonaut stands at the nexus of three freeways in Moscow, arms outstretched like a cold war superhero.

Gagarin’s achievement, and the Soviet playbook that shaped it, made him the most celebrated Soviet hero since Lenin, a triumph of nationalist glory, a role model for the young, a hypermasculine sex symbol. His deification set the “right stuff” tone that NASA would follow with its own astronauts: the lumbering icons in their puffy, complicated suits, incapable of error or weakness or even, it sometimes seemed, emotion.

In reality, Gagarin was 5 feet 2 inches tall and nice as heck. He was chosen because of his willingness to follow orders, to be a small part of the technological immensity of the Soviet space program. It is this quality, rather than courage or bravado, that makes him, in a sense, a most modern spacefarer.

Gagarin was, to be sure, the model Soviet citizen. When I visited the Yuri Gagarin museum in Star City, near Moscow, the curator showed me his childhood report cards, “all with excellent marks,” and a toy airplane he made at the industrial school he attended as a boy.

But for all his precocious talent, the space program’s chief designer, Sergey Korolev, is reported to have chosen Gagarin for the history-making mission partly because he was the only one of the original cosmonaut squad to remove his shoes before stepping inside a model of the Vostok I capsule in which he would travel into space.

“Everybody liked him,” said the curator, fanning herself as though overcome by the mere thought of him.

Indeed, Gagarin’s affable willingness to go with the program made him perfect for a mission in which he was, essentially, human cargo. Beyond coming down alive — nailing it first — his only assignment was to write down his observations and sensations (which he mostly failed to do, because he inadvertently let go of his pencil in orbit, and it floated out of sight).

Like the chimpanzees and the Moscow street mutts that went into space before them, Gagarin and other early spacemen were in part an experimental payload. There was a great deal of concern, at both the Soviet space agency and at NASA, about the unknown physiological and psychological consequences of space and zero gravity. Would breaching the infinite blow the crewman’s mind? Would weightlessness cause his eyeballs to change shape, his blood to stop circulating? Gagarin went up to find out.

Strangely, the first man to ascend into the cosmos was a skilled pilot forbidden to use his skills. The controls of Vostok I were locked; the capsule was maneuvered entirely from the ground. As Gagarin himself put it, “I’m not sure if I was the first man in space or the last dog.”

But nothing about Gagarin’s personality prevented him from becoming a Soviet demigod. His museum holds hundreds of official gifts and honors bestowed on him during the 27-nation tour that followed his flight: case after case of plaques and medals and proclamations and keys, a sombrero from the president of Mexico, giant salad tongs from who knows where.

Gagarin was uncomfortable with the adulation and fuss. He wrote in his autobiography of noticing that his shoelace was untied while he walked the red carpet before the presidium of the Central Committee of the Communist Party of the Soviet Union, and being unable to think about anything else. When he found himself seated beside Queen Elizabeth II at a Buckingham Palace luncheon, he reached under the table and squeezed her knee — not out of lasciviousness but, Gagarin biographer Lev Danilkin told me, “to receive evidence that he was not sleeping.” (Her Majesty pretended not to notice.)

Contemporary space travelers have hewed closer to the real-life Yuri Gagarin than his larger-than-life public image. Whatever bravado was tolerated during NASA’s earliest manned space programs has been ironed out; in an era of large-crew, long-duration missions, it is very much the wrong stuff. There is no room for expansive egos, for swagger and machismo, on a year-long stay in a bus-sized space station habitat or a two-plus-year mission to Mars.

A recent list of desirable attributes in NASA astronauts includes empathy, fairness and a good sense of humor. It’s hard to say whether and when the United States will send a human being to Mars, but Yuri Gagarin would be as perfect a choice today as he was in 1961.

I remember the first time the concept of another world entered my mind. It was during a walk with my father in our garden in Sri Lanka. He pointed to the Moon and told me that people had walked on it. I was astonished: Suddenly that bright light became a place that one could visit.

Schoolchildren may feel a similar sense of wonder when they see pictures of a Martian landscape or Saturn’s rings. And soon their views of alien worlds may not be confined to the planets in our own solar system.

After millenniums of musings and a century of failed attempts, astronomers first detected an exoplanet, a planet orbiting a normal star other than the Sun, in 1995. Now they are finding hundreds of such worlds each year. Last month, NASA announced that 1,235 new possible planets had been observed by Kepler, a telescope on a space satellite. Six of the planets that Kepler found circle one star, and the orbits of five of them would fit within that of Mercury, the closest planet to our Sun.

By timing the passages of these five planets across their sun’s visage — which provides confirmation of their planetary nature — we can witness their graceful dance with one another, choreographed by gravity. These discoveries remind us that nature is often richer and more wondrous than our imagination. The diversity of alien worlds has surprised us and challenged our preconceptions many times over.

It is quite a change from merely 20 years ago, when we knew for sure of just one planetary system: ours. The pace of discovery, supported by new instruments and missions and innovative strategies by planet seekers, has been astounding.

What’s more, from measurements of their masses and sizes, we can infer what some of these worlds are made of: gases, ice or rocks. Astronomers have been able to take the temperature of planets around other stars, first with telescopes in space but more recently with ground-based instruments, as my collaborators and I have done.

Two and a half years ago, we even managed to capture the first direct pictures of alien worlds. There is something about a photo of an alien planet — even if it only appears as a faint dot next to a bright, overexposed star — that makes it “real.” Given that stars shine like floodlights next to the planetary embers huddled around them, success required painstaking efforts and clever innovations. One essential tool is adaptive optics technology, which, in effect, takes the twinkle out of the stars, thus providing sharper images from telescopes on the ground than would otherwise be possible.

At the crux of this grand pursuit is one basic question: Is our warm, wet, rocky world, teeming with life, the exception or the norm? It is an important question for every one of us, not just for scientists. It seems absurd, if not arrogant, to think that ours is the only life-bearing world in the galaxy, given hundreds of billions of other suns, the apparent ubiquity of planets, and the cosmic abundance of life’s ingredients. It may be that life is fairly common, but that “intelligent” life is rare.

Of course, the vast majority of the extra-solar worlds discovered to date are quite unlike our own: many are gas giants, and some are boiling hot while others endure everlasting chills. Just a handful are close in size to our planet, and only a few of those may be rocky like the Earth, rather than gaseous like Jupiter or icy like Neptune.

But within the next few years, astronomers expect to find dozens of alien earths that are roughly the size of our planet. Some of them will likely be in the so-called habitable zone, where the temperatures are just right for liquid water. The discovery of “Earth twins,” with conditions similar to what we find here, will inevitably bring questions about alien life to the forefront.

Detecting signs of life elsewhere will not be easy, but it may well occur in my lifetime, if not during the next decade. Given the daunting distances between the stars, the real-life version will almost certainly be a lot less sensational than the movies depicting alien invasions or crash-landing spaceships.

The evidence may be circumstantial at first — say, spectral bar codes of interesting molecules like oxygen, ozone, methane and water — and leave room for alternative interpretations. It may take years of additional data-gathering, and perhaps the construction of new telescopes, to satisfy our doubts. Besides, we won’t know whether such “biosignatures” are an indication of slime or civilization. Most people will likely move on to other, more immediate concerns of life here on Earth while scientists get down to work.

If, on the other hand, an alien radio signal were to be detected, that would constitute a more clear-cut and exciting moment. Even if the contents of the message remained elusive for decades, we would know that there was someone “intelligent” at the other end. The search for extraterrestrial intelligence with radio telescopes has come of age recently, 50 years after the first feeble attempt. The construction of the Allen Telescope Array on an arid plateau in northern California greatly expands the number of star systems from which astronomers could detect signals.

However it arrives, the first definitive evidence of life elsewhere will mark a turning point in our intellectual history, perhaps only rivaled by Copernicus’s heliocentric theory or Darwin’s theory of evolution. If life can spring up on two planets independently, why not on a thousand or even a billion others? The ramifications of finding out for sure that ours isn’t the only inhabited world are likely to be felt, over time, in many areas of human thought and endeavor — from biology and philosophy to religion and art.

Some people worry that discovering life elsewhere, especially if it turns out to be in possession of incredible technology, will make us feel small and insignificant. They seem concerned that it will constitute a horrific blow to our collective ego.

I happen to be an optimist. It may take decades after the initial indications of alien life for scientists to gather enough evidence to be certain or to decipher a signal of artificial origin. The full ramifications of the discovery may not be felt for generations, giving us plenty of time to get used to the presence of our galactic neighbors. Besides, knowing that we are not alone just might be the kick in the pants we need to grow up as a species.

We can establish a human outpost on Mars in our generation, and reputable scientists are finally getting on board with the idea. Risky though it may be, we have the technology to place a person on the Red Planet. But, if NASA demands that the Mars explorer must return to Earth, then the idea becomes more like science fiction, and colonization probably can’t be achieved within the lifespan of those now reading this article.

For a Mars colony to be a reality within the next 15 or so years, the first traveler would have to live out his or her life as a permanent resident of an alien desert world. That person could eventually be joined by others, but return would not be an option.

When we eliminate the requirement to bring the explorer back, we remove a major obstacle to mission practicality. Carrying a special return vehicle with rocket fuel to the surface of Mars, or somehow manufacturing fuel on the planet for a return launch, will not be feasible for decades. Planning is underway for a robotic mission to bring a one- or two-pound sample of Martian soil back to Earth for analysis, but even such a roundtrip mission to retrieve a tiny amount of dirt is a major technical challenge.

For a human mission, the life support and resupply would be greatly simplified if it’s a one-way trip and there is only one astronaut. In such an expedition, a small person would hold an advantage — a female astronaut might be preferable — because smaller bodies make less demand on life-support systems. Perhaps the first mission might consist of two people; maybe even a male/female team. That privileged couple would follow the tradition of creation stories of many earthly religions, becoming more than just historic characters — they would become legends.

The Mars base, with life support, communication and other technical equipment, would be prepositioned on the surface before the first colonist lands and moves in. Every year we would have to supply each human on Mars with about 10,000 Earth pounds of food, water, oxygen, etc. Therefore, the smaller the crew, the better.

Robotic expeditions will always be cheaper than sending humans. But if we wait many years before initiating the effort to place a living explorer on Mars, we may never have the nerve to accept the expense or the risk of failure.

We’ll never be able to justify the cost of a Mars settlement based on potential economic payoffs because the benefits are distant and exotic. It’s hard to predict the return from capital investment in things that haven’t been tried before. But the builders of the Panama Canal, the U.S. transcontinental railroad and our interstate highway system couldn’t have imagined the transforming, long-term benefits that have come from those projects. Such would be the case with the opening of a new frontier on Mars.

The Apollo moon landing effort once employed nearly half a million people. Most Americans had a relative or an acquaintance who was, in some way, connected to the effort. The country had mobilized for war on several occasions, but never had it so widely organized to pursue a peaceful goal. It made us proud to be Americans. A Mars colonization program would do the same.

It may seem too risky to rely on one astronaut. But on Earth, in many dangerous endeavors — such as commercial diving — the practitioners often go it alone. And we may find it hard to imagine that one of our kind could survive the deprivations of a lonely existence on Mars. Yet, solo sailors have been trapped in the Arctic icepack. Research scientists have lived in isolation for months in dark, damp caves. It’s apparent that humans can cope with social separation. Some actually seek out and thrive in such environments.

Our prehistoric ancestors must have been self-reliant risk takers, quite unlike many modern humans whose lives involve constant cooperative behavior in a safe environment. We seek assistance with even the most trivial of daily challenges. Most people today never have to test the limits of their personal capabilities. Our instinctual survival skills are seldom exercised.

The first traveler to Mars will represent the tip of a long spear of human evolution. If there is such a thing as inherited memory, the astronaut may well carry the dreams of our cave-dwelling ancestors who gathered around campfires and puzzled over the bright spot of orange that was Mars wandering across the night sky. To delay colonizing Mars, when after a million years of human progress we finally have the ability to do so, is to reject those amazing qualities that set us apart from all other living creatures.

The French writer Antoine de Saint-Exupéry said, “If you want to build a ship, don’t drum up the people to collect wood and don’t assign them tasks and work, but rather teach them to long for the endless immensity of the sea.” In our human family, a yearning to expand into that “endless immensity” — the sea of the universe — is strong, and now we just need to build the ship!

Hace más de 50 años (1957), los soviéticos lanzaron el primer satélite en órbita del mundo, superando a EE.UU. en el espacio. Para los estadounidenses, el “momento Sputnik” fue un llamado de atención que empujó a Estados Unidos a aumentar la inversión en tecnología y educación científica. Meses más tarde, EE.UU. lanzó el satélite Explorer 1, con lo que la carrera entró en movimiento. Se animó a los niños a estudiar matemáticas y ciencias, y los conocimientos estadounidenses ayudaron al país ante el desafío.

Pero el ritmo ha disminuido drásticamente desde entonces, y la NASA ha estado tratando desde principios de noviembre de aprestar su último transbordador para el lanzamiento. En diciembre, el presidente Barack Obama habló de la necesidad de un nuevo “momento Sputnik” para revitalizar el papel que Estados Unidos tuvo en el pasado como líder tecnológico.

Irónicamente, ese momento ocurrió dos días después, pero lamentablemente con poca cobertura mediática. Sin embargo, este momento Sputnik – en realidad un “momento Dragon” – transmite un mensaje un tanto diferente. El lanzamiento de la nave Dragon fue, de hecho, un logro en el espíritu estadounidense tradicional. El 8 de diciembre, una empresa de EE.UU., SpaceX, fundada por un inmigrante y financiada principalmente por inversionistas privados de Estados Unidos, puso con éxito una nave espacial en órbita y luego la recuperó tras amerizar en el Océano Pacífico.

El mensaje no es sólo que es necesaria la educación en ciencia, tecnología, ingeniería y matemáticas (STEM, por sus siglas en inglés), sino también que este logro de una empresa privada costó sólo una fracción del presupuesto de dinero y tiempo de la NASA. Los gobiernos se desempeñan muy bien en lo referente a la financiación y la investigación, pero las empresas privadas competitivas con ánimo de lucro y gloria tienden a ser más eficientes y rápidas en alcanzar resultados.

Un ejemplo notable: justo antes del lanzamiento, los ingenieros de SpaceX encontraron algunas grietas en la extensión de la boquilla del motor de segunda etapa. En lugar de transportar la nave espacial de regreso a los talleres para su reparación, simplemente analizaron la falla, cortaron el tramo afectado y procedieron a realizar el lanzamiento. (Por cierto, habrían actuado de otra manera si Dragon hubiera estado transportando seres humanos.)

El mensaje del momento Dragon no es que la NASA no tenga idea de lo que hace, sino que las agencias de investigación del gobierno no son el tipo de organización correcto para ejecutar operaciones de rutina que podrían ser mejor manejadas por las empresas. (La NASA, en particular, se ha visto limitada por años de luchas políticas y clientelismo en el Congreso de EE.UU., hasta el punto de su misión parece ser conservar empleos y no la exploración del espacio.)

Por supuesto, debo confesar un interés personal en el asunto. Escribo esto desde Cabo Cañaveral, Florida. Como miembro del Comité Asesor del Consejo de la NASA, estoy visitando su Centro Espacial Kennedy, que necesita con urgencia mejoras y reparaciones. Sin embargo, en estos momentos la NASA gasta 475 millones dólares en un programa que ya ha sido cancelado, en lugar de destinarlos al centro espacial La razón: un congresista logró introducir una disposición legal que prohíbe a la NASA detener el gasto hasta que un nuevo presupuesto haya sido aprobado. Puesto que la NASA sigue funcionando bajo un presupuesto obsoleto, el programa cancelado se sigue financiando.

Imagínese cómo deben de sentirse los trabajadores: agradecidos por los cheques de pago, pero completamente cínicos sobre el valor de la labor que están haciendo. ¿Por qué no les pagan la misma cantidad para que compartan sus conocimientos y habilidades en las escuelas secundarias? Sería una respuesta más adecuada.

Pero volvamos a Dragon, que tuvo éxito por una serie de razones. En primer lugar, SpaceX es una empresa privada. El dinero de alguien está en juego, por lo que no se desperdicia. Su fundador, Elon Musk, un inmigrante de Sudáfrica (que en su tiempo libre dirige además Tesla, la compañía de automóviles eléctricos), lo financió con su propio dinero (que obtuvo en PayPal, otro de sus emprendimientos) y el de otros inversionistas privados. (Sí, SpaceX tiene contratos con la NASA, pero a un precio fijo por cada lanzamiento.)

El énfasis en SpaceX está en hacer realidad el trabajo, en lugar de sólo ir tirando. Mientras los gobiernos y los contratistas del gobierno en general disfrutan de la seguridad en el empleo, las empresas privadas saben que el dinero puede agotarse. Además, las empresas privadas compiten. Detrás de SpaceX hay una multitud de otras empresas privadas que desarrollan naves espaciales, como Masten Space Systems, XCOR Aerospace, Armadillo Aerospace y Blue Origin.

Estas empresas no están compitiendo por construir precisamente el mismo tipo de vehículo; de hecho, cada una considera como superior su propio enfoque . Este tipo de redundancia es en realidad eficiente en el largo plazo, ya que cada actor experimenta y todos ellos aprenden de los fracasos y los éxitos del resto. Mientras tanto, cada uno de ellos compite no por un gran premio único, sino por una participación en un mercado en crecimiento, arriesgando el dinero de los inversionistas y su propia reputación.

Debemos agradecer y reconocer esta economía de libre mercado, que premia la innovación útil y la toma de riesgos conscientes. El gobierno de los EE.UU. (o los gobiernos europeos, para el caso) no puede sacarnos de nuestro actual embrollo económico mejor que nos puede llevar a la luna en este momento. En la mayoría de las áreas de emprendimiento, el gobierno debe ser un cliente exigente en lugar de un proveedor (o subvencionador).

En los EE.UU., el gobierno fomentó el negocio de las aerolíneas en gran parte mediante la compra de servicios de carga de las compañías aéreas privadas. También construyó lo que se convirtió en la Internet y luego, reveladoramente, dejó la mayor parte del desarrollo y las operaciones del día a día en manos del sector privado.

Ahora, bajo la nueva y sensata política espacial de Obama, el gobierno de EE.UU. tiene previsto centrarse en el vuelo a Marte y los llamados “objetos cercanos a la Tierra”, la compra de transporte de rutina a la Estación Espacial Internacional a compañías como SpaceX (en lugar de al Programa Espacial Ruso a unos 60 millones de dólares por astronauta por viaje de ida y vuelta). Lo que el momento Dragon deja en claro es que la capacidad de comercializar la innovación, no sólo crearla, es lo que ha dado tanta solidez a la economía de los EE.UU. en el largo plazo.

For centuries, speculation about the existence of life elsewhere in the universe was the preserve of philosophers and theologians. Then, 50 years ago last month, the question entered the scientific sphere when a young American astronomer named Frank Drake began sweeping the skies with a radio telescope in hopes of picking up a signal from an extraterrestrial civilization. Initially, his quest was considered somewhat eccentric. But now the pendulum of scientific opinion has swung to the point where even a scientist of the stature of Stephen Hawking is speculating that aliens exist in other parts of our galaxy.

The search for extraterrestrial intelligence is predicated on the assumption, widely held today, that life would emerge readily on Earth-like planets. Given that there could be upward of a billion Earth-like planets in our galaxy alone, this assumption suggests that the universe should be teeming with life.

But the notion of life as a cosmic imperative is not backed up by hard evidence. In fact, the mechanism of life’s origin remains shrouded in mystery. So how can we test the idea that the transition from nonlife to life is simple enough to happen repeatedly? The most obvious and straightforward way is to search for a second form of life on Earth. No planet is more Earth-like than Earth itself, so if the path to life is easy, then life should have started up many times over right here.

Searching for alternative life on Earth might seem misconceived, because there is excellent evidence that every kind of life so far studied evolved from a common ancestor that lived billions of years ago. Yet most of the life that exists on Earth has never been properly classified. The vast majority of species are microbes, invisible to the naked eye, and scientists have analyzed only a tiny fraction of them. For all we know, there could be microbes with other ancestral origins living literally under our noses — or even inside our noses — constituting a sort of shadow biosphere, containing life, but not as we know it.

The denizens of the hidden “alien” biosphere — let’s call them Life 2.0 — might employ radically different biochemical processes than the life we know and love. Microbiologists could easily have overlooked their existence, because their methods are focused on the biochemistry of standard life. Obviously, if you go looking for A, you will find A and not B.

One way to go about tracking down Life 2.0 is to make educated guesses about what its biochemistry might be like. Alternative microbes might, for example, have different chemical elements. One shrewd suggestion, made by Felisa Wolfe-Simon of the United States Geological Survey, is that phosphorus — crucial to life as we know it — could be replaced by arsenic. She and her colleague Ron Oremland are dredging bugs from arsenic-contaminated Mono Lake in California in search of arsenic life.

Other researchers are focusing on the handedness of molecules. In standard life, the key amino acids are always left-handed, and the sugars are right-handed. Scientists are not sure why standard life has made this particular choice; nonliving chemical mixtures tend to contain equal amounts of both left- and right-handed molecules.

If life started again, perhaps it would select different handedness for its key molecules. Should a shadow biosphere of “mirror microbes” exist, the organisms could be identified by culturing microbial samples in “mirror soup” — a cocktail of nutrients with the handedness reversed, available from commercial suppliers. Standard life would find the soup unpalatable, but mirror life would thrive on it. Some experiments along these lines are being carried out at NASA’s Marshall Space Flight Center, in Huntsville. Ala.

Life 2.0 would be easier to identify if it inhabited distinct niches beyond the reach of regular life. Microbes are known to dwell in the superheated water around volcanic vents in the deep ocean, for example. Others survive extremes of cold, salinity, acidity or radiation. Yet all these so-called extremophiles that have been investigated to date are the same life as you and me. Regular life is clearly very hardy and adaptable, and can tolerate amazingly harsh conditions. Nevertheless, there will be limits. If Life 2.0 has a different chemical constitution, it may lurk in pockets at even more extreme temperatures or higher levels of radiation.

An argument often given for why Earth couldn’t host another form of life is that once the life we know became established, it would have eliminated any competition through natural selection. But if another form of life were confined to its own niche, there would be little direct competition with regular life. And, in any case, natural selection doesn’t always mean winner-takes-all. Some years ago it was discovered that simple microbes actually belong to two very distinct domains — bacteria and archaea. Genetically, these groups differ from each other as much as they differ from humans. Yet they have peacefully co-existed in overlapping habitats for billions of years.

If my theory turns out to be correct, it will have sweeping consequences. Should we find a second form of life right here on our doorstep, we could be confident that life is a truly cosmic phenomenon. If so, there may well be sentient beings somewhere in the galaxy wondering, as do we, if they are not alone in the universe.

Our space program, once the envy of every nation on Earth, has been showing its age of late. Its ambitions, though laudable, are starting to appear a little outdated. Technologies that once dazzled the masses now seem almost everyday and routine. Visions of new planetary terrain, once the fodder of science fiction, seem somewhat commonplace in light of the discoveries made by robotic spacecraft and the capabilities of other countries. And while the moon remains a fascinating destination, an entire galaxy of other regions – and countless possibilities – is just waiting to be explored.

With a renewed sense of energy and vision, NASA is well-positioned to reinvent itself.

Last week, President Obama outlined an ambitious new plan that focuses NASA’s efforts on bold new exploration goals through the development of exciting aerospace technologies.

While some are lamenting the cancellation of a return to the moon’s surface, the type of inspiring vision proposed is exactly what is needed to propel the U.S. beyond the trappings of the technologies developed nearly 50 years ago and to again take a leadership role through innovation and daring, the qualities that first took us to the lunar surface in 1969.

While some of the president’s plans are exceptionally grand in scope – landing on an asteroid, walking on Mars – the bulk of this vision will have a tangible and positive impact upon scientific development, our brightest talent and economic growth.

The most exciting element of NASA’s new direction is a greater emphasis on research and innovation. Instead of limiting ourselves to repeating past accomplishments, this renewed emphasis establishes new and challenging goalposts that once again can place the U.S. in a technological leadership position that can and will be admired by the rest of the world.

To move beyond the moon will require new transportation architectures, propulsion systems and a host of other technological innovations. This new vision of U.S. space exploration encourages NASA to collaborate with academia, private industry and its international partners to design and develop these technologies, a challenge that couldn’t be more timely.

A commitment to working with start-up companies to develop the technologies and hardware necessary for success will inspire and create a new generation of businesses and technology-focused jobs and will nurture and strengthen our top research institutions. With this new emphasis, NASA will return to its roots as an important catalyst for innovation and economic expansion for the U.S. economy.

Aerospace companies aren’t created in a vacuum. The fundamental ideas and breakthroughs that form the core of these businesses are typically developed at research institutions, focused on fundamental science and commercializing the technologies developed. These institutions have historically served as the cradle of progress, providing opportunity in all sectors of our economy.

In an almost prescient manner, the president’s budget request for NASA lays a foundation for future generations of technologists, engineers and scientists by committing to major new initiatives in education, from middle and high schools to the university and postgraduate level.

One of the most exciting elements is a new graduate fellowship program – equivalent in stature to current opportunities from the National Science Foundation – that will enable 500 graduate students per year to develop new technologies and work at NASA research centers.

This new attitude is truly reflective of the 21st century, engaging industry, academia and our international partners to work together and collaborate in order to reach once unimaginable goals.

Space is a big place with many compelling destinations. Focusing NASA’s budget on the technology of space travel will unleash a host of new options for exploration well beyond Earth’s orbit. A future sojourn to the lunar regions – which admittedly is a worthy goal and still has plenty of terrain left to explore – could one day prove easy by comparison.

The president has presented us with a difficult challenge, one that will push our definition of progress and the limits of our imagination.

If we succeed – even partially – we will in the process have created exciting new industries and dynamic new traditions and will have re-established the United States as the premier center of innovation and technological development in the world.

That surely is a worthy aspiration.

Le 2 février 2010, l’administration Obama a annoncé une nouvelle politique spatiale. Elle comporte trois décisions essentielles: le subventionnement par la NASA du développement de systèmes privés pour acheminer les astronautes jusqu’à la Station spatiale internationale; l’annulation du programme Constellation consacré au développement des équipements nécessaires aux vols habités vers la Lune; l’abandon du concept de fixation d’objectif de mission pour les vols habités, au profit d’une approche basée sur le financement d’une recherche technologique ayant pour but de permettre une mission qui sera éventuellement choisie plus tard.

La première de ces trois décisions est positive et attendue depuis longtemps. La seconde, considérée en soi, est néfaste mais elle pourrait être bonne si quelque chose de mieux que le programme Constellation était proposé. La troisième, cependant, est une terrible erreur qui, si elle était acceptée, assurerait que le programme de vols habités américain, à l’horizon actuel, ne déboucherait sur absolument aucun résultat.

Tout au long de son histoire, la NASA a suivi deux modes opérationnels distincts. Le premier, qui a toujours été celui des missions robotiques d’exploration mais qui fut aussi employé pour les vols habités pendant la période 1961-1973, peut être dénommé le «mode Apollo». Et le second, employé pour les vols habités depuis 1974: le «mode Navette».

Le processus du mode Apollo est le suivant: on choisit d’abord un objectif de mission, puis une architecture est mise au point pour l’atteindre. Ensuite, on conçoit des équipements pour atteindre cet objectif et, si nécessaire, on développe de nouvelles technologies pour rendre ces équipements pleinement efficients. On construit enfin les équipements et la mission est lancée dans l’espace.

Si l’on applique le mode Navette, on commence par développer les technologies et les équipements selon les souhaits des diverses communautés techniques. Ces recherches sont ensuite justifiées par la probabilité qu’elles pourraient s’avérer utiles plus tard, lorsque des projets de vols conséquents seront lancés.

On voit donc que ce qui anime le mode Apollo, c’est l’objectif, tandis que ce qui anime le mode Navette c’est la technologie ou, plus précisément, la force politique de l’élu sur le territoire duquel la technologie est développée. Dans le cas du mode Apollo, le développement technologique est réalisé pour des raisons justifiées par une mission. Dans le cas du mode Navette, les projets sont entrepris pour satisfaire des groupes de pression techniques (internes ou externes) et justifiés ensuite a posteriori; les efforts de la NASA sont régis par le hasard et l’entropie.

En dollars d’aujourd’hui, le budget moyen de la NASA, de 1961 à 1973, était d’environ 18 milliards de dollars par an. C’est le même que celui de la NASA aujourd’hui. Pour comparer la productivité du mode Apollo à celui du mode Navette, il est par conséquent pertinent de comparer les accomplissements de la NASA entre les périodes 1961-1973 et 1998-2010. Le brillant tableau de réussites dans le domaine des vols habités et sur le plan technologique durant la période Apollo, comparé à celui de la décennie passée, parle de lui-même. Même en ne se plaçant que sur le plan des développements technologiques, la période Apollo fut très supérieure.

En même temps qu’elle annonçait sa nouvelle politique spatiale, la NASA a informé que les trois inventions clés qui devaient changer les règles du jeu seraient la propulsion électrique à plasma VASIMR, les dépôts spatiaux de carburant sur orbite et la technologie des lanceurs lourds. Mais la propulsion VASIMR n’offre pas d’avantage clair par rapport au système de propulsion électrique ionique existant. De plus, l’affirmation que VASIMR (ou quelque autre mode de propulsion) permettrait des temps de vols jusqu’à Mars beaucoup plus courts que ceux qu’on peut réaliser avec des systèmes de propulsion chimique existants ne repose sur aucune réalité technique.

Le dépôt de carburant orbital était quant à lui la «marotte» de l’un des membres de la Commission Augustine, qui a recommandé la nouvelle politique. Cependant, son utilité potentielle comme moyen de permettre les missions vers la Lune ou vers Mars n’est absolument pas établie.

En fin de compte, il n’est simplement pas exact que nous ayons besoin de nouvelles technologies pour créer des systèmes de lancements lourds. Nous avons fait voler notre premier lanceur lourd, le Saturn V, en 1966. Ce dont nous avons besoin pour nous procurer un lanceur lourd qui fonctionne, c’est simplement la décision de le construire. Ainsi, dans le cadre de la nouvelle politique spatiale Obama, sans direction marquée par une mission clairement définie, dix ans vont encore passer et plus de 100 milliards de dollars vont être dépensés pour le programme des vols habités de la NASA, sans qu’on ne réalise rien de significatif.

Le peuple américain mérite un programme qui va vraiment «quelque part», pas simplement «n’importe où» mais jusqu’à une destination qui en vaut vraiment la peine. Cette destination, c’est Mars. La planète rouge est la Pierre de Rosette qui nous dira si le développement de la vie à partir d’éléments chimiques est un phénomène commun dans l’Univers et si la vie telle que nous la connaissons sur Terre suit le modèle que suit toute vie partout ailleurs ou si, au contraire, nous sommes un exemple exotique d’un éventail de possibilités considérablement plus vaste et plus intéressant. De plus Mars est l’astre le plus proche qui dispose des ressources nécessaires à l’établissement de l’homme.

Mais, quel que soit le choix d’une destination, ce qui est essentiel c’est qu’il y en ait une, que cette destination induise un plan de mission, le choix d’un ensemble d’équipements, et ensuite les technologies à développer et les équipements qu’il faut se procurer. On trouvera ainsi plusieurs méthodes pour rassembler les éléments nécessaires d’un système de vol, y compris des méthodes conventionnelles d’appels d’offres publics ou de partenariat avec des entreprises privées, mais ces méthodes doivent être employées d’une manière cohérente pour atteindre un objectif défini.

Si cela n’est pas fait, alors, dans dix ans, on ne sera pas plus près d’envoyer des astronautes sur la Lune ou sur Mars que nous ne le sommes aujourd’hui. L’administration Obama prétend que sa nouvelle politique spatiale ouvre un «chemin flexible». En réalité, c’est une incitation à une nouvelle aventure dispendieuse.

What do rockets burn for fuel? Money. Money that is contributed by working families who have mortgages and children who need braces. And why do the American people support our efforts in space? Because they still believe, to some extent or another, in that shining dream of exploring other worlds. So it could be said that rockets really run on dreams.

The exploration of space is the grandest adventure challenging the human race. As a filmmaker I have celebrated this greatest of dreams in my movies and documentaries, and I remain as passionate about the discoveries ahead as I was when I was a kid. So it was with some trepidation that I waited for the NASA budget to be unveiled this week. I was concerned that amid the nation’s fiscal crises, space exploration would fall off the priority list. But the NASA budget reveals a pathway to a bright future of exploration. It simply reflects the deep changes and hard decisions necessary to accomplish that goal.

Last year President Obama instructed the Augustine commission to report on the likely prognosis for NASA’s exploration activities. After months of study, the conclusions the panel released in October were gloomy. The Constellation program, designed to put humans back on the moon by 2020, could not possibly succeed within that time frame or budgeted amount, it reported.

In response, the president and NASA have crafted a bold plan that truly makes possible this nation’s dreams for space. Their plan calls for the full embrace of commercial solutions for transporting astronauts to low Earth orbit after the space shuttle is retired this year. This frees NASA to do what it does best: deep space exploration, both robotic and human. By selecting commercial solutions for transportation to the international space station, NASA is empowering American free enterprise to do what it does best: develop technology quickly and efficiently in a competitive environment.

As Peter Diamandis, chairman of the nonprofit X Prize Foundation, wrote this week: “The U.S. Government doesn’t build your computers, nor do you fly aboard a U.S. Government owned and operated airline. Private industry routinely takes technologies pioneered by the government and turns them into cheap, reliable and robust industries.” When the shuttle is finally retired after about three decades of service, the United States will be dependent on the Russian Soyuz to get our astronauts to the international space station, at a cost of $50 million per person. But under the new NASA plan, private industry will take over this capability within a few years, much more quickly than Constellation would have, and at a competitive price.

The money saved will be plowed into research and development of robotic explorers that will act as precursors and technology demonstrators, paving the way for human exploration of the moon, asteroids and Mars. Additional funding has been committed to the development of advanced propulsion technology, which can bring down the cost of spaceflight. And the space station’s lifespan will be extended several years, which in turn will increase the science yield and satisfy our international partners. This cooperative international effort is important as a model for how future large-scale missions will be organized and funded. In addition, money is being made available to both Earth and planetary science, which can help us understand climate change on our own world and the processes at work on some of the other worlds in our solar system.

Over the past 15 years, I have gotten to know a lot of people at NASA while working on projects to advance space and ocean exploration. I’ve found that many, if not most, started as starry-eyed childhood dreamers. Maybe they loved science-fiction stories, with their promise of alien worlds, or maybe they were geeks like me, peering through a telescope in the back yard until their moms yelled again for them to come inside — “It’s a school night!” They grew up to become engineers, brilliant planetary scientists and steely-eyed missile men who collectively have pushed our human presence out to the moon and our robotic presence not just to Mars but also to the outer reaches of the solar system. I applaud President Obama’s bold decision for NASA to focus on building a space exploration program that can drive innovation and provide inspiration for the world. This is the path that can make our dreams in space a reality.

Our planet has just enjoyed a weekend of rare company. The “wolf Moon”, as it is known to native Americans, has hung huge and full at its nearest point to Earth. Mars, meanwhile, has made its closest approach in six years, its red glow almost as bright as any star. Yet at this moment of tantalising proximity to our celestial neighbours, Barack Obama stands accused of pushing them farther away.

The Nasa budget that he presented yesterday cancels the new rockets that might return astronauts to the Moon and the plans for a manned lunar base as a stepping-stone to Mars. But it also closes a chapter in the history of human spaceflight: the US Government is getting out of the business of building craft to send people into orbit and beyond.

The decision has been condemned as a failure of imagination, the antithesis of audacity and hope. It should more properly be seen as a long overdue triumph of realism. By scaling back manned spaceflight, America will in no way betray its pioneer spirit. It will remain a proud spacefaring nation. It is just that its spacefaring will increasingly be done not by people but by the true pioneers of our age — robots. Astronauts do precious little exploring. Human beings are poorly designed for the job. They need food, water and oxygen, they must be shielded against radiation and they generally want to come home. That makes every launch prohibitively expensive, and limits where they can go.

Mechanical probes have none of these shortcomings. They can fly farther and faster, to destinations such as Venus and Jupiter to which no man, however bold, could go. They can roll around planets for years: the Spirit and Opportunity rovers have been prospecting Mars since 2004.

Their scientific returns dwarf those of manned missions for a fraction of the outlay. The Kepler planet- hunting probe cost $600 million — the equivalent of one and a half shuttle flights — while the next Mars rover, Curiosity, will cost less than the proposed Moon rockets would have consumed every year. And when robots go wrong, nobody dies.

Even astronauts’ vaunted ability to inspire is more than matched by machines. Do feats such as fixing the space station’s toilet really fire the imagination more than Cassini’s close-ups of Saturn?

Manned spaceflight may have a future in the private sector, as the Obama plan acknowledges. If it has value, the market will surely find it. But as robots can accomplish so much more than crewed spacecraft, so much more cheaply, it is essential to ask if the latter are a luxury that US taxpayers can afford. The President is right to say “no we can’t”.

Hace 40 años, el hombre pisó por primera vez la Luna. Cuarenta años después, las dos grandes potencias que compitieron ferozmente por alcanzar la Luna cooperan todos los días a bordo de la Estación Espacial Internacional. En la actualidad, una tripulación de seis astronautas de distintas nacionalidades vive y trabaja de forma permanente en un inmenso laboratorio, del tamaño de un estadio de fútbol, que orbita 250 kilómetros por encima de nuestras cabezas fruto de la colaboración entre Estados Unidos, Europa, Rusia, Japón y Canadá.

Hoy en día, con la ventaja de la retrospectiva, sabemos que el significado de la conquista de la Luna es muy distinto del que la opinión pública interpretó en 1969. Porque, 40 años después, la famosa “carrera espacial” entre EE UU y la Unión Soviética es tan sólo un mueble más del desván de la historia y, en cambio, para sorpresa de muchos, las tecnologías asociadas al espacio se han convertido en un instrumento fundamental para garantizar la supervivencia a largo plazo de nuestra civilización y preservar nuestro planeta.

Europa, que no tenía apenas presencia en la escena espacial en 1969, ha hecho en estas cuatro décadas progresos extraordinarios: actualmente lidera, por ejemplo, la investigación espacial en el área del cambio climático y el medio ambiente, y posee una familia de cohetes lanzadores de primer nivel. Nuestro continente ha realizado este salto de gigante a través de la Agencia Espacial Europea (ESA), la Comisión Europea y sus Estados miembros, incluyendo España, que se encuentra entre los seis países más importantes en el terreno espacial y acoge en Villafranca del Castillo (Madrid) el establecimiento de la ESA dedicado a ciencia espacial.

El descubrimiento más importante del programa norteamericano Apolo no fue, paradójicamente, la Luna, sino el planeta Tierra, visto a 384.000 kilómetros por los astronautas como una pequeña pelota de golf. Esa imagen, imponente y sobrecogedora, visualizó que nuestro planeta es sólo una minúscula pieza del universo, y, desde ese mismo instante, ya nadie pudo seguir defendiendo las anacrónicas doctrinas antropocéntricas. Otra consecuencia imprevista de la estampa de la Tierra observada desde el exterior fue una intensa sensación psicológica de globalidad, que difuminaba las fronteras políticas que separan los cerca de 200 países del mundo; nunca antes había sido tan evidente que el futuro de la humanidad es global y que los riesgos que acechan el porvenir de nuestra civilización afectan a todos los seres humanos, sin distinciones de ninguna clase. Finalmente, un tercer corolario, quizá menos inmediato, fue que la tecnología espacial, aquella que había hecho posible este cambio de paradigma, debía ser, salvo en materia de seguridad y defensa, una herramienta para estimular la cooperación internacional.

De manera invisible, la vida cotidiana de los ciudadanos europeos se sustenta, hoy en día, en sistemas espaciales: la información meteorológica que proporcionan los satélites Meteosat, que nos ayuda a decidir nuestras actividades de ocio, mejorar la seguridad del tráfico aéreo y planificar las cosechas; las telecomunicaciones por satélite, que ofrecen canales de televisión digital y cobertura telefónica en zonas remotas; y el sistema de posicionamiento por satélite GPS, que facilita la búsqueda de una calle desconocida cuando nos desplazamos en coche y, sobre todo, acorta el tiempo que ambulancias y policías tardan en localizar el lugar donde se produce una emergencia. Asimismo, la tecnología espacial tiene un protagonismo creciente en los sistemas de seguridad y defensa, el conocimiento de los factores explicativos del cambio climático y la prevención de catástrofes naturales (inundaciones, huracanes, etcétera). El espacio, en definitiva, se ha convertido en las últimas décadas en una herramienta para mejorar el bienestar de los ciudadanos.

Durante las décadas de 1950 y 1960, los criterios de la enorme inversión en tecnologías y demostradores espaciales de EE UU y la antigua Unión Soviética se inscribieron en la lógica competitiva de la guerra fría. Europa inició su plan espacial más tarde que las dos superpotencias y en algún aspecto esto representó una ventaja, ya que, desde el principio, pudo orientar su esfuerzo a la cooperación internacional -en particular, en el área de la exploración del universo- y a la mejora de las condiciones de vida en el planeta Tierra.

En la actualidad, uno de los programas espaciales más importante de nuestro continente es el dedicado al conocimiento científico de la Tierra y a las aplicaciones para el medio ambiente y la seguridad. Sin duda, Europa puede sentirse orgullosa de sus logros en el espacio: sondas científicas como Huygens aterrizando en una de las lunas de Saturno (Titán) y descubriendo un mundo nuevo, o como Mars Express encontrando agua en Marte; Envisat monitorizando la atmósfera y la superficie terrestre para comprender mejor las condiciones de vida; Galileo definiendo posiciones de objetos con una precisión insólita… son únicamente unos pocos ejemplos de las más de 70 misiones que la ESA ha cumplido con éxito en sus 40 años de existencia.

Por su parte, la contribución europea a la Estación Espacial Internacional se materializa en infraestructuras y vuelos de astronautas, como el que el español Pedro Duque realizó en 2003. El laboratorio europeo Columbus se incorporó a la Estación a principios de 2008 y acoge cientos de experimentos en ciencias de los materiales, física de fluidos y otras disciplinas. Otra aportación europea significativa ha sido la producción de los vehículos ATV (vehículo de transferencia automatizado), que además de transportar provisiones a la Estación y evacuar residuos, corrigen la posición orbital de las instalaciones.

España, que empezó su actividad espacial incluso con mayor retraso que Europa, ocupa hoy un lugar destacado en la ESA gracias al continuo apoyo del Gobierno español (a través del CDTI), a las capacidades tecnológicas y competitividad de sus empresas, así como a la excelencia de sus científicos. Como hitos contemporáneos, merecen especial mención el reciente lanzamiento del satélite europeo SMOS, que, liderado por empresas e investigadores españoles, medirá la salinidad de los océanos y la humedad del suelo (variables clave para comprender las oscilaciones de las temperaturas); la construcción del satélite de observación óptica de la Tierra Ingenio; o el programa de sostenimiento de la vida Melissa, dirigido por la Universitat Autònoma de Barcelona y basado en microorganismos y plantas que reciclan aire, agua y comida con el fin de hacer viable, a medio plazo, el viaje de humanos a Marte.

Todos los artefactos espaciales señalados en los párrafos precedentes son Made in Europe gracias al talento y la dedicación de decenas de miles de profesionales, procedentes de una amplia gama de disciplinas científico-técnicas, que trabajan en empresas altamente especializadas y centros de investigación de vanguardia.

Cuarenta años después de la llegada del hombre a la Luna, sabemos que los ciudadanos europeos son los beneficiarios últimos de la actividad espacial de la ESA. En primer lugar, por el valioso conocimiento generado, que nos ofrece nueva información no sólo sobre el universo y sus orígenes, sino también sobre la complejidad de nuestro planeta y las condiciones que hacen posible la vida. En segundo término, por la transferencia de tecnologías originarias del espacio a otros sectores de actividad económica que producen nuevos bienes y servicios (como, por ejemplo, los pañales, las sartenes de teflón o la fibra de carbono que configura la estructura de los aviones). Y, finalmente, por las aplicaciones directas que los satélites tienen en nuestro quehacer diario y están llamados a tener en el formidable desafío que la humanidad enfrenta en las próximas décadas: la preservación de la Tierra.

In Silicon Valley we have a saying: launch early, launch often. It’s an acknowledgment that successful, innovative companies are the ones that rapidly try new ideas, see what works, improve their products and repeat. Businesses that launch frequently are also able to take advantage of economies of scale to make launchings faster and easier. In many ways, the key to innovation is speed of execution.

NASA, an agency that depends on innovation, could benefit from the same mindset. To meet its new goals for human spaceflight, NASA must be able to be creative and take risks, or else it will be unable to adapt to new technology and changing political realities. Grand plans stretching over decades will become irrelevant and eventually collapse.

In the 12 years before I left NASA in 2007, we averaged about four space shuttle launchings per year. We had periods when the rate was even lower: in the late ’90s, during the early construction phase of the International Space Station, and in 2003, in the wake of the space shuttle Columbia disaster. I saw firsthand the harm that low launching rates do to innovation.

With precious few flights, every available opportunity to test new equipment or run scientific investigations was filled for years into the future, and this discouraged engineers from trying out new ideas. Without actual flight test data on, for example, prototypes for new life-support equipment, management was forced to substitute analysis for real engineering experience.

As operations slowed, morale dropped and proficiency in mission control, hardware handling and other operations all declined. The space shuttle is a magnificent machine, but it is so expensive and difficult to maintain that most of NASA’s effort was aimed at simply getting things up, so there were few resources left for actually exploring space. Imagine how different it would have been if we had had regular weekly launchings!

There is an important distinction to be made between the launching system (the rocket), and the spacecraft and payload (scientific instruments, experiments, people and so on) that it carries. In planning for spaceflight, the goal should be to make the launching system as robust as possible, and then launch rockets frequently so you can experiment and improve on the spacecraft and payloads that carry out missions.

I recognize that NASA cannot push a system to launch more frequently than it is capable of, because this could mean overrunning the budget or, worse, cutting corners on safety. Instead, future systems should be designed so that they can be rapidly prepared for launching by small teams.

This would not only increase NASA’s ability to send up innovative payloads but also make launching systems more reliable. After all, the more a rocket is flown, the better it can be understood and the safer it becomes. Frequent launchings would also reduce costs per flight in the long run.

This strategy does have a downside: Given the reality of fixed budgets, a requirement to launch frequently would push designers to create smaller rockets. So any large spacecraft would need to be assembled and fueled in space, rather than on the ground. But if the flight rate is high and the launching system is robust, then such complications could be overcome. If, on the other hand, NASA is able to launch rockets only a few times a year, it will be difficult to maintain the innovation needed to sustain any long-term program.

The Russian Soyuz rocket demonstrates the value of frequent launching. Variants of this rocket have flown more than 1,700 times, averaging more than 30 launchings a year. As a result, the Soyuz is among the most reliable of all existing rockets. In fact, I flew into space aboard a Soyuz rocket in 2003 when NASA space shuttles had been grounded after the Columbia disaster.

There is no reason American companies could not build a similar, but modernized, medium-sized, economical workhorse of a rocket that is simple enough to sustain frequent launching. If NASA were to promise to buy one such rocket a week, the manufacturers could also profitably sell copies for launching commercial spacecraft and satellites — at much lower than current prices — and this would spur the development of space-based industries in fields like telecommunications, earth imaging and even space tourism.

To maintain a vibrant, innovative program, NASA needs to step up the rate of rocket launchings. It should set a requirement that any new launching system fly once a week, then put out contracts for private companies to design and build rockets that can operate this frequently. By launching early and launching often, NASA could get back in the business of exploring space.

Picture a habitat atop a hill in warm sunlight on the edge of a crater near the south pole of the Moon. There are metal ores in the rocks nearby and ice in the shadows of the crater below. Solar arrays are set up on the regolith that covers the Moon’s surface. Humans live in sealed, cave-like lava tubes, protected from solar flares and sustained by large surface greenhouses. Imagine the Moon as the first self-sustainable human settlement away from Earth and a high-speed transportation hub for the solar system.

We can finally begin to think seriously about establishing such a self-sufficient home on the Moon because last week, NASA announced that it had discovered large quantities of water there.

While we have known for decades that the Moon had all the raw chemicals necessary for sustaining life, we believed they were trapped in rocks and thus difficult to extract. The discovery of plentiful lunar water is of tremendous importance to humanity and our long-term survival.

There have been 73 missions, manned and unmanned, to the Moon, and understanding its chemical composition, particularly finding water, has always been a priority. So why haven’t we seen significant amounts of water until now?

The answer lies in the Moon’s rotation. Unlike Earth, which rotates on a significant tilt to the Sun, the Moon is barely tilted at all. At the poles, some hills remain in permanent sunlight while some troughs are always in shadow. When water lands in sunny spots, perhaps carried by comets or asteroids, the water transforms directly into gas; if it lands in shadow, the water freezes and can remain indefinitely. The lack of light explains why spectrometers — instruments that can be used for remote water detection but rely on reflected light to do so — never picked up on the water.

This changed last month, when NASA shot a satellite into a permanently shadowed region on the Moon’s surface, throwing a plume of material containing water up out of the shadow.

From the perspective of human space exploration, that water is the most important scientific discovery since the ’60s. We can drink it, grow food with it and breathe it — by separating the oxygen from the hydrogen through a process called electrolysis. These elements can even be used to fuel rocket engines. (Discovering water on Mars was not quite as significant because the major hurdle to establishing permanent settlements there is the eight-month journey.)

Creating a permanent lunar habitat is important primarily for our species’ survival. Humanity needs more than one home because, with all our eggs in one basket, we are at risk of low-probability but high-consequence catastrophes like asteroid strikes, nuclear war or bioterrorism.

But it would also lead to valuable technological and other advancements. Consider the side-effects of the Apollo program: it drove the development of small computers, doubled the number of doctoral students in science and math in about a decade and marked a new stage in relations between the Americans and Soviets.

Imagine what we could learn from living on the Moon permanently. On its far side, shielded from the Earth’s radio noise, there is a quiet zone perfect for radio astronomy — which allows us to see objects we can’t from Earth. Out of necessity we could develop bacteria to extract resources directly from the regolith — a useful technology for Earth as well. And an international venture could open a new era of global cooperation.

Almost as surprising as NASA’s announcement is the lack of attention it has received. Thirty years ago, a development like this would have been heralded as one of humanity’s greatest discoveries. Perhaps the indifference is partly because of the disappointment of astronomers, amateur and professional, who tried to watch NASA’s October blast through their telescopes, but couldn’t see the plume. Or perhaps it’s a symptom of our age, that the problems that bedevil us on Earth limit our interest in other worlds — just when we need them (and the inspiration they offer) most

Now that the hype surrounding the 40th anniversary of the Moon landings has come and gone, we are faced with the grim reality that if we want to send humans back to the Moon the investment is likely to run in excess of $150 billion. The cost to get to Mars could easily be two to four times that, if it is possible at all.

This is the issue being wrestled with by a NASA panel, convened this year and led by Norman Augustine, a former chief executive of Lockheed Martin, that will in the coming weeks present President Obama with options for the near-term future of human spaceflight. It is quickly becoming clear that going to the Moon or Mars in the next decade or two will be impossible without a much bigger budget than has so far been allocated. Is it worth it?

The most challenging impediment to human travel to Mars does not seem to involve the complicated launching, propulsion, guidance or landing technologies but something far more mundane: the radiation emanating from the Sun’s cosmic rays. The shielding necessary to ensure the astronauts do not get a lethal dose of solar radiation on a round trip to Mars may very well make the spacecraft so heavy that the amount of fuel needed becomes prohibitive.

There is, however, a way to surmount this problem while reducing the cost and technical requirements, but it demands that we ask this vexing question: Why are we so interested in bringing the Mars astronauts home again?

While the idea of sending astronauts aloft never to return is jarring upon first hearing, the rationale for one-way trips into space has both historical and practical roots. Colonists and pilgrims seldom set off for the New World with the expectation of a return trip, usually because the places they were leaving were pretty intolerable anyway. Give us a century or two and we may turn the whole planet into a place from which many people might be happy to depart.

Moreover, one of the reasons that is sometimes given for sending humans into space is that we need to move beyond Earth if we are to improve our species’ chances of survival should something terrible happen back home. This requires people to leave, and stay away.

There are more immediate and pragmatic reasons to consider one-way human space exploration missions.

First, money. Much of the cost of a voyage to Mars will be spent on coming home again. If the fuel for the return is carried on the ship, this greatly increases the mass of the ship, which in turn requires even more fuel.

The president of the Mars Society, Robert Zubrin, has offered one possible solution: two ships, sent separately. The first would be sent unmanned and, once there, combine onboard hydrogen with carbon dioxide from the Martian atmosphere to generate the fuel for the return trip; the second would take the astronauts there, and then be left behind. But once arrival is decoupled from return, one should ask whether the return trip is really necessary.

Surely if the point of sending astronauts is to be able to carry out scientific experiments that robots cannot do (something I am highly skeptical of and one of the reasons I don’t believe we should use science to attempt to justify human space exploration), then the longer they spend on the planet the more experiments they can do.

Moreover, if the radiation problems cannot be adequately resolved then the longevity of astronauts signing up for a Mars round trip would be severely compromised in any case. As cruel as it may sound, the astronauts would probably best use their remaining time living and working on Mars rather than dying at home.

If it sounds unrealistic to suggest that astronauts would be willing to leave home never to return alive, then consider the results of several informal surveys I and several colleagues have conducted recently. One of my peers in Arizona recently accompanied a group of scientists and engineers from the Jet Propulsion Laboratory on a geological field trip. During the day, he asked how many would be willing to go on a one-way mission into space. Every member of the group raised his hand. The lure of space travel remains intoxicating for a generation brought up on “Star Trek” and “Star Wars.”

We might want to restrict the voyage to older astronauts, whose longevity is limited in any case. Here again, I have found a significant fraction of scientists older than 65 who would be willing to live out their remaining years on the red planet or elsewhere. With older scientists, there would be additional health complications, to be sure, but the necessary medical personnel and equipment would still probably be cheaper than designing a return mission.

Delivering food and supplies to these new pioneers — along with the tools to grow and build whatever they need, for however long they live on the red planet — is likewise more reasonable and may be less expensive than designing a ticket home. Certainly, as in the Zubrin proposal, unmanned spacecraft could provide the crucial supply lines.

The largest stumbling block to a consideration of one-way missions is probably political. NASA and Congress are unlikely to do something that could be perceived as signing the death warrants of astronauts.

Nevertheless, human space travel is so expensive and so dangerous that we are going to need novel, even extreme solutions if we really want to expand the range of human civilization beyond our own planet. To boldly go where no one has gone before does not require coming home again.

Pertenezco a un grupo -creo que bastante numeroso- cada vez más decepcionado con la política nacional. Ofende a la inteligencia, a la capacidad de razonamiento lógico que caracteriza a los humanos, contemplar como una buena parte de los políticos españoles se sumergen en campañas electorales como la que tuvo lugar hace poco para elegir a nuestros representantes en el Parlamento Europeo y no hablan para nada de política europea, empleando la mayor parte del tiempo en descalificarse mutuamente, ejercicio en el que continúan empeñados. Bien harían estos servidores públicos en seguir la receta que Carlos Fuentes ofreció en uno de sus libros (En esto creo): “La política como costumbre virtuosa, receptiva de los datos de la cultura, la tradición, el respeto del individuo y el vigor de la colectividad”.

Como antídoto ante tanta zafiedad sociopolítica, no viene mal mirar a los cielos. Agosto es buen mes para ello: muchos abandonarán las ciudades donde la luz artificial no deja contemplar el majestuoso espectáculo del cielo nocturno. Además, este año tienen lugar dos celebraciones que constituyen una buena excusa para informarse acerca del universo: los 40 años de la llegada de humanos a la Luna y el Año Internacional de la Astronomía, homenaje a los cuatro siglos que han pasado desde que Galileo construyera un rudimentario telescopio, con el que contempló la irregular superficie de la Luna, satélites orbitando en torno a Júpiter, así como miles de “luces” hasta entonces indistinguibles en la Vía Láctea, y de la publicación de un texto de Kepler que conviene recordar, Astronomia nova, en el que presentó sus primeras dos leyes del movimiento (elíptico) planetario.

Lo que en la actualidad, 400 años después de aquellos acontecimientos, conocemos acerca del universo constituye una de las mejores demostraciones de la inteligencia e inventiva de nuestra especie, así como, claro, de las muchas sorpresas que esconde el cosmos. “Un pequeño paso para el hombre, pero un salto gigantesco para la humanidad”, es la famosa frase de Armstrong al llegar a la Luna, y ambas caracterizaciones -pequeño paso y salto gigantesco- se ajustan a la verdad. ¿Cómo minimizar el que hayamos sido capaces de pisar un objeto planetario diferente de la Tierra? Ahora bien, dejando a un lado su dimensión psicológica, se trató más de un logro tecnológico que de un avance significativo en el ámbito científico. Para la ciencia fue un pequeño, aunque notable, paso.

Gracias a sondas espaciales que se han beneficiado del increíble avance tecnológico, ahora sabemos que no es preciso abandonar el Sistema Solar para encontrar mucha más variedad de la existente en la Luna. Las misiones Pioneer, Voyager y Galileo que exploraron el gigantesco (su diámetro es 11 veces el de la Tierra) Júpiter y sus lunas mostraron que una de ellas, Europa, está cubierta de una profunda capa de hielo, bajo el cual acaso existan océanos generados por el calor interno producido por las tensiones de origen gravitacional entre Júpiter y sus satélites. Tal vez en sus profundidades exista vida; ¿no la hay en las oscuras simas de los océanos terrestres? Análogamente, la sonda Cassini, lanzada en 1997, descubrió un océano salado bajo la superficie del polo sur de Encélado, una de las lunas heladas de Saturno, planeta en torno al cual la sonda comenzó a orbitar en julio de 2004.

Y si miramos aún más lejos, a las profundidades de nuestra galaxia o del universo, hallamos muchas más novedades: estrellas de neutrones, quasares, púlsares o los misteriosos agujeros negros, que han resultado no ser fantasmas producto de las complejidades matemáticas de una teoría maravillosa -la relatividad general-, sino objetos muy reales, que podemos encontrar, por ejemplo, en núcleos de galaxias, como si fueran el manantial del que éstas brotan. Creíamos que disponíamos de una buena imagen de lo que contiene el universo y en la última década nos hemos dado cuenta de que es más lo que desconocemos que lo que sabemos. Me estoy refiriendo a la materia y energía oscuras: parece que alrededor del 3% del universo está formado por masa ordinaria, el 30% de masa oscura (que se detecta a través de su fuerza gravitacional) y el 67% de energía oscura (inferida al constatar que el universo se expande con mayor aceleración de la que podemos explicar).

Otro desarrollo reciente es la identificación de planetas asociados a estrellas. En 1992 se descubrieron dos orbitando alrededor de un púlsar; tres años después se identificó en torno a la estrella 51 Pegasi un planeta del tamaño de Júpiter. Desde entonces el número de planetas extrasolares conocidos ha aumentado considerablemente, superando ya los 300. Aunque la mayor parte de ellos son mucho más masivos que la Tierra y demasiado cercanos a su estrella madre para albergar vida, terminaremos encontrando otros en los que se den condiciones favorables para su aparición. Cualquiera se puede imaginar las consecuencias de todo tipo que se podrían extraer del descubrimiento de vida en las profundidades del cosmos, la noticia que a mí más me gustaría recibir.

Ante semejantes hechos, no es difícil dejar volar la imaginación; pensar en instalar una estación permanente en la Luna o en misiones tripuladas a Marte, proyectos que en principio ya tienen fecha: 2025 y 2050, respectivamente. O en un telescopio instalado en la cara oculta de la Luna, mucho mejor situado, por tanto, que el fenomenal telescopio espacial Hubble, del que tanto hemos aprendido. Es como si asistiésemos a una fiesta del conocimiento, libre de las miserias y de los compromisos de la vida diaria. No es así, sin embargo. Fiesta del conocimiento, sí, pero no en un mundo ajeno a las circunstancias políticas. De hecho, la historia de la exploración espacial muestra una intensa relación entre ciencia y tecnología, por un lado, y política por otro. Wernher von Braun, por ejemplo, soñó desde joven con construir cohetes que le llevarían a la Luna y a Marte, pero finalmente lo que hizo fue servir a Hitler, construyendo los tristemente célebres V-2, cuyo destino no era nuestro satélite sino Londres y su carga no astronautas sino bombas. Tras la II Guerra Mundial fue trasladado a Estados Unidos, país al que también sirvió con lealtad y donde colaboró en la construcción (1958) del primer satélite artificial estadounidense, dirigiendo después en la NASA el desarrollo del vehículo que llevó al Apollo 11 a la Luna, propulsado por motores de cuyo diseño se beneficiarían los misiles balísticos intercontinentales. Y si hablamos de la NASA, hay que recordar que esta agencia espacial es hija -fue creada por Eisenhower en 1958- de la reacción de Estados Unidos ante el lanzamiento por parte de la Unión Soviética, el 4 de octubre de 1957, del famoso Sputnik. En otras palabras, la exploración espacial que condujo a la llegada a la Luna únicamente se puede entender en el contexto de la guerra fría.

Bien, pensarán algunos, la guerra fría es cosa del pasado. Seguramente así es (en parte), pero aún podemos identificar manifestaciones de la intervención de la “razón política” en la investigación espacial. La Estación Espacial Internacional, cuyos primeros módulos se instalaron en 1998, constituye un magnífico ejemplo en este sentido. Su origen tiene que ver con el deseo de Estados Unidos de propiciar una colaboración con Rusia, cuya estación espacial MIR, orgullo del Estado soviético, era cada vez más obsoleta. Desde el punto de vista propagandístico y de la política internacional, la Estación Internacional parece eficaz, pero desde el científico su utilidad es más que dudosa.

La exploración espacial, de la que tantos gozos intelectuales hemos extraído, es pues fiel reflejo de la personalidad de la humanidad. Representa una noble empresa -la de intentar superar nuestras ataduras terrestres-, pero también los deseos nacionales de mostrar poder: el espacio como un elemento más del mapa geopolítico global. No es casualidad que China se haya incorporado hace poco a la ciudadanía espacial: el 15 de octubre de 2003 lanzó su primer cohete tripulado y el 27 de septiembre de 2008 taïkonautas (hombres del gran vacío) chinos realizaron la primera salida al espacio. El universo se convierte así en un crisol en el que ciencia y política se funden produciendo una curiosa, sin duda fascinante, amalgama.

The public meetings and media reports about the Human Space Flight Plans Committee, a 10-member advisory panel appointed at the request of President Obama, indicate that NASA’s mission is about to change. It needs to.

For the past five decades, NASA has concentrated on exploration of our solar system. It has done a marvelous job. We have tremendous knowledge about virtually all the nearby planets and satellites, and great detail on the moon and Mars. While much has been learned from the manned space program, the scientific return from robotic spacecraft has yielded much more information about our solar system.

NASA officials believe the manned space program, which is allocated the great majority of the agency’s funding, is what attracts public interest and helps support the agency overall. But the review committee, led by retired aerospace executive Norman Augustine, is likely to announce that the objectives articulated by President George W. Bush in 2004 — to return to the moon and send a manned mission to Mars — are off course. They are: A manned mission to Mars would be difficult to justify scientifically, and extremely expensive. What more could we do on the moon that we have not already done with the Apollo missions and the lunar orbiters?

The United States has reached the point of diminishing returns on solar system exploration. We should think about other, higher-priority tasks for NASA. The continued exploration of the solar system can and should be carried on with robotic missions at a fraction of the NASA budget. The agency’s focus on the manned space program should be reoriented toward more pressing needs, such as the deflection of asteroids and NASA should seriously reconsider leading the search for extraterrestrial life outside our solar system.

First, if there is life elsewhere in the universe, it seems much more likely that it will be found through a search of other solar systems by the use of radio signals. In the past, NASA has supported programs for the detection of intelligent life through radio signals, but congressional opposition has forced the agency to shift gears. In the interim, private funding has been found to support a small but active program. There has been substantial progress in understanding the best techniques for search and detection of extraterrestrial signals. Given the basic groundwork that has been done and the level of resources and technology that NASA could provide, the probability of successful detection could be greatly increased. Members of Congress who are educated on the possibilities might be persuaded to support such a program. If this is the only way we will ever learn of intelligent life elsewhere in the universe — and I believe it is — shouldn’t NASA lead and fund this effort?

Second, NASA’s new priorities should also include the development of the means to detect and deflect asteroids that might impact Earth. We know that asteroid impacts have been responsible for catastrophic damage, even leading to the extinction of many species. Recent impacts on Jupiter illustrate the danger of such collisions. There is no reason to wait for a real threat. Since 1994, NASA has funded programs to search for asteroids that might hit Earth, but the effort has been on the back burner. We have developed the basic technology to detect and intercept dangerous asteroids, if we apply it in a timely way, but the development of spacecraft that could intercept and deflect objects on course to intersect with Earth is still years from fruition. There is no real consensus on the best ways to intercept and deflect dangerous objects, let alone designs for the spacecraft that would be needed, and by the time we detect an asteroid posing such a threat, it may be too late to develop the means to deflect it. Instead of developing new manned spacecraft to travel to the moon and Mars, we should be developing spacecraft that can travel to objects that endanger the Earth. Doesn’t the protection of humanity deserve high priority and funding? Why theorize about trying to establish colonies on Mars to preserve humanity in the event of a catastrophic asteroid impact on Earth rather than trying to preserve our planet by avoiding the catastrophe?

Any reevaluation of the NASA mission should seriously consider prioritizing how to save our planet from impacts by exterior bodies and to take on the leadership of searching for intelligent life through the detection of radio signals from other planetary systems.

Until the 1950s space travel was a futuristic concept, familiar from H. G. Wells and Jules Verne — and from comics and cornflake packets. But Sputnik, followed by Yuri Gagarin’s (and John Glenn’s) circling of the Earth made it real. The advent of the space age crystallised into reality human fantasies that dated back centuries.

The Moon landings came less than 70 years after the first powered flight — Orville Wright’s “brief hop” at Kitty Hawk — and only 12 years after the launch of Sputnik. Had the space race sustained its momentum, one might by now have expected a permanent lunar base, or an expedition to Mars. Neither has happened. The Apollo programme was a transient spin-off from the rivalry of the Cold War. The impetus was lost — a prime example of the ever widening chasm between what can be done technically and what there is a motive for doing (Concorde is another instance).

Manned spaceflight has understandably lost much of its glamour, as it hardly seems inspiring, 40 years after Neil Armstrong’s triumph, merely to circle the Earth in the space shuttle. Close-ups of the Martian surface and of Jupiter’s moons and cosmic images from the Hubble Telescope receive more media coverage than routine shuttle flights. It is only when disaster strikes that the shuttle makes headlines.

The burgeoning scientific, commercial and military applications of space do not need people, but have benefited from the technical advances that have brought mobile phones with far more computer power than the whole of Nasa had at the time of the Apollo programme. There seems little practical or scientific purpose in sending people into space at all: certainly none that can justify the costs. Every advance in robotics makes the case weaker.

There is nonetheless broad enthusiasm for space exploration, to the Moon, to Mars and beyond, as an adventure for (at least a few) humans. But it will have to be in a different style, with different motives.

The next human beings to walk on the Moon may be Chinese. China has a dirigiste government that could bankroll a risky Apollo-style programme. In the US, a panel of experts is advising President Obama on whether to set a goal of landing on Mars, and whether to construct a permanently manned lunar base. Such a programme would involve huge expense, and “safety culture” may make the cost prohibitive. The US public reaction to the shuttle’s safety record — two disasters, each a national trauma, in 120 flights — suggests that it is unacceptable for tax-funded projects to expose civilians even to a 2 per cent risk.

Even if the US embarks on such an enterprise, Europe would be ill advised to become a minor partner in it; unless the “entry ticket” were very cheap, it would be far better to focus on achieving a world lead in robots and miniaturisation.

To keep the costs of manned spaceflight acceptable, it must be openly accepted that it is hazardous. The first explorers venturing towards Mars would confront risks far higher than in a Shuttle flight: even “one-way tickets”. (It is astonishing that the Apollo astronauts avoided disaster. President Nixon’s speechwriters prepared a eulogy in case Armstrong was stranded on the Moon, never to return.) But why should we wish to occupy an environment far more hostile than the Antarctic or the ocean depths? There is a parallel with terrestrial exploration. Columbus, Vespucci and Magellan were as much enmeshed in nationalism and politics as astronauts have been.

Some explorers, for instance Captain Cook’s expeditions to the South Seas, were publicly funded, at least in part, as a scientific enterprise. For some — generally the most foolhardy — the enterprise was primarily a challenge: the motive that drives test pilots, mountaineers, round-the-world sailors and the like.

Any of these motives could drive the first travellers to Mars, or the first long-term denizens of a lunar base. Manned spaceflight could be a lot cheaper if it were not state-funded or a multinational programme, but bankrolled privately. There have long been maverick dreamers with schemes for space exploits. Such enthusiasts now include wealthy people with genuine commercial and technical savvy. Companies funded by Jeff Bezos, of Amazon, and Elon Musk, the founder of PayPal, are developing new rockets. The recent “Google prize” to launch a robotic lunar lander is engaging many ingenious inventors, and leveraging far more money than the prize itself. Potential sponsors with an eye on posterity might note that Queen Isabella is now remembered primarily for her support of Columbus.

If humans venture back to the Moon and beyond, they may carry commercial insignia rather than national flags. Perhaps future space probes will be plastered in logos, as Formula One racers are now.

Perhaps “robo-wars” in space will be a lucrative spectator sport. Perhaps pioneer settlers in space communities will live (and even die) in front of a worldwide audience — the ultimate in “reality TV”.

One plausible scenario would involve a permanently manned lunar base, pioneers on Mars, and perhaps small artificial habitats cruising the solar system, attaching themselves to asteroids or comets.

Issues of environmental ethics then arise. Would it be appropriate to exploit Mars, as did the pioneers who advanced west across America? Should we send “seeds” for plants genetically engineered to grow and reproduce there? Or should the Red Planet be designated a natural wilderness, like the Antarctic?

The answer, I think, depends on what the pristine state of Mars actually is. If there were life there — especially if it had different DNA, testifying to quite separate origins from life on Earth — there would be widely voiced insistence that Mars be preserved as unpolluted as possible.

What would actually happen might depend on the character of the first expeditions. If they were governmental (or international), Antarctic-style restraint is feasible. But if the explorers were privately funded adventurers of a free-enterprise disposition, the Wild West model would be more likely.

Eugene Cernan was the last man to walk on the Moon. On leaving he said: “We leave as we came, and God willing, as we shall return, with peace and hope for all mankind.” Whether or not there is a resurgence of manned spaceflight, the Apollo programme will always be a pioneering feat of engineering, organisation and courage.

Il y a quarante ans, le 20 juillet 1969, Neil Armstrong posait le pied sur la Lune. Ce “petit pas” portait les fruits d’une vision grandiose. A peine huit ans plus tôt, le président Kennedy déclarait au Congrès sa conviction : “Ce n’est pas un seul homme qui ira sur la Lune, c’est le pays tout entier. Car chacun d’entre nous doit se mobiliser pour l’y envoyer.”

A l’époque, l’Europe était peu active dans le domaine spatial. La situation a radicalement changé aujourd’hui, notre industrie spatiale est l’une des plus puissantes au monde. Ses applications simplifient notre vie quotidienne et nous fournissent des informations inestimables sur l’évolution de notre environnement.

Ces cinq dernières années seulement, l’Europe a créé quelque 15 000 emplois nouveaux dans le secteur, pour atteindre 40 000 emplois en 2008. Les secteurs associés représentent, eux, 250 000 emplois supplémentaires.

Après Ariane 4, le lanceur Ariane 5 garantit à l’Europe un accès indépendant à l’espace. Cet outil puissant vient de placer en orbite le plus grand satellite de communications au monde. En 2008, l’Europe a arrimé le laboratoire spatial Colombus et le véhicule spatial automatique (ATV) à la Station spatiale internationale. Cette année-là a été à cet égard exceptionnellement fructueuse. L’empreinte européenne dans l’espace n’a jamais été aussi grande.

Cette réussite européenne est-elle suffisante ? Non, si nous souhaitons continuer à jouer un rôle de premier plan dans les décennies à venir. Car l’écart s’accroît encore entre le budget que l’Europe consacre aux activités spatiales – quelque 6 milliards d’euros par an – et le budget américain, huit fois plus élevé. De plus, la Russie a recommencé à injecter des milliards dans son industrie spatiale.

Mais d’autres acteurs émergent, notamment en Asie. La Chine projette une mission habitée vers la Lune pour 2030 et une mission habitée vers Mars pour 2050. Elle investit actuellement au moins autant que l’Europe dans les technologies spatiales. Ces dernières années, les Chinois ont fait progresser leurs investissements spatiaux de 12 % par an. L’Inde a augmenté de 25 % ses dépenses liées au secteur spatial. Le Brésil veut, lui aussi, affirmer sa présence spatiale. En comparaison, le budget de l’Europe est resté à peu près stable.

Les vols spatiaux habités jouissent d’une priorité mondiale. En 2007, ils représentaient une très large part du budget globalement consacré à l’espace, avec 12 milliards de dollars, en progression de 8 % sur 2006. La compétition s’intensifie et l’exploration spatiale est un enjeu aussi fort qu’il y a quarante ans. Pour conserver son rang de grande puissance spatiale, l’Europe a besoin d’une nouvelle vision. Celle-ci doit s’articuler autour de plusieurs objectifs visant à renforcer à la fois la position de l’Europe dans le secteur spatial et la compétitivité de l’économie européenne dans un environnement mondialisé :

1. – L’Europe a besoin de Galileo. Ce système de navigation permettra de créer plus de 100 000 emplois. Il ouvrira les portes d’un nouveau monde d’opportunités et de découvertes. L’Europe est lente dans la mise en oeuvre de son ambition. D’autres font preuve de plus de détermination. En 2008, les Etats-Unis ont décidé d’investir 10 milliards de dollars dans leur GPS de troisième génération. La Russie achève son Glonass et la Chine lance Compass. L’Europe doit le comprendre : Galileo est une occasion à ne pas rater ; cela suppose d’accélérer le rythme de sa réalisation ;

2. – Nous devons assurer l’indépendance de notre accès à l’espace. La solution, c’est Ariane 6, le nouveau lanceur. Elle est recommandée par les trois sages mandatés par le gouvernement pour réfléchir aux orientations de la politique spatiale. Il faudra que l’Europe s’engage au début de la prochaine décennie pour une entrée en service vers 2025-2030. Les Etats-Unis, la Russie et la Chine ont investi massivement dans les lanceurs. Pour lancer Ariane 6, l’Europe doit agir vite et avec détermination ;

3. – Si l’Europe veut explorer Mars ou la Lune, nous avons besoin de capsules spatiales capables de ramener sondes, équipements et astronautes. Le véhicule de rentrée atmosphérique est la prochaine étape après l’ATV. L’essentiel des technologies est disponible. Il faut les assembler. Ce n’est pas hors de notre portée.

La question centrale de l’ambition spatiale européenne réside dans la place que nous accorderons à l’exploration spatiale habitée. Aurons-nous le courage de poursuivre avec d’autres la plus grande des aventures ? Allons-nous nous laisser distancer par d’autres ? Notre engagement européen commun doit rester fidèle à cette ambition d’étendre les connaissances humaines et de faire reculer leurs limites. Les vols spatiaux habités seront la meilleure preuve de notre confiance dans l’avenir, de notre confiance dans l’Europe.

No es lo mismo ir a la Luna que estar en ella. Lo segundo alude a quienes creen en lo primero. ¿Cuarenta años ya? No me toquen las pelotas. Yo tenía treinta y dos y estaba como un queso de mozzarella de búfala. ¿Quién iba a imaginarse que ocho lustros después, podrido por la gusanera de la ancianidad, lo sería de cabrales?

De búfala, decía, porque el paripé del alunizaje me pilló en Italia. Roma era entonces una fiesta. ¿Tanto como el París de Hemingway? ¡Hombre, no se me pongan así! Cada ciudad con su copla. Las chicas se me rifaban, lo cual es de por sí una fiesta, y la mía aseguraba que yo era il ragazzo piú hemingwayano della costa.

Con ella vi por la tele de su madre (nosotros no la teníamos) aquella burda representación de teatro infantil con la que los de Washington quisieron bajar los humos a los de Moscú. Éstos habían lanzado en octubre del 57 su famoso Sputnik, y eso sí que me lo creí, porque yo era entonces comunista y el meinkampf del agitprop me lo exigía. El notición me pilló en el tranvía que iba de Moncloa a Paraninfo. Llegué a la Facultad de Letras y en su vestíbulo un camarada me dijo: «Ya ves, esos analfabetos de la Unión Soviética han puesto en órbita un satélite artificial. ¡A ver qué dicen ahora los capitalistas!».

Dijeron, dijeron, aunque optaron por servir el plato de la vendetta más frío que nunca. Lógico porque toda aquella pugna fue capítulo de la guerra fría. ¡Doce años de retraso! ¿Teníais un Sputnik? ¡Pues os vais a enterar! ¡Hale! ¡A la Luna! ¡Picar más alto no cabe!

Y montaron, a bombo y platillo, el paripé al que me he referido. Yo lo vi, como decía, en Roma y me pareció una mala representación de La venganza de don Mendo.

De don Mendo o del Tío Sam. En el salón de actos de mi cole nos salía mucho mejor. ¿Estoy de coña? Pues sí, porque de coña me pareció la función. ¡Ya podían haber llamado al Orson Welles de La guerra de los mundos, que andaba viendo toros por España, o a cualquier director de Hollywood! Los tenían excelentes, bien cerquita y de toda confianza, porque muchos habían puesto su granito de denuncia en la cacería de brujas rojas del senador McCarthy. Buenos días y buena suerte. Aquello no había quien se lo creyera. Y yo, quod erat demonstrandum, no me lo creí. Nunca he sido hombre de fe.

Pasé toda la noche en vela, acompañado por mi chica, por su madre, por el escritor Alberto Lecco y no sé si por alguien más. Todos han muerto, así que no puedo aportar testigos, pero juro por la memoria de Pirrón que cuando empezó la farsa yo era un creyente y cuando terminó ya era lo que sigo siendo: un escéptico.

Los hay a miles, y existe una vasta bibliografía en la que exponen sus argumentos, que no son los míos. A mí me bastó con lo visto, y aparqué el asunto. ¿Explorar el espacio exterior? No, gracias. Prefiero el viaje interior. Eso sí que está por descubrir.

Eximo de responsabilidad al bueno de Hermida. No, no se lo inventó todo para ponerse en órbita (nunca mejor dicho), porque su equivalente italiano, cuyo nombre se me escapa, terminó tan fané, descangallado y desgreñado como él después del palizón informativo. A los periodistas se la metieron doblada, pero a mí, que era el chaval más hemingwayano de la costa, no me la dieron con queso ni de cabrales ni de búfala. ¿La luna? ¡Venga ya! Sabido es que tiene fama de mentirosa, y mentira hubo.

Ya sé, ya sé que este artículo es una cachondada. Discúlpemela el lector, pero no puedo escribir en serio sobre algo que siempre me he tomado a broma. No se detendrá por mi culpa el mundo (ni, menos aún, EL MUNDO). Seguro que aquí, a mi vera, cualquier sesudo analista les hablará con tediosa sensatez de lo que para todos ustedes -para mí, no- ha supuesto la carrera espacial. Bueno… Sólo una cosa es segura: nos ha salido carísima. ¿Merecía la pena? ¡Tanto dólar para que cuatro imbéciles se inscriban ahora, pagándolo a golpe de millón, en estúpidos viajes turísticos que nunca se realizarán!

Total… Que yo, aquella mañana, una vez concluida la farsa, y tan descangallado como Hermida, dejé a la chica en la cama y, sin decírselo, fiel a mi condición de ragazzo hemingwayano, me fui a ver a otra novia, que era hija de un general. Nada menos. Vacaciones en Roma. Festa.

Y posdata… Pirrón era un filósofo del Peloponeso que convirtió la duda en columna vertebral de su filosofía. Diderot también lo hizo. Dicen que su última frase, pronunciada un instante antes de hincar el pico y la cuchara en un plato de sopa, fue: «La duda es el primer paso hacia el conocimiento».

Tomen nota los chicos de la LOGSE. A ellos no les han explicado quiénes fueron Pirrón y Diderot, pero seguro que les han contado lo de la Luna y, los pobres, se lo han creído. Yo soy de otro plan de estudios.

Michael Crichton escribió en una ocasión que si le hubiera dicho a un médico de 1869 que en cuestión de 100 años el hombre viajaría a la Luna, y después perdería el interés por el satélite, el facultativo le habría declarado de inmediato «demente». En el año 2000, yo cité esta misma anécdota expresando la incredulidad de Crichton ante la dejadez de EEUU con la Luna. Pues bien, ya es 2009 y ésta despierta aún menos interés.

Hoy se cumple el 40º aniversario del primer aterrizaje lunar. Y se nos dice que el hombre regresará en el año 2020. Pero esa promesa fue hecha por el anterior presidente, y bien sabemos que el actual es la antítesis de George Bush. Además, a pesar de todas las cualidades kennedyescas de Barack Obama, éste no ha expresado nada del entusiasmo de Kennedy por la exploración espacial humana.

De manera que con el programa lunar Apolo olvidado hace mucho, y con el Constellation -su presunto sucesor- que todavía es poco más que una esperanza, seguimos apartándonos del espacio. Sorprendente. Tras incontables siglos de soñar con la conquista del espacio, despegamos por fin en Kitty Hawk en 1903, y sólo 66 años después -un nanosegundo en la historia de la humanidad-, habíamos aterrizado en la Luna. Sin embargo, en las décadas transcurridas desde entonces, apenas nada.

Siendo precisos, cabe hablar de casi 40 años perdidos en órbita geoestacionaria, en los que apenas se han estudiado los efectos de la ingravidez y algunos misterios cósmicos. Lo hemos hecho con la máquina más hermosa, intrincada y compleja -y en última instancia, irremediablemente menos práctica- construida nunca por el hombre: el transbordador espacial. Convertimos este pájaro magnífico en un camión de mudanzas con el que acarrear cosas y personas hasta un mecano que llamamos Estación Espacial Internacional, construido expresamente durante un ataque de preocupación internacionalista posterior a la Guerra Fría; un lugar donde personas de diferentes nacionalidades pueden cantar el kumbayá en ingravidez.

La lanzadera es ya demasiado peligrosa, demasiado frágil y demasiado cara. Siete vuelos más y habrá que jubilarla y trasladarla -igual que el Concorde o el Hércules H4- al Museo de Cosas Demasiado Hermosas y Complejas para Perdurar.

El programa espacial tripulado estadounidense es un despropósito. Dentro de 14 meses, por primera vez desde 1962, EEUU será incapaz no sólo de poner un hombre en la Luna sino de poner a nadie en órbita. Estaremos varados por completo. Tendremos que suplicar un paseo a los rusos o puede que hasta a los chinos.

¿Y qué pasa, dirá usted? ¿No tenemos problemas aquí en la Tierra? Venga ya. La pobreza y las enfermedades y los problemas sociales van a estar con nosotros siempre. Si esperásemos a que fueran corregidos antes de aventurarnos a salir, seguiríamos viviendo en cavernas.

Sí, sufrimos una crisis financiera. Nadie está pidiendo un Proyecto Manhattan de golpe. Todo lo que necesitamos es recibir la financiación suficiente para construir el Constellation y devolvernos a la órbita terrestre y a la Luna medio siglo después del primer alunizaje.

¿Y por qué hacerlo? No es por sentido práctico. No fuimos a la Luna para desarrollar trajes aislantes ni fruta deshidratada. Cualquier avance tecnológico es un extra, no un motivo. Vamos por la maravilla y la gloria de ello. O, por decirlo menos grandiosamente, por sus inmensas posibilidades. Elegimos hacer cosas así, decía JFK, «no porque sean fáciles, sino porque son difíciles». Y cuando se hacen cosas extraordinariamente difíciles -ya sea enviar a descubrir nuevos mundos a Magallanes o a Neil Armstrong- se abren nuevas posibilidades humanas totalmente impredecibles.

¿El mayor ejemplo? ¿Quién habría predicho que los viajes lunares iban a generar el incentivo más irresistible -y símbolo- de la conciencia medioambiental aquí en la Tierra: Earthrise, la fotografía icónica del Planeta Azul que trajo el Apolo VIII?

Irónicamente, la nueva conciencia motivada por el carácter único y la fragilidad de la Tierra alejó la imaginación contemporánea del espacio y la devolvió a la Tierra. Estamos ahora inmersos en una fase híper-terrestre, la era del iPod y el Facebook, de las redes sociales y el eco-respeto.

Pero levante la vista de su BlackBerry alguna noche. Eso es la luna. En su superficie hay exactamente 12 pares de huellas humanas, intactas, impasibles, abandonadas. Por primera vez en la Historia, la luna no es sólo un misterio o una musa, sino una reprimenda nocturna. Un presidente vigoroso y joven nos emplazó una vez a llegar a esta nueva frontera, llamando al viaje «la mayor aventura, más peligrosa y arriesgada en la que el hombre se haya embarcado nunca».

Llegamos, vimos, nos retiramos. ¿Cómo pudimos?

Well, let’s see now … That was a small step for Neil Armstrong, a giant leap for mankind and a real knee in the groin for NASA.

The American space program, the greatest, grandest, most Promethean — O.K. if I add “godlike”? — quest in the history of the world, died in infancy at 10:56 p.m. New York time on July 20, 1969, the moment the foot of Apollo 11’s Commander Armstrong touched the surface of the Moon.

It was no ordinary dead-and-be-done-with-it death. It was full-blown purgatory, purgatory being the holding pen for recently deceased but still restless souls awaiting judgment by a Higher Authority.

Like many another youngster at that time, or maybe retro-youngster in my case, I was fascinated by the astronauts after Apollo 11. I even dared to dream of writing a book about them someday. If anyone had told me in July 1969 that the sound of Neil Armstrong’s small step plus mankind’s big one was the shuffle of pallbearers at graveside, I would have averted my eyes and shaken my head in pity. Poor guy’s bucket’s got a hole in it.

Why, putting a man on the Moon was just the beginning, the prelude, the prologue! The Moon was nothing but a little satellite of Earth. The great adventure was going to be the exploration of the planets … Mars first, then Venus, then Pluto. Jupiter, Mercury, Saturn, Neptune and Uranus? NASA would figure out their slots in the schedule in due course. In any case, we Americans wouldn’t stop until we had explored the entire solar system. And after that … the galaxies beyond.

NASA had long since been all set to send men to Mars, starting with manned fly-bys of the planet in 1975. Wernher von Braun, the German rocket scientist who had come over to our side in 1945, had been designing a manned Mars project from the moment he arrived. In 1952 he published his Mars Project as a series of graphic articles called “Man Will Conquer Space Soon” in Collier’s magazine. It created a sensation. He was front and center in 1961 when NASA undertook Project Empire, which resulted in working plans for a manned Mars mission. Given the epic, the saga, the triumph of Project Apollo, Mars would naturally come next. All NASA and von Braun needed was the president’s and Congress’s blessings and the great adventure was a Go. Why would they so much as blink before saying the word?

Three months after the landing, however, in October 1969, I began to wonder … I was in Florida, at Cape Kennedy, the space program’s launching facility, aboard a NASA tour bus. The bus’s Spielmeister was a tall-fair-and-handsome man in his late 30s … and a real piece of lumber when it came to telling tourists on a tour bus what they were looking at. He was so bad, I couldn’t resist striking up a conversation at the end of the tour.

Sure enough, it turned out he had not been put on Earth for this job. He was an engineer who until recently had been a NASA heat-shield specialist. A baffling wave of layoffs had begun, and his job was eliminated. It was so bad he was lucky to have gotten this stand-up Spielmeister gig on a tour bus. Neil Armstrong and his two crew mates, Buzz Aldrin and Mike Collins, were still on their triumphal world tour … while back home, NASA’s irreplaceable team of highly motivated space scientists — irreplaceable! — there were no others! …anywhere! … You couldn’t just run an ad saying, “Help Wanted: Experienced heat-shield expert” … the irreplaceable team was breaking up, scattering in nobody knows how many hopeless directions.

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How could such a thing happen? In hindsight, the answer is obvious. NASA had neglected to recruit a corps of philosophers.

From the moment the Soviets launched Sputnik I into orbit around the Earth in 1957, everybody from Presidents Eisenhower, Kennedy and Johnson on down looked upon the so-called space race as just one thing: a military contest. At first there was alarm over the Soviets’ seizure of the “strategic high ground” of space. They were already up there — right above us! They could now hurl thunderbolts down whenever and wherever they wanted. And what could we do about it? Nothing. Ka-boom! There goes Bangor … Ka-boom! There goes Boston … Ka-boom! There goes New York … Baltimore … Washington … St. Louis … Denver … San Jose — blown away! — just like that.

Physicists were quick to point out that nobody would choose space as a place from which to attack Earth. The spacecraft, the missile, the Earth itself, plus the Earth’s own rotation, would be traveling at wildly different speeds upon wildly different geometric planes. You would run into the notorious “three body problem” and then some. You’d have to be crazy. The target would be untouched and you would wind up on the floor in a fetal ball, twitching and gibbering. On the other hand, the rockets that had lifted the Soviets’ five-ton manned ships into orbit were worth thinking about. They were clearly powerful enough to reach any place on Earth with nuclear warheads.

But that wasn’t what was on President Kennedy’s mind when he summoned NASA’s administrator, James Webb, and Webb’s deputy, Hugh Dryden, to the White House in April 1961. The president was in a terrible funk. He kept muttering: “If somebody can just tell me how to catch up. Let’s find somebody — anybody … There’s nothing more important.” He kept saying, “We’ve got to catch up.” Catching up had become his obsession. He never so much as mentioned the rockets.

Dryden said that, frankly, there was no way we could catch up with the Soviets when it came to orbital flights. A better idea would be to announce a crash program on the scale of the Manhattan Project, which had produced the atomic bomb. Only the aim this time would be to put a man on the Moon within the next 10 years.

Barely a month later Kennedy made his famous oration before Congress: “I believe that this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the Moon and returning him safely to Earth.” He neglected to mention Dryden.

Intuitively, not consciously, Kennedy had chosen another form of military contest, an oddly ancient and archaic one. It was called “single combat.”

The best known of all single combats was David versus Goliath. Before opposing armies clashed in all-out combat, each would send forth its “champion,” and the two would fight to the death, usually with swords. The victor would cut off the head of the loser and brandish it aloft by its hair.

The deadly duel didn’t take the place of the all-out battle. It was regarded as a sign of which way the gods were leaning. The two armies then had it out on the battlefield … unless one army fled in terror upon seeing its champion slaughtered. There you have the Philistines when Little David killed their giant, Goliath … and cut his head off and brandished it aloft by its hair (1 Samuel 17:1-58). They were overcome by a mad desire to be somewhere else. (The Israelites pursued and destroyed them.)

More than two millenniums later, the mental atmosphere of the space race was precisely that. The details of single combat were different. Cosmonauts and astronauts didn’t fight hand to hand and behead one another. Instead, each side’s brave champions, including one woman (Valentina Tereshkova), risked their lives by sitting on top of rockets and having their comrades on the ground light the fuse and fire them into space like the human cannonballs of yore.

The Soviets rocketed off to an early lead. They were the first to put an object into orbit around the Earth (Sputnik), the first to put an animal into orbit (a dog), the first to put a man in orbit (Yuri Gagarin). No sooner had NASA put two astronauts (Gus Grissom and Alan Shepard) into 15-minute suborbital flights to the Bahamas — the Bahamas! — 15 minutes! — two miserable little mortar lobs! — then the Soviets put a second cosmonaut (Gherman Titov) into orbit. He stayed up there for 25 hours and went around the globe 17 times. Three times he flew directly over the United States. The gods had shown which way they were leaning, all right!

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At this point, the mental atmospheres of the rocket-powered space race of the 1960s and the sword-clanking single combat of ancient days became so similar you had to ask: Does the human beast ever really change — or merely his artifacts? The Soviet cosmo-champions beat our astro-champions so handily, gloom spread like a gas. Every time you picked up a newspaper you saw headlines with the phrase, SPACE GAP … SPACE GAP … SPACE GAP … The Soviets had produced a generation of scientific geniuses — while we slept, fat and self-satisfied! Educators began tearing curriculums apart as soon as Sputnik went up, introducing the New Math and stressing another latest thing, the Theory of Self-Esteem.

At last, in February 1962, NASA managed to get a man into Earth orbit, John Glenn. You had to have been alive at that time to comprehend the reaction of the nation, practically all of it. He was up for only five hours, compared to Titov’s 25, but he was our … Protector! Against all odds he had risked his very hide for … us! — protected us from our mortal enemy! — struck back in the duel in the heavens! — showed the world that we Americans were born fighting and would never give up! John Glenn made us whole again!

During his ticker-tape parade up Broadway, you have never heard such cheers or seen so many thousands of people crying. Big Irish cops, the classic New York breed, were out in the intersections in front of the world, sobbing, blubbering, boo-hoo-ing, with tears streaming down their faces. John Glenn had protected all of us, cops, too. All tears have to do with protection … but I promise not to lay that theory on you now. John Glenn, in 1962, was the last true national hero America has ever had.

There were three more Mercury flights, and then the Gemini series of two-man flights began. With Gemini, we dared to wonder if perhaps we weren’t actually pulling closer to the Soviets in this greatest of all single combats. But we held our breath, fearful that the Soviets’ anonymous Chief Designer would trump us again with some unimaginably spectacular feat.

Sure enough, the C.I.A. brought in sketchy reports that the Soviets were on the verge of a Moon shot.

NASA entered into the greatest crash program of all time, Apollo. It launched five lunar missions in one year, December 1968 to November 1969. With Apollo 11, we finally won the great race, landing a man on the Moon before the end of this decade and returning him safely to Earth.

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Everybody, including Congress, was caught up in the adrenal rush of it all. But then, on the morning after, congressmen began to wonder about something that hadn’t dawned on them since Kennedy’s oration. What was this single combat stuff — they didn’t use the actual term — really all about? It had been a battle for morale at home and image abroad. Fine, O.K., we won, but it had no tactical military meaning whatsoever. And it had cost a fortune, $150 billion or so. And this business of sending a man to Mars and whatnot? Just more of the same, when you got right down to it. How laudable … how far-seeing … but why don’t we just do a Scarlett O’Hara and think about it tomorrow?

And that NASA budget! Now there was some prime pork you could really sink your teeth into! And they don’t need it anymore! Game’s over, NASA won, congratulations. Who couldn’t use some of that juicy meat to make the people happy? It had an ambrosial aroma … made you think of re-election ….

NASA’s annual budget sank like a stone from $5 billion in the mid-1960s to $3 billion in the mid-1970s. It was at this point that NASA’s lack of a philosopher corps became a real problem. The fact was, NASA had only one philosopher, Wernher von Braun. Toward the end of his life, von Braun knew he was dying of cancer and became very contemplative. I happened to hear him speak at a dinner in his honor in San Francisco. He raised the question of what the space program was really all about.

It’s been a long time, but I remember him saying something like this: Here on Earth we live on a planet that is in orbit around the Sun. The Sun itself is a star that is on fire and will someday burn up, leaving our solar system uninhabitable. Therefore we must build a bridge to the stars, because as far as we know, we are the only sentient creatures in the entire universe. When do we start building that bridge to the stars? We begin as soon as we are able, and this is that time. We must not fail in this obligation we have to keep alive the only meaningful life we know of.

Unfortunately, NASA couldn’t present as its spokesman and great philosopher a former high-ranking member of the Nazi Wehrmacht with a heavy German accent.

As a result, the space program has been killing time for 40 years with a series of orbital projects … Skylab, the Apollo-Soyuz joint mission, the International Space Station and the space shuttle. These programs have required a courage and engineering brilliance comparable to the manned programs that preceded them. But their purpose has been mainly to keep the lights on at the Kennedy Space Center and Houston’s Johnson Space Center — by removing manned flight from the heavens and bringing it very much down to earth. The shuttle program, for example, was actually supposed to appeal to the public by offering orbital tourist rides, only to end in the Challenger disaster, in which the first such passenger, Christa McAuliffe, a schoolteacher, perished.

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Forty years! For 40 years, everybody at NASA has known that the only logical next step is a manned Mars mission, and every overture has been entertained only briefly by presidents and the Congress. They have so many more luscious and appealing projects that could make better use of the close to $10 billion annually the Mars program would require. There is another overture even at this moment, and it does not stand a chance in the teeth of Depression II.

“Why not send robots?” is a common refrain. And once more it is the late Wernher von Braun who comes up with the rejoinder. One of the things he most enjoyed saying was that there is no computerized explorer in the world with more than a tiny fraction of the power of a chemical analog computer known as the human brain, which is easily reproduced by unskilled labor.

What NASA needs now is the power of the Word. On Darwin’s tongue, the Word created a revolutionary and now well-nigh universal conception of the nature of human beings, or, rather, human beasts. On Freud’s tongue, the Word means that at this very moment there are probably several million orgasms occurring that would not have occurred had Freud never lived. Even the fact that he is proved to be a quack has not diminished the power of his Word.

July 20, 1969, was the moment NASA needed, more than anything else in this world, the Word. But that was something NASA’s engineers had no specifications for. At this moment, that remains the only solution to recovering NASA’s true destiny, which is, of course, to build that bridge to the stars.

How did we allow “vision” and “inspiration” to become dirty words when discussing science? Why are these regarded as fluffy concepts that have no place in the modern world of scientific research? The science journal Nature has carried out an online, international, cross-disciplinary survey of scientists who have published in their journal in the last three years. Of the 800 or so respondents, more than half cite Project Apollo as having directly influenced them to become a scientist. I was stunned. This is Nature-published authors we’re talking about, not contributors to the Liechtenstein Journal of Flying Saucers – they’re supposed to be a more rational breed.

That’s 400-odd scientists, of some standing, who say Apollo was the thing that launched their personal scientific odysseys. And if there are hundreds to be found in that narrow sample then there must be thousands, maybe tens of thousands of others for whom the same is true.

This isn’t the only evidence that human space exploration can draw people towards science. But it is pretty clear that space science, and astronauts in particular, are great at generating precisely the kind of graduate that we are so very short of at this time; the type that we are constantly told is the key to the future stability of our economy. Despite these facts “inspiration” continues to be discounted as a factor when considering the value of a thing. Vision and inspiration, of themselves, have no quantifiable value and, to the metric-obsessed society in which we live, therefore no value at all.

Now, before I get trolled for suggesting that getting people all warm and glowy is the sole justification for the multibillion-dollar Apollo escapades, let me be clear: I do not think that inspiration argument alone justifies human space flight. No single item alone – not the science or the spin-offs or the benefits to education – is enough to make it worth it: it is, as I’ve said before, all of those things together.

Apollo was of its time and the future exploration of space cannot and should not be conducted in the same way; not even that of Mars. The international agencies must co-operate fully while allowing their collective monopoly over all things astronautic to be at least part broken, thus reducing the cost to individual nations and their respective taxpayers.

But whatever the future holds for space exploration, humans will continue to be a part of it. Mission planners and architects of all programmes of scientific exploration would do well to remember what the vital ingredients of such efforts are. Science is at its best when its skies are at their bluest. A successful programme of exploration is one in which the whole is greater than the sum of its individual parts; one in which no single element makes sense on its own. It is a thing of culture, an idea so big, so well executed that it stands for all time and makes itself felt, in a positive way, in every corner of our society. Such feats cannot be achieved in the absence of vision or inspiration and we should allow these words to creep back into respectable vocabulary.

It’s a birthright proffered by science and prophesied by “Star Trek,” “Battlestar Galactica” and a thousand other space operas: We’re destined to go to the stars. Our descendants will spread beyond this nondescript solar system and seek adventure and bumpy-headed pals in the stellar realms.

Well, cool your warp jets, Mr. Scott, because we’re not about to breach the final frontier. Piling into a starship and barreling into deep space may long remain — like perfect children or effort-free bathroom cleaners — a pipe dream.

The fastest rocket ever launched, NASA’s New Horizons probe to Pluto, roared off its pad in 2006 at 10 miles per second. That pace would be impressive in the morning commute, and it’s passably adequate for traversing the solar system, something we’ve done and will continue to do. Combustion rockets, like New Horizons, can deliver you to the Moon in a matter of days, Mars in a matter of months, and the outer planets in a matter of years. But a trip to Proxima Centauri, the nearest star beyond the Sun and 100 million times farther from us than the Moon, would consume a tedious 800 centuries or so. You’ll want to upgrade.

We’ll build faster spacecraft, of course. Many have been designed, including ion beam rockets that shoot particles from their nozzles rather than hot gas, and nuclear-powered models. The former made their debut in NASA’s Deep Space 1 mission to investigate asteroids and could conceivably cruise at 50 miles per second. Atomic rockets, whose development was halted by test-ban treaties in the ’60s, had a target velocity 20 times greater. Alas, despite these snappier speeds, such craft are still untenable for manned journeys to the stars, taking at least a dozen lifetimes to reach the nearest.

Carting humans into deep space requires technology akin to wormhole rockets or matter-antimatter engines, the standard transports of science fiction. Wormhole travel, which takes shortcuts to the stars by warping space, looks appealing on blackboards, but physicists can’t yet say whether it would ever work in practice. Matter-antimatter engines use the enormous energy released when ordinary atoms encounter their exotic, opposite numbers, demanding the creation and storage of large amounts of hard-to-contain antimatter — a Sisyphean task, to put it gently.

In addition, such sci-fi crafts would get embarrassingly bad mileage. The energy required to reach even the nearest stars in a decade or less with a very modest-size starship (say, the tonnage of the 17th-century Mayflower) equals the total energy consumed in the United States last year. At 10 cents per kilowatt-hour, that’s a fuel bill of $5 trillion.

The pace of improvement in rocketry is languid. It will be a decade before NASA’s new Orion spacecraft allows humans to revisit the Moon, a short cosmic hop. And while today’s launching vehicles are more powerful than their predecessors, the speeds are hardly impressive. The New Horizons probe cleared the pad at a clip barely twice that of the Atlas rocket that hoisted John Glenn into orbit at the dawn of the space age.

So while there’s little doubt that humanity will soon explore and eventually colonize the Moon, Mars and the satellites and asteroids of the outer solar system, sending humans beyond that is impractical for the foreseeable future.

But there’s another technology that’s developing at a breakneck clip, and with which our grandchildren could make virtual trips to other solar systems. It’s called telepresence — a collection of technologies that extends vision, hearing and touch far beyond the corporeal confines of our nervous system.

Consider that in 1965 the Mariner 4 spacecraft made the first fuzzy photos of Mars with a black-and-white TV camera boasting 40,000 pixels. The HiRISE camera now operating onboard NASA’s Mars Reconnaissance Orbiter sports 200 million pixels. It can snap photos of objects just three feet across.

That’s resolution comparable to what’s on Google Earth, which many people use to examine remote parts of the globe or inspect cities known only from the nightly news. Google Mars takes advantage of the high-quality imagery being collected by our robotic orbiters, enabling armchair astronauts to peruse the red planet in considerable detail without the angst of transporting their delicate protoplasm 34 million miles into space.

Photography from the Mars Exploration Rover is so good that the data have been interpreted in an IMAX film, giving audiences a near-lifelike experience in strolling the red planet’s rusty, dusty desert. The Phoenix Mars lander has sent back pictures of individual sand grains. In other words, it’s already possible for anyone to make a rigorous reconnaissance of another planet — even though not a single human has yet stomped his boots in the Martian dust.

This is not merely the tired argument over manned versus unmanned space missions. Sending humans to the stars is simply not in the offing. But this is how we could survey other worlds, around other suns. We fling data-collecting, robotic craft to the stars. These proxy explorers can be very small, and consequently can be shot spaceward at tremendous speed even with the types of rockets now available. Robot probes don’t require life support systems, don’t get sick or claustrophobic and don’t insist on round-trip tickets.

A plausible solution would be to re-energize NASA’s development of nuclear-powered rockets, with the intention of building a craft able to send clusters of micro-bots into deep space at velocities of, say, one-tenth light speed. Depending on financing and our ability to garner international cooperation, these probes could be sent off before the 21st century starts to wane. By the middle of the following century, on-the-scene data from Epsilon Eridani, the nearest known planetary system, could be in our hands.

These microbots would supply the information that, fed to computers, would allow us to explore alien planets in the same way that we navigate the virtual spaces of video games or wander through online environments like Second Life. High-tech masks and data gloves, sartorial accessories considerably more comfortable than a spacesuit, would permit you to see the landscape, touch objects and even smell the air.

Our desire to walk a landscape that basks in the light of another star, to hear the whistle of an alien planet’s wind and feel its sting on our faces, will not — any century soon — be sated by hurling massive, human-filled starships into space. Instead, we will extend our senses light-years beyond Earth with these telepresence proxies and data collectors. That’s a far more realistic version of the “Star Trek” future: to explore distant worlds, under alien suns, without leaving the familiar surroundings of our terrestrial home.

A cancer is overtaking our space agency: the routine acquiescence to immense cost increases in projects. Unmistakable new indications of this illness surfaced last month with NASA’s decision to spend at least $100 million more on its poorly-managed, now-over-$2 billion Mars Science Laboratory. This decision to go forward with the project, a robotic rover, was made even though it has tripled in cost since its inception, it is behind schedule, there is no firm estimate of the final cost, and NASA hasn’t disclosed the collateral damage inflicted on other programs and activities that depend on NASA’s limited science budget.

The decision to pour more money into the Mars Science Laboratory, which is scheduled for launching next year, may have been like many I witnessed as NASA’s associate administrator for science. If so, then NASA’s accomplished administrator, Mike Griffin, may have calculated that any move to cancel the Mars mission would be rebuffed by members of Congress protecting local jobs.

And the Mars Science Laboratory is only the latest symptom of a NASA culture that has lost control of spending. The cost of the James Webb Space Telescope, successor to the storied Hubble, has increased from initial estimates near $1 billion to almost $5 billion. NASA’s next two weather satellites, built for the National Oceanic and Atmospheric Administration, have now inflated to over $3.5 billion each! The list goes on: N.P.P., S.D.O., LISA Pathfinder, Constellation and more. You don’t have to know what the abbreviations and acronyms mean to get it: Our space program is running inefficiently, and without sufficient regard to cost performance. In NASA’s science directorate alone, an internal accounting in 2007 found over $5 billion in increases since 2003.

As a scientist in charge of space sensors and entire space missions before I was at NASA, I myself was involved in projects that overran. But that’s no excuse for remaining silent about this growing problem, or failing to champion reform. And when I articulated this problem as the NASA executive in charge of its science program and consistently curtailed cost increases, I found myself eventually admonished and then neutered by still higher ups, precipitating my resignation earlier this year.

Endemic project cost increases at NASA begin when scientists and engineers (and sometimes Congress) burden missions with features beyond what is affordable in the stated budget. The problem continues with managers and contractors who accept or encourage such assignments, expecting to eventually be bailed out. It is worsened by managers who disguise the size of cost increases that missions incur. Finally, it culminates with scientists who won’t cut their costs and members of Congress who accept steep increases to protect local jobs.

The result? The costs of badly run NASA projects are paid for with cutbacks or delays in NASA projects that didn’t go over budget. Hence the guilty are rewarded and the innocent are punished.

Consider these examples: In NASA’s astronomy program, the James Webb Space Telescope’s $4 billion in cost increases have prevented the development of other important astronomy missions. In NASA’s Earth science program, the ballooning price tags of missions already being built have severely delayed proposed missions to study global climate change and to pioneer early-warning systems for earthquakes, among others. In NASA’s human exploration program, cost increases have slowed the development of a shuttle replacement, extending the looming multiyear gap in America’s ability to launch human spaceflight missions. This is not to the benefit of science, or space exploration, or the nation.

And this is not the only damage being done. Our once-broad planetary program that has launched missions to the Moon, comets, asteroids and five planets since the mid-1990s has been so reduced — largely by years of Mars overrun — that all that remains in hardware development are just one lunar and one outer-planet mission. Even those two missions are endangered now by the Mars Science Laboratory’s spiraling cost.

NASA’s main defense for paying still more for this new Mars rover: the $1.8 billion or more in already sunk cost. But good executive managers know that sunk costs are already spent — more important is the collateral damage done to NASA’s future portfolio, and how the coddling of errant projects encourages soaring costs, rather than cost control.

This cancer is bad, but it is curable. The new presidential administration could begin by accounting for cost increases more honestly, using the initial basis on which missions are started, rather than today’s practice of neglecting certain kinds of cost escalation. Further, scientists and engineers should be required, when formulating missions, to ensure their scope matches their budget. And NASA should be charged to reduce or cancel development projects that are not performing to cost. Of equal importance, Congress should turn from the self-serving protection of local NASA jobs to an ethic of responsible government that delivers results.

Yes, controlling the costs of space missions, while ensuring their success and safety, will be a steep challenge for NASA, but NASA’s workforce, from technicians to top executives, is among the government’s most dedicated and capable. This is a challenge that can be met with appropriate leadership.

America’s space program has been the envy and inspiration of the world. It has made landmark scientific discoveries that are a lasting legacy of this nation’s greatness. It has studied Earth in ways no other nation can match. And it is leading the world to develop the first outpost on the Moon and the first historic human expeditions to the planets.

An unmanned spacecraft from India — that most worldly and yet otherworldly of nations — is on its way to the moon. For the first time since man and his rockets began trespassing on outer space, a vessel has gone up from a country whose people actually regard the moon as a god.

The Chandrayaan (or “moon craft”) is the closest India has got to the moon since the epic Hindu sage, Narada, tried to reach it on a ladder of considerable (but insufficient) length — as my grandmother’s bedtime version of events would have it. So think of this as a modern Indian pilgrimage to the moon.

As it happens, a week before the launching, millions of Hindu women embarked on a customary daylong fast, broken at night on the first sighting of the moon’s reflection in a bowl of oil. (This fast is done to ensure a husband’s welfare.) But reverence for the moon is not confined to traditional Indian housewives: The Web site of the Indian Space Research Organization — the body that launched the Chandrayaan — includes a verse from the Rig Veda, a sacred Hindu text that dates back some 4,000 years: “O Moon! We should be able to know you through our intellect,/ You enlighten us through the right path.”

One is tempted, in all this, to dwell on the seeming contradiction between religion and science, between reason and superstition. And yet, anyone who has been to India will have noted also its “modernity of tradition.” The phrase, borrowed from the political scientists Lloyd and Susanne Rudolph, might explain the ability of devout Hindus — many of them, no doubt, rocket scientists — to see no disharmony between ancient Vedic beliefs and contemporary scientific practice.

The Hindu astrological system is predicated on lunar movements: so the moon is a big deal in astrology-obsessed India. That said, the genius of modern Hinduism lies in its comfort with, and imperviousness to, science. A friend tells me of an episode from his childhood in Varanasi, the sacred Hindu city. Days after Apollo 11 landed on the moon, a model of the lunar module was placed in a courtyard of the most venerable temple in the city. The Hindu faithful were hailing man-on-the-moon; there was no suggestion that the Americans had committed sacrilege. (Here, I might add — with a caveat against exaggeration — that science sometimes struggles to co-exist with faith in the United States in ways that would disconcert many Indians.)

Of course, the Chandrayaan is also a grand political gesture — space exploration in the service of national pride. This kind of excursion may provoke yawns at NASA, but judging from round-the-clock local coverage it has received, the mission has clearly inflamed the imagination and ambition of Indians. Yes, even moon-worshipping ones.

Among the many tough decisions facing the next president is the future of our civilian space program. There are conflicts over how long to fly the space shuttle, which are linked to questions about continued American access to the international space station — built at the cost of billions of U.S. taxpayer dollars — and whether U.S. astronauts will return to the moon before 2020.

The premiere this week of the PBS “Nova” documentary “Space Shuttle Disaster” brings many of these questions to the fore. The 2003 Columbia Accident Investigation Board, of which I was a member, concluded that the United States should “replace the shuttle as soon as possible as the primary means for transporting humans to and from Earth orbit.” In practical terms, lacking any U.S.-created alternative, retiring the shuttle would mean relying on the Russian Soyuz spacecraft to carry American astronauts to the space station for at least four years. NASA Administrator Mike Griffin has described U.S. dependence on Russia for transportation to space as “unseemly.” Indeed it is, but it is preferable to continuing to fly the shuttle past 2010. Another accident could delay or even end the U.S. program of human spaceflight.

This choice is made more complex by renewed Russian assertiveness, as demonstrated by its incursion into disputed Georgian territory in August. A decision not to use Soyuz could increase tensions in other areas of the U.S.-Russian relationship. Should altering American plans to depend on the Soyuz spacecraft be one of the ways in which the U.S. government shows its disapproval of Russian actions?

I think not. The United States would benefit from working to maintain the positive space relationship that has evolved between our two countries, particularly over the past 15 years. Pressure has recently been mounting on NASA to fly the shuttle beyond 2010, but I see no compelling reason to go against the judgment of the Columbia board. Yes, NASA has made many improvements in the shuttle since the accident with Columbia. But the shuttle remains a very risky vehicle.

NASA estimates the probability of losing the crew on any single shuttle mission as one in 80. The chances for disaster if 10 additional shuttle flights are scheduled between 2011 and 2015 are simply too high. Losing another crew would probably result in a multiyear delay in the U.S. human spaceflight program and undercut plans for resuming exploration beyond Earth’s orbit.

Beginning next year, the international space station will have a six-person crew that must be able to exit immediately as a safety measure. Two Soyuz spacecraft, which each carry three people, need to be in place at the space station at all times. The shuttle, never designed for long stays in space, is not able to stay at the space station longer than a few weeks at a time; this rules it out as a viable rescue option.

The shuttle is also very expensive to operate; this year’s shuttle budget is close to $3 billion. If the United States continues to spend that money on flying the shuttle beyond 2010, it will take even longer to develop a replacement vehicle, further delaying U.S. plans to venture beyond low Earth orbit.

The prudent choice here is to get on with current plans, which call for a U.S.-led international effort to return to the moon and then prepare for voyages to Mars. This is a smarter and more forward-looking decision than continuing to operate a costly, flawed system. The space shuttle is a remarkable technological achievement, but replacing it soon is the best path to the future. We should not let false pride or international tensions get in the way of an intelligent approach to exploring the final frontier.

As we face $4.50 a gallon gas, we also know that alternative energy sources — coal, oil shale, ethanol, wind and ground-based solar — are either of limited potential, very expensive, require huge energy storage systems or harm the environment. There is, however, one potential future energy source that is environmentally friendly, has essentially unlimited potential and can be cost competitive with any renewable source: space solar power.

Science fiction? Actually, no — the technology already exists. A space solar power system would involve building large solar energy collectors in orbit around the Earth. These panels would collect far more energy than land-based units, which are hampered by weather, low angles of the sun in northern climes and, of course, the darkness of night.

Once collected, the solar energy would be safely beamed to Earth via wireless radio transmission, where it would be received by antennas near cities and other places where large amounts of power are used. The received energy would then be converted to electric power for distribution over the existing grid. Government scientists have projected that the cost of electric power generation from such a system could be as low as 8 to 10 cents per kilowatt-hour, which is within the range of what consumers pay now.

In terms of cost effectiveness, the two stumbling blocks for space solar power have been the expense of launching the collectors and the efficiency of their solar cells. Fortunately, the recent development of thinner, lighter and much higher efficiency solar cells promises to make sending them into space less expensive and return of energy much greater.

Much of the progress has come in the private sector. Companies like Space Exploration Technologies and Orbital Sciences, working in conjunction with NASA’s public-private Commercial Orbital Transportation Services initiative, have been developing the capacity for very low cost launchings to the International Space Station. This same technology could be adapted to sending up a solar power satellite system.

Still, because building the first operational space solar power system will be very costly, a practical first step would be to conduct a test using the International Space Station as a “construction shack” to house the astronauts and equipment. The station’s existing solar panels could be used for the demonstration project, and its robotic manipulator arms could assemble the large transmitting antenna. While the station’s location in orbit would permit only intermittent transmission of power back to Earth, a successful test would serve as what scientists call “proof of concept.”

Over the past 15 years, Americans have invested more than $100 billion, directly and indirectly, on the space station and supporting shuttle flights. With an energy crisis deepening, it’s time to begin to develop a huge return on that investment. (And for those who worry that science would lose out to economics, there’s no reason that work on space solar power couldn’t go hand in hand with work toward a manned mission to Mars, advanced propulsion systems and other priorities of the space station.)

In fact, in a time of some skepticism about the utility of our space program, NASA should realize that the American public would be inspired by our astronauts working in space to meet critical energy needs here on Earth.

The triumphant landing of the Phoenix craft on Mars is a tribute to the team of engineers at the Jet Propulsion Laboratory in California – one of whom, Peter Smith, was a colleague of mine on the Beagle 2 mission to the planet in 2003. Using the Mars reconnaissance orbiter, they selected an excellent place to land, and were able to use thrusters to hit the spot safely and softly.

But it’s also a tribute to the perseverance of Nasa, which has launched missions to the planet every 26 months. They have built at least 23 orbiting spacecraft, and have now had three successful landings. They’ve had a policy of following the water, the essential element of life. We have known for 200 years that Mars has polar caps, which could have contained a mixture of water and carbon dioxide. Nasa has seen, from orbit, where the most likely places are for water to be found; they have also identified minerals that appear to have been deposited from water. But though the orbiters can suggest water is present – from radar signals and an abundance of hydrogen – they haven’t been able to identify water unambiguously. That’s why Nasa has had to send a lander.

It is, though, very difficult to steer a craft towards the poles – orbiting around the equator is far easier – so the Phoenix mission has landed at a site which is, in relative terms, as far north as Greenland. The pictures beamed back so far show no obvious signs of snow or ice, but the craft’s robotic arm can reach up to two metres, and dig a trench, in the hope that there is permafrost to be found below the surface.

I’m 99% certain they will find water. And, if so, they will also be able to identify the salts within it, and whether they are suitable for micro-organisms to live on. They’ll be able to clearly answer whether this place could be suitable for life to evolve. They are also going to check for organic molecules. I really hope they find them. Though we have found carbon on meteorites on earth, nobody has ever discovered a single atom of carbon on Mars – other than the carbon dioxide in the atmosphere.

And this is where the mission’s limitations could set in. The measuring equipment they have on board won’t be able to tell if any carbon is biological (ie, living carbon) or simply the debris of meteorites that may have crashed on the planet.

I can’t help feeling frustrated, because the Beagle 2 mission would have been able to make this distinction. The Phoenix design is based on a craft that crash-landed in 1999, and building Beagle technology into this mission simply wasn’t feasible in the planning time they had. After the 1999 loss, Nasa simply shrugged their shoulders, learned their lessons, and got on with the next mission. With Beagle, the British government and the European Space Agency sighed a collective “oh dear,” and stopped there. There was no reason why another Beagle mission couldn’t have worked, but they seemed to lose the will to go on.

As it is, the next European mission will not be until 2015, by which time it may feel out of date (and there’s a chance it may not happen). It will cost €1.5bn, six times more than the current Nasa mission. That’s why I get frustrated, because it proves this is not a question of money: a Beagle mission would have been even cheaper than Nasa’s, so the ESA could easily have tried again.

We had enough time to have launched another mission last year, ahead of Nasa, and with instruments capable of identifying every carbon atom in all its forms – to detect whether life exists, or has ever existed.

We could have solved the question all humanity really wants answered: are we alone? If we could show that life on Earth was not unique, the discovery would be on a par with Copernicus saying the Earth went round the sun. It would bring a fundamental shift in the way we all think about ourselves.

Nasa have another spacecraft, set to launch in 2009, that will be carrying a much more sophisticated instrument on a car-sized, roving module. With their findings from Phoenix, they will be able to choose a suitable landing spot and give themselves a much better chance of answering whether there is, or was, life on Mars. These are big stakes. If a British mission had made this breakthrough, it would have inspired our whole country: we’d have kids wanting to take up science, which is what so many people want; and we would have sent a message to the world that Britain, once the dominant power over the seas, is now a space-faring nation.

As it is, Britain and Europe chose shortsightedness over scientific endeavour. Their inaction must go down as a huge missed opportunity.

It is more than 35 years since Harrison Schmidt and Eugene Cernan, the last men on the Moon, returned to Earth. The Apollo programme now seems a remote historical episode: children all over the world learn that America landed men on the Moon, just as they learn that the Egyptians built the Pyramids; but the motivations seem almost as bizarre in the one case as in the other.

The recent film In the Shadow of the Moon depicted these historic – indeed heroic – events, but to today’s young audiences the outdated gadgetry and the “right stuff” values seemed almost as antiquated as a traditional Western. Manned spaceflight has never recovered the same glamour – understandably so, because it hardly seems inspiring, nearly 40 years after the Apollo lunar landings, for astronauts merely to circle the Earth in the Space Shuttle and the International Space Station. Ironically, it is only when disaster has struck, as it has twice in more than 100 launches, that the shuttle has made real headlines.

The burgeoning scientific, environmental, commercial and military applications of space have not needed manned spaceflight, but have benefited from the technical advances – unimagined in the 1970s – that have given us mobile phones and the internet. Close-ups of the Martian surface and of Jupiter’s moons, and cosmic images from the Hubble telescope, received more media coverage than routine shuttle flights. We depend on space technology for communications, weather forecasting, mapping, position-finding and so forth – quite apart from the science it has given us.

Just this week, astronauts are installing the European-built “Columbus module” – a laboratory for scientific experiments – on the space station. This is in itself good news, but it is the end of a prolonged and unsatisfactory saga. This laboratory was conceived in the early 1980s; it was named in the hope that it would be launched on the 500th anniversary of Columbus’s voyage. It is therefore 16 years late, and few regard this as good value for money. Without a redefined mission the space station, even when completed, will remain a turkey in the sky.

It is claimed by Nasa that tens of billions more dollars must be spent to finish the space station, in order to keep faith with the foreign partners who have built parts of it. However, whatever their public rhetoric, most European scientists regret having got involved; they could all have been contentedly paid off far more cheaply than it will cost the Americans to finish the space station. Indeed, I think the real, albeit undeclared, reason for persisting with the project is that, were the US to abandon it, the Russians would then take full possession of the “high ground” – and to the Americans that would be a massive indignity. And there is now a challenge from the Chinese, who may be the next nation to land a man on the Moon.

President Bush has proposed a long-term programme to return to the Moon, establish a manned base there and then go to Mars. Were I an American taxpayer, I would be opposed to this: if it is done Nasa-style, it will be hugely expensive and vulnerable to delays and political setbacks. I hope, nonetheless, that some people now living will walk on Mars – though they will be adventurers, perhaps sponsored privately or commercially, accepting extreme cost-cutting and much higher risks than it is politically acceptable for Nasa to impose on publicly funded civilian astronauts.

As a European, I believe we should learn a lesson from the space station, and limit our collaboration with Nasa to “bite-sized” unmanned projects; we should be wary of committing ourselves, as an inevitably “minor partner”, to a hugely expensive manned programme.

In economic and intellectual firepower, Europe is fully a match for the US. But the activities of Europe’s Space Agency (ESA), though successful and generally cost-effective, have been more modest: America’s activities in space were ramped up to a higher level because of superpower rivalry during the Cold War. But most of Nasa’s large budget is spent on the Shuttle and the space station, and will thereafter be committed to further manned projects. If we in Europe eschewed manned spaceflight (unless tickets became very cheap) and concentrated our expenditure on space robotics, fabrication and miniaturisation, we could gain an ascendancy over the US in all those aspects of space that are of greatest practical value, as well as of greatest scientific interest.

Even by European standards, space has not figured highly in our national priorities: France has been far more committed. However, we have achieved successes in space science, and in important niche markets as well – for instance, the University of Surrey’s commercial microsatellites. But it is now time for the UK, which has been a minor player even within Europe, to raise its game.

Everyone has heard of Nasa, many have heard of ESA, but few have heard of BNSC (the British National Space Centre). That is why the Royal Society has urged a higher-profile UK space agency so that we can seek cost-effective collaborations with India, China and the US, as well as within Europe, and promote and develop our nation’s success in the cost-effective use of space, and the associated “cutting-edge” technologies.

Today the Government publishes a new strategy for space. This is an opportunity to increase our leverage in high-tech developments that are becoming ever more pervasive in our lives – and to recover some of the inspiration of the open frontier.

Fifty years ago this week, America was shaken out of technological complacency by a beeping 180-pound aluminum ball orbiting overhead. Sputnik was a shock because we had always assumed that Russia was nothing but a big, lumbering and all-brawn bear. He could wear down the Nazis and produce mountains of steel but had none of our savvy or sophistication. Then one day we wake up and he has beaten us into space, placing overhead the first satellite to orbit the Earth since God placed the moon where it could give us lovely sailing tides.

At the time, all thoughts were about the Soviets overwhelming us technologically. But the panic turned out to be unwarranted. Sputnik was not subtle science. The Soviets were making up for their inability to miniaturize nuclear warheads — something that does require sophistication — by developing massive rockets. And they had managed to develop one just massive enough to hurl a ball into Earth orbit.

We had no idea how lucky we were with Sputnik. The subsequent panic turned out to be an enormous boon. The fear of falling behind the Communists induced the federal government to pour a river of money into science and math education. The result was a vast cohort of scientists who gave us not only Apollo and the moon, but the sinews of the information age — for example, ARPA (established just months after Sputnik) created ARPANET, which became the Internet — that have ensured American technological dominance to this day.

There was another lucky outcome of Sputnik. Two years earlier, President Dwight D. Eisenhower had proposed “Open Skies,” under which the United States and Russia would permit spy-plane overflights so each would know the other’s military capabilities. The idea was to reduce mutual uncertainty and strengthen deterrence. Soviet leader Nikita Khrushchev rejected the idea out of hand.

The advent of the orbiting satellite circumvented the objection. By 1960, we had launched our first working spy satellite. But our greatest luck was the fact that the Soviets got to space first. Sputnik orbiting over the United States — and Eisenhower never protesting a violation of U.S. sovereignty — established forever the principle that orbital space is not national territory but is as free and open as the high seas. Had we beaten the Russians into orbit — and we were only a few months behind — Khrushchev might very well have protested our presence over sovereign Soviet territory and reserved the right to one day (the technology was still years away) shoot us down.

Sputnik and the space age it launched had one other curious, wholly unexpected effect. Before Sputnik, while still dreaming about outer space in science fiction, we always assumed that one step would create the hunger for the next — ever outward from Earth orbit to the moon to Mars and beyond.

Not so. It took only 12 years to go from Sputnik to the moon, which we jumped about on for a brief interlude and then, amazingly, abandoned.

There are technological, budgetary and political reasons to explain this. But the most profound is psychological. It’s cold out there. “In the Shadow of the Moon” is a magnificent new documentary of the remembrances of some of those very few human beings who have actually gone to the moon. They talk, as you’d expect, about the wonder and beauty and grandeur of the place. But some also recall the coldness of that desolation. One astronaut tells how on the moon’s surface he was seized with the realization that he and his crewmate were utterly alone on an entire world.

On Earth, you can be wandering a forbidding desert but always with the hope that there might be something human over the horizon. On the moon there is nothing but dust and rock, forever. And then — just about all the astronauts talk about this — you look up and see this beautiful blue marble, warm and fragile, hanging in the black lunar sky. And you long for home.

The astronauts brought back that image in the famous photo “Earthrise” — and, with it, that feeling of longing. That iconic image did not just help spur the environmental movement. With surpassing irony, it created at the very dawn of the space age a longing not for space but for home.

This is perhaps to be expected for a 200,000-year-old race of beings leaving its crib for the first time. We will, however, outgrow that fear. It was 115 years from Columbus to the Jamestown colony. It will take about that same span of time for a new generation — ours is too bound to Earth — to go out and not look back.

Fifty years ago, on October 4 1957, my father, the Soviet premier Nikita Khrushchev, was waiting for a call from Kazakhstan: the designer, Sergei Korolev, was due to report on the launch of the world’s first satellite. My father was in Ukraine, on military business, and that evening he dined with Ukrainian leaders. I sat at the end of the table, not paying attention to their conversation. Around midnight my father was asked to take a phone call. When he came back, he was smiling: Sputnik’s launch had been successful.

Soviet engineers began designing Sputnik in January 1956. The plan was to launch it with an intercontinental ballistic missile in development since 1954. But the rest of the world paid no attention to the vague pronouncements of a possible launch that had been appearing in the Soviet press; everybody outside the Soviet Union thought the US would launch the world’s first satellite.

Soviet scientists believed that the Americans would keep their plans secret until after they had succeeded in launching a satellite, so all our efforts were put into beating the Americans to the launch. In August and September, missiles were successfully launched. Work went on around the clock.

Sputnik’s launch made the front page of Pravda but without banner headlines. The reason was simple. My father and all the Soviet people thought that Sputnik’s success was natural; that, step by step, we were getting ahead of the Americans. After all, we – not the Americans – had opened the world’s first nuclear power plant, our MiG jets set world records and the Soviet Tu-104 was the most efficient airliner of its class.

Nor did the press report Korolev’s name. The KGB knew that there was really no need to keep his name secret, but, as the then KGB chief, Ivan Serov, told me, the enemy’s resources were limited, so let them waste their efforts trying to uncover “non-secret” secrets. The world, however, was desperate to learn his identity, and when the Nobel prize committee decided to give an award to Sputnik’s “chief designer”, it requested his name from the Soviet government.

My father weighed his response carefully. His concern wasn’t confidentiality. The council of chief designers was in charge of all space projects. Korolev was the head, but the others – more than a dozen – considered themselves no less significant. My father knew they were ambitious, jealous people. If the prize went only to Korolev, the others would fly into a rage and refuse to work with him. A well-organised team would collapse, dashing the hopes for future space research. As my father saw it, you could order scientists to work together, but you couldn’t force them to create.

In the end, my father told the Nobel committee that all of the Soviet people had distinguished themselves on Sputnik and all deserved the award. The Nobel prize went to somebody else.

But despite the pains my father had taken, the other designers felt discontent about Korolev taking the credit. The first to revolt was designer Valentin Glushko, whose liquid-propellant engine was used on Russian – and some US – rockets. During one meeting, Glushko said: “My engines could send into space any piece of metal.” Korolev was offended; his rocket wasn’t just a piece of metal. The dispute led to Glushko offering his services to Korolev’s rivals.

My father couldn’t make peace between them. Glushko, by government decree, continued to design engines for Korolev, but the work wasn’t good. So, despite Sputnik’s initial triumph, a decade later the Soviet Union lost the race to the moon.

Decades ago, a shift in NASA priorities sidelined progress in human space exploration. As momentum gathers to reinvigorate human space missions to the moon and Mars, we risk hurting ourselves, and Earth, in the long run. Our planet — not the moon or Mars — is under significant threat from the consequences of rapid climate change. Yet the changing NASA priorities will threaten exploration here at home.

NASA not only launches shuttles and builds space stations, it also builds and operates our nation’s satellites that observe and monitor the Earth. These satellites collect crucial global data on winds, ice and oceans. They help us forecast hurricanes, track the loss of Arctic sea ice and the rise of sea levels, and understand and prepare for climate changes.

NASA’s budget for science missions has declined 30 percent in the past six years, and that trend is expected to continue. As more dollars are reallocated to prepare for missions back to the moon and Mars, sophisticated new satellites to observe the Earth will be delayed, harming Earth sciences.

The National Academy of Sciences has noted that the Landsat satellite system, which takes important measurements of global vegetation, is in its fourth decade of operation and could fail without a clear plan for continuation. The same is true for the QuikSCAT satellite, which provides critical wind data used in forecasting hurricanes and El Niño effects.

In January, a partnership of university and NASA scientists demonstrated that climate change and higher ocean temperatures were reducing the growth of microscopic plants and animals at the heart of the marine food web.

Their analysis was based on nearly a decade of NASA satellite measurements of ocean color, which unfortunately are at risk of being interrupted for several years.

Sea levels are rising, and the Arctic Ocean may be ice-free in summer. The buildup of carbon dioxide in the oceans threatens to make them more acidic, which may in turn hinder the ability of some types of marine life, including corals, to build their shells and skeletons. We must learn as much as we can to assess these threats and develop solutions.

Satellites provide coverage of vast, remote regions of our planet that would otherwise remain unseen, especially the oceans, which play an important role in climate change. Without accurate data on such fundamentals as sea surface height, temperatures and biomass, as well as glacier heights and snowpack thickness, we will not be able to understand the likelihood of dangers such as more severe hurricanes along the Gulf Coast or more frequent forest fires in the Pacific Northwest.

Climate change is the most critical problem the Earth has ever faced.

Government agencies and the private sector, as well as individual citizens, need to better grasp the risks and potential paths of global climate change. Mitigating these risks and preparing for the effects of warming will require scientific understanding of how our complex planet operates, how it is changing, and how that change will affect the environment and human society.

John F. Kennedy’s brilliant call to put a man on the moon by the end of the 1960s set an arbitrary deadline, but the deadline we face today is set by nature. NASA must continue to play a vital role in helping find ways to protect our planet for (and perhaps from) its intelligent life. Exploration of space is a noble quest. But we can’t afford to be so starry-eyed that we overlook our own planet.

AFTER years of spending our nation’s space budget building an orbiting space station of questionable utility, serviced by an operationally expensive space shuttle of unsafe design, NASA has set a new direction for the future of human spaceflight. Once again, we have our sights on the Moon … and beyond. We are finally, bodily, going to make our way into space, this time to stay.

It is an opinion long and widely held within the space-exploration community that the Nixon administration’s termination of the program that built the Saturn V Moon rocket was a gargantuan mistake.

One of the biggest challenges in exploring space is propulsion — that is, getting from point A to B efficiently, safely and quickly. And when the cargo is human, the challenges are even greater. One of our crowning technological achievements during the 1960s was the Apollo program and, in particular, the development of the Saturn V rocket. The Saturn V was the largest, most powerful vehicle the United States had ever built. It had a launching capacity more than five times greater, a developmental cost 25 percent lower and a build-and-operate cost less than half of that of today’s space shuttle.

In those early days, the possibilities for human space travel were intoxicating. Back then, NASA plans called for an aggressive integrated human flight program that would expand on the developments of Apollo: the establishment of a 50-person lunar base, a 100-person Earth-orbiting space station and human landfall on Mars, all by the mid-1980s. Those plans also included a 50-person semi-permanent Martian base by the end of the 20th century. Instead, we went nowhere.

Why? Because, largely for political reasons, we renounced the Moon, abandoned Apollo and the Saturn V and retreated to low Earth orbit, where we’ve spent the last 25 years going around in circles.

The cost to the nation of this misstep was enormous. For starters, we lost an investment, adjusted for inflation to 2007 dollars, of $160 billion. That was the cost to get to, land on, walk on, drive on and otherwise explore the Moon. (Of that amount, $29 billion, in inflation-adjusted dollars, was the approximate cost of the Saturn V.)

What’s more, the production facilities for the Saturn V and the other lunar exploration components, like the command and lunar modules, were all closed. At that point, we lost both the technological means for human deep space exploration and the collective knowledge of tens of thousands of engineers and scientists trained in human spaceflight.

Equally troubling is what we put in place of Apollo. The $38 billion developmental cost of the shuttle has gotten us nowhere in the solar system fast. And the International Space Station could have been built with only half a dozen Saturn V launchings instead of the more than two dozen shuttle trips that will be required to finish it. The bottom line: a colossal misuse of funds and a disheartening lack of progress and loss of time.

The termination of the Saturn V program also had a stifling effect on the robotic exploration of other planets. In essence, we lost the ability to deliver larger, and in some cases faster, payloads elsewhere in the solar system.

Take, as an example, the 5,600-kilogram Cassini spacecraft, which was launched in 1997 and is now in orbit around Saturn. Its launching was timed so that after spending two years looping around the inner solar system to pick up speed, it could rendezvous with massive Jupiter for an additional boost that would send it to Saturn. All told, its flight time took seven years.

Had the Saturn V, modified with an appropriate fourth upper stage, been used to launch Cassini directly to Jupiter first, its flight time to Saturn could have been cut by more than half. In space, as on Earth, time is money, and the money saved could have been spent elsewhere.

Alternatively, for the same flight time, a vehicle of greater launching capacity can deliver a heavier payload. Take as an example the 480-kilogram New Horizons spacecraft, launched over a year ago to fly by Pluto in 2015 and eventually to explore the Kuiper Belt of icy debris that lies beyond it. Had it been launched on a modified Saturn V rocket, New Horizons could have carried a payload that was 15 times heavier and far more scientifically capable.

In the end, instead of having a ubiquitous presence throughout the solar system, humans haven’t set foot on the Moon in 35 years, and even our robotic explorations in that time have been throttled because we deliberately reduced our access to deep space.

Today, however, NASA is again looking up and out. Vigorous efforts are under way to complete the space station in order to fulfill international commitments that would be unwise to violate. When that is done, the plan is to retire the space shuttle in 2010 in favor of a new program to return to the Moon, with a party of humans, by 2020. A mainstay of this program is the Ares launching system, capable of sending 65 metric tons to the Moon — exceeding the capacity of the Saturn V by more than 40 percent.

The official plans call not for flag-planting and grab-a-few-rocks-and-go but, by 2025, a solar-powered, human-tended, continuously inhabited research outpost rising from either the north or south pole of the Moon, where sunlight is persistent and water ice may be present. Sustainability, made possible in part by the use of lunar resources, is one goal. Another is on-site preparations for a push to the next outpost, Mars.

And human spaceflight is not the only enterprise to benefit. Robotic reconnaissance, which by necessity must precede the dispatch of humans, has been ongoing for nearly 50 years. In that time, all the simple things have been done. Future missions to the planets and their moons will be more ambitious than anything yet tried.

As one example, imagine what our future robotic travels around Saturn might be like. The Saturn planetary system includes Titan, a cold Mercury-sized moon with a dense, organic-laden, hazy atmosphere and a strangely Earth-like, variegated surface sculptured by winds and hydrocarbon rains. It also includes Enceladus, a moon one-tenth the size of Titan, whose jets of water vapor and fine icy particles extend thousands of miles into space and may very likely erupt from organic-rich liquid water reservoirs just below its surface — making this satellite arguably the most promising target we have available to us for astrobiological investigation.

A scientifically comprehensive mission to this part of the solar system, using Ares and a Cassini-like trajectory to Saturn, could easily include several exploratory vehicles. One would be a Saturn orbiter far more capable than Cassini. This vehicle, in turn, would be large enough to carry and deliver a fully equipped balloon-borne scientific payload to float through the atmosphere of Titan and study its surface up close, and an Enceladus lander with equipment that could determine the moon’s physical properties and ascertain whether or not pre-biotic chemistry, and perhaps life, has arisen there.

In other words, robotic exploration, and the insights that will be gained from it into the character, development and evolution of planetary bodies and even life itself, will be taken to new heights and, in turn, pave the way for the eventual arrival of humans throughout the solar system. Anyone up for an extreme excursion to the Enceladus Interplanetary Geyser Park?

All told, the subtext is invigorating and unmistakable: Humanity’s future need not be confined to mere survival on our home planet. Other worlds beckon, we know how to reach them and we will once more be outward bound.

And we will not be alone. China, India and Russia, all eager to be or remain prominent players on the world stage, have independent plans to stride the lunar surface. And Australia, Canada, Japan and the member nations of the European Space Agency will be pooling their resources with us in the return to the Moon — a circumstance that will bring the cost of the effort to any one nation within reason.

THIS won’t be a space race so much as a global exodus undertaken by an international community. And peaceful cooperation among nations, as a tangible means to build strong lasting international partnerships and defuse tensions and conflicts in the future, will be a welcome result.

In hindsight, maybe the pace of progress was predictable. Humans first explored Antarctica in the early 20th century. Decades passed before we had the technology that would allow us to establish a permanent presence. History will indicate the same for our interplanetary forays. Our initial “small step for a man” on the Moon took place in 1969. A half-century later, we will be there anew, to live and work.

To reach that future will require two critical ingredients: adequate financing and a long-term cross-administration commitment that supports steady, uninterrupted progress. Our first reach for the Moon took us from President Kennedy’s spoken words to the lunar surface in little over eight years under a budget profile that saw peaks in annual NASA budget of more than $30 billion in current dollars — a shocking number by today’s standards and a good measure of how important we then considered the endeavor.

While sustained budgets of that magnitude are out of the question today, what is not out of the question is our ability to pay to keep the goal front and center. We are now spending in Iraq, in a single month, $9 billion — more than half the annual budget NASA needs to stay on course.

Forty-five years ago today, John Glenn Jr. became the first American to venture into orbit around the Earth. Just 9 years old, I knew at that moment that the future would be big and wide, and that I might go places no one had ever been before.

There could be no better way today to encourage an equally optimistic belief in the future than to embark on an odyssey that presents tremendous challenges, demands discipline and rigor, requires decades-long focus, inspires international cooperation, promotes lasting peace, improves life for all and paints a stirring vision of an expanded human presence beyond the Earth. There could be no better way to say: the future is boundless, and it belongs to us.

The Moon was always the reflection of our dreams. Only in the most recent fraction of human history have we known that it is a place, a rock, a thing, rather than an idea, a phenomenon or a god.

The moon was a veiled ghost, the deity of time and madness. It pulled the tides, measured out our months and perhaps too the ovulation of woman, the origin of human life itself.

We gave the Moon names, in every culture, and for every season: Harvest Moon, Blue Moon, Strawberry Moon. The Sun has no equivalent adjectival richness. For century after century, we gazed at the Moon and wondered what it was. When John Heywood remarked in his Proverbes of 1546 that “The moon is made of greene cheese” (greene meaning freshly made, not rotten) he was making an ironic comment on human nature: we did not know what the Moon was, but imagining it was an evergreen preoccupation.

The very first Inquisition victims to be burnt as witches worshipped the lunar goddess Madonna Oriente. Where some cultures detected a man in the Moon’s face, others saw a rabbit, a frog, a buffalo. Shelley saw an “orbed maiden”. In Nepal, the dead reside in the Moon. Jack and Jill (who went up the hill) were originally Hijuki and Bil of Norse myth, whose journeys uphill and down are a metaphor for the waxing and waning of the Moon.

The Moon seemed close — so close that a cow might jump over it — but also impossibly distant. The ancients even debated the peculiar proposition that the “Moon is exactly as large as it looks”. The Moon was a metaphor for the unreachable, the virgin Diana in Roman myth, unattainably distant.

In an extraordinary surge of ingenuity, we did reach the Moon in 1969, and walked on it and gathered its dust and rocks. Then, just as suddenly in the scale of human history, like a child abandoning a gift it has long coveted, we discarded the Moon. “The Moon is about as interesting as an old gravel quarry,” remarked the novelist J. G. Ballard. The Moon no longer seemed strange and divine, but a dull, dead stone.

For the past 30 years we have not ventured further than 400 miles from the Earth’s surface. Most of us barely notice the Moon now; indeed, due to light pollution, it is sometimes barely visible. Space travel was born in the fantasies of H. G. Wells and Jules Verne, and made real by the extravagant creativity of modern science, but once we had walked across it, the Moon ceased to be a source of imaginative inspiration. Since the 1970s space science has concentrated on unmanned robotic probes and orbiting stations more than human exploration and discovery. It seemed that the poet Jack Anderson might have been right: “To set foot on the Moon even once, is to corrupt it utterly.” The Man in the Moon was dead.

But now, it seems, he may be coming back to life. Nasa unveiled plans this week to build a permanent Moon base within 20 years, a stepping stone to Mars, but also a lookout point from which to monitor the Earth. The project is daunting, for the new base will have to generate water, breathable oxygen and perhaps hydrogen rocket fuel, on site, in fantastically harsh conditions. Like every voyage to a new world, it will require untapped reservoirs of intelligence, technology and raw courage.

Putting Man back on the Moon may put the wonder of the Moon back in Man, with incalculable benefits, scientifically and culturally. Exploration is the index of cultural vigour, and every vibrant society has always looked beyond its horizons. Only stagnating cultures stare inward.

The last Moon race helped to create satellites, mobile telephone batteries, inertial guidance and Velcro. The Moon is just three days away, an ideal supply base for voyaging farther into space. The last Moon landings were fuelled by Cold War rivalry, but for the next stage Nasa is looking to pool global knowledge, inviting contributions from China, Russia and Europe. This time around, we come to the Moon not as national colonists but as interplanetary pilgrims, and now we are planning to stay, if our nearest neighbour will accommodate us.

Getting there will be cheap at the price. The Moon mission in the decade after 1962 cost less than the Vietnam War did in any single year: apply that accountancy to the Iraq war, and the trip to the Moon and points beyond looks like a bargain.

Most importantly, by becoming, at last, a multi-planet species, we can look back at our Earth and perhaps understand it better. Four billion years of history in this small corner of the solar system are written in the Moon’s preserved dust; by studying that record we may understand better the evolution of our Sun and the future of our planet. From the Moon, we will be able to monitor our own ice caps and oceans.

This week scientists reported what appeared to be streaks of mineral deposits on the face of Mars, evidence of liquid water, crucial to sustaining life. By working out the fate of water on the red planet we might slow or stop the wreckage of our green one.

Apollo 8’s Jim Lovell once remarked that going to the Moon “makes you realise just what you have got back there on Earth”. That is what exploration means: it is about getting there, and being there, but mostly it is about coming home. As T. S. Eliot wrote:

We shall not cease from exploration
And the end of all our exploring
Will be to arrive where we started
And know the place for the first time.

The Moon is not a god, or a lump of cheese; it is an idea, eons ancient, that we must now rediscover in order to know our own place for the first time.