Pale Blue Dot

  The notion that rare materials might be available elsewhere is tempered by the fact that freightage is high. There may, for all we know, be oceans of petroleum on Titan, but transporting it to Earth will be expensive. Platinum-group metals may be abundant in certain asteroids. If we could move these asteroids into orbit around the Earth, perhaps we could conveniently mine them. But at least for the foreseeable future this seems dangerously imprudent, as I describe later in this book.

  In his classic science fiction novel The Man Who Sold the Moon, Robert Heinlein imagined the profit motive as the key to space travel. He hadn't foreseen that the Cold War would sell the Moon. But he did recognize that an honest profit argument would be difficult to come by. Heinlein envisioned, therefore, a scam in which the lunar surface was salted with diamonds so later explorers could breathlessly discover them and initiate a diamond rush. We've since returned samples from the Moon, though, and there is not a hint of commercially interesting diamonds there.

  However, Kiyoshi Kuramoto and Takafumi Matsui of the University of Tokyo have studied how the central iron cores of Earth, Venus, and Mars formed, and find that the Martian mantle (between crust and core) should be rich in carbon—richer than that of the Moon or Venus or Earth. Deeper than 300 kilometers, the pressures should transform carbon into diamond. We know that Mars has been geologically active over its history. Material from great depth will occasionally be extruded up to the surface, and not just in the great volcanos. So there does seem to be a case for diamonds on other worlds—on Mars, lied not the Moon. In what quantities, of what quality and size, and in which locales we do not yet know.

  The return to Earth of a spacecraft stuffed with gorgeous multicarat diamonds would doubtless depress prices (as well as the shareholders of the de Beers and General Electric corporations). But because of the ornamental and industrial applications of diamonds, perhaps there is a lower limit below which prices will not go. Conceivably, the affected industries might find cause to promote the early exploration of Mars.

  The idea that Martian diamonds will pay for exploring Mars is at best a very long shot, but it's an example of how rare and valuable substances may be discoverable on other worlds. It would be foolish, though, to count on such contingencies. If we seek to justify missions to other worlds, we'll have to find other reasons.

  BEYOND DISCUSSIONS OF PROFITS and costs, even reduced costs, we must also describe benefits, if they exist. Advocates of human missions to Mars must address whether, in the long term, missions up there are likely to mitigate any of the problems down here. Consider now the standard set of justifications and see if you find them valid, invalid, or indeterminate:

  Human missions to Mars would spectacularly improve our knowledge of the planet, including the search for present and past life. The program is likely to clarify our understanding of the environment of our own planet, as robotic missions have already begun to do. The history of our civilization shows that the pursuit of basic knowledge is the way the most significant practical advances come about. Opinion polls suggest that the most popular reason for "exploring space" is "increased knowledge." But are humans in space essential to achieve this goal? Robotic missions, given high national priority and equipped with improved machine intelligence, seem to me entirely capable of answering, as well as astronauts can, all the questions we need to ask—and at Maybe 10 percent the cost.

  It is alleged that "spinoff" will transpire—huge technological benefits that would otherwise fail to come about—thereby improving our international competitiveness and the domestic economy. But this is an old argument: Spend $80 billion (in contemporary money) to send Apollo astronauts to the Moon, and we'll throw in a free stickless frying pan. Plainly, if we're after frying pans, we can invest the money directly and save almost all of that $80 billion.

  The argument is specious for other reasons as well, one of which is that DuPont's Teflon technology long antedated Apollo. The same is true of cardiac pacemakers, ballpoint pens, Velcro, and other purported spinoffs of the Apollo program. (I once had the opportunity to talk with the inventor of the cardiac pacemaker, who himself nearly had a coronary accident describing the injustice of what he perceived as NASA taking credit for his device.) If there are technologies we urgently need, then spend the money and develop them. Why go to Mars to do it?

  Of course it would be impossible for so much new technology as NASA requires to be developed and not have some spillover into the general economy, some inventions useful down here. For example, the powdered orange juice substitute Tang was a product of the manned space program, and spinoffs have occurred in cordless tools, implanted cardiac defibrillators, liquid-cooled garments, and digital imaging—to name a few. But they hardly justify human voyages to Mars or the existence of NASA.

  We could see the old spinoff engine wheezing and puffing in the waning days of the Reagan-era Star Wars office. Hydrogen bomb-driven X-ray lasers on orbiting battle stations will help perfect laser surgery, they told us. But if we need laser surgery, if it's a high national priority, by all means let's allocate the funds to develop it. just leave Star Wars out of it. Spinoff justifications constitute an admission that the program can't stand on its own two feet, cannot be justified by the purpose for which it was originally sold.

  Once upon a time it was thought, on the basis of econometric models, that for every dollar invested in NASA many dollars were pumped into the U.S. economy. If this multiplier effect applied more to NASA than to most government agencies, it would provide a potent fiscal and social justification for the space program. NASA supporters were not shy about appealing to this argument. But a 1994 Congressional Budget Office study found it to be a delusion. While NASA spending benefits some production segments of the U.S. economy—especially the aerospace industry—there is no preferential multiplier effect. Likewise, while NASA spending certainly creates or maintains jobs and profits, it does so no more efficiently than many other government agencies.

  Then there's education, an argument that has proved from time to time very attractive in the White House. Doctorates in science peaked somewhere around the time of Apollo 11, maybe even with the proper phase lag after the start of the Apollo program. The cause-and-effect relationship is perhaps undemonstrated, although not implausible. But so what? If we're interested in improving education, is going to Mars the best route? Think of what we could do with $100 billion for teacher training and salaries, school laboratories and libraries, scholarships for disadvantaged students, research facilities, and graduate fellowships. Is it really true that the best way to promote science education is to go to Mars?

  Another argument is that human missions to Mars will occupy the military-industrial complex, diffusing the temptation to use its considerable political muscle to exaggerate external threats and pump up defense funding. The other side of this particular coin is that by going to Mars we maintain a standby technological capacity that might be important for future military contingencies. Of course, we might simply ask those guys to do something directly useful for the civilian economy. But as we saw in the 1970s with Grumman buses and Boeing/Vertol commuter trains, the aerospace industry experiences real difficulty in producing competitively for the civilian economy. Certainly a tank may travel 1,000 miles a year and a bus 1,000 miles a week, so the basic designs must be different. But on matters of reliability at least, the Defense Department seems to be much less demanding.

  Cooperation in space, as I've already mentioned, is becoming an instrument of international cooperation—for example, in slowing the proliferation of strategic weapons to new nations. Rockets decommissioned because of the end of the Cold War might be gainfully employed in missions to Earth orbit, the Moon, the planets, asteroids, and comets. But all this can be accomplished without human missions to Mars.

  Other justifications are offered. It is argued that the ultimate solution to world energy problems is to strip-mine the Moon, return the solar-wind-implanted helium-3 back to Earth, and use it in fusion reactors. What
fusion reactors? Even if this were possible, even if it were cost-effective, it is a technology 50 or 100 years away. Our energy problems need to be solved at a less leisurely pace.

  Even stranger is the argument that we have to send human beings into space in order to solve the world population crisis. But some 250,000 more people are born than die every day—

  which means cans that we would have to launch 250,000 people per day into space to maintain world population at its present levels. This appears to be beyond our present capability.

  I RUN THROUGH such a list and try to add up the pros and cons, bearing in mind the other urgent claims on the federal budget. To me, the argument so far comes down to this question: Can the sum of a large number of individually inadequate Justifications add up to an adequate justification?

  I don't think any of the items on my list of purported justifications is demonstrably worth $500 billion or even $100 billion, certainly not in the short term. On the other hand, most of them are worth something, and if I have five items each worth $20 billion, maybe it adds up to $100 billion. If we can be clever about reducing costs and making true international partnerships, the justifications become more compelling.

  Until a national debate on this topic has transpired, until we have a better idea of the rationale and the cost/benefit ratio of human missions to Mars, what should we do? My suggestion is that we pursue research and development projects that can be justified on their own merits or by their relevance to other goals, but that can also contribute to human missions to Mars should we later decide to go. Such an agenda would include:

  • U.S. astronauts on the Russian space station Mir for joint flights of gradually increasing

  duration, aiming at one to two years, the Mars flight time.

  • Configuration of the international space station so its principal function is to study the

  long-term effects of the space environment on humans.

  • Early implementation of a rotating or tethered "artificial gravity" module on the

  international space station, for other animals and then for humans.

  • Enhanced studies of the Sun, including a distributed set of robot probes in orbit about the

  Sun, to monitor solar activity and give the earliest possible warning to astronauts of

  hazardous "solar flares"—mass ejections of electrons and protons from the Sun's corona.

  • U.S./Russian and multilateral development of Energiya and Proton rocket technology for

  the U.S. and international space programs. Although the United States is unlikely to depend primarily on a Soviet booster, Energiya has roughly the lift of the Saturn V that sent the Apollo astronauts to the Moon. The United States let the Saturn V assembly line die, and it cannot readily be resuscitated. Proton is the most reliable large booster now in service. Russia is eager to sell this technology for hard currency.

  • Joint projects with NASDA (the Japanese space agency) and Tokyo University, the

  European Space Agency, and the Russian Space Agency, along with Canada and other nations. In most cases these should be equal partnerships, not the United States insisting on calling the shots. For the robotic exploration of Mars, such programs are already under way. For human flight, the chief such activity is clearly the international space station. Eventually, we might muster joint simulated planetary missions in low Earth orbit. One of the principal objectives of these programs should be to build a tradition of cooperative technical excellence.

  • Technological development—using state-of-the-art robotics and artificial intelligence—

  of rovers, balloons, and aircraft for the exploration of Mars, and implementation of the first international return sample mission. Robotic spacecraft that can return samples from Mars can be tested on near-Earth asteroids and the Moon. Samples returned from carefully selected regions of the Moon can have their ages determined and contribute in a fundamental way to our understanding of the early history of the Earth.

  • Further development of technologies to manufacture fuel and oxidizer out of Martian

  materials. In one estimate, based on a prototype instrument designed by Robert Zubrin and colleagues at the Martin Marietta Corporation, several kilograms of Martian soil can be automatically returned to Earth using a modest and reliable Delta launch vehicle, all for no more than a song (comparatively speaking).

  • Simulations on Earth of long-duration trips to Mars, concentrating on potential social

  and psychological problems.

  • Vigorous pursuit of new technologies such as constant-thrust propulsion to get us to

  Mars quickly; this may be essential if the radiation or microgravity hazards make one-

  year (or longer) flight times too risky.

  • Intensive study of near-Earth asteroids, which may provide superior intermediate-

  timescale objectives for human exploration than does the Moon.

  • A greater emphasis on science—including the fundamental sciences behind space

  exploration, and the thorough analysis of data already obtained—by NASA and other space agencies.

  These recommendations add up to a fraction of the full cost of a human mission to Mars and—spread out over a decade or so and done jointly with other nations—a fraction of current space budgets. But, if implemented, they would help us to make accurate cost estimates and better assessment of the dangers and benefits. They would permit us to maintain vigorous progress toward human expeditions to Mars without premature commitment to any specific mission hardware. Most, perhaps all, of these recommendations have other justifications, even if We were sure wed be unable to send humans to any other world in the next few decades. And a steady drumbeat of accomplishments increasing the feasibility of human voyages to Mars would—in the minds of many at least—combat widespread pessimism about the future.

  THERE'S SOMETHING MORE. There's a set of less tangible arguments, many of which, I freely admit, I find attractive and resonant. Spaceflight speaks to something deep inside us—many of us, if not all. An emerging cosmic perspective, an improved understanding of our place in the Universe, a highly visible program affecting our view of ourselves might clarify the fragility of our planetary environment and the common peril and responsibility of all the nations and peoples of Earth. And human missions to Mars would provide hopeful prospects, rich in adventure, for the wanderers among us, especially the young. Even vicarious exploration has social utility.

  I repeatedly find that when I give talks on the future of the space program—to universities, business and military groups, professional organizations—the audiences are much less patient with practical, real-world political and economic obstacles than 1. They long to sweep away the impediments, to recapture the glory days of Vostok and Apollo, to get on with it and once more tread other worlds. We did it before; we can do it again, they say. But, I caution myself, those who attend such talks are self-selected space enthusiasts.

  In 1969, less than half the American people thought the Apollo program was worth the cost. But on the twenty-fifth anniversary of the Moon landing, the number had risen to two thirds. Despite its problems, NASA was rated as doing a good-to-excellent job by 63 percent of Americans. With no reference to cost, 75 percent of Americans (according to a CBS News poll) favored "the United States sending astronauts to explore Mars.' For young adults, the figure was 68 percent. I think "explore" is the operative word.

  It is no accident that, whatever their human flaws, and how ever moribund the human space program has become (a trend that the Hubble Space Telescope repair mission may have helped to reverse), astronauts and cosmonauts are still widely regarded as heroes of our species. A scientific colleague tells me about a recent trip to the New Guinea highlands where she visited a stone age culture hardly contacted by Western civilization. They were ignorant of wristwatches, soft drinks, and frozen food. But they knew about Apollo 11. They knew that humans had walked on the Moon. They knew the names of Armstrong and Aldrin and Co
llins. They wanted to know who was visiting the Moon these days.

  Projects that are future-oriented, that, despite their political difficulties, can be completed only in some distant decade are continuing reminders that there will be a future. Winning a foothold on other worlds whispers in our ears that we're more than Picts or Serbs or Tongans: We're humans.

  Exploratory spaceflight puts scientific ideas, scientific thinking, and scientific vocabulary in the public eye. It elevates the general level of intellectual inquiry. The idea that we've now understood something never grasped by anyone who ever lived before—that exhilaration, especially intense for the scientists involved, but perceptible to nearly everyone—propagates through the society, bounces off walls, and comes back at us. It encourages us to address problems in other fields that have also never before been solved. It increases the general sense of optimism in the society. It gives currency to critical thinking of the sort urgently needed if we are to solve hitherto intractable social issues. It helps stimulate a new generation of scientists. The more science in the media-especially if methods are described, as well as conclusions and implications-the healthier, I believe, the society is. People everywhere hunger to understand.

  WHEN I WAS A CHILD, my most exultant dreams were about flying—not in some machine, but all by myself. I would be skipping or hopping, and slowly I could pull my trajectory higher. It would take longer to fall back to the ground. Soon I would be on such a high arc that I wouldn't come down at all. I would alight like a gargoyle in a niche near the pinnacle of a skyscraper, or gently settle down on a cloud. In the dream—which I must have had in its many variations at least a hundred times—achieving flight required a certain cast of mind. It's impossible to describe it in words, but I can remember what it was like to this day. You did something inside your head and at the pit of your stomach, and then you could lift yourself up by an effort of will alone, your limbs hanging limply. Off you'd soar.