The Case for Mars: The Plan to Settle the Red Planet and Why We Must, by Robert Zubrin with Richard Wagner, New York: The Free Press, 328 pages, $25.00
Mining the Sky: Untold Riches from the Asteroids, Comets, and Planets, by John S. Lewis, Reading, Mass.: Helix Books/Addison-Wesley, 274 pages, $26.00
Why should humans go to Mars? One reason is that the job market there looks pretty good. Martian society will experience a chronic shortage of labor, due to the small size of its initial population and the high cost of transportation from Earth. Hence, wages will be high, career opportunities will abound, and innovation will be rewarded. Paperwork, bureaucracy, and the quest for purely formal credentials will be kept to a minimum. Such are the exigencies of life on a harsh frontier.
Such ruminations might sound far-fetched, the stuff of some distant future, perhaps, but of no practical interest to anyone alive today. But that future may be closer than most people, including many space experts, currently think. In The Case for Mars, Robert Zubrin and Richard Wagner present a powerful and pragmatic argument for near-term exploration and colonization of our celestial neighbor. In their telling, the first humans could be on Mars within a decade, and many thousands could be living there by the mid-21st century.
Zubrin, formerly a senior engineer at Lockheed Martin, is the leading proponent of "Mars Direct," a plan for a stripped-down, no-frills, manned mission, using existing or readily developable technologies. Under the plan, a four-member crew travels straight to the Martian surface in a heavy-lift rocket (making no intermediate stops in Earth or Mars orbit); explores large swaths of territory with the aid of ground rovers; and then returns to Earth using an oxygen-methane fuel synthesized from the Martian atmosphere. Eliminated from this scenario are the vast spaceports and Battlestar Galactica type spaceships traditionally envisioned for interplanetary travel.
By drastically lowering mission costs, Mars Direct could extricate the red planet from its current political oblivion. When President George Bush called for a manned Mars mission, the National Aeronautics and Space Administration responded with a bloated, 30-year, $450 billion plan, which Congress quite justifiably shot down. Mars Direct, by contrast, might cost between $20 billion and $30 billion. (A modified version, called Mars Semi- Direct, with an estimated cost of $55 billion, is now accepted by NASA as a "baseline" for formulating yet more plans. No actual mission is currently scheduled.)
Moreover, cost overruns and bureaucratic inertia could be avoided by turning Mars Direct into a "Mars Prize." Under this approach, formulated by Zubrin and the Progress and Freedom Foundation at the behest of Newt Gingrich, government's role is simply to provide cash incentives for the private sector to perform the mission. This would be done in stages: preliminary rewards for such feats as automated fuel synthesis in the Martian atmosphere, and a $25 billion grand prize for getting a crew to Mars (and back). Unlike the traditional "cost-plus" contracts of the aerospace industry, a Mars Prize would inspire the work to be done under budget.
In addition, Mars Direct's particular trajectory through the solar system, and its avoidance of time spent in orbit, enable an extended (500-day) stay on the surface, rather than a plant-the-flag mission of limited scientific value. The crew, consisting of two field scientists and two high-tech mechanics, would give priority to the search for signs of past or present life on Mars. That cosmic question cannot be explored adequately just by examining Martian meteorites on Earth, or even by sending robot probes to Mars. Imagine, write Zubrin and Wagner, parachuting a remote-controlled rover into the Rocky Mountains and trying to locate a dinosaur fossil.
Increasingly, however, human activity on Mars would be oriented toward the future, toward the building of a permanent society. The Case for Mars sketches out what that might entail, including ever-larger domed habitats and eventual terraforming to raise temperatures and oxygenate the atmosphere. Beyond such technological challenges, moreover, the book addresses the crucial economic issue: A large-scale human presence on Mars cannot endure indefinitely as a black hole for subsidies from Earth. The fourth planet must pay its own way. How might it do that?
Mars will need a thriving export sector to pay for its imports of manufactured goods from Earth. (Even with a high degree of automation, Martian society's labor shortage ensures that imports will be necessary far into the future. Furthermore, such trade will be desirable, given the rule of comparative advantage.) Fortunately, Mars contains a plenitude of natural resources with export potential. Deuterium, a fuel useful for today's nuclear-power industry and essential for future nuclear-fusion reactors, is a particularly promising candidate for interplanetary commerce.
Ideas as well as natural resources could make valuable exports, as Martian innovations in biotechnology and robotics are licensed for use on Earth. Indeed, the authors argue, investment in the Martian economy could begin even before any humans have set foot there. Mining rights, for example, could be allocated to any company that sends a probe to survey a piece of Martian territory to some specified degree of precision; such rights could be traded actively right now, much as land grants to trans-Appalachian America were bought and sold decades before settlers actually arrived.
Moreover, licensing and direct exports to Earth are not the only means by which the inhabitants of Mars could make a living. Much as colonial America was the linchpin of a "triangle trade" between Great Britain and the British West Indies, Mars might become a key intermediary for economic activities elsewhere in space. In particular, note Zubrin and Wagner, the planet would be a convenient local supplier for mining operations in one of the solar system's most resource-rich neighborhoods: the "Main Belt" of asteroids between the orbits of Mars and Jupiter.
The vast economic potential of asteroids and other extraterrestrial bodies is the subject of Mining the Sky. John S. Lewis, co-director of the NASA/University of Arizona Space Engineering Research Center, argues that the payoff from space exploration will be bigger than virtually anyone has recognized. Much bigger.
Consider: The asteroid belt contains an estimated 825 quintillion (a billion times a billion) tons of iron--enough to build shells around planets, gigantic cities in space, and starships carrying entire civilizations. How much is this iron worth? Lewis performs a fanciful calculation: At present prices of around $50 a ton, the asteroids yield $7 billion of the metal per person for everyone alive today, or an affluent standard of living for a population far larger. Moreover, iron is merely one element found in the Main Belt, which also contains gold, silver, copper, manganese, titanium, uranium, and much else.
Nor does the Main Belt have a monopoly on space's potential riches. Mining the Sky ranges broadly across the solar system, finding technological and economic possibilities all the way from the moon and "near-Earth" asteroids to the distant orbits of Uranus and Neptune. Lewis sometimes blurs the distinction between near-term technologies and distant or improbable ones, an effect that is intensified by the book's fictional vignettes about asteroid miners and other colorful characters. Nonetheless, Mining the Sky succeeds in conveying a sense that space is anything but an empty, unimprovable wasteland.
The moon's ample supply of helium-3, long touted by space buffs as a potential fuel for advanced fusion reactors, is duly noted, as are the even larger supplies of the substance in the atmospheres of all of the giant outer planets. Jupiter and Saturn present particularly daunting prospects for exploitation, Lewis acknowledges, since their powerful gravitational fields would require any departing vehicle to have an extremely high escape velocity. However, with a flourish of untrammeled technological optimism, he points out that souped-up helium-3 rockets just might do the trick.
Even some of the dangers posed by extraterrestrial objects might turn out to be opportunities. Lewis points out that near-Earth asteroids (some of which are easier to get to than the moon) could be mined to reduce their mass, thus minimizing the threat of a cataclysmic collision. The asteroidal material then could be converted into solar-power satellites that would collect and transmit energy for Earth. Moreover, Lewis notes, some near-Earth asteroids also pass in the vicinity of Mars and the Main Belt; these bodies, suitably hollowed-out, someday may serve as the "traveling hotels" of the solar system.
Lacking in Mining the Sky, but present in abundance in The Case for Mars, is a clear set of priorities for practical action. Lewis provides little concrete advice on how to bridge the chasm between the present state of space exploration and the bountiful future he envisions. By contrast, Zubrin and Wagner provide not only a detailed program for going to Mars but also a critique of competing objectives. In particular, the Mars enthusiasts seek to shoot down the moon as a goal for human colonization; the satellite, they note, is relatively impoverished in water and other resources needed for survival (a point still valid despite the recent detection of ice on the moon).
The Case for Mars and Mining the Sky both draw a sharp contrast between a brilliant space-faring future and a bleak existence if humanity remains Earth-bound. Both make reference to the dictum of H.G. Wells that "the choice is the Universe--or nothing." However, the books differ notably in their discussion of that choice.
Mining the Sky contends that the notion that natural resources are running out is a myth--but one that's all too true if Earth is the only source considered; Lewis even hazards a prediction of global collapse into subsistence agriculture around 2030 unless the riches of space are tapped. The Case for Mars, ultimately, is based more on the need for a frontier than on any shortage of terrestrial minerals. Zubrin and Wagner warn that Earth is slipping into a malaise of bureaucracy, cultural homogeneity, and diminished technological progress. Mars, they argue, would give rise to a dynamic new branch of human civilization, one whose entrepreneurial energies would reinvigorate Earth society as well.
Eventually, Mars, the asteroids, and the rest of the solar system may have been explored and settled. What then? Mining the Sky ends with a call for humanity to expand throughout the entire galaxy, creating a population of countless quintillions; Lewis's sheer maximalism may discomfit even some space enthusiasts. In The Case for Mars, Zubrin and Wagner proclaim that our distant descendants on a multitude of worlds, even with all their advanced capabilities, will still marvel at the boldness of those who began the great push into space. Science fiction has long been filled with such entertaining and inspiring visions. These two books show they might be affordable, too.