On a crisp fall evening in 1985, the Princeton University chapter of Students for the Exploration and Development of Space (SEDS) held an open meeting. About two dozen undergrads attended, spreading out in groups of two or three among the raised, hardwood pews of a small lecture hall.

The club's President, Jeff Bezos, talked a little about SEDS and a lot about his dreams for a glorious future in space. At one point he was describing a scheme to build gigantic space habitats that theoretically could house millions of people. The construction technique involved using huge solar mirrors to heat a metal asteroid until it was completely molten. Then workers would plunge a long tungsten tube into its center and inject large quantities of water. This would flash into steam, inflating the asteroid like a balloon to make a spherical hull—

A loud slam cut him off. A student in the middle of the room jumped up and, choking back sobs of rage, yelled, "How dare you rape the universe!" After she had stormed out, Jeff, more bemused than ruffled, leaned toward me and another SEDS officer and said: "Did I hear her right? Did she really just defend the inalienable rights of barren rocks?"

Jeff, like the rest of us, had no trouble brushing aside criticism before it could sink in. Having grown up in the belt-tightening Carter administration, under the Cold War threat of Mutually Assured Destruction, the Earth seemed small to us: fragile and crowded. Beyond lay boundless space, with limitless energy, resources and opportunity. Out There, population and consumption, and hence science and the arts, could grow forever.

Our template was Gerard K. O'Neill’s The High Frontier (1976),[1] a plan to build Manhattan-sized habitats along the inside walls of huge, spinning cylinders in orbit. Green and spacious, O'Neill colonies would house tens of thousands or even millions of people. The colonists would earn their way by building giant orbiting solar power stations that would beam energy down to microwave receivers on Earth. Everything would be built using lunar and asteroidal ores, eventually moving all polluting industry off-Earth. According to O'Neill, the colonies could earn and grow fast enough to off-load Earth’s entire population in a mere 35 years.[2] The Moon and asteroids had enough mineral resources to build thousands of Earths-worth of new, enclosed land. In the era of energy crises, Limits to Growth and Skylab, O'Neill’s proposal made the front pages of Physics Today, Science and the New York Times, attracting a grass-roots following of techno- and eco-humanists that has not been rivaled since.

Still, a long and notable list of critics were as furious at the concept as Jeff’s accuser. Historian Lewis Mumford regarded space colonies as "technological disguises for infantile fantasies." Nobel prize-winning biologist George Wald wrote "Let me say at once that I view them with horror." Educational reformer John Holt remarked that O'Neill and his followers had "lost the feel of real things."[3] To the critics, the whole mythology of finding escape in the heavens from the wreckage we seemed certain to make of Earth seemed both apocalyptic and futile. Given our struggles to sustain ourselves on Earth, where evolution and long experience have adapted us to its abundance, how could a single generation hope to do better in an unexplored, radioactive vacuum?

Privately, I had a few doubts of my own. Not about space colonies; the problem was the Space Shuttle. Still in the design stages when O'Neill first proposed his colonies, it was finally flying—at fifty times the ticket price that the National Aeronautics and Space Administration (NASA) had promised. Of course that killed O'Neill’s colonies, which depended on low transportation costs. But NASA was the only game in town. Where else could spacers such as myself go to realize our dreams?

That fall, I sought out celebrity physicist-author Freeman Dyson for some career counseling. On the theory that the Henry Fords of rocketry would emerge from garages rather than NASA centers, he gently suggested that I get out of space entirely and earn my living in the much more lucrative field of computers. With some luck, perhaps I could earn enough money to experiment with new launch schemes as a hobbyist. I believed him, but I couldn’t turn away—not even a few months later, when the Space Shuttle Challenger crashed. Instead, I went into astronomy, managed an archive of images from NASA’s planetary missions, designed satellite orbits and parts, published astronomy software and trained to operate the Microphone experiment aboard the doomed Mars Polar Lander.

Meanwhile, cleverer souls followed Dyson’s plan. In college, Jeff Bezos switched from aerospace to computer science. Later he founded, made billions, and launched a very secretive space company that, according to its web site (, is "creating an enduring human presence in space." Bezos is hardly alone. In recent years, at least six self-made billionaires have begun to experiment with passenger space transport. Unlike Christopher Columbus or Nazi rocketeer Wernher von Braun, they don’t need to convince skeptical rulers or dip into the national treasury; they already have the money. They can explore space any way they want. They know technology. They know business. They know what to do.

Or do they? Giving the old space dreams a new, corporate face would hardly comfort the critics. Will Bezos, Musk, Branson and the rest have any better "feel for real things" than NASA? Will they beat NASA’s prices by factors of tens to hundreds? Will they make space launch safe enough to attract millions of travellers? And if they succeed, can humanity expand into space without also expanding its fatal wars on itself and nature, as the critics had warned?

With these questions in mind, I began building spreadsheet models of a rocket business. To inject some economic reality into the analysis, I started with a hefty operating profit margin and worked back through the technical details to obtain a better estimate of ticket price (which rocketeers all too often and quite erroneously equate to their operating costs). The results were mixed. I found that a private company probably could send a passenger safely and profitably into orbit for $110,000 rather than today’s going rate of $20 million. But the development costs, lifted straight from published figures in aviation, came to several times as much as the space entrepreneurs appear to be spending. Worse, many of them are building the wrong kind of rocket and trying to sell it to the wrong customer.

Next I turned to O'Neill’s cylindrical colony design—and recoiled as technical flaws leapt out of nearly every system. With an inherently unstable rotation, mirrors too large to hold their shape and a chemically volatile atmosphere, the design was a giant Rube Goldberg contraption just waiting to burn up or fly apart. O'Neill and colleagues had known about some of these issues, but angrily waved them away as engineering details. With a cadre of True Believers at NASA and elsewhere, the design and its economic basis in beamed solar power have remained largely unchallenged. Until now.

I began by simplifying the habitat design, making its hollow shape short and squat for stability and turning it on its side to avoid pointing problems. I got rid of the co-rotating mirrors, external shielding, agriculture pods, dish antennae and other protrusions. This made it easier and cheaper to build and maintain. As with an O'Neill colony, it would spin to simulate gravity, allowing people to live on its inside walls. I chose a thick hull so it could hold an Earth-like atmosphere at sea-level pressure. This also helped it resist radiation. To simplify the problem of recycling, I surveyed the biospherics literature for clues about relying less on untried mechanical systems and more on familiar plants and soils. This drew me deeper into ecology—and led to a paradox.

In the mid-1970s, Australian ecologists Bill Mollison and David Holmgren had developed permaculture, a practice of designing homes, towns and cities that sustained themselves through complex, forest-like ecologies. This may seem a step backward until you consider the enormous efficiency of forest systems. For example, acorns from an oak woodland can match a wheat field in terms of calories produced per acre.[4] Yet unlike our monocrop agriculture, a natural forest includes many other plant species, all of which are edible—either by humans or hundreds of other animals. Healthy forests can also have hundreds to thousands of times less soil erosion and dozens of times better nutrient recycling than monocrop agriculture.

As a designer, I could not ignore these efficiencies. How might permaculture work in space? I imagined, as Russian space pioneer Konstantin Tsiolkovsky had over a century ago, a "greenhouse conservatory" that could run on sunlight as autonomously as the Earth itself.[5]

How odd, then, that O'Neill and his libertarian followers, who knew of Tsiolkovsky, would design their tiny world as a colony: an economic possession of a distant nation or corporation. Like colonial powers throughout history, these owners would have every incentive to secure and control their formidable assets by any means available, including debt bondage and coercive monopolies. About the last thing they would ever want to do is make the colonies autonomous. Thus the colonists themselves would have even less freedom than today’s ground-controlled astronauts.

My notion of an autonomous, permacultural mini-world did not fit the colonial model. Lacking significant exports or need for imports, it would offer prospective investors little by way of recurring income. For residents, though, it would provide plenty of value as permanent real estate—the very thing that launched O'Neill and his students into space studies in the first place.

But if not a colony, what should I call it? Certainly not a habitat, which connotes problems long-since solved. The word biosphere fit, but it also fit everything from sealed glass bubbles with algae and brine shrimp to the entire Earth itself. Paolo Soleri’s arcology, Dandridge Cole’s Macro-Life, Isaac Asimov’s spome and the Artemis Society’s xity each described space dwellings, sometimes employing biological metaphors. But all of these schemes were urban and human-centered, housing only selected species as necessary to provide food, water and air. If anything, these designs maximized our separation from living nature, sealing off its essential life support functions in vats and tubes, except where it was pleasing to the eye to have a pretty lawn or flower garden.

By contrast, my work was becoming increasingly focused on our physical, psychological and social need to live fully within nature in all of its wildness, diversity, robustness and efficiency. To call attention to the difference between this mode of living and the other schemes, I eventually coined a word for it:

Gaiome ('gī•ōm) n., an artificial world in space that sustains iself using natural ecology. From Gaia, the theory of the Earth as a living, self-regulating organism, and rhizome, the underground stem of certain plants.

Gaiomes began as a modest attempt to update Tsiolkovsky and O'Neil’s designs, which had been gathering dust for decades. But as question after question led back to ecology, I ended up with something unexpected: a direct challenge to the story of escape and conquest that drove space exploration for over a century. Where space colonies once promised endless growth for our current way of life, gaiomes, as living ecosystems, would require us first to find a new way to live. I also began to see how the same pattern of war and waste that threatens us on Earth has measurably begun to cripple us in space.

Make no mistake: human space flight is in jeopardy today. Despite mega-leaps in computer and materials technology since 1969, it has become more costly and dangerous than ever to send people into orbit. Neither money nor new technology nor political will has cracked the problem thus far. Nor, in my view, are they likely to. Working on what we must do to make space habitation possible is like asking what a caterpillar must do in order to fly. Wrong question! It can’t fly. The important thing to ask is what it can become.

Are we the kind of civilization that can live large in the universe? Chapter 1 (Far and Away) dissects the space frontier myth to discover that for the moment, we are not. The evidence suggests that we aren’t even qualified to live here on Earth, where we have all but spent the abundant inheritance of evolution. In order to survive beyond Earth, the chapter concludes that we first must embrace ecology here on Earth, where the lessons are easier and we have the most help from species that evolved alongside us.

Still, we have become conscious of the wider cosmos; it would be a shame to turn our backs on it. Long before we can become a cosmic species, we will need everyday space travel. Chapter 2 (Space for Everyone) borrows engineering and economic models from other transportation industries to establish the minimal criteria for safe, routine and sustainable passenger space flight. The chapter then proposes a strategy to achieve these goals.

Astronauts today echo our consumer culture by using pre-packaged stores of food, water and air lifted at great expense to orbit. Ecologically speaking, this does not even qualify as life support. Chapter 3 (Gaia and Her Children) examines how life makes the connections necessary to support itself regeneratively on three scales: globally, in sealed terraria, and in thousands of permaculture farms and gardens world-wide. The chapter will extract from this discussion seven lessons and six heuristics that will help us to design self-supporting worlds.

Long before any settlers depart for lands beyond Earth, their choice of where to live will begin to shape their values. Chapter 4 (New Worlds, Found and Made) prospects the solar system for suitable places, revisiting numerous past schemes for settlement and their likely social consequences.

With the foregoing lessons in mind, the next two chapters discuss how we might design and build a living world. Chapter 5 (Design) describes the constraints placed on gaiome architecture by the space environment and lays out some traditional and original design solutions. As with Chapter 1, you may glimpse the occasional statistical reflection of your own being: as a consumer, as beneficiary of the vast web of life, as a composite organism. Chapter 6 (Construction) looks at who might build these tiny worlds, how they might do it, how soon and at what cost.

As I developed the detailed computer models for these chapters, it became clear that a "master plan" for space travel and habitation would be premature. Too many basic astronomical, biological and political questions remain unanswered or even unasked. Still, I have backed my work with the most accurate data I could find, so that hard engineering numbers can join the hard lessons from ecology as the basis for a new discussion. Gaiome, then, is not so much a proposal as a new way to talk about space; a challenge to get out of our present rut and take a fresh look at what it means to be alive in the wider cosmos.

What kind of civilization would build gaiomes? Who would live in them? How would they change with time? Chapter 7 (Adaptation) will discuss gaiomic life and its prospects, first on the scale of humanity’s near future, then on evolutionary and cosmic time scales. As regenerative ecosystems, gaiomes would qualify as living organisms in their own right, with unique consequences for their residents. These extrapolations illustrate the advantage of biological and cultural diversity, rather than total energy use, as a measure of cosmic progress.

Throughout these pages, you will encounter space not as a frontier for human conquest, but as an evolutionary challenge for all of Earth life—including your own. Chapter 8 (Homework) invites you to seize the challenge of cosmic metamorphosis, not through esoteric practices, nor by joining or renouncing any organization, but through deliberate choices in your everyday routines and relationships. These "assignments" outline the work necessary to make a lasting home for ourselves on Earth and beyond.


1. ^ Gerard K. O'Neill, The High Frontier: Human Colonies in Space. Apogee Books. Burlington, ON, Canada. 3rd Edition. 2000.

2. ^ Gerard K. O'Neill. The Colonization of Space. Physics Today, 27 (9): 32-44, September, 1974.

3. ^ Stewart Brand, editor. Space Colonies: A CoEvolution Book. The Whole Earth Catalog/Penguin Books. 1st edition, 1977.

4. ^ Jim Merkel. Radical Simplicity: Small Footprints on a Finite Earth. New Society Publishers, Gabriola Island, BC, Canada, 2003.

5. ^ Konstantin Tsiolkovsky. The Science Fiction of Konstantin Tsiolkovsky. University Press of the Pacific. Honolulu, HI 1979. Trans. from monographs originally published in Moscow between 1893 and 1935.