In this Latest Revival of Space Habitat Projects, We’re Forgetting Something: We Still Don’t Know How to Make Them Viable: “Ecological Considerations for Space Colonies” Revisited
--adapted from Bruce Clarke, Gaian Systems: Lynn Margulis, Neocybernetics, and the End of the Anthropocene (University of Minnesota Press, 2020)
Arriving in the mid-1970s, Princeton physicist Gerard K. O’Neill’s proposals for space habitats in high orbit and their memorable depictions by NASA artists were significantly contemporaneous with the introduction of the Gaia hypothesis. O’Neill’s speculative technological constructions presented images of environmental closure that translated Gaia’s terrestrial implications into idealized built worlds of dubious ecological merit but powerful emotional appeal. Architecture professor Fred Scharmen lays out O'Neill's part of this history lesson in “Jeff Bezos Dreams of a 1970s Future,” confirming that Bezos’s Blue Origin project has revived both the design templates and the talking points of O’Neill’s fifty-year-old space colonies project. Here's Bezos in full flight on this topic:
At the same moment of the 1970s that O’Neill’s project was under broad initial discussion, Lynn Margulis and James Lovelock published “The Atmosphere as Circulatory System of the Biosphere: The Gaia Hypothesis” in the Summer 1975 number of CoEvolution Quarterly. That fall CoEvolution Quarterly devoted its first thirty pages to O’Neill’s space colony proposals.
In the midst of these developments, Margulis gathered a group of ecologists together to take up the issue of O’Neill’s high-orbital design specs: “There appears to be growing interest in the possibility of establishing large space colonies capable of supporting hundreds or thousands of people in isolation from the earth for long periods.“ Also published in CoEvolution Quarterly, their position statement urged paying more robust attention to the life-and-death issues involved in creating and sustaining viable closed ecosystems: “Such colonies would present extremely difficult biological and ecological problems. These should be addressed at the very outset if any serious effort toward designing satellites or colonies on celestial bodies other than the earth is to proceed.”
These cautionary notes are as cogent in 2019 as they were in 1976. But you would hardly know that from Bezos’s revival of O’Neill colonies as a scheme worthy of serious reconsideration. The basic proposition of such artificial habitats is that, once their shells are set in place, Earth’s own “ecosystem services” shall be replicated within that materially closed vessel. What is anticipated, in other words, is the design and production of miniature Gaias. “Ecological Considerations for Space Colonies” duly noted how much Gaian complexity remained unfathomed, the exceedingly recondite dynamics by which viable planetary regimes arose and maintained operations, the wicked difficulty of achieving working and lasting replicas of living ecosystems in artificial form. O’Neill aimed “to build a new meta-stable ecosystem, complete with biotic resources and closed cycles for other essential resources, and capable of supporting man over long periods”; however, “No such system has ever been constructed on earth. The probability that such a system can be built and maintained indefinitely at present seems remote. It seems especially remote when we realize that we have no background in the analysis of the problem” (96). As Margulis also understood, sustained research into the Gaia hypothesis would amount precisely to an “analysis of the problem.” But at that moment such efforts were confined to disparate and inconclusive research projects by ecosystem ecologists at the scale of terrariums and greenhouses.
Artist's rendering of a materially closed ecology, CoEvolution Quarterly 12 (Winter 1976-77)
O’Neill’s own promotional materials provided scant recognition of this reasoned but downbeat assessment, assuming on the contrary that the interior ecologies of miniature self-supporting worlds fit for long-term human habitation were engineering problems to be mopped up once the structures were hurled into orbit. Using arguments repeated virtually verbatim by Bezos, O’Neill explained that “expanding technological civilizations“ should prefer artificial space habitats to other planetary surfaces. Why, he asked, just when we’ve built the rockets to lift us up and out of Earth’s gravity hole, should we want to drop down another gravity hole?
The classic science fiction idea of colonization is always you go off and you find another planetary surface, like the moon or Mars. . . . They’re the wrong distance from the sun . . . . The sort of analogy I like to use nowadays is to say that, “Here we are at the bottom of a hole which is 4,000 miles deep. We’re a little bit like an animal who lives down at the bottom of a hole. And one day he climbs up to the top of the hole, and he gets out, and here’s all the green grass and the flowers and the sunshine coming down. And he goes around and it’s all very lovely, and then he finds another hole, and he crawls down to the bottom of that hole.” And if we go off and try to get serious about colonizing other planetary surfaces, we’re really doing just that.
In O'Neill's narrative, until now we have labored under the weight of gravity. Gravity has been holding us down. But we can now master gravity by going off into space. An artificial high-orbit environment will turn the absence of gravity to our advantage. O’Neill declared in “The High Frontier” that “the L5 Earth-Moon Lagrange libration point . . . could be a far more attractive environment for living than most of the world’s population now experiences.” But, he cautioned, we lose that advantage if we capitulate to another, alien gravity hole. Take your pick: the virginal pastoral Eden of life in a high-orbital space colony with "the green grass and the flowers and the sunshine coming down," or life mired at the dim bottom of a deep hole called Earth.
The ironies within O’Neill’s scheme and its articulation underscore the larger problems abundantly documented in “Ecological Considerations” and also in the critical commentaries Brand published alongside O’Neill’s presentations. It is simply that the range of knowledge needed to engineer materially closed ecologies making the proposed space colonies even temporarily habitable without constant resupply did not then exist. Nor does it now, half a century later. Sagan and Margulis would later speculate that “the full scientific exploration of Gaian control mechanisms is probably the surest single road leading to the successful implementation of self-supporting living habitats in space.” But in 1975, O’Neill took that implementation for granted.
CoEvolution Quarterly’s own space-colony debates were wide ranging. A number of commentators there worry the vexing sociological issues that would be involved in the constitution of a specific human population for a particular space colony. But such demographic problems do not seem insurmountable. Granting that engineering solutions enable high-orbit space colonies to be built in the first place, the more challenging issue confronting them is precisely the Gaian ecology to be initiated and established there and then shared and maintained by their full ensemble of living inhabitants in a designed ecosystem. The most learned commentators on this score, including some contributors to “Ecological Considerations for Space Colonies,” were near unanimous in their conclusion that the current state of research and technique was not adequate to the life-support issues space colonies would confront.
Paul and Anne Ehrlich made a statement to this effect. Ehrlich is famous for authoring The Population Bomb, a much-debated popular text of 1968 warning of coming resource depletion on an overpopulated Earth. Those touting the space colony program were of course talking up its utility for siphoning off excess human population, or even for providing a last refuge for a remnant of humanity after it destroyed the bulk of itself along with the viability of the Earth. The Ehrlichs acknowledged these arguments: “The prospect of colonizing space presented by Gerard O’Neill and his associates has had wide appeal especially to young people who see it opening a new horizon for humanity. The possible advantages of the venture are many and not to be taken lightly.” Nonetheless, they were not convinced:
On the biological side things are not so rosy. The question of atmospheric composition may prove more vexing than O’Neill imagines, and the problems of maintaining complex artificial ecosystems within the capsule are far from solved. The micro-organisms necessary for the nitrogen-cycle and the diverse organisms involved in decay food chains would have to be established, as would a variety of other micro-organisms necessary to the flourishing of some plants. . . . Whatever type of system were introduced there would almost certainly be serious problems with its stability--even if every effort were made to include many co-evolved elements. We simply have no idea how to create a large stable artificial ecosystem.
Another skeptical commentator is John Todd, a distinguished design ecologist who already had considerable practical and experimental experience on research questions that had occupied ecosystem ecology since the 1950s--the composition, construction, and testing of artificial environments open for energy flow but materially closed, creating manufactured replicas of solar-powered natural ecosystems.  His lengthy critique displays the appropriate epistemological humility:
After a decade of living intimately with designed ecosystems I am coming to know that nature is the result of several billion years of evolution, and that our understanding of whole systems is primitive. There are sensitive, unknown and unpredictable ecological regulating mechanisms far beyond the most exotic mathematical formulations of ecologists. When I read of schemes to create living spaces from scratch upon which human lives will be dependent for the air they breathe, for extrinsic protection from pathogens and for biopurification of wastes and food culture, I begin to visualize a titanic-like folly born of an engineering world view.
We might well build and launch a titanic space colony only to see it shipwrecked before long by the failure of its internal ecology, its devolution toward a non-viable state. This scenario actually happened in 1992 with the most significant and large-scale experiment in closed ecological habitats to date, Biosphere 2. After seventeen months, the O2 level of its closed atmosphere dipped precipitously, the habitat became unviable for its human inhabitants, and the closed environment had to be opened up for the survival of its crew.
The Western mindset tends to dismiss its own co-evolutionary embeddedness within diverse living and nonliving environments that transcend human understandings and controls. The dirty little secret is that we would be over an ecological barrel if we ever actually tried to build and populate the current generation of space habitats. This is not to say that a space colony could not be viable if it can work out how to take Gaia with it. That is, if its human complement can orchestrate a fully integrated consortium of Gaian systems, resting on virtuous microbial foundations and environmentally interlaced with the necessary suite of elemental geochemical cycles, perhaps it could grow its own long-term ecosystem. But first, let us try it out in Biosphere 3.
 Fred Scharmen, “Jeff Bezos Dreams of a 1970s Future,” https://www.citylab.com/perspective/2019/05/space-colony-design-jeff-bezos-blue-origin-oneill-colonies/589294/. See also Scharmen's excellent, profusely illustrated Space Settlements (New York: Columbia Books on Architecture and the City, 2019).
 Antonio Ballester, E. S. Barghoorn, Daniel B. Botkin, James Lovelock, Ramon Margalef, Lynn Margulis, Juan Oro, Rusty Schweickart, David Smith, T. Swain, John Todd, Nancy Todd, and George M. Woodwell, “Ecological Considerations for Space Colonies,”CoEvolution Quarterly 12 (Winter 1976-77): 96.
 Gerard K. O’Neill with Stewart Brand, “Is the Surface of a Planet Really the Right Place for an Expanding Technological Civilization?” CoEvolution Quarterly6 (Fall 1975): 20.
 Gerard K. O’Neill, “The High Frontier,” in Stewart Brand, ed., Space Colonies (New York: Penguin, 1977), 8.
 Dorion Sagan and Lynn Margulis, “Gaia and Philosophy” (1984), in Margulis and Sagan, Dazzle Gradually: Reflections on the Nature of Nature (White River Junction, VT: Chelsea Green, 2007), 13.
 For other takes on this cultural episode, see Kirk, Counterculture Green, 170-76; and Anker, From Bauhaus to Ecohouse, 113-25. Thanks to Christopher Witmore for the Anker reference.
 Paul and Anne Ehrlich, Correspondence, in Brand, ed., Space Colonies, 43.
 John Todd's most recent work is Healing Earth: An Ecologist's Journey of Innovation and Environmental Stewardship (North Atlantic Books, 2019).
 John Todd, Correspondence, in Brand, ed., Space Colonies, 48-49.
 See Rebecca Reider, Dreaming the Biosphere: The Theater of All Possibilities (Albuquerque: University of New Mexico Press, 2009).
Banner space colony painting from NASA Ames Research Center from https://commons.wikimedia.org/wiki/File:Spacecolony3.jpeg