THE FUTURIST, February 1976
An earth-like space colony could be orbiting our world by 1990, says a Princeton University physicist. The colony�s 10,000 inhabitants would enjoy green plants, animals, plains, valleys, hills, and streams. The colonists would pay off the cost of building their extraterrestrial home by manufacturing satellite solar power stations, which would supply cheap, virtually inexhaustible power to the earth.
||Author Gerard O�Neill, Professor of Physics at Princeton University, hopes that space colonization will be a cooperative international program, bringing world peace a step closer.|
During the past decade, a number of premises about the basic problems of the world have become very widely accepted. The more important of these accepted ideas are:
In my opinion, based on studies carried out at Princeton University, these three basic premises on which most discussions of the future have been based are simply wrong. The human race stands now on the threshold of a new frontier whose richness is a thousand times greater than that of the new western world of 500 years ago.
That frontier can be exploited for all humanity, and its ultimate extent is a land area many thousands of times that of the entire earth. As little as 10 years ago we lacked the technical capability to exploit that frontier. Now we have that capability, and if we have the willpower to use it, we can not only benefit all humanity, but also spare our threatened planet and permit its recovery from the ravages of the industrial revolution.
The high frontier which I will describe is space, but
not in the sense of the Apollo program, a massive effort whose main lasting
results were scientific. Nor is it space in the sense of the communications
and observation satellites, useful as they are. Least of all is it space
in the sense of science-fiction, in which harsh planetary surfaces were
tamed by space-suited daredevils. Rather, it is a frontier of new lands,
located only a few days travel time away from the earth, and built from
materials and energy available in space.
The two key factors that make space colonization an economically sound idea are solar energy and lunar materials. As everyone knows, the sun is a virtually inexhaustible source of clean energy. On earth, solar energy use is hampered by nighttime, by seasonal variation in the day-length, and by clouds; in space, solar energy is always available, and also much more intense. The amount of solar energy which flows unused, in a year, through each square meter of free space is 10 times as much as falls on an equal area in even the most cloud-free portions of Arizona or New Mexico. A solar-energy installation in space, therefore, is potentially able to operate at a tenth the cost at which it could operate on earth.
The cost of space colonization could be reduced further by obtaining construction materials from the moon. On earth, we are the "gravitationally disadvantaged." We are at the bottom of a gravitational well 4000 miles deep, from which materials can be lifted into space only at great cost. The energy required to bring materials from the moon to free space is only one twentieth as much as from the earth, and Apollo samples indicate that the moon is a rich source of metals, glass, oxygen, and soil. The moon�s lack of an atmosphere reduces further the cost of transporting lunar materials to orbiting space colonies.
Lunar surface raw materials, would be transported by a launching device called a mass driver; it exists now only on paper, but it can be designed and built with complete assurance of success because it requires no high-strength materials, no high accelerations or temperatures, and its principles are fully understood. The mass driver would be a linear electric motor, forming a thin line several miles long, which would accelerate small 10-pound vehicles called buckets to lunar escape velocity, at which time they would release their payloads and then return on a side track for reuse. The mass driver would be an efficient machine, driven by a solar-powered or nuclear electric plant.
The wheel-like design shown above (and also on the cover) might be used for the first space colony. The mirror floating above the colony reflects sunlight into the ring mirrors below, which reflect it through 100-foot strip windows into the colony�s interior for light and agriculture. Above the core sphere are communications and spacecraft docking facilities. Long rectangle in foreground is a heat radiator. The facility below the colony is the manufacturing area where lunar ore is melted with solar power. Lower central sphere is the original "construction shack" for the colony.Drawing: NASA
Below is an artist's conception of a segment of the wheel-shaped space colony during final stages of construction. Shown is an agricultural area with a lake and a river. These farming sections are interspersed with three more-populated areas, all protected by a shield of lunar slag attached to the outside of the colony shell.Drawing: NASA
A modified space shuttle and a chemical space tug would be used to transport basic construction equipment, supplies, and 2,000 workmen to a point in space called L5. (L5 is a point in the moon�s orbit equidistant from the earth and the moon at which objects will remain in a stable orbit, stationary with respect to the moon.) A smaller work force of about 200 people would establish a lunar outpost which would provide 98% of the raw materials needed for the construction of Island One.
The mass driver, operating only 25% of the time, could lift 500,000 tons of material to L5 in the six-year construction time of Island One. An identical machine, located in space, could be a very effective reaction motor for the shifting of heavy payloads in the 100,000-ton range.
Lunar soil is 40% oxygen, 19.2% silicon, 14.3% iron, 8% calcium, 5.9% titanium, 5.6% aluminum, and 4.5% magnesium. The aluminum would be the primary building material and the oxygen would be used as atmosphere and to fuel rocket engines. Lunar surface materials are poor in carbon, nitrogen, and hydrogen, which would have to be brought from earth. For every ton of hydrogen brought from earth, nine tons of water could be made at the colony site, using oxygen from the processing of lunar oxides.
The removal of half a million tons of material from the surface of the moon sounds like a large-scale mining operation, but it is not. The excavation left on the moon would be only five meters deep and 200 meters long and wide, not even enough to keep one small bulldozer occupied for a five-year period.
In the long run, we can use the fact that the asteroids
are also a source of materials. The three largest asteroids alone contain
enough materials for the construction of new lands with a total area many
thousands of times as large as that of the earth. Once the asteroidal resources
are tapped, we should have not only metals, glass, and ceramics, but also
carbon, nitrogen, and hydrogen. These three elements, scarce on the moon,
are believed to be abundant in the type of asteroid known as carbonaceous
The first space community would house 10,000 people; 4,000 would be employed building additional colonies, while 6,000 would be producing satellite solar power stations. The interior of the colony will be as earth-like as possible�rich in green plants, trees, animals, birds, and the other desirable features of attractive regions on earth. The design would allow a line of sight of at least a half mile, giving the residents a feeling of spaciousness. The landscape would feature plains, valleys, hills, streams, and lakes. The residential areas might consist of small apartment buildings with big rooms and wide terraces overlooking fields and groves. Near the axis of the structure, gravity would be much reduced and, consequently, human-powered flight would be easy, sports and ballet could take on a new dimension, and weight would almost disappear. It seems almost a certainty that at such a level a person with a serious heart condition could live far longer than on earth, and that low gravity could greatly ease many of the health problems of advancing age.
The space colony would have separate residential, agricultural,
and industrial areas, each with its optimal gravity, temperature, climate,
sunlight, and atmosphere. Intensive agriculture would be possible, since
the day-length and seasonal cycle would be controllable independently for
each crop and care would be taken not to introduce into the agricultural
areas the insect pests which hamper earth agriculture. Agriculture could
be efficient and predictable, free of the extremes of crop failure and
glut which the terrestrial environment forces on our farmers. Only 111
acres would be needed to feed all 10,000 residents.
Non-polluting light industry would probably be carried on within the living-habitat, convenient to homes and shops. Heavy industry, though, could be located in nearby external non-rotating factories because of the advantages of zero gravity. The combination of zero gravity and breathable atmospheres would permit the easy assembly�without cranes, lift-trucks, or other handling equipment�of very large, massive products. These products could be the components of new colonies, radio and optical telescopes, large ships for the further exploration of the solar system, and power plants to supply energy for the earth. Within a century, other industries might be shifted to space colonies because of the abundant, free, pollutionless energy supply and the greater efficiency made possible by zero gravity and the vacuum of space.
Process heat for industry, at temperatures of up to several thousand degrees, would be obtainable at low cost, simply by the use of aluminum-foil mirrors to concentrate the ever-present sunlight. In space, a passive aluminum mirror with a mass of less than a ton and a dimension of about 100 meters, could collect and concentrate, in the course of a year, an amount of solar energy which on earth would cost over a million dollars at standard electricity rates.
Electrical energy for a space community could be obtained at low cost, within the limits of present technology, by a system consisting of a concentrating mirror, a boiler, a conventional turbogenerator, and a radiator, discarding waste heat to the cold of outer space. It appears that, in the environment of a space community, residents could enjoy a per capita usage of energy many times larger even than what is now common in the United States, but could do so with none of the guilt which is now connected with the depletion of an exhaustible resource.
|Gerard O�Neill offers the following reasons
why a colony in space is more practical than one on the surface of the
The analogy that I use is that in our old-fashioned talk about colonizing planetary surfaces, we were rather like a small animal which was deep down in a hole in the ground. The animal climbs at great cost up to the top of the hole and looks out and sees all the grass and flowers and sunshine, and walks across the grass. Then he finds another hole and climbs down to the bottom of that hole again: And in gravitational terms that is exactly what we are doing if we go into free space and then climb down again to the surface of the moon.
The transport costs to get to the moon are about twice as high as they are to go out into free space; that means that the capitalization for productive equipment is up by the same factor of 2.
Each colony would consist of a pair of cylinders, connected by cables and spinning in opposite directions so that the total system would have almost no spin. Alternating stripes of land and window areas would run the length of the cylinders; the cylinder walls would be made of aluminum and glass. Agriculture would be housed in auxiliary capsules connected to the cylinders.
The smallest cylindrical colony, like the torus, would support 10,000 people. Each cylinder would be 3,280 feet long and 328 feet wide. A Model II colony would have three times more area and as many as 100,000 people, and would be less dependent on earth for resources. Model III, which might be built early in the next century, would be so large that a portion of the island of Bermuda or a section of the California coast like Carmel could fit easily within one of its "valleys." Model III residents would begin mining the asteroid belt for resources and would no longer need to import any materials from earth.
A Model IV colony consisting of two cylinders, each 19 miles long and four miles in diameter, could house several million people comfortably. Its atmosphere would be deep enough to include blue skies and clouds. The endcaps of the cylinders could be modeled into duplicates of a mountain range such as the Grand Tetons, with 8,000-foot peaks. A reflected image of the ordinary disc of the sun would be visible in the sky, and the sun�s image would move across the sky from dawn to dusk as it does on earth. The land area of one cylinder could be as large as 100 square miles.
Eventually, it may be possible to build even larger spherical structures with diameters of up to 12 miles and a total habitable land area of 250 square miles.
The date of realization of Model IV colonies does not depend on materials or engineering�those we have already. Rather, it depends on a balance between productivity, a rising living standard, and the economies possible with automation. Under the space colony conditions of virtually unlimited energy and materials resources, a continually rising real income for all colonists is possible�a continuation rather than the arrest of the industrial revolution. Reasonable estimates of 3% per year for the real income rise, 8% for interest costs, and 10% for automation advances put the crossover date (the date when large colonies become economically feasible) about 40 to 50 years from now�well within the lifetimes of most of the people who are now alive.
The largest (Model IV) space colonies, which could he functioning by 2025, will probably consist of two connected cylinders, each 19 miles long, four miles in diameter, and containing as much as 100 square miles in total land area. The most beautiful living areas on earth could be duplicated in the colonies. The bridge shown here, to give an idea of the dimensions involved, is similar in size to the San Francisco Bay Bridge. A Model IV colony could hold up to several million people comfortably, but the interior design pictured here is intended for only about 200,000 people.
Night is approaching in this Model IV space colony cylinder, which is 19 miles long and four miles in diameter. The atmosphere in the large colonies is deep enough to include blue skies and clouds. A reflected image of the sun moves across the sky from dawn to dusk. The amount of light entering the cylinder is controlled by mirrors outside the stripes of window areas which alternate with the land areas in the colony. The earth-like atmospheric effects make the colony seem more spacious and natural.
The Apollo project provided trips to the moon for a total of 12 men, at a cost of about three billion dollars per man. In space colonization we are considering, for Island One, a thousand times as many people for a long duration rather than for only a few days. With the cost savings outlined earlier, it appears that we can accomplish this thousand-fold increase at a cost of at most a few times that of the Apollo project.
a) Panama Canal $2 billion b) Space Shuttle Development $5.8 billion c) Alaska Pipeline $6 billion d) Advanced Lift Vehicle Development $8-25 billion e) Apollo $39 billion f) Super Shuttle Development $45 billion g) Manned Mission to Mars $100 billion h) Project Independence $600-2000 billion
The eventual cost of building the first colony will be affected significantly by the following variables:
With these factors in mind, three different preliminary cost estimates have been made for construction of Island One. My own spartan estimate, $33 billion, would allow for no crew rotation, an oxygen atmosphere, little resupply, and small power plants (10Kg/Kw) on the moon and at L5. The NASA Marshall Space Flight Center made two independent cost estimates for the project last year. The initial estimate, $200 billion, includes chemical and nuclear tugs, super shuttle development, orbital bases, an oxygen/nitrogen atmosphere, extensive crew rotation, resupply at 10 pounds per man/day, and power plants at 100 Kg/kW. A later re-estimate, carrying a $140 billion price tag, eliminates unnecessary lift systems, but still includes the oxygen/nitrogen atmosphere, crew rotation, resupply at 10 pounds per man/day, and power plants at 100 Kg/kW. The two NASA estimates also appear to include a contingency factor for problems not yet identified.
|Noted science writer Isaac Asimov, in a
written statement submitted to the House Subcommittee on Space Science
and Applications in August 1975, said, "It is my opinion that the important
goal for space exploration over the next century is the establishment of
an ecologically independent human colony on the Moon, or on artificial
space colonies that use the Moon as a quarry for raw materials. The reasons
for this follow:
Nuclear power is moderately expensive (1.5 cents/KWH) and is accompanied by the problems of nuclear proliferation and radioactive waste disposal. Fossil fuels are scarcer now, and intensive strip-mining for coal will almost inevitably further damage the environment. Solar energy on the earth is an unreliable source, suitable for daytime peak loads in the American southwest, but not clearly competitive in most applications at the present time.
For several years, design groups at Boeing Aircraft and at Arthur D. Little, Inc., have studied the concept of locating large solar power stations in geosynchronous orbit�where sunlight is available 99% of the time�to convert solar energy to electricity and beam it by microwaves to earth, where it would be reconverted to ordinary electricity. Already, an overall transmission efficiency of 54% has been demonstrated in tests. The main stumbling block has been the problem of lift costs. Construction of the satellite solar power station (SSPS) units at the space colony, using lunar materials to avoid the high lift costs from earth, would make solar energy competitive with other energy sources even from the start, according to my calculations. Eventually, solar electric power rates would be much lower than those of coal-fired or nuclear power plants. No thermal, chemical, or radioactive pollution would be created, and the microwave intensity would not exceed official exposure limits.
If development of the space colonies proceeds on the fastest possible time-scale (with intensive design beginning this year and major construction of the first colony beginning in 1982), the program could pay back all of the total investment (plus 10% interest) in 24 years. The total investment cost includes the development and construction cost of the first colony; the cost of lifting the materials needed from the earth for subsequent colonies and for non-colony-built SSPS components; a payment in dollars on earth of $10,000 per person/year to every colonist, representing that portion of salaries convertible to goods and services on earth (for subsequent use on visits or, if desired, on retirement); and a carrying charge of 10% interest on the total investment (outstanding principal) in every year of the program. The economic output of the program is measured in the sale of solar power at initial rates of 1.5 cents per Kilowatt-hour, gradually dropping to one cent per Kilowatt-hour.
To produce the necessary number of power satellites within this time-scale, a total work force of 100,000-200,000 people would be required. In our calculations, we assumed that the construction of the first colony would take six years; thereafter, each colony could replicate itself in two years.
Each colony would produce two SSPS units per year. The productivity implied, 13-25 tons/person-year, is similar to that of heavy industry on earth. New colony construction would be halted after the 16th colony, due to market saturation. In this scenario, the benefit/cost ratio would be 2.7.
By the 11th year of the program (1993 on the fastest possible time-scale), the energy flowing to the power grids on earth from L5-built SSPS units could exceed the peak flow rate of the Alaska pipeline. By the 13th year, the SSPS plants could fill the entire market for new generator capacity in the U.S. By year 17, the total energy provided could exceed the total estimated capacity of the entire Alaska North Slope oil field. Given the rapid growth of the manufacturing capacity and the possibility of power cost reductions, true "energy independence" for the nations taking part in the L5 project could occur before the year 2000, with a shift to production of synthetic fuels.
It would be naive to assume that the benefits of space colonization will be initially shared equitably among all of humanity, but the resources of space are so great that those who are first to exploit them can well afford to provide the initial boost that will allow their less advantaged fellow humans to share the wealth. Suddenly given a new world market of several hundred billion dollars per year, the first group of nations to build space manufacturing facilities could easily divert some fraction of the new profits to providing low-cost energy to nations poor in mineral resources, and to assisting underdeveloped nations by providing them with initial space colonies of their own. The resources of space are so great that even those nations which achieve the ability to use them only after a long delay will still find an abundance remaining. It should also be emphasized that the provision of unlimited low-cost energy to the developing nations will probably be the most effective contribution we could make to solving the world�s food problem, because the cost of chemicals for high-yield agriculture is almost entirely the cost of energy for their production.
If we use our intelligence and our concern for our fellow
human beings in this way, we can, without any sacrifice on our own part,
make the next decades a time not of despair, but of fulfilled hope, of
excitement, and of new opportunity.
"The human race stands now on the threshold of a new frontier whose richness is a thousand times greater than that of the new western world of 500 years ago."
A volunteer organization in Tucson, Arizona, recently spent an intensive week trying to get information to people about the space project, and two weeks later carried out a random sampling telephone survey. They report that 45% of the people in that city now know about this project, and of those who know about it, two-thirds of them are already in favor of it.
The mail that I get�from many nations around the world, as well as the United States�runs 100-to-1 in favor of the project. Also, encouragingly, less than 1% of all mail is in any way irrational. Many of the correspondents have offered volunteer help, and are actively working at the present time in support of the space colonization concept. The letters express the following reasons why this concept, in contrast to all other space options now extant, is receiving such broad support:
"The evidence of the past year indicates that, in-terms of public response, space colonization may become a phenomenon at least as powerful as the environmental movement."
|During the past year, Gerard O�Neill�s
space colonization concept has captured the imagination of a rapidly increasing
number of people. He reports that he gets more mail than he can answer,
and 99% of the letters are favorable.
Last July, O�Neill�s testimony also impressed the Subcommittee on Space Science and Applications of the U.S. House of Representatives. Near the end of the testimony, Subcommittee Chairman Don Fuqua (a Florida Democrat) said of the space colonization project, "It�s something that will happen, and even though it kind of boggles the mind at the present time, it is not beyond the realm of possibility. I hope I live to see it." The Subcommittee concluded, in its official report, that orbital colonies were "potentially feasible" and deserving of close examination. it also stated that "concepts and methods for the space-based generation of electricity, using energy from the sun, should be developed and demonstrated as a significant contribution to solution of the fossil fuel dilemma."
Finally, the Subcommittee gave its support to "an expanded space program in FY 1977-1978, at least 25% greater than current funding, to undertake new space initiatives." Fuqua later said that "... bold new space programs; the possibility of space colonization, based on realistic appraisals of potential space progress, deserve serious consideration. It's apparent that the imagination, skill, and technology exists to expand the utilization and exploration of space."
Astronomer Carl Sagan, testifying before the subcommittee, declared that "our technology is capable of extraordinary new ventures in space, one of which is the space city idea, which Gerard O'Neill has described to you. That�s an extremely expensive undertaking, but it seems to me historically of the greatest significance. The engineering aspects of it as far as I can tell are perfectly well worked out by O�Neill�s study group. It is practical." O�Neill says that Wernher von Braun has also expressed interest in his project.
The space colony idea also was examined last year by 28 physical and social scientists participating in the NASA/ASEE/Stanford University 1975 Summer Study at the Ames Research Center in Mountain View, California. The 10-week study was sponsored by NASA�s Ames Research Center, Stanford University, and the American Society for Engineering Education (ASEE). The group found no insurmountable problems that would prevent successful space colonization and recommended "that the United States, possibly in cooperation with other nations, take specific steps toward the goal of space-colonization."
A Princeton Conference on Space Manufacturing Facilities was hosted by O�Neill last May. The Proceedings will be published later this year.
A number of technical papers supporting the space colony idea have appeared recently, including "R & D Requirements for Initial Space Colonization" by T. A. Heppenheimer and Mark Hopkins (both of the Summer Study) and "Space Production of Satellite Solar Power Stations," an analysis by William Agosto, a project engineer with the Microwave Semiconductor Corporation, Somerset, New Jersey.
University courses are beginning to be offered dealing with various aspects of space colonization. Magoroh Maruyama of Portland State University is teaching a course on Extraterrestrial Community Systems, which explores new cultural options; possible psychological and social problems; and alternative physical, architectural, environmental, and social designs. Massachusetts Institute of Technology now has an undergraduate course in space systems engineering, emphasizing space colonies. Beginning this May, futurist Dennis Livingston will teach a course at Rensselaer Polytechnic Institute in Troy, New York, called "Space Colonies: A Technology Assessment." The course will cover technical, economic, moral, political, and social aspects of space colonies.
The American Institute of Aeronautics and Astronautics is lobbying for more congressional support for O�Neill�s project, and he was a keynote speaker during the Institute�s Annual Meeting in Washington, D.C., on January 30.
For those interested in keeping informed about the latest developments in O�Neill�s space colonization efforts, several newsletters are now available.
Gerard O�Neill puts out his own Newsletter on Space Colonization periodically. The newsletter summarizes recent work, lists the latest magazine articles and books dealing with space colonies, lists lectures scheduled on the subject, reports on the status of the space colony group at Princeton University, and advises of future plans. The newsletter is free. Simply write to Professor Gerard K. O�Neill, Physics Department, Princeton University, P.O. Box 708, Princeton, New Jersey 08540.
L-5 News is a monthly newsletter produced by the L-5 Society, a group formed recently "to educate the public about the benefits of space communities and manufacturing facilities, to serve as a clearing house for information and news in this fast developing area, and to raise funds to support work on these concepts where public money is not available or is inappropriate." L-5 News contains news articles; listings of courses, lectures, publications, and conferences; and letters. Membership in the L-5 Society costs $20 (regular) or $10 (student), which should be sent to L-5 Society, 1620 North Park Avenue, Tucson, Arizona 85719.
Another newsletter which reports on O�Neill�s ideas occasionally (as well as other space concepts) is the EARTH/SPACE Newsletter. EARTH/SPACE describes itself as a commercial space venture dedicated to free space enterprise and "focusing on market development and methods of making space profitable to the commercial user." The EARTH/SPACE Newsletter is available for $5 per year from EARTH/SPACE, 2319 Sierra, Palo Alto, California 94303.
O�Neill received a small grant from NASA in 1975, but he believes that additional funding this year of between 0.5 and 1.0 million dollars is needed for basic research if the project is to continue to develop at the fastest possible rate.
From the vantage point of several decades in the future, I believe that our children will judge the most important benefits of space colonization to have been not physical or economic, but the opening of new human options, the possibility of a new degree of freedom, not only for the human body, but much more important, for the human spirit and sense of aspiration.
"By 2150, there could be more people living in space than on earth. . Earth might serve mainly as a tourist attraction�a carefully preserved monument to man's origin."