When the first men landed on the moon in 1969, President Nixon hailed their flight as “the greatest week since the Creation.” Later that year another group of astronauts went to the moon, and on their return were feted at the White House. Also in that year the environment began to be a hot issue, and the Vietnam war became an even hotter issue. Three hundred thousand people gathered at the Washington Monument to sing “Give Peace a Chance.” The Beatles recorded their next-to-last album together, “Abbey Road.” Senator Edward Kennedy drove off the Chappaquiddick bridge. Vince Lombardi coached his last season in professional football.

And at Princeton University, it was Gerry O’Neill’s turn to teach the big freshman physics course, Physics 103.

Dr. Gerard K. O’Neill is tall, quiet, and a modish dresser. He was a Navy non-corn in the closing days of World War II, and then went to Cornell, where in 1954 he received a Ph.D. in physics. Later, at Princeton, he taught, did research in high-energy physics, and became a full professor. In 1967 he applied for one of the new astronaut positions then open, getting as far as the more detailed testing procedures in Houston before being turned down.

In 1969 he became deeply involved in the freshman physics course. He was concerned over student disenchantment with science and engineering. There were students who were very good in these areas, but many of them felt defensive about their studies because their friends were telling them that they weren’t doing anything relevant. So he set up a special seminar for some of the brightest, most ambitious students. There were only six or eight of them; they met once a week for several weeks.

O’Neill’s idea was to invite them to solve world problems through technology. It occurred to him that the first reasonable question to ask was, “Is the surface of a planet really the right place for an expanding technological civilization?”

Within the available time the students for the most part were only able to look things up in the library, such as the land area of the world. But one problem they were able to study was how big can you make a rotating pressurized vessel in space to hold an atmosphere and provide gravity? What would be the limitations of such habitats? Would they necessarily be small, like space stations, so that only astronauts would want to go there? O’Neill threw out this problem, and the answer came back pretty quickly. It already started to look interesting, because the answer emerged as several miles in diameter.

The next question the students considered was how much land area could you build in such habitats, using the material resources of the moon or the asteroids, which may be readily available in space? What are the limits to growth?

The first answers they came up with indicated there was more than a thousand times the land area of Earth as the potential room for expansion. They concluded that the surface of a planet was not the best place for a technical civilization. The best places looked like new, artificial bodies in space, or inside-out planets.

The classical science-fiction idea, of course, is to settle on the surface of the moon or Mars, changing the conditions there as desired. It turned out that there were several things wrong with this, however. First, the solar system doesn’t really provide all that much area on the planets—a few times the surface area of Earth, at most. And in almost all cases the conditions on these planets are very hard to work with.

The idea of using a planet to provide gravity and to hold an atmosphere really represents the hard way to go about doing these things. Really tremendous amounts of material must be collected, enough to make a planet 5000 miles in diameter, before there is enough gravity to hold down an atmosphere and keep it from leaking into space. Even Mars isn’t quite big enough—its atmosphere has almost entirely leaked away. Ever since Wernher von Braun published his space-station articles in Collier’s over twenty years ago, people have been aware that a few tons of metal will suffice to build such an inside-out world, to give gravity and an atmosphere.

Also space is not an empty, hostile environment. It is a culture medium, rich in energy and in the resources needed for life. An artificial world in space gets solar energy full time, without the day-night cycles and the atmospheric absorption of a planet. Further, planets have strong gravity fields against which a spacecraft must fight. The earth’s gravity is strong enough to have the same effect as a hole, 4000 miles deep, out of which we must climb. If we wish to colonize the surface of another planet, we are just climbing up a deep hole, passing through the sunshine of space—and then going down another hole.

With these interesting new ideas, Dr. O’Neill became concerned with how to make such a colony as Earthlike as possible. He certainly didn’t want to invent just another design for a big space station. He wanted it to have a normal appearance inside: a comfortable atmosphere and gravity and a sun. He came up with the simple design of a cylinder whose surface would be in alternating long strips of land and window areas with large mirrors to reflect the sunlight into the colony. But this raised the problem of moving the cylinders, of shifting their position so they would always face the sun. The cylinders would be rotating to provide gravity and would act as gyroscopes, resisting any change in pointing direction. It wasn’t until sometime later that the answer occurred to him: have two cylinders spinning in opposite directions and linked together. The resulting system would behave as if it were not spinning at all and could easily be made to track the sun.

Even within the first month or two, O’Neill began to believe these ideas really were practical and possibly quite important. But his work on this was quite occasional, a few minutes every week. He couldn’t drop his other research and become a full-time space colonizer. Despite the pressure of his regular work O’Neill managed to write a magazine article about his space colony concept which, after much rewriting to meet the objections of various publishers, some of whom were not receptive to new ideas, appeared in Physics Today in 1974.

Early that year he decided he wanted to have a little conference, to try to get some people in to talk over the ideas, to see whether they were really all right or whether there might be some fatal flaw. It occurred to him that it ought to be possible to get some money to do a few things that would make such a conference a little better. So he decided to spend a few hours becoming educated in the problem of how to get money to do something entirely new.

He started calling foundations, with disappointing results. Someone suggested the Point Foundation in San Francisco, which is managed by the publishers of the Whole Earth Catalog.

He visited their offices while on a trip to Stanford. The Point Foundation came up with $600, which funded the first conference. It was not given without strings, however. The foundation stipulated that the money go through the offices of Princeton University rather than be given to him personally.

This turned out to be a very good thing. Because the Point Foundation’s contribution was handled as an official university grant, a statement of that grant came across the desk of the university publicity office. It sent out a press release on it so that news reporters came down to that conference. One of them was Walter Sullivan of the New York Times.

The conference was held in May with about ten or fifteen people attending. One was Gary Feinberg, a physicist from Columbia University, who a few years earlier had proposed the existence of tachyons; particles traveling faster than light. Eric Hannah, a graduate student at Princeton, was present too. Also there was Eric Drexler, a nineteen-year-old undergraduate from Massachusetts Institute of Technology. While still in high school, he had become interested in extending Earth’s civilization to the asteroids. In college he found out about O’Neill through the grapevine. There was Joe Allen, a NASA astronaut, who had also heard of the space colony through the grapevine. A couple of people from NASA Headquarters, one of them from the advanced launch vehicle group, came to the conference.

The first day they sat around a table and tried to review some of the ideas. Princeton physicist Freeman Dyson came, bringing his speculations on advanced stellar societies. He got very excited, and stayed for the second day as well. So did a few other people. The second day was open to the press, and there were a couple of local reporters along with Walter Sullivan, who wrote a news article which the editors of the Times put on the front page. Things began to pick up. There was a short article on the meeting in Time magazine. The BBC was on the phone very shortly seeking an interview; the Canadian Broadcasting Company followed, along with various stations from New York and from the West Coast. The Associated Press did an article, and the Los Angeles Times requested one, too. In August there was an article in the British journal, the New Scientist. The Physics Today article came out in September, with its cover showing a painting of a colony and the words “Colonies in space.”

The Physics Today article prompted a good deal of response from technical people who wrote in to offer objections or criticisms. These letters prompted O’Neill to work out more of the technical details, justifying a lot of things with calculations, which up to then he had just had a hunch would work out. Bernard Oliver, vice-president at Hewlett-Packard, wrote a very detailed critique. This was answered in due course not only by O’Neill but by a friend of his, Al Hibbs of the Jet Propulsion Laboratory. It turned out that there were good answers to the most important of the critics’ questions.

In addition O’Neill was beginning to think about the problem of economics, of putting the colonies on a paying basis. His Physics Today article had mentioned some opportunities for manufacturing in space, but what was needed was some really large-scale manufacturing operation. Jesco von Puttkamer, the NASA official who controlled his funding, supplied just the idea he was looking for. Von Puttkamer suggested that O’Neill investigate the possibility of the colonies’ furnishing energy to Earth. In searching for the best way this could be done, O’Neill improved upon a concept which had originally been proposed by Peter Glaser in a 1968 article in Science. Glaser’s method of obtaining energy from space for use on Earth was to build solar power satellites on Earth and launch them from the ground by rockets. The satellites would then send electricity down to Earth via microwave beam. O’Neill’s idea was to build the power satellites in space colonies, using resources from the moon. The satellites would then be moved into high Earth orbit, where they would convert sunlight into electricity. They would transmit the electricity to Earth using Glaser’s method.

In early 1975 O’Neill had received a grant from NASA and was able to hire an assistant to work full-time on space colonization. He was Eric Hannah, who had acquired his Ph.D. shortly after the first Princeton conference. O’Neill also began to look ahead to two major events for 1975: a second Princeton conference and a NASA-sponsored study of key ideas. He gave several more talks, including one at Jet Propulsion Laboratory, early in February, which I attended. JPL is a hotbed of interest in space colonization, and the 300-seat Von Karman Auditorium (named for the aeronautical pioneer was founded JPL) was completely filled. I went up after his talk and met him and so was introduced into the community of space colonizers. I offered to give a paper at the next Princeton conference and eventually was invited to do this.

The second Princeton conference was sponsored by the leading technical aerospace society, the American Institute of Aeronautics and Astronautics. It was also sponsored by NASA, which provided a grant to underwrite it. At almost the last moment, the National Science Foundation likewise came up with a grant; so the participants had their travel and lodging expenses paid.

Perhaps the most important consequence of the Princeton meeting was the creation of a community of interested specialists among the participants, thus broadening the colonization studies well beyond the work of O’Neill and his close associates.

There were a number of rather distinguished people among the conferees. Peter Glaser, the inventor of satellite power stations was there, as was Gordon Woodcock of Boeing, who had come up with a different type of design. Eric Drexler was back again, from MIT. But this time he brought along the father-confessor to his group of MIT students studying space colonization—Arthur Kantrowitz, chairman of Avco-Everett Research Labs. There was Edward Finch, former ambassador to Panama, to speak on space law. Assorted NASA officials were there to discuss what would be needed in the way of launch vehicles and how space colonization might fit into NASA plans for the future.

A great deal of useful work came out of that conference. There were key technical results involving space transportation, sources of lunar materials, and space power sources, as well as proposals for possible social and cultural organizations in a colony. Agriculture received its share of attention too. Present at the conference were Carolyn and Keith Henson, of Tucson, Arizona. They raise turkeys, rabbits, and chickens on their lot, and get their milk from pet goats. They had come to talk about farming in space, which they proposed to build around—that’s right—the raising of rabbits and goats.

With the Princeton conference over, attention turned to the forthcoming NASA study, the second major event for 1975. This study was to take place during the entire summer at NASA’s Ames Research Center near Stanford University, forty miles south of San Francisco. It was sponsored by the American Society for Engineering Education and represented its annual summer program in engineering systems design. This program was also sponsored by NASA to give experience in systems design to about two dozen members of university faculties chosen from around the country. One of the more noteworthy of these summer studies had been the 1971 effort led by Bernard Oliver. Cyclops, an immense array of radio telescopes to be used in seeking signals from civilizations around other stars, had been designed at this meeting.

The study started in the middle of June. Gerry O’Neill was out there for the summer to carry on his regular work in physics at Stanford. But he wound up spending most of his time with the summer study participants at Ames, whose task had been given: “Design a system for the colonization of space.”

Eric Drexler again came out, this time bringing with him his entire crew of half a dozen students from MIT and Harvard. Several of them turned out to know more than most of the faculty members in the study; they did a great deal of useful work. There was Mark Hopkins, a graduate student in economics at Harvard. His economic studies helped greatly to determine the probable cost of the project ($100 billion) and the economic return from building power satellites (very high). Also there was Larry “Wink” Winkler.

Wink, as everyone called him, was particularly interested in the physiological limits to human habitation in space. He was especially concerned with the rate at which a colony should spin to provide artificial gravity. If it spun too rapidly, the colonists would suffer motion sickness. The proposal had been that the first colony should be 600 feet in diameter, rotating at 3 revolutions per minute to give normal gravity. The colony would then be a cylinder a mile long. But Wink’s studies showed that there could be trouble if the spin were faster than one rpm. This meant the colony could not be a cylinder but had to be redesigned into the shape of a bicycle tire, the shape known as a torus. This is the classic shape of the space station in 2001. It would be over a mile in diameter with people living on the inside of the “tire,” 400 feet wide.

The work of the Summer Study cleared up the last major doubts as to the feasibility and practicality of space colonization. It treated in some detail such important matters as space transport of people and material, obtaining and processing metals from the moon, space agriculture, architecture and urban planning for a space community, the economics of colonization, and the provision of radiation shielding for the colony.

Toward the end of July, Gerry O’Neill went to Washington to testify before the space-science subcommittee of the House committee on science and technology. This powerful committee had recently extended its influence by taking major responsibilities for the nation’s energy policies. Now it was holding hearings on possible new directions for the United States in space. Arthur C. Clarke flew from Ceylon to testify at the hearings. Gerry O’Neill gave an overall review of his work, drawing heavily on the economic studies of Mark Hopkins. Then he went off to a meeting, previously arranged, with Congressman Morris Udall.

Udall was a candidate for the Democratic nomination for president, and had quite a busy schedule. He agreed to spend a few minutes, however, with O’Neill. As a liberal Democrat, he had often voted against the space program. But he had heard about space colonization through the efforts of two of his constituents, Carolyn and Keith Henson. Udall was sufficiently impressed by O’Neill’s presentation to write a letter to Robert Seamans, the head of the Energy Research and Development Administration, urging that the ERDA fund the design study of the space colony concept.

Near the end of August, the participants in the Summer Study held a press conference at Ames Research Center which drew a large group of reporters. Meanwhile, public interest was growing, as more magazine articles came out.

In November, the House committee on science and technology released its report based on the hearings in July. It called for a 25 percent increase in NASA’s funding, or some $750 million, “to lay the foundation for advanced projects, such as moon bases and orbital colonies.” The chairman of the subcommittee which had held the hearings, Don Fuqua of Florida, issued a statement: “It is hard to predict tomorrow, and although I do not have the vision to say precisely where the future will take us, I do know that our space program is only in its infancy stage.”