FOR more than 20 years, Gerard K. O'Neill, president of the Space Studies Institute in Princeton, N.J., has been thinking about how people will live and work in space. He spoke recently with Laurent Belsie, staff writer of The Christian Science Monitor. Excerpts from his remarks follow.
How did you get involved in studying space colonies?
The fundamental impetus for my work on the subject, which began more than 20 years ago, was the conclusions of the Club of Rome report in the 1960s. [It said] the only viable future for humanity was to give up the idea of economic and political progress, in the sense of greater political freedom, and accept absolute physical limits on the capability of Earth to support a population. I recall sentences out of the Club of Rome report, which really asked: In such a steady-state society, can we permit freedo m of thought? And the writers, though fundamentally of a Western persuasion, concluded that there could not be true freedom of thought in such a society, or else it would blow apart. That seemed like such a miserable world to leave to our children that I was driven to look for alternatives.
How did you latch on to the idea of space colonies?
I sat down to address a thought experiment to myself.... All societies run on energy. The most advanced nations use about 100 times as much energy per capita as the average resident of India. But the living standard is also about 50 times as high.
We have so far not figured out a good way of having an affluent use of energy without substantial harm to the environment.
Although I was educated as a nuclear physicist, I don't happen to be enthralled by the idea of nuclear reactors as the source of energy for the future. My calculation was that, by the year 2050, you would need about 63,000 nuclear reactors in operation all over the world.
Solar energy intercepted on the surface of Earth is also not an answer to the problem, because it happens that this is about the worst place for several million miles around to intercept solar energy. It's turned off by the day-night cycle. It's turned off by clouds. It's coming at a funny angle most of the time.
There is one perfect source of energy in the solar system and that is, of course, the fusion reactor which has thoughtfully been provided for us 100 million miles away. So I was immediately driven to consider constructing colonies in space.
Why not colonize the moon or another planet?
It takes you about twice as much energy to get to the lunar surface as it does to get to a high orbit over the moon. We're so locked into our thinking that's come down to us through the generations. We assume that going to another planet is somehow easier or cheaper than going out to free space. In fact, the reverse is true.
So we would build space colonies because Earth needs a better energy source.
You don't just go out and build space colonies because it's a nice thing to do. There has to be something of economic value that is coming to Earth as a result of establishing the space colony. The clear solution that we feel is the right one is to build solar-power satellites, which would supply clean energy to Earth.
Is that technologically feasible?
It's a very well-understood technology. The basic idea of solar-power satellites is to use the best power source in the solar system, namely the sun, and intercept that sunlight in a place where it's reliable. A typical power satellite would put out on Earth perhaps as much power as 10 nuclear plants.
How long will it take before we see the first one?
If people set their minds to it, we could certainly have a small, demonstration power satellite in operation within five to eight years. The first full-size power satellite built out of lunar materials is probably ... 20 years away.
What would a colony look like?
It is a spherical shape, basically connected to cylinders at each end. The cylinders are arranged to have a lot of daylight and be the agricultural growing areas. And the sphere is the habitable living area. The size of a moderate-scale space colony would be about a mile in circumference at the equator.... The population, which I derived from pleasant living areas here on Earth, would be about 10,000 people.
Would it feel like living on Earth?
You might have a colony that has an extreme variation of seasons or you might have one that has a sort of Hawaiian-type climate. It's entirely your choice. But once you've made that choice you'd better not change your mind. Though the people are very adaptable, the plants are not. And once you've decided on pine trees you can't suddenly decide to have palms instead.
So there would be plants and animals on these colonies.
It would be planted throughout. And because of the fact that you don't have to bring any of the plant pests from Earth, you don't have to use pesticides out there. There are also a fair number of parasitic forms of life that you'd leave behind. You wouldn't take mosquitoes, for example. You would take bees because of their use in pollination. But you probably wouldn't take rats!
What else would be different in a space colony?
In our society, materials are relatively cheap and energy is relatively expensive. However, a space colony would be quite the reverse. Their energy would be very cheap and abundant - and totally reliable, coming from the sun. Materials would be more expensive than they are here on the surface of Earth. You don't dig them out of the ground. You have to transport them. It's a situation that favors total recycling.
How far could colonization go?
Suppose we go 60 years in the future to the middle of the next century. And we [conclude] this is such an attractive way of making energy, and it's so environmentally benign that we want all energy on the planet to be made this way. If we do that, then the market is very large. The market would be about $6 trillion per year. It would become one of the largest industries on Earth, if not the largest.
The idea has many ramifications. What are the implications for life on Earth?
One of the most important changes is that it would no longer be a world of the energy haves and have-nots, because energy from power satellites could be used just as well by one country as well as any other.
It would be a very much cleaner world throughout. Environmentally, it would be an enormously more attractive world than the one that we're heading for right now. We would stop the dumping of carbon dioxide into the atmosphere, therefore stop the increase of the greenhouse effect and global warming and everything that goes with it. And I would hope that over time with the construction of space satellites, we would end up with a less crowded world and a much more beautiful world.