NASA Ames Research Center

In the summer of 1975, at the behest of NASA, a group of professors, volunteers, and students at Stanford University spent 10 weeks imagining what human colonization of space would look like and how, exactly, it would work. Their aim was to outline a system "as technologically complete and sound as it could be made in ten weeks" for thousands upon thousands of people to live, on a permanent basis, in space.

This is what they came up with:

The Stanford Torus, as it's known, was not the first imagined colony to take the shape of a donut. But it was, perhaps, the most completely thought out.

It was meant to house at least 10,000 people, and the team considered not just the technical specifications of the colony but things like how its commerce and agriculture would work. They estimated how much space would be needed for housing, businesses, schools, hospitals, churches, community halls, recreation, storage, transportation, waste treatment, and electricity generation. They described how mirrors would provide natural light and how solar energy would power the ship. They walked through what it would be like to arrive for the first time:

The space colony appears as a giant wheel in space. Still you cannot comprehend its size, but you know it must be huge.

One of the other passengers who has been on the trip before tells you it is 1800 m in diameter. He points to the six spokes connecting the wheel rim to its hub and tells you each is five times as wide across as is the cabin of your space transport. You look in awe. He tells you that the rough-looking outer "tire"is really a radiation shield built of rubble from the Moon. It protects the colony's inhabitants from cosmic rays.

Then, you're inside:

[Y]ou enter a busy community without skyscrapers and freeways; a city which does not dwarf its inhabitants. The human scale of the architecture is emphasized by the long lines of sight, the frequent clusters of small fruit trees and parks, and the sense of openness produced by the broad expanse of yellow sunlight streaming down from far overhead. This is the central plain running the full circumference of the torus along the middle of the tube.

Houses are the most numerous structures. You are impressed by the architectural achievement in housing 10,000 people on 43 ha (106 acres) while maintaining a spacious environment. Spaciousness is achieved by terracing structures up the curved walls of the torus and also by placing much of the commerce (e.g., large shops, light industry, mechanical subsystems) in the volume of the torus which lies below the central plain on which most inhabitants live.

Who are these inhabitants, exactly? The team thought about that, too. The colony would begin with 2,000 construction workers, who would soon bring 1 to 3 members of their family:

Selective hiring of construction crew members tends to bias this population toward certain highly desirable skills, and toward the younger ages. In anticipation of the labor needs of the colony and the need to avoid the kinds of burdens represented by large dependent populations, a population is planned with a smaller proportion of old people, children and females than the typical U.S. population. It is a close analog of earlier frontier populations on Earth.

And, unlike many imagined space colonies a torus colonist would be able—if they "strongly wish for it"—to return home relatively easily. "Although," the researchers noted, "it might be necessary to devise ways to discourage commuting."

For you grammarians who think our headline is incorrect—astronauts themselves say "on orbit."

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