During several summers in the 1970s, a small team of experts — professors of engineering, physical science, social science, and architecture, as well as volunteers and students — set out to design a system for large-scale space colonization.

Cylindrical colonies: double cylinder colony, exterior. | (NASA Ames Research Center)

Working at the NASA Ames Research Center in California, these field experts explored every feasible aspect of building self-sufficient, Earth-orbiting cities. In an extensive report detailing the many technical, financial, logistical requirements, alongside intricate illustrations of three conceptual spacecrafts, the study concluded that space settlement was possible, if exceptionally difficult and expensive.

Bernal spheres: exterior. | (NASA Ames Research Center)

The size of the spacecrafts ranged from a half-mile to a few miles across and could accommodate populations of 10,000 people each. The colonies would rotate to provide pseudo-gravity, and each had its own entirely independent biosphere, meaning all oxygen, water, waste, and other materials were constantly recycled.

Powered by solar energy, the colonies could sustainably support Earth's various agricultural systems — from dairy farms to wheat fields to greenhouses. And, in addition to the unparalleled galaxy views, the massive spacecrafts boasted a unique, tantalizing feature to lure the Earthbound: customized living.

"Since the entire environment is man-made, you can really get what you want," a report summary noted. "Like lake-front property? Make lots of lakes. Like sunsets? Program sunset simulations into weather system every hour. Like to go barefoot? Make the entire environment foot-friendly."

Cylindrical colonies: interior view looking through large windows. |(NASA Ames Research Center)

Scientists imagined these settlements to be just the beginning. As the populations grew, millions of space colonies spread throughout the galaxy would be built to meet the needs of this new untethered era.

The concepts outlined by the researchers four decades ago do retain some of their original futuristic glow. But the illustrations are, ironically, a delightful trip back in time. Heavy on shag-carpet greens and kitchenware pastels, the illustrated mid-century neighborhoods and utopian woodlands of our still-distant future look a lot like the idyllic California suburbs of our not-so-distant past. Which doesn't sound half bad! Enjoy this trippy peek at what could have been.

Cylindrical colonies: interior with long suspension bridge. | (NASA Ames Research Center)

Bernal spheres: colony construction crew at work. | (NASA Ames Research Center)

Toroidal colonies: cutaway exposing the interior. | (NASA Ames Research Center)

Cylindrical colonies: interior featuring clouds and vegetation. | (NASA Ames Research Center)

Bernal spheres: cutaway exposing the interior. | (NASA Ames Research Center)

Toroidal colonies: interior. | (NASA Ames Research Center)

Bernal spheres: agriculture module with cutaway exposing the interior. | (NASA Ames Research Center)

Bernal spheres: interior, featuring human-powered airplane (upper left). | (NASA Ames Research Center)