
NASA's imagined space colonies —
In 1975 a research group led by Princeton professor Gerard O'Neill conducted a 10 week study of future space colonies. Acclaimed space artists Rick Guidice and Don Davis were commissioned to illustrate the fantastical and as yet unrealized concepts.

Envisaging the future —
O'Neill's team settled on three potential designs for the future space stations: the Bernal Sphere, the Toroidal Colony (here imagined by Davis) and the Cylindrical Colony. Potential capacity ranged from 10,000 people to one million, and featured circular designs which rotated to generate artificial gravity.

From page to screen —
The Cylindrical Colony -- imagined here by Guidice -- is the most spacious of O'Neill's concepts. The design, later dubbed the 'O'Neill Cylinder', was riffed on in Christopher Nolan's intergalactic blockbuster "Interstellar" forty years later.

Crystal palace —
The Bernal Sphere was first proposed by John Desmond Bernal as far back as 1929, with O'Neill's team adapting the half-century old idea. Here, Guidice imagines a colorful, highly-curved living surface that featured a "crystal palace" for agriculture and light reflected in via windows near the poles.

1990: A Space Odyssey? —
In a paper presented to NASA, O'Neill uses 1990 as a hypothetical start date for a space colony, with the team drawing up a number of potential costs for construction and transportation -- even the volume of livestock each station would need to ship in. Here, Davis depicts how this could work.

Cutaway of the Bernal Sphere —
Rick Guidice's painting of a cutaway of the Bernal Sphere also shows some of the huge solar arrays required to power the station and its rotation.

Lush green landscapes —
Despite the futuristic technology required to put such a massive structure in space, all of the artwork from Guidice and Davis -- including this image by Davis -- shows lush green landscapes -- a far cry from the reality of the International Space Station today.

Solar eclipse from space —
Don Davis' illustration of a Cylindrical Colony imagines what a solar eclipse would look like from space. Davis' work can also be seen on the Discovery Channel and the Science Channel.

Construction crew at work on a colony —
Here, Davis depicts a construction crew piecing together a Bernal Sphere -- complete with houses, grass and rivers, seemingly unscathed by the vacuum of space.

Bernal sphere —
In this image, Rick Guidice imagines a Bernal Sphere with tilted arrays to maximize exposure to the sun. Guidice illustrated for NASA for 15 years, before becoming a building designer. Guidice has designed homes for many of Silicon Valley's leaders.

The orbiting colony —
The Cylindrical Colony was never envisaged as a solitary structure, instead orbiting with a partner -- as demonstrated by Guidice's painting.

Reflecting sunlight —
Davis also depicted the exterior view of a Toroidal colony, featuring a giant tilted mirror providing sunlight to the interior surface of the ring.



