Dec 15, 2022

The O'Neill cylinder in fiction

The year is 1974, three years after Apollo XVII, the last Apollo mission to the moon. Physics lecturer at Princeton, Gerard O’Neill, publishes his and his students' work on massive structures in space. His goal was to show that living in space could be possible in the future. Two years later, he published a book on space colonization The High Frontier: Human colonies in Space (New York, 1977, 288 p.), which would change the sci-fi landscape forever and have a deep impact on how space colonization is now perceived, and this will be the object of our article.

In both publications, O’Neill presents three mega structures called “Islands”, designed for extended life in outer space. One of them, Island Three, is what is known today as “O’Neill cylinder”.

Space colony 3, artist depiction of an O’Neill cylinder’s interior – Rick Guidice (NASA)

It consists of two rotating cylinders of 8 kilometres in diameter and a length of 30 kilometres. The cylinders are divided into six slices each: two of them are designed for living and the remaining three are giant windows on outer space.

Finally, an outer ring of 14 kilometres in radius is located at the top of the cylinder: the purpose of this ring is to house agricultural fields.

Space colony 1, artist depiction of a couple of O’Neill cylinders – Rick Guidice (NASA)

In order not to impact crops production and industrial matters, the rings, the top and the bottom of the cylinders spin at a different speed which produces an effect of gravity akin to the one we experience on Earth.

The idea of a manmade structure that would allow a sizeable amount of people to sustain a normal life in outer space was, at that time, ground-breaking and it is no wonder that it would have a deep impact on human imagination. Many works of fiction reappropriated the idea throughout the years.

One of the better examples of a reimagining of an O’Neill cylinder is the one from “Rendezvous with Rama” (1973) by Arthur C. Clarke: in this novel, the cylinder Rama cruises across space but does not rotate as gravity is produced through other means. Furthermore, the station does not have any visual openings leading towards space but produces artificial light instead.

One of the most famous depictions of an O’Neill cylinder in a live-action movie is the one from “Interstellar” (2014). At the end of the movie, we discover that humanity has finally been able to master the science required to build an O’Neill cylinder and it is implied that many similar stations are available. One key characteristic that differentiates Interstellar’s cylinder from Island Three is the fact that crops seem to be grown on site rather than in a separate part of the station.

Frame depicting crops in an O’Neill cylinder, Interstellar (2014) - ©Paramount Pictures, ©Warner Bros.

Lastly, a less famous example is the “bunkers” or space cities from Chinese author Liu Cixin’s Remembrance of Earth’s Past trilogy. In the last volume of the trilogy, “Death’s End” (2010), most of humanity has left Earth to live in 38 gigantic space stations hidden behind Saturn, Uranus and Neptune. However, those stations do not only come in the shape of cylinders; there are tori/rings, spheres, or even stations shaped like bicycle wheels.

While very similar to Interstellar’s cylinders (agricultural and industrial production sites coexisting with living areas), Liu Cixin’s stations have key differences: first, the “bunkers” use artificial suns (between 1 and 3 each) in order to generate light but also some of the gravity and energy necessary to make the station viable. Furthermore, if needed, some of the most modern cities are designed to connect themselves to each other essentially creating even bigger cities.

O’Neill’s concept has inspired a lot of artists in their depiction of a potential future in space for humanity. Sadly, though, the sheer scale of such constructions as well as operating questions (cost, necessary energy to build an O’Neill cylinder, technical advances necessary to make the project possible…) are a sign that we certainly won’t be seeing such stations in the real world any time soon.