Generation ship
A generation ship is a hypothetical starship that travels across great distances between stars at a speed much slower than that of light (see interstellar travel). Since such a ship might take from as little as below a hundred years to hundreds or even tens of thousands of years to reach even nearby stars, the original occupants might either grow old or die during the journey and leave their descendants to continue traveling, depending on the life span of its inhabitants and relativistic effects.
It is estimated that, in order to assure genetic diversity during a centuries-long trip, a generation starship would require at least 500 inhabitants.[citation needed] Sperm banks or egg banks can drastically reduce the requisite number. Additionally, the ship would have to be almost entirely self-sustaining (see Biosphere and life support), providing food, air, and water for everyone on board. It must also have extraordinarily reliable systems that could be maintained by the ship's inhabitants over long periods of time.
It has been suggested that humans create large, self-sustaining space habitats before sending generation ships to the stars.[citation needed] Each space habitat would be isolated from the rest of humanity for a century, but remain close enough to Earth for help. This would test whether thousands of humans can survive on their own before sending them beyond the reach of help.
In fiction
Generation ships are often found in science fiction stories. The invention is credited to J. D. Bernal in his 1929 novel The World, The Flesh, & The Devil. A common theme is that inhabitants of a generation ship have forgotten they are on a ship at all, and believe their ship to be the entire universe.
Other examples of fictional generation ships include:
- The Trigun anime and manga
- Captive Universe, novel by Harry Harrison
- Non-Stop, novel by Brian Aldiss
- The Dark Beyond the Stars, novel by Frank M. Robinson
- Orphans of the Sky, novella by Robert A. Heinlein
- Book of the Long Sun, four-novel series by Gene Wolfe
- The Starlost, short-lived 1970s TV series by Harlan Ellison
- The Ballad of Beta-2, novella by Samuel R. Delany
- Colony, novel by Rob Grant
- Original Video Animation Megazone 23
- The Rama series of books by Arthur C. Clarke and Gentry Lee
- Kelvan Multi-Generation Ship - from the Andromeda Galaxy in the Star Trek: TOS episode By Any Other Name
- The Star Trek episode "For the World is Hollow and I Have Touched the Sky"
- The Star Trek: Voyager episode "The Disease"
- All Judgment Fled and The Watch Below, stories by James White
- Mayflower II, a novella by Stephen Baxter
- The Naked God, a novel by Peter F. Hamilton
- Learning the World: A Novel of First Contact by Ken Macleod
- The Exiles Trilogy, a series by Ben Bova
- "Ship of Fools" by Richard Paul Russo
- Nemesis by Isaac Asimov
- Seed of Light by Edmond Cooper
- Chasm City by Alastair Reynolds
- Le Papillon des Etoiles by Bernard Werber.
Bruce Sterling's short story Taklamakan is about a group of Chinese habitats that simulate generation ships in a cave under the Taklamakan desert.
- The oft-lampooned, low-budget film "Space Mutiny" takes place aboard a generation ship known as the Italic textSouthern Sun.Italic text
The television series Firefly is set in a far-away planetary system that was colonized by generational ships.
Some have compared planets with life to generation ships; this idea is usually called "Spaceship Earth".
The Marathon series of video games were based around a Generational Interstellar vessel called the "Marathon". The vessel itself is known as a "Colony Ship" and was converted from the Martian moon Deimos.
The Sega Genesis video game Phantasy Star III takes place on a generation ship (although this is not revealed specifically until very late in the game).
Sid Meier's Civilization II allows for the construction of a generation ship (though the in-game transit time is less than what would be required of a generation ship).
The 1977 science fiction pop music concept album "The Intergalactic Touring Band" features a storyline based on generation ships.
In the upcoming MMOG Infinity: The Quest for Earth, The Geodesan people construct a massive generation ship named IOS - 1 (Interstellar Operational Spaceship) to carry 1.1 million Geodesans away from their dying star, Delta.