Generation Ship Science Fiction

When a space voyage would take a thousand years to make and there is no faster-than-light travel or time-bending technology a generation starship is the practical answer—another option is suspended animation. The idea is that as the ship journeys across the universe generations will live and die onboard. The original crew will never see the final destination. The final crew will have never set foot on Earth. There will be passengers that don't know either place.

The concept has been alive in science since 1928, but the first realization of the idea in Sci Fi was in Don Wilcox's “The Voyage that Lasted 600 Years,” which appeared in Amazing in October 1940. This story is structured around a captain who is in a hibernation mode and wakes every hundred years or so to check on the ship's progress. He is witness to much social change.

The starship itself is usually pretty luxurious—it does have to sustain the equivalent of an entire ecosystem of generations and generations. The ship may be bolts and machines or it may be a fully realized habitat with shrubbery and what-nots. Usually the starship will have a destination, a distant planet to colonize or, to at least escape planet Earth. Sometimes the ship is a trade ship, connecting colonies or installing space highways. Regardless of the mission, the story tends to be about the crew, how the crew deals with extended periods of time in space, and social development.

Other Features of Generation Ship Science Fiction

Level of Real Science
High. Generation starships are a perhaps more realistic approach to long range space travel than the more common faster-than-light crafts or time-bending technologies. The science and technology used to build and maintain a generation ship is feasible and closer to our current scientific understanding.
Level of Grand Ideas/Social Implications
High. What happens to the familial structure on a starship hurtling through space for a thousand years? How does each generation change? How does extended periods of space travel affect passengers? How does a generation that lives its whole life on a starship relate to humanity as a whole? What happens to governance when living in close proximity for so long? There are many, many questions about the human condition to explore in a generation ship. Indeed, because it is a kind of bottle effect, albeit on a slightly larger scale, the whole thing can be seen as a sort of social experiment.
Level of Characterization
Low-Moderate. With so many possibilities in regards to social development and with potentially massive amounts of time passing, individual characterization can be minimal. Indeed, even when readers are able to spend time with a character, the character is often used as a vehicle to explore the social changes the ship has gone through.
Level of Plot Complexity
Moderate. Generation Ship Sci Fi is a saga; it is a voyage; it is a really, really long journey, which means the plot will sometimes jump forward in time. The plot may also be more overarching than detailed. Or, just the opposite in that life onboard the ship is more important than the journey. Either way, it can be difficult to manage the overarching plot of a long journey and the more detailed plot of everyday life for spacefaring folks.
Level of Violence
Variable. Whether or not violence is a part of the story is going to depend on the themes the author develops. For example, one common theme in Generation Ship Sci Fi is the degradation of society and in this instance, violence is common. Though not all stories go that route.

Related Science Fiction subgenres

Colonization Science Fiction. Generally, the end goal of a generation starship is to colonize another world.
Social Science Fiction. A generation starship is a sort of social experiment in space.

Popular Generation Ship Science Fiction Books

1 Orphans of the Sky

By Robert A. Heinlein. A classic of the sub-genre. In this book, a combination of two earlier stories, the crew has forgotten that they are on a ship until an intelligent hero has a conceptual breakthrough.
2 Starship (also called Non-Stop)

By Brian W. Aldiss. Aldiss' first book and a response to Heinlein's Orphans of the Sky, it shares many of the same themes. Written in the 50s, it is surprisingly dark and nightmarish.
3 Captive Universe

By Harry Harrison. The crew has undergone cultural engineering and become medieval monks and Aztec peasants.
4 Promised Land

By Brian M. Stableford. Takes place after the generation starship has arrived and features a society whose social structure is based on what was developed over generations onboard the ship.
5 The Space-Born

By E.C. Tubb. Life for the 13th and 14th generations onboard the starship is short and organized by a computer—even your death is decided by the computer. The chief of the psych-police knows how the computer works and he knows the computer will bring up his name for elimination soon—but he is not ready to die.
6 Rite of Passage

By Alexei Panshin. Not a pure example because the ship can travel through hyperspace.
7 The Ballad of Beta-2

By Samuel R. Delany The Star Folk left Earth centuries ago, but two of the twelve generation starships didn't make it. A galactic anthropology student is tasked with figuring out what happened to the two ships, now that faster-than-light travel is possible.
8 Book of the Long Sun

By Gene Wolfe. A four volume series set entirely on the vast generation starship Whorl. Religion, gods, prophets, outsiders—this is an epic story.
9 200 Years to Christmas

By J.T. McIntosh. This is the story of societal cohesion set onboard a generation ship about halfway through its 400 year journey. The ship is going through a libertine phase and transitioning to a more puritan phase.
10 The Watch Below

By James White. A side-by-side telling of two generation ship stories: humans stuck under the sea and water-dwelling aliens traversing space towards Earth.