This weekend, I put together the resource list of books, RPGs, TV/movies, and web sites about generation ships for Modiphius Entertainment's forthcoming FATE supplement, Project Generations. One of my re-discoveries in the process was an episode of Space: 1999 called "The Mission of the Darians". In this episode, a giant space ship - about 50 miles long by 5 miles wide - suddenly appears over Moonbase Alpha, giving off a distress call warning that a great proportion of the space ark's passengers have died.
The Alphans of course fly over to investigate. No suits, no-nothing to protect themselves against whatever caused the disaster and killed most of the crew. But things are apparently in their favor. No plagues or radiation to ruin their day. They split the party in three, explore a bit, and discover that there are survivors on the ark
In time, the Alphans find the disaster has apparently divided the ship's crew into two populations. Commander Koning and Victor Bergman discover a refined, aristocratic group who control the ship and call themselves Darians (just as the people who launched the ark did). They learn from this group that although the ship has been damaged, it is in fact on course and will reach its intended destination - a new planet to colonize - in 100 years. However, the Darians need supplies and materials to repair their ship; lists are drawn-up so that the Alphans may provide assistance. But there may be other raw materials that the Darians seek from the Alphans...
Meanwhile, the other Alphans exploring the Darian ark discover a second population that has degenerated into bedraggled and dirty cavemen types, roaming the numerous damaged and disused areas of the generation ship.
So here we have a classic generation ship story set-up: a disaster has happened on the ship, and the ship's crew or population have diverged into at least two distinct social groups, at least one of which has "degenerated" into a state of primitivism or barbarism.
As always, it is important to figure out who the real barbarians are in the story.
Watch and discover for yourself...