Mission of the Darians (1974)

the moon approaches what appears to be a colossal spaceship, the daria. on board koenig and bergman meet kara and neman, who tell the commander that now only a few survivors remain of the vast population of the darians and their aim is to bring the genetic database of their millennial civilization to a new world. the rest of the ship, over eighty kilometers long, is abandoned to the raids of seemingly primitive and dangerous beings. helen russell is captured by a group of these savages who intend to sacrifice it to their god.