Out of Gas - S1-E5
Corrected entry: Although the premise of the episode is the complete failure of Serenity's major systems (life support, navigation, etc.), the gravity stays on throughout the episode. "Stays on," because a ship would require a major, operational electromagnetic system to mimic gravity - or it would need to be in a controlled spin - either of which option would fail as the rest of the ship did. As well as freezing and asphyxiating, by the rules of the episode, Mal and the others should be floating throughout.
Correction: How is there gravity in the ship? Is it an active system (requiring power) or a passive system (always on)? It is never mentioned, in the brief series, how they maintain gravity on ships. The series is set hundreds of years into the future. You can't guess what future technology might be invented.
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