I remember watching a live-action TV episode or film on TV (English, USA) sometime in the early to mid 1990's that featured a prison starship. The prisoners all live in a single "room" on one of the starship decks, separated from the ship's crew and freedom by a long row of prison bars. The prisoners have a shared hope of liberation, some sort of prophecy or promise that someone would come one day to break them out. They don't know who the person is, but they have a copy of that person's coat of arms hidden away on a wall behind a curtain, which turns out to be none other than the Superman "S" shield logo. I do remember that the story gave me quite a foreboding feeling, resembling a horror story more than a traditional superhero flick.
None of the 1970's or 1980's Superman films seem to match. I'm almost certain this was not a DCEU or Arrowverse production as both of those continuities started in the early 2010's, at least 10-15 years after I saw this.
The takes-place-on-a-starship-but-in-a-DC-universe setting reminds me of DC's Legends of Tomorrow, but that series was produced 20 years too late to be what I am looking for.