Weird dreams.
Last night I had a dream obviously heavily influenced by Wreck of the River of Stars (a good novel, I recommend it). Very similar in plot, only with dream logic and, for some reason, the last people on board this ship were tossing animals out of airlocks (they also went right past a number of planets). I'm also pretty sure that that bit only came at the end of the dream, and that there was a lot more to it than 'oh shit malfunction', but the stuff beforehand is mainly fuzzy.