5) Silent Running
Speaking of the adverse psychological effects of space: Bruce Dern, everybody.
In Silent Running, Dern is Freeman Lowell, a cuckoo-crazy beatnik who no responsible space program director should ever have allowed onto a space craft. Lowell, an ecologist sent in amongst the stars to man a greenhouse on board a space station, spends most of his time with helper robots and quite clearly feels more affection for plant life than for his fellow humans. Clearly, this was never going to end well.
Silent Running is terrifying for two reasons: one, it argues that too much time in the void can loosen the screws on a person, isolating them almost to the point of dehumanization. Two, it displays just what happens if you’re unlucky enough to be on the receiving end of the ire of someone like that.
For Lowell’s fellow crew members, it’s death by space nuke – and all because the apparently peaceful space-groundskeeper wanted his plants to himself, the maniac.