2001: A Space Odyssey (1968)
"Open the pod-bay doors, HAL."
Despite being made before the first moon landing, Stanley Kubrick and Arthur C Clarke's masterpiece is a strikingly realistic depiction of space travel.
Among the film's neater details:
Additionally, crew members are shown coping with the boredom and routine of a long, straightforward trek across empty space.
Newtonian physics is strictly obeyed in the behaviour of the ship and little "pods" that the astronauts use to travel outside it. Trouble only starts when a carefully-aligned radio transmitter, the crew's lifeline to Earth, begins to drift out of position.