Destination Moon (1950)

Irving Pichel's film is a landmark in many ways, accurately depicting weightlessness, space walks and the technique of moon landing way ahead of even later films, rewarded with an Oscar for special effects. Scripted by sf writer Robert Heinlein, the tension comes from various escapades on the way to the moon and then the problems of returning, when the remaining fuel isn't enough to leave and all weight must be shed.