A few days ago I happened upon Destination Moon (1950) on TCM. I had never even heard of it before, much less seen it, and the little snippet I caught made it seem so laughable that I recorded it for later viewing.
But when I came back to watch the whole thing I was quite surprised to learn that, despite some staggering implausibilties (e.g., they decide to take off earlier than planned, on 17 hours’ notice, with an essentially untrained crew), it was the first Hollywood feature to deal with space travel in a serious, scientific fashion.
And it was based on a story, and co-written, by Robert Heinlein, a fact that TCM host Ben Mankiewicz inexplicably didn’t even mention.
It was an odd mix of accurate physics and engineering with ludicrous (from a post-Apollo POV) implausibilties, but it was light years beyond anything seen before, like Buck Rogers and Flash Gordon. And it won an Oscar for Best Special Effects, thanks to in part to great matte paintings by Chesley Bonestell.
Unfortunately, it’s no longer available at TCM, but if it ever comes back, it’s definitely worth watching.