We've had a few threads like this, but it's rare that there is a movie I haven't seen, either when I was a kid or more recently. So to my surprise someone brought up this movie on a technology website and I've never seen it!! Riders to the Star 1954. It's probably a hard movie to recommend, except to dedicated scifi fans, but if you've seen The George Pal space movies, you can understand the style of it. It's not just intended to be realistic, it's almost a documentary! The movie can be seen here: https://www.youtube.com/watch?v=v9SLTpEZOBQ It is also available on Amazon in a collection of 50 science fiction movies.
More info from TCM: http://www.tcm.com/this-month/article.html?isPreview=&id=253063|89015&name=Riders-to-the-Stars
...and Wikipedia:
https://en.wikipedia.org/wiki/Riders_to_the_Stars
More info from TCM: http://www.tcm.com/this-month/article.html?isPreview=&id=253063|89015&name=Riders-to-the-Stars
...and Wikipedia:
https://en.wikipedia.org/wiki/Riders_to_the_Stars