Felix the Cat is probably most recognizable to today's audiences from the 1950s-1960s TV show where he has a magic bag of tricks, and is surrounded by the Professor, Poindexter, and others. It turns out that Felix originally appeared in a cartoon series starting in 1919. In the original cartoons, he looked a bit different than he did on the show.
Anyway, 1926's "Felix the Cat Flirts with Fate" has him falling for a cat who lives on Mars. This was probably the first time that he went to space, as the TV show had him and Poindexter occasionally go to the moon, where they met the evil Master Cylinder (who turned out to be one of the Professor's former students).
The most impressive parts of this particular cartoon is the dance sequence. Otherwise, it's nothing spectacular. Cartoons in the '20s didn't have complex plots. It wasn't until the late '30s that Warner Bros. Started making satirical cartoons that the medium really evolved.