[Kamen Rider Lucha]

I guess a totally-space series could happen, but I don't see it as a real possibility. At least, not one that convincingly takes place on alien-looking planets. Sentai's production demands require that they use a handful of regular urban locations and previously-erected soundstages.

I suppose we could have one where all civilizations in the galaxy look like contemporary Tokyo... but I think a ton of people would complain about that, too.