I dunno about space, but a future-ish Zelda could work if it's done right. Cranes and stuff may be futuristic by LoZ standards, but it's still pretty antiquated by real-life standards. But the Master Sword would have to stay the same--not only would a "Master Lightsaber" look retarded, but the Master Sword is one of the things that's always constant across almost all the Zelda games.
Of course, all of this is dancing around a bigger issue, which is that every single Zelda game (with one or two notable exceptions) is just the same stuff over and over again. I've said elsewhere that I think Nintendo needs to think about a game that ties together all the others somehow--in other words, give us some reason why this same handful of people keep getting reincarnated together and having basically the same adventure over and over and over again, because the way it is now, it looks like it's all just a huge random coincidence. That's a storytelling no-no, honestly. It's similar to how the Resident Evil games used to be made--up until RE4, it seemed like the creators weren't really interested in creating a coherent overarching plot across all the games, they were just tacking more stuff onto the core idea of "zombies" and making a bigger and bigger mess of it because they were obviously just making it up as they went along. Starting with RE4, though, the storyline got a lot tighter and more coherent. (At least as coherent as RE ever gets.) I think they need to do something like that with the LoZ "mythos" (quotes added because there's really not much of a mythos at the moment). Thoughts?