

I think anything from an existing franchise isn't possible from copyright, but Mojang could make a few parodies of them. Still finding one would be very rare, almost an easter egg from the developers. There could be a couple preset planets, which are coded to be easier to find than the random ones. Oh, maybe you suggested random i suggested pre-made, some could be pre-created and you can also go to randomely generated ones. But if you can get there via a portal in the Overworld, you don't have to worry about this issue. Now, sure, the space travel physics don't have to be realistic, this isn't Kerbal Space Program, but even beyond style, there are other balance related reasons why spacecraft aren't the best way to travel around the galaxy, the main one being the fact that if you die on a planet, your spacecraft remains in orbit around the planet or landed on the planet and you're back on the Overworld. Minecraft's technology is a mess, but I can tell you that anything from beyond the earliest of the 1900s is pretty much out of the picture, and we're not even talking about rockets here, we're talking about spaceships which can retain enough fuel to escape the orbit of a planet, enter the orbit of another planet and return to the original planet all without needing to leave behind rocket stages or temporary fuel tanks. That doesn't mean it has a theme- a sort of adventurous Medieval/Renaissance tech level world with random abberations, perhaps overall settling at around 1500-1550- but it's nowhere near solidly set the way a game like Skyrim is. Really, to at all quantify Minecraft's technology is a fallacy in and of itself the gap between its high and low tech is 700 years or more, and things pop up all over the place.

Redstone itself might be some form of enchanted substance, but other things are solidly in the mechanical scale things like dispensers, pistons, levers, and whatnot.
