Wouldn't I be able to patent the idea of landing a rocket using a reverse launch process and stabilization fins and jets, even if I'm not even capable of landing a stone? If the implementation doesn't matter than I just locked everyone else out of landing rockets for decades.
The idea is worth something but so is the implementation because ideas are generic and the more specific you make them, the more you actually define an implementation, in the physical world at least.
Your patent has to fully describe how the invention works. And if it doesn't work at all, then who cares if you own a patent for it, it's a useless invention anyway.
If your rocket does work, then yes being able to lock everyone else out of it for decades is the entire point.
But once those decades are over, anyone else can copy your idea, which has been documented for all of eternity. There's an almost endless list of inventions before patents that were never made public, and nobody knows how they worked.
Unfortunately, that's the idea for how patents are supposed to work. In the real world what we have is patent trolls.
> Your patent has to fully describe how the invention works.
Exactly, a patent can't be just for "an idea" which is intrinsically generic but rather for the actual implementation with details. Patenting ideas would probably be the very definition of an overly broad patent.
> even if I'm not even capable of landing a stone?
No, because the disclosure has to enable a person of ordinary skill in the art to practice the full scope of the invention. This is called the “enablement” requirement.
The idea is worth something but so is the implementation because ideas are generic and the more specific you make them, the more you actually define an implementation, in the physical world at least.