> making a sustainable economic system which does not exploit

How about solving the actual actual root cause: humans are currently wired to seek dominance over any and all resources?

Barring that, our alternatives are:

  1) Open the final frontier to the nearly unlimited mass and energy resources of the solar system (and then on to the stars).
  2) Massively reduce the population via increased death or birth control.
  3) Put everyone into Matrix-like virtual reality tubes where they use minimal real-world resources.

I prefer option 1, as it's the only one that doesn't require a totalitarian state (however beneficent).