The key to making this work is the development of self replicating systems. We need to send seed factories[0] to asteroids or the moon to keep initial launch m

The key to making this work is the development of self replicating systems. We need to send seed factories[0] to asteroids or the moon to keep initial launch mass low. Once the seed factories produce sufficient copies of themselves they can produce larger scale mining equipment that can be used to refine the material in space before it is sent back to Earth for use in manufacturing. Over time we can move more and more manufacturing off world to eliminate pollution that is destroying our ecosystem. [0] https://en.wikibooks.org/wiki/Seed_Factories https://en.wikibooks.org/wiki/Seed_Factories