>You don’t even need a rocket. You can use a mass driver to fling the material from the moon to earth’s orbit.

That's not how orbital machanics work. You will need some sort of independant propulsion system to actually slow it down and circularize the orbit. You can't just "shoot stuff into orbit".

Oversimplifications like this are exactely why this is basically "a loony idea" and not going to happen in the forseeable future. And neither is there a "$100-billion-plus lunar economy looming" as the article claims, because there is no basis for such an economy.