It sounds completely like science fiction, something out of a campy space thriller where the protagonist is a miner taking a daily shuttle to the Moon to mine all the precious metals that the Earth needs to sustain itself.  But in real life, for a long time, it was thought that the Moon was a dead rock, completely useless to humanity except as the gravitational force to provide the amazing tides in the bay of Fundy.  Today we know so much more about the Moon, and its value has (pun intended) skyrocketed. For one, the low gravity of the Moon...