"We believe it's the destiny of humans to explore and to reach beyond our own confines. By returning to the Moon, we will be taking the next steps in human exploration to learn how to live on the surface of another world."
In the silent vacuum of space, five autonomous robots churn through the lunar surface, digging up a loose layer of rock and dust and leaving rows of uniform tracks in their wake. Stopping only to recharge at a central solar power station, the car-sized machines process the lunar dirt internally to extract a type of helium so rare on Earth that a palm-sized container is estimated to be worth millions.