Outer space has an endless supply of resources. Within rocket’s reach there are light buckets full of intense solar energy, at least out to Mars. Then there are valuable materials on the Moon, as well as on Mars and its moons. Near Earth asteroids offer yet another mother lode of minerals. At present, the vast gulf of space prohibits access to these treasures, but a loosely knit group of like-minded experts believe that by tapping the rich resources of space, humanity’s foothold on other worlds will be far more secure and long-lived.