What would it be like if entrepreneurs could literally ''mine the sky'' to solve Earth's three major fulfillment problems: energy, mineral resources, and food? That is the engaging premise of John S. Lewis's visionary new book. What if we could chemically break down the atmosphere of Mars for substances that can be used as spacecraft propellants; hollow out asteroids to transform them into livable habitats for billions of space-bound homesteaders; mine the asteroids for precious metals to be used in space construction projects; milk the comets and the moons of Mars for their vast supplies of water; extract helium from moon rocks and radioactive minerals from asteroids, for use as fuel in fusion reactors? With the expansive reach of science fiction, John Lewis's Mining the Sky shows just how these plans are achievable using technology that either exists already or will become available in the very near future. Based on his decades of work at the Lunar Planetary Institute in Tucson, Arizona, Lewis makes the bold proposal that the depletion of the earth's natural resources, as well as the overpopulation of the planet, are solvable problems; indeed, that the unlimited wealth of resources orbiting the sun will ultimately sustain ten quadrillion people living in the many worlds - both natural and man-made - that will compose our enhanced solar system. And reaping the fruits of these nearby solid objects is only the beginning: In the gas-giant outer planets - Jupiter, Saturn, Uranus, and Neptune - there is sufficient natural hydrogen and helium to power enough fusion reactors to meet our energy needs almost for eternity.