Some of you may remember devouring those paperbacks with lurid, futuristic covers, imagining the worlds conjured up by Isaac Asimov, Arthur C. Clarke, Robert Heinlein, and Ray Bradbury: the planetary entrepreneurs, the galactic empires, and the firemen who burned books. Back in 1941, Asimov wrote a story about solar power space stations that beamed the energy to Earth. Arthur C. Clarke later (1951) laid out how to use satellites for communications in The Exploration of Space, but he also noted a German idea, from decades earlier, to put mirrors…