The calculating stars

On a cold spring night in 1952, a huge meteorite fell to earth and obliterated much of the east coast of the United States, including Washington D.C. The ensuing climate cataclysm will soon render the earth inhospitable for humanity, as the last such meteorite did for the dinosaurs. This looming threat calls for a radically accelerated effort to colonize space, and requires a much larger share of humanity to take part in the process.