How Will Humans Get to Alpha Centauri?

Astronomers have discovered an Earth-sized exoplanet orbiting a star in Alpha Centauri, just 4.3 light-years from Earth. With surface temperatures in excess of 2,000 degrees fahrenheit, this particular planet would be inhospitable, but the fact that it exists at all raises hopes of finding another, more human-friendly… » 10/18/12 8:15am 10/18/12 8:15am