Astronaut Chris Hadfield has left the planet three times already, now he wants to do more. After seeing the bullet holes left by asteroids on our planet's surface, he believes our only chance of survival is to escape Earth and build a colony off-world. But it will be the toughest journey humanity has ever faced: space radiation, microgravity and the bacteria inside us will conspire against us. So could we earthlings ever survive off our one strange rock?