The most innovative area of human motion lies not on Earth, but with the exploration of space. Space is the most hostile environment we know. Navigating it involves crossing unprecedented distances. It's the greatest engineering challenge humanity has ever undertaken.
Meet the pioneers who've dreamed of reaching other worlds, pushing the boundaries of space exploration, and the private space entrepreneurs jostling to offer the tantalizing prospect of cheap, frequent travel beyond the atmosphere into Earth orbit.

Many argue that flying saucers and other extra-terrestrial space ships continuously visit the earth. If that were true, what kinds of technologies would such alien spacecraft require? And do eyewitness reports of UFO sightings jibe with modern theories of how interstellar travel might be possible? Authors, astronomers and theoretical physicists weigh in with the blueprints for inertia-canceling devices, nuclear-powered craft, antimatter propulsion systems and even warp drives. Based on Einstein's theories and countless scientific studies, we'll find out how these visitors might bridge the vast distances between the stars. And if they could survive such hazardous journeys, are they flesh and blood or intelligent machines?