Mars One plans one-way missions to Mars; the goal is not simply to explore, but to colonize the red planet. A one-way trip saves billions and eliminates the risk of a return voyage. But can the crew survive in such utter isolation? Some candidates for the mission reflect on this challenge.
Ideas about time and space are explored in the changes that constellations undergo over time, the redshift and blue shift measured in interstellar objects, time dilation in Albert Einstein's theory of relativity, the designs of both Leonardo da Vinci and spacecraft that could travel near light speed, time travel and its hypothetical effects on human history, the origins of the Solar System, the history of life, and the immensity of space. In Cosmos Update, the idea of faster-than-light travel by wormholes (researched by Kip Thorne and shown in Sagan’s novel Contact) is discussed.