Sending humans to Mars used to seem like an impossible dream. But with the discovery of flowing water on Mars and the blockbuster movie "The Martian," even NASA is talking about a human mission to Mars. So why do people want to go to the Red Planet? We hear from a Mars One finalist and from the commander of one of NASA's Mars simulations; for 8 months she lived in a dome on the side of a volcano. Also, two science fiction heavyweights: Andy Weir describes the improbable origins of his blockbuster novel "The Martian," and Kim Stanley Robinson wonders what it would be like to travel to the nearest habitable star system 12 light years away. His answer? Like being trapped in a Motel 6. SEE NASA'S "MARS EXPLORERS WANTED" POSTERS HERE One in A Hundred: Finalist for Private Mars Program On Her Hopes and Fears; The Modern Mars MacGyver: Andy Weir on his Breakout Novel "The Martian"; Simulating Mars — From a Dome in Hawaii; Could Traveling to Mars Save Humanity?; Whistlers and Bow Shocks: Hearing the Sounds of Space; Leaving the Cradle: Kim Stanley Robinson on Traveling Beyond Our Star System.