It could be NASA's last chance to set wheels down on Mars until the end of the decade: in August 2012, a rover named Curiosity will touch down inside Mars' Gale Crater, carrying 10 new instruments that will advance the quest for signs that Mars might have once been suitable for life. But Curiosity's mission is risky. After parachuting through the Martian atmosphere at twice the speed of sound, Curiosity will be gently lowered to the planet's surface by a "sky crane." This first-of-its-kind system has been tested on Earth, but will it work on Mars? With inside access to the massive team of scientists and engineers responsible for Curiosity's on-the-ground experiments, NOVA is there for the exhilarating moments after Curiosity's landing -- and for the spectacular discoveries to come. But no rover does it alone: Curiosity will be joining a team that includes the Mars Odyssey, Express and Reconnaissance orbiters, along with the tireless Opportunity rover. As we reveal the dynamic new picture of Mars that these explorers are painting, we discover the questions raised by 40 years of roving Mars: How do we define life? How does life begin and what does it need to survive? Are we alone in the universe?