Free Online HD on Lookmovie. On September 15, 2017, Cassini, the biggest interplanetary spacecraft NASA has ever built, will make a fatal dive into Saturn's atmosphere, collecting unprecedented science to end 13-years of discovery at the ringed jewel of our solar system. MISSION SATURN, a one-hour special will tell this story and chronicle the epic end designed to protect any potential for life at Saturn's moons - places of future exploration.