Horizon goes behind the scenes at NASA as they countdown to the landing of a 2.5 billion-dollar rover on the surface of Mars. In six days time, the nuclear-powered vehicle - the size of a car - will be winched down onto the surface of the Red Planet from a rocket-powered crane. That's if things go according to plan: Mars has become known as the Bermuda Triangle of space because...,纪录片地平线系列：火星任务于2012年在英国上映,青柠影院为您免费提供地平线系列：火星任务HD在线观看" />
