NASA's Opportunity and Spirit rovers touched down on Mars in 2004 for a planned 90-day tour; six years and a few serious snags later, the latter of the two is facing its death of cold. Since March 22, 2010, Spirit's been slumbering on the surface -- stuck and unable to generate enough power to communicate -- and while internal heaters and a favorable position on a sun-facing slope allowed the rover to survive previous Martian winters, this time the chances aren't so good. "The rover is experiencing the coldest temperatures it's ever be
