In less than a week, on November 12, 2014, the Philae lander will separate from ESA’s Rosetta spacecraft and descend several kilometers down to the dark, dusty and frozen surface of Comet 67P/Churyumov-Gerasimenko. Its three spindly legs and rocket-powered harpoon are all that will keep the 100-kilogram spacecraft from crashing or bouncing hopelessly back out…