The Rosetta spacecraft’s Philae lander is attempting to land on the awkwardly named comet, 67P/Churyumov–Gerasimenko. The slightly-above 100kg probe will fall for seven hours. If everything goes according to plan, it will land on a suitable patch of the 4km-long comet.
Stephan Ulamec, the head Rosetta lander, said that “The most critical point was and still is the landing itself, the touchdown on the surface. This is where we will need some portion of luck."
Tiny margins, massive problems
Even the slightest landing error ...