Those two little Mars rovers, Spirit and Opportunity, have far outlasted their original expected lifespans, but they have their limitations. They may have traveled far, but they have sometimes gotten stuck along the way. And we never saw them attempt to traverse a cliff or crevasse. The tethered "Cliffbot," however, looks to be far sturdier and more adventurous. It was designed to sample rock outcrops on Mars and the Moon, where there is plenty of interesting geology to explore. Testing has to be done here on earth, though, so where did scientists go to find a Mars-like surface? Svalbard, Norway.