Dig Deep: DARPA Contest Aims to Take People Underground

From the seas to mountain peaks, humans

have colonized almost every inch of Earth's surface.
Now, humans may soon be able to routinely venture below the planet's surface, at least if the military has any say in the matter.
The Defense Advanced Research Projects Agency (DARPA) has announced its latest challenge, called the Subterranean or "SubT" Challenge. The global competition asks entrants to develop systems that can help humans navigate, map and search in underground locations that are normally too perilous to visit.