To war by robot! Underground!
Thanks to the tip from Freeper.
"What Lies Beneath: Inside DARPA’s Subterranean Challenge"
"DARPA’s Subterranean Challenge is trying to address those needs. It’s a multi-phase competition aimed at promoting robotics technologies that can traverse, navigate, map and search underground environments. It will feature three different circuits — tunnel, urban underground and cave — before culminating in the grand finale that combines elements of each."
The future is now! See this You Tube video a drone useful to map large cavernous areas. A large cave, a mine shaft, even a warehouse. Apparently autonomous with lots of high-tech. Science fiction in fruition. But only for again large cavernous areas with lots of flying space.
See this previous blog entry, from the era of the Cold War, Soviet underground warfare technology.