A Cave Is No Place for Humans, So DARPA Is Sending In the Robots

utside its cavernous passageways, the mine’s entrance is emblazoned in red lettering that reads “Safety Research Coal Mine.” This site is just one of two mine systems at the Bruceton Research Center in Pittsburgh. They were once part of a full mine system but were split apart for research purposes after the U.S. Bureau of Mines leased 38 acres of land from the Pittsburgh Coal Company in 1910.

For more than a century, the U.S. government has been using these facilities to create and assess technologies that will help keep miners safe. The National Institute of Occupational Safety and Health’s (NIOSH) Pittsburgh Research Laboratory tests everything you could imagine, from how coal dust behaves to how to improve rescue missions when disaster strikes.

But tests were put on hold for eight days this August. Instead, the mines served as a testbed for the Defense Advanced Research Projects Agency’s (DARPA) latest endeavor: The Subterranean Challenge, or Sub-T for short.