https://qz.com/1296361/this-flying-robot-can-explore-places-where-it-is-too-dangerous-for-humans-to-go/

Around the world, mines are often dark, dangerous places where humans fear to tread. Mapping them can be a perilous task, involving surveyors who must enter with equipment at the risk of personal injury. But now, a Philadelphia company has developed a drone system that can enter a mine and, at the touch of a button, fly autonomously through the darkness and fully map the space in 3D.

The company, Exyn Technologies, was born out of the GRASP Laboratory at the University of Pennsylvania, which has done cutting-edge research on autonomous flying robots. The system it has developed has wide application in other industries like construction and warehouse management, where autonomous mapping and real-time situational awareness could be of immense value.