A drone flying over open ground can track its position using satellites.

Take it inside a boiler, a tunnel, or a tight gap between machines, and that signal is gone.

This matters because many of the places worth inspecting are exactly those confined, hard-to-reach spaces where sending a person is slow and dangerous.

, a Delhi startup, builds drones designed to work there.

Its drones navigate on their own, no GPS, no compass, no pilot.