Nebraska researchers using drones as firefighting tool

A team from the University of Nebraska-Lincoln flew an unmanned aircraft over the prairie at the Homestead National Monument of America on Friday, dropping ping pong-like balls filled with a chemical mixture to ignite brush-clearing grass fires. Local and federal officials are interested in the technology because it could help clear overgrown vegetation in rugged, hard-to-reach terrain, said Michael Johnson, a spokesman for the National Park Service. The balls are filled with a chemical powder, potassium permanganate, before they're loaded into the drone. During flight, the aircraft pierces the ball with a needle and injects it with another chemical, glycol, before releasing it. The technology is already used by helicopters to start controlled burns, but researchers note that the drone is cheaper and more portable.