Drone Co-habitation Services operates a Phantom 3 commercial drone, one of 11 vehicles in a NASA field demonstration in Nevada. (Dominic Hart/NASA Ames)
By 2020, an estimated 7 million drones could be zipping around the US delivering packages, taking photos, inspecting infrastructure or conducting search and rescue missions.
But before that happens, they'll need a system in place to avoid crashing into each other – or worse, passenger aircraft.
