Drone operators dread the thought of their vehicle losing power mid-flight, and not just because of the expensive crash that's likely to follow -- it's that the drone might hit something or someone on its way down. ParaZero thinks it can set those pilots' minds at ease, however. It recently unveiled a reusable parachute system, SafeAir, that slows drones when they're in free fall. The concept isn't completely novel, but it promises extremely quick reactions that could avoid accidents. As you'll see in the clips below, the chute deploys within milliseconds and can rescue a craft even if it's at very low altitudes. A lightweight drone (under 4.4 pounds) should be relatively safe even if it drops from 6.6 feet above the ground.