Amazon's Prime Air delivery drones already have a glaring problem: how do you keep them charged and sheltered when dedicated facilities are likely to be few and far between? The company has an idea. It recently received a patent for a "UAV docking station" concept that would offer a temporary perch for drones in need. If a drone runs low on battery or needs to take shelter from an impending storm, it would only have to travel to a station on top of a street light, cell tower, church steeple or another high-up location. The drone could even drop off a package for another drone, turning a delivery into an aerial relay race.