Are drones really on the verge of delivering packages to your doorstep?

Professor Sajiv Singh of Carnegie Mellon University robotics institute, who runs a “critical cargo delivery” company called NearEarth, said that piloting a state-of-the-art drone was a little more like leaving it a trail of breadcrumbs: go to this altitude, perform this short task, go back home. But even short flights from a mobile landing pad pose serious logistical problems, he said.