task, go back home. But even short flights from a mobile landing pad pose serious logistical problems, he said. “They’re not proposing to deliver from one uninhabited place to another uninhabited place; they’re proposing to deliver from a warehouse to where the consumer is, which is likely an urban area or a suburban area,” he said. “In those particular cases, there are going to be hazards along the way that the vehicle is going to have to detect. Maybe there will be terrain that the map doesn’t know about, unless you’ve mapped that exact route before. Even then, maybe there’s construction equipment that wasn’t there but is there now. Maybe GPS signals are blocked or partially blocked, in which case it’s going to have an incorrect idea about where it is.” All this is surmountable, he said – but it’s difficult. One major problem is maintaining radio contact with a drone and planning for what happens if that contact breaks. “If you have an off-the-shelf UAV [unmanned aerial vehicle], it’ll just keep going and crash into the ground,” said roboticist Daniel Huber. That’s not a hard problem for an engineer to fix; it’s just that the fix isn’t yet an industry standard. Furthermore, “you can’t do everything with a 25kg aircraft”, said Jay McConville, director of business development for unmanned systems at defence and business contractor