The engineers at MIT have come up with a way for tiny surveillance aircraft to never have to return to base. By enabling them to latch on to power lines, they can charge themselves up whenever they want.
The trick to making this possible, it turns out, is making them perform a controlled stall, like what birds do when landing on wires. When they approach the wire, they point their nose up at the right trajectory to slow them down and let them hook right onto the wire. This keeps them from landing too hard on the wire or overshooting it.
It's a pretty neat trick! And boy, I sure am glad that there will be a whole army of unmanned surveillance aircraft out there that can charge up whenever they want! I don't see how that could go wrong! [New Scientist via Slashdot]