Amazon just announced it will be launching a new drone delivery service called PrimeAir as early as 2015, but safety concerns will be key — no one wants an Amazon delivery falling out of the sky. As Amazon CEO Jeff Bezos says, "Look, this thing can’t land on somebody’s head while they’re walking around their neighborhood." Check out this new video by Mark Mueller out of Raffaello D'Andrea's Flying Machine Arena at ETH Zurich (note: D'Andrea is the tech wizard behind Amazon's robotic warehouse) — it shows a new failsafe algorithm that allows an unmanned aerial vehicle to recover and land safely following propeller loss. According to the researchers, the algorithm allows the vehicle to remain in flight despite the loss of one, two, or possibly even three propellers.