The 'vampire' drone that disappears in sunlight

Drones can drop supplies to hidden Special Forces or essential medical kit in warzones, but there’s the risk that their presence may give away the recipient’s location, or that the technology ends up in enemy hands. To solve this problem, the Pentagon is calling for designs for ‘vampire’ drones that disappear in daylight. The Defense Advanced Research Projects Agency (Darpa) is funding a new project to develop aircraft that can ‘fully vanish within four hours of payload delivery or within 30 minutes of morning civil twilight (assuming a night drop), whichever is earlier’.