Predators and Dragons

摘要

Although unmanned aerial vehicles are often touted as the future of air war, they've been around since 1917, when Ohio inventor Charles Kettering designed a flimsy unmanned biplane called the Liberty Eagle, better known as the Kettering Bug. Built on the cheap, the Bug was developed as a flying bomb, meant to carry explosives to targets 50 miles away. But the first world war ended before it could be used, and the Bug remained classified until World War II.