from the article: >>A hypersonic weapon test carried out by China in July featured a missile fired at five times the speed of sound - a technological feat which no other country has demonstrated, according to US intelligence. The hypersonic glide vehicle - a spacecraft with the ability to carry a nuclear warhead - fired a missile mid-flight over the South China Sea, catching Pentagon scientists unawares. Experts at Darpa - the Pentagon's advanced research agency - are apparently still baffled at how China was able to defy the constraints of physics to fire a weapon from the vehicle travelling at hypersonic speed, the Financial Times reports.