NASA tests hypersonic Blackswift

dijkstra writes: Blackswift was previously rumored to be a super secret hypersonic scamjet-based aircraft co-named HTV-3X, essentially a 21st century version of the SR-71. Today NASA has unveiled the real Blackswift, which uses pulse detonation engines (PDEs). A PDE is essentially a modern version of the old V-1 buzz bomb engine. This engine requires significantly less moving parts and achieves much higher efficiency than a turbofan, and is technically able to go hypersonic without any kind of 'dual-stage' engine.