<a class="link" rel="nofollow" href="http://www.ufoblogger.blogspot.com">www.ufoblogger.blogspot.com</a> "Blackswift was previously rumored to be a super secret hypersonic scramjet-based aircraft co-named HTV-3X, essentially a 21st century version of the SR-71. Today NASA has unveiled the real Blackswift (video link), 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 fewer moving parts and achieves much higher efficiency than a turbofan, and is technically able to go hypersonic without any kind of 'dual-stage' engine."
