In one test, a missile built by Boeing flew more than 230 miles in just four minutes. In another, a prototype designed by Lockheed Martin blasted off like a rocket and streaked back through the atmosphere at more than 20 times the speed of sound. China has reportedly tested its version over a lake in Inner Mongolia. And in February, Russia joined the fray when it tested a model that intelligence experts assert could be designed to carry a nuclear warhead.
Such hypersonic weapons, intended to attack targets many times faster than the speed of sound — before a defender could even react — have become the newest hope for military commanders seeking to gain an edge over potential adversaries. While most details and the level of funding remain classified, some predict they could be perfected within the next five years. http://www.politico.com/story/2015/08/russia-china-arms-race-goes-hypersonic-weapons-future-121230
What is needed is the development of a nuclear engine powerful enough to place a spacecraft (plural) powerful enough to knock down any missile launch. SAC in space. /Fantasy.
Even the Aussies were pretty far advanced in Hypersonics back in the day. I’ve been following some of the stuff you’re talking about. Surprisingly none of the stuff in the 90’s dealing with Hypersonics was classified. I read many open source white papers. Those white papers helped me greatly in my efforts on some of the later technologies I worked on. I’m sure it helped the Chinese get to where they are today too.