Sferrin, who said "That's why we keep failing left and right when it comes to hypersonics"? You? What data universe set are you using to come to that conclusion?
The one where we keep failing. You know, RATTLRS, HyFly, X-51, etc. Perhaps you could direct me to our vast list of successes to show me the errors of my ways?
The examples that you quote weren't failures. You're acting like in a test program that there can be no failures, or tests that don't reach objectives for a program to continue to be viable. There has never been an experimental flight test regime that didn't have problems/issues. And sometimes, programs fall to political intrigues.
RATTLRS was cancelled. AFAIK, it never got to prototype stage, just mock-up. A lot of design work took place before cancellation, though. That is always applied to another subsequent venture. Corporate memory is important.
HyFly actually went to flight test of the launch vehicle and full scale engine. But prior to the two full scale powered tests that didn't fully meet flight objectives (the problems not sourced to the engine), there was a successful subscale test of the entire thing under FASST that flew under scramjet power for 15 seconds in December 2005. Based on a quick Web search, it may have been cancelled in 2009/2010 in white world activity.
X-51 successfully flew, and flew at Mach 5.1 for over 200 seconds on its fourth flight test. That is a white world record for scramjet duration.
Had the X-24C continued in its white world development, it was scheduled to fly at Mach 6 for 30 seconds, if my memory serves.
And I should add these two further comments. Other hypersonic windtunnel centers include Sandia and Lockheed. Lockheed actually had a hypersonic wind tunnel back in the 1980s. It went to at least Mach 9. I know this because of my colleagueship with Dr. John Nicolaides. He had his N-wing tested in the tunnel to that speed in a series of three tests. Not just three tests. Three series of. Some of the tests lasted between five and ten minutes in length. I actually saw the actually used test article. No scorching. Not on the lanyards, either. Then in the post-2000s Lockheed put together another one. They have a website devoted to this new windtunnel complex.
Also, you can go hypersonic without the use of scramjet engines. You can have subsonic flow ramjet engines that can push your vehicle to Mach 4, and Mach 5, even Mach 5.5. It's been done already previously in the 1970s in the United States at those speeds. At least five "advanced technology" test flights conducted by 1978. At approx. 80,000 to 85,000 foot altitude. By Marquardt.
As everyone is aware, Lockheed is working on the SR-75, and it has an associated propulsion unit that will allow the vehicle to go hypersonic for longer periods than before.
So sferrin's claim that the USA's hypersonic program has had a trend of continual failures (and thereby, by inference, is just a FUBARed enterprise overall) is not supported by publicly available facts.