Originally Posted by
tartare
For me the interesting part in all of this is that they claim to have developed a way of incorporating an off the shelf fighter weight turbojet into a working scramjet. If this is true - potentially there are much wider applications than just the SR-72.
In this case I believe that the
claim of having developed a way to use a turbojet is still a very long way from proving it can be made to work. One of the problems with hypersonic flight is that it is very difficult to prove risk reduction with ground tests as duplicating the flight environment is very hard.
There have only been two recent flight tests for hypersonic vehicles/propulsion; Lockheed's HTV-2 test on approximately April 26, 2010 and Boeing's X-51 flight on May 03, 2013. The Lockheed test was not considered a success, and the Boeing X-51 flight lasted 3.6 minutes but the vehicle was rocket assisted.
Again, I am not saying it is not feasible. I am saying that having a tested propulsion system and a full up operationally usable vehicle is a long way off.