How long did it travel at hypersonic speeds while operating it's air breathing engine? I'm going to guess it was shorter than the thermal soak time of whatever material they were using for the inlet. The non-simple conical form of a scramjet means shockwave impingment has to happen in there somewhere and you can bet there's no material on Earth that's going to last more than a couple minutes.
Hypersonic air-breathing craft that generate lift just aren't a reasonable thing to make. Hypersonic "gliders" and other rocket lofted things that get up to speed outside of the atmosphere and then just briefly travel through it make sense. But all this 'research' towards lift generating air-breathing hypersonics is just a trap to get nation states to dump money and effort.
Hypersonic air-breathing craft that generate lift just aren't a reasonable thing to make. Hypersonic "gliders" and other rocket lofted things that get up to speed outside of the atmosphere and then just briefly travel through it make sense. But all this 'research' towards lift generating air-breathing hypersonics is just a trap to get nation states to dump money and effort.