SOC, I'll grant you that. However, most of these reports and articles originated in the 1990-91 timeframe. That's almost 20 years. Hell, you have prototypes like Tacit Blue and Boeing's Bird Of Prey getting declassified in that timeframe. So where's the "Flaming Pumpkinseed" or even Aurora for that matter?
And if it did exist, what would have been the point of programs like the X-43, the late Blackswift , the X-51, or FALCON? Granted those are all scramjet projects. However, if external combustion was workable, don't you think we'd have seen an actual demonstrator or even a proposal by now?
Seriously.
Look, the only thing I can think of is that somewhere along the line, MAYBE, just MAYBE, something was tried and it failed. Nobody likes to advertise their failures. However since there's nothing other than a NASA windtunnel model to back up this claim, it really doesn't exist. Short of declassification.
And to Vulture, if you're still convinced the Pumpkinseed is out there, maybe you should go on ATS.com.