[DiogenesLamp]

the US mil is, at the minimum, 50 years beyond what is publicly known;

I think 50 years is an exaggeration. Maybe 20 years, but not 50

We know a little about the Aurora project and it's advanced pulse detonation engine, and these things may have came out of that same skunworks area.

[PUGACHEV]

"I think 50 years is an exaggeration. Maybe 20 years, but not 50,,

I wouldn't be surprised to learn that there is technology developed by the military in the '60s that we still don't know about.

[PIF]

20 years is your figure, but the common one is 50 years - also quoted by notable people in the secretive aviation community like Kelly Johnson and others who worked at either the Phantom or Skunkworks

[PIF]

Actually, we know absolutely nothing about the Aurora project beyond its name and even that is suspect. All else is internet speculation.