Aurora etc
Anyone in the military Flt Test field ( Brit let alone U.S. ) will know 'something has being going on' for a lot longer than the 1990's.
I've heard corroborating stories from serving Test Pilots & ex- military U.S. aircrew. I think it will prove that there's more than one black project, both the replacement SR-71 job and a replacement F-117 - as mentioned, why retire such a thing unless you've got something better ...
The rest we han only guess at, but I was thinking of Scott Crossfield's desciption of hypersonic flight in the X-15 - " the floor was smoking, everthing was hot to touch, let's say Test Pilot's aren't supposed to be afraid, but I was ...impressed !"
For any rumour junkies out there there was a far better one going on in military circles about the S.D.I. 'Star Wars' system - remember a certain speech by Ron.Reagan about 'something which would unite the countries of the world' ?
I've always been surprised that was not followed up further - from what I alone heard it was the real deal.
-mayble I'll get a ride in an Omega shortly ( my boss in a crap job had one, I thought it rubbish. ) Bye !