In the 80s, I had read an article where sonic booms had been detected by seismographs. Pictures of the craft producing the sonic booms were unobtainable, though its contrails were visible as the "doughnuts-on-a-string" configuration. These have been speculated to have been produced by a then "still experimental pulse-detonation engine", and had been mated to the X-Plane dubbed "Aurora". Calculations has put the speed of this aircraft at 3500+mph, and an altitude exceeding100,000 ft. Any additional information?
The pulse-detonation engine is the simplest of all engine design. It requires only valves to allow the flow of air into a combustion chamber where it is mixed with fuel twice (once to promote compression and then the actual detonation process) all this must be done in a fraction of a second the repeated immediately and continuously. The results is a deafening noise when operating properly. Be useful in high altitudes, but more of a nuisance at altitudes lower than 80K.

[edit on 18/8/04 by Intelearthling]

In the So. California area we used to see/hear them regularly for a few weeks. It usually occurred on thursday mornings and the donuts-on-a-rope were easily visible from the ground. The trajectory was in-line with an approach to the mojave area and it appeared to be at over 40k' as commercial aircraft appeared under the contrail. Once it hit the press the flights suddenly stopped.

see the articel on ATS about the 'super valkryie' craft. It is indeed probable your referencing a Pulse Wave Detonation Engine in action, in which the fuel vapors are ignited as they enter/leave the combustion chamber (usually a hydrogen mix or a methane mix). I'm still researching this one, and several others, but my money's on a PWDE engine on the Aurora or similair craft.

I'm in So Cal too and I remember the weekly Thursday morning mini quakes. I always questioned what they were. I guess Cal Tech (our local earthquake monitoring center) got a lot of calls about it so one ingenious geologist at Cal Tech actually set up some kind of imaging device (can't remember if it was photography or radar imaging) and actually took a photo of a diamond shaped craft in the sky on one of those Thursday mornings! It wasn't the sharpest picture, but you could definitely make out a clearly defined diamond (not triangular) shaped craft. This same Asian geologist was the one the TV stations would interview after each earthquake. Well, after that photo was aired one time only on the TV news, it seems to have vanished! (can't find it on the internet anywhere) and the Asian geologist was never on TV again either! I guess the government didn't like him photographing their secret aircraft!

[edit on 17-8-2004 by Makuahine]

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I know NASA outfitted a SR-71 with one PDE several months ago for running test trials. GE, amoung others companies, is currently doing research trying to perfect this engine. I am wondering who has already developed a working prototype, 20 yrs. ago? The concept is simple, though application is complex.

I'm another SoCal'er who remembers those days. There were a few Thursdays in a row, in the very early morning, where the sonic booms were so intense they broke the windows of beach houses in Orange County.

Naturally, that got people miffed. Everyone believed it was the military, but (of course) they denied it. No one else had any explanations. So one congressman (a bright one, for a change) started saying that it's some unexplained phenomena that might be a national security threat and that the military should be INVESTIGATING it, and letting us know what it is. :-)

The sonic booms suddenly stopped.

Originally posted by Intelearthling
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I know NASA outfitted a SR-71 with one PDE several months ago for running test trials. GE, amoung others companies, is currently doing research trying to perfect this engine. I am wondering who has already developed a working prototype, 20 yrs. ago? The concept is simple, though application is complex.

Where is the link?

I thought the NASA sr-71 was retired after testing the aerospike enginges for the x-33 that was cancelled.

your link doesnt work anyways so i cant put it in AARP, maybe try finding the right link

Originally posted by phantompatriot
your link doesnt work anyways so i cant put it in AARP, maybe try finding the right link

My apologies Phantompatriot. I made corrections to the address so it should work now.

Originally posted by Intelearthling

Originally posted by phantompatriot
your link doesnt work anyways so i cant put it in AARP, maybe try finding the right link

My apologies Phantompatriot. I made corrections to the address so it should work now.

and thank you.

[edit on 29-8-2004 by phantompatriot]