Does it exist? It seems that it does. Look at it this way, the SR-71(Strategic Reconaissance-71) spyplane was produced 40 years ago. Fourty years before that, we were flying biplanes that could barely break 100 mph. And technology hasn't stood still. There are photographic, and video evidence of unusual contrails that look like a knotted rope. Experts claim that these are the result of Pulsed Detonation Wave Engines. Basically, these engines run intermittantly, rather than continuously. Much like an internal combustion engine explodes its fuel in short bursts. This innovative approach allows it to travel at high speeds while still conserving fuel.
To view an avi of auorora in flight, click on the image above. The animation depicts the aircraft transitioning from internal ramjet, to external propulsion. The background is a realistic reproduction of Area 51/Nevada Test Site. It was created from satellite imagery, and USGS digital elevation data.
Aurora is a general name for a family of hypersonic vehicles. The unusual version depicted here has two modes of propulsion, a ram jet for traveling at subsonic, and supersonicspeeds, and an external burning engine for hypersonic travel. In the latter case, fuel is sprayed within the shockwave created by the vehicle, and the enormous temperatures generated by hypersonic speeds ignites the fuel. The explosion propels the craft forward, similar to squeezing a wet pumpkin seed between your fingers.
The ramjets are fed by four NACA ducts in the forward section. Two on top, and two on the underside. As for the exhaust, there are four ports positioned at the rear of the craft. When traveling at hypersonic speeds, the intake and exhaust ports close, leaving an clean aerodynamic shape, somewhat like a flattened diamond, or a skipping stone.
There are several control surfaces. Two on the leading edges of the craft, and one beaver tail like flap at the rear. Obviously, this unique wingless shape requires very wide turning circles. When the vehicle is ready to land, three landing legs deploy. One in the front and two at the rear. Since the arcraft gets so hot at hypesonic speeds, the wheels are mad of braided steel. Polymer wheels would just melt.
Click on the image above to see a larger view.
There are tiny morsels of evidence that point to the existence of hypersonic aircraft. Sky quakes have been picked up by USGS earthquake sensors. Also, radar operators have tracked objects traveling at mach 6 and above. Some reports go as high as mach 17! Can this be possible? Well, if planes went from 150 mph to 2100 mph (mach 3) in forty years, it does seem possible to go from mach 3 to mach 17 in another 40 years.
The newest member of the aurora family sounds more like science fiction, than fact. They rely on more exotic methods of propulsion, such as magnetohyrodynamics. This type of engine uses powerful magnetic fields to propel the air past the body of the plane, creating forward motion. It most likely is used in conjunction with a plasma torch at the nose of the plane, which helps to reduce drag, and heating due to friction with fast moving air.