The Aurora is a rumored supersonic capable aircraft, and might go as fast as Mach 20.
Here's the basic deatails in a nutshell:
What the Aurora's statistics are thought to be:
Mission:
Reconnaissance
Length:
About 110 feet
Width:
About 60 feet
Take-off Weight:
Completely unknown
Fuel:
LH2/LO2
Fuel Weight:
Completely unknown
Main Propulsion:
At subsonic speeds:
Conventional jet engines.
At supersonic speeds, there are 4 possible propulsion systems:
Pulse Detonation Wave Engine
Ramjet
Scramjet
Regular Pulsejet
Get more information on these propulsion systems with the book, Advanced Airbreathing Propulsion.
Take-off Thrust:
Probably very high
Maximum Speed:
Mach 6-20 (Most people believe that its speed is Mach 6-8, but some think that it could go up to Mach 20.)
Armament:
Unlikely to be capable of armament but may be capable of launching Phoenix Air to Air missiles.
The most likely system of thrust it uses is a Pulse Detonation Wave Engine. Heres a site link:
http://www.abovetopsecret.com/pages/pdwe.htmlPost whether you think it exists or not, and it would be pretty cool if a user made a model for fsx.