UFO

[Floid]

Dunno, but I'm wondering if the whole 'Aurora' thing isn't part of our apparent quest for a 'politically-acceptable ICBM:'

http://www.darpa.mil/tto/programs/falcon.htm
(Current DARPA incarnation...)

http://www.globalsecurity.org/military/systems/munitions/hyfly.htm
(More on previous testing...)

http://www.afa.org/magazine/Jan1999/0199mission.asp
(Nice shot of an aerospike test on a SR-71...)

http://en.wikipedia.org/wiki/Aerospike_engine
(Seems toroid/annular configurations have become favored generally...)

I could be underestimating the need for a good reconaissance vehicle to scout the targets in the first place, of course... but stealth matters either way, and for some reason 'air strikes' don't create quite the furor that 'missile strikes' would.