X-33 SSTO: Could It be Feasible With Modern Technology?

[Seret]

Just imagine multiple scramjet missile armed x-37 space planes orbiting earth with the excuse of scientific research.

Er, I think you might find air-breathing missiles less use than you would like in space.

Besides, you don't really need a lot of rocket motor to hit targets on Earth from orbit, you can trade that much altitude into a lot of kinetic energy, which equals a lot of manuever or cross-country range. To deliver a weapon from orbit all you'd need to do would be give it enough retro to de-orbit, re-enter, then pop some aerodynamic control surfaces. Even guided bombs dropped from regular aircraft can actually make pretty substantial horizontal distances, and they've only got little fins.

[Simon Ross]

In truth, yes

13 years have passed since the X-33 cancellation, the technology has moved forward, Northrop Grumman themselves have publicly stated that the design and material issues associated with the original problems with the fuel tank are now solved.

Unfortunately there is no spare money in the NASA budget to try again :-(