X-33 Revived by the Military
When I was an impressionable teenager investigating what career I might choose I read a lot of scifi books (which resulted in a bad decision, but good interests & hobbies). Many books have scenarios where an armed-to-the-teeth shuttle is launched and just orbits silently waiting for orders. An example of this was "Footfall" by Larry Niven & Jerry Pournelle.
X-33 Stay of Execution
Pentagon Plans Space Bomber
Bush Plans Space Bomber