I believe X-planes are impractical and is most likely impossible to develope because it violates a mutual agreement between nations with outerspace
capabilities to create a "peaceful enviorment for the research of outer space". Put in simpler words is that outerspace should not be used as a
mean to lauch missiles or wage wars or such. If that mutual agreement is broken. It won't be a long time before China, Russia and the U.S. launch
nuclear-armed satelites (there is a movie on this i remember, Space Cowboys or something like it). That i would be truely the end of the world. It is
not easy to shoot a satelite down and shooting one down might mean HUGE human casulties (the Soviets had the biggest nukes and they can be easily fit
into a satelite. One can wipe out the whole east cost). Anyway, the experimentation with war waged from space is dangerous. Even it is legal, there is
still a lot of technical difficulties and the technology is just not there yet.


