Converting Rocket Thrust to angular momentum via a fly wheel and vice versa. invisible force verses invisible force?

No doubt about it.  heavy flywheels rotating in a vacuum can  probably be used to brake a rocket or accelterate it .  How to convert invisible momentum to  rotation?  we can take trust and instead of forcing the rocket foreward use it to spin the wheel .  There has to be eqivalence somewhere or somehow.  So lets say we can vaporize the spaceship by hitting a solid wall at 30,000 meters per second forward motion, if instead we had that energy moving the fly wheels or flywheels on the craft even if in opposite directions to counteract any gyroscopic forces and the wall is hit at almost no velocity at all it might also vaporize in the exact same manner.  If there is equivalence .  One phenomenon is completely inivisible to the space travelers onboard the craft.  the  travelers also possess the energy  of their mass moving at 30,000 meters per second also ready in a flash of a collision to completely vaporize.  In the same space craft where all that thrust is used instead to turn flywheels at speeds that use the same amount of energy , possibily more than 30,000 meters per second in the circumference  that can become visible to the travelers?  or maybe not.  first they could never reach out and touch it without vaporizing.  There could be no imbalance in the machine or it would vaporize.  It might even happen that the entire apparatus of the fly wheel becomes invisible as a result of spinning that fast or at least would look like a mirrored surface.  The speed of light or photons reflecting off it would be just like a mirror if the surface was reflective because the speed of light is constant.  the geometry of the wheel would  be the shape of the mirrored surface.