Patent ID: 8051640

Claim:
A propulsion system, comprising: (a) a pressure vessel having an interior and exterior, (b) a rocket nozzle connected to the pressure vessel, (c) propellant slidably disposed within the interior of the pressure vessel, said propellant comprising at least two discrete solid propellant grains, each of said propellant grains having an end surface where combustion is initiated and occurs, said end surfaces opposing one another in an end-to-end spaced relation, thereby forming a gap between said end surfaces, said propellant grains being movable relative to one another, and (d) one or more actuator means connected to said solid propellant grains, said actuator means being operable to selectively move burning ends of solid propellant grains relative to one another, whereby to control rate of combustion of the solid propellant grains by varying spacing distance between the burning ends of the solid propellant grains.