US Patent 7210282 Case burning rocket

A case-burning rocket booster includes a combustible case containing a solid rocket fuel, a combustion chamber adjustably coupled to the case for burning the case and the solid rocket fuel, a nozzle connected to the combustion chamber for expelling the burned case and fuel to generate thrust, and a drive system for pulling the combustion chamber and nozzle up the case as the case and fuel burn. A hybrid version of the case-burning rocket also includes an oxidizer supply system for supplying varying amounts of oxidizer to the combustion chamber to vary the thrust generated by burning the case and the fuel.