Abstract: A rocket engine with an augmentation gas system that improves performance of the hypergolic combustion process. The augmentation gas system includes an acoustic cavity manifold mounted between an outer perimeter of an injector face and the combustion chamber. The augmentation gas system injects an augmentation gas active element such as hydrogen or an inactive element such as helium to provide significantly enhanced boundary layer coolant effect to reduce heat loading on the combustion chamber wall and enhance the specific impulse of the rocket engine.