Abstract: A system or method of propelling a vehicle with a multimodal propulsion system is provided. This multimodal propulsion system includes a primary inlet, a high-pressure gas generator, a gas generator exhaust system, a secondary fluid inlet, and a propulsion exhaust system. The primary inlet receives an incoming fluid flow that is provided to the high-pressure gas generator. The high-pressure gas generator coupled to the primary inlet produces a high-pressure exhaust from the incoming fluid flow. The high-pressure gas generator exhaust and secondary inlet couple to the propulsive exhaust system which mixes the two flow streams. The secondary flow may be gaseous or liquid fluid flow such as air flow for airborne flight and water for waterborne operation. The mixed fluid flow is expelled by the propulsive exhaust system that can propel the vehicle.

Abstract: A system or method of propelling a vehicle with a multimodal propulsion system is provided. This multimodal propulsion system includes a primary inlet, a high-pressure gas generator, a gas generator exhaust system, a secondary fluid inlet, and a propulsion exhaust system. The primary inlet receives an incoming fluid flow that is provided to the high-pressure gas generator. The high-pressure gas generator coupled to the primary inlet produces a high-pressure exhaust from the incoming fluid flow. The high-pressure gas generator exhaust and secondary inlet couple to the propulsive exhaust system which mixes the two flow streams. The secondary flow may be gaseous or liquid fluid flow such as air flow for airborne flight and water for waterborne operation. The mixed fluid flow is expelled by the propulsive exhaust system that can propel the vehicle.

Abstract: According to one embodiment of the invention, a rocket booster for launching a payload into space includes a fuselage adapted to support one or more fuel tanks inside the fuselage and a booster engine coupled to an aft portion of the fuselage. The booster engine is operable to provide thrust during an ascent phase of operation of the rocket booster. The rocket booster further includes a nacelle coupled to a forward portion of the fuselage and a flyback engine disposed within and coupled to the nacelle. The flyback engine is operable to provide thrust during a flyback phase of operation of the rocket booster. The rocket booster also includes one or more control surfaces coupled to the fuselage that are operable to control a flight pattern of the rocket booster during the flyback phase of operation. The flyback engine of the rocket booster is located forward of an aerodynamic center of the rocket booster.