A selectable ramjet propulsion system for propelling a rocket or missile includes a gas generator adjacent a booster. A frangible diaphragm is disposed between the gas generator and the booster. The booster and fuel gas generator can be operated in normal sequence, or operated at the same time in order to increase the thrust produced for short-range missions. A logic circuit contained on the rocket or missile determines a time to rupture the frangible diaphragm based on whether or not the distance to the target exceeds a threshold distance.

A selectable ramjet propulsion system for propelling a rocket or missile includes a gas generator adjacent a booster. A frangible diaphragm is disposed between the gas generator and the booster. The booster and fuel gas generator can be operated in normal sequence, or operated at the same time in order to increase the thrust produced for short-range missions. A logic circuit contained on the rocket or missile determines a time to rupture the frangible diaphragm based on whether or not the distance to the target exceeds a threshold distance.

Various implementations of an extinguishable, solid propellant divert system for a flight vehicle are disclosed. Also disclosed are methods for using the divert system to control the flight of a flight vehicle. In one implementation, a divert system includes a hot gas generator pneumatically linked to one or more divert thrusters and an extinguishment valve. The extinguishment valve can be opened to rapidly depressurize the hot gas generator and extinguish the solid propellant burning inside. In another implementation, a method of controlling the trajectory of the flight vehicle includes repeatedly igniting and extinguishing the solid propellant in a hot gas generator and using the hot gas to provide divert thrust for the flight vehicle.

Various implementations of an extinguishable, solid propellant divert system for a flight vehicle are disclosed. Also disclosed are methods for using the divert system to control the flight of a flight vehicle. In one implementation, a divert system includes a hot gas generator pneumatically linked to one or more divert thrusters and an extinguishment valve. The extinguishment valve can be opened to rapidly depressurize the hot gas generator and extinguish the solid propellant burning inside. In another implementation, a method of controlling the trajectory of the flight vehicle includes repeatedly igniting and extinguishing the solid propellant in a hot gas generator and using the hot gas to provide divert thrust for the flight vehicle.

A high density, generally recognized as safe, hybrid rocket motor is described, having a density-specific impulse similar to a solid rocket motor, with good performance approaching or equal to a liquid rocket motor. These high density hybrid motors resolve the packaging efficiency/effectiveness problems limiting the application of safe, low cost hybrid motor technology.

A high density, generally recognized as safe, hybrid rocket motor is described, having a density-specific impulse similar to a solid rocket motor, with good performance approaching or equal to a liquid rocket motor. These high density hybrid motors resolve the packaging efficiency/effectiveness problems limiting the application of safe, low cost hybrid motor technology.

A precursor formulation comprising, before curing, a hydroxyl-terminated polybutadiene (HTPB) prepolymer or a hydroxyl-terminated polyether (HTPE) prepolymer, an oxidizer, a dimer fatty diol, and an isocyanate curative. A solid propellant comprising a reaction product of the HTPB prepolymer or HTPE prepolymer, the dimer fatty diol, and the isocyanate curative is also disclosed, as is a rocket motor comprising a case and a solid propellant in the case, the solid propellant comprising the reaction product and an oxidizer. A method of reducing a burn rate of a solid propellant is also disclosed.

A precursor formulation comprising, before curing, a hydroxyl-terminated polybutadiene (HTPB) prepolymer or a hydroxyl-terminated polyether (HTPE) prepolymer, an oxidizer, a dimer fatty diol, and an isocyanate curative. A solid propellant comprising a reaction product of the HTPB prepolymer or HTPE prepolymer, the dimer fatty diol, and the isocyanate curative is also disclosed, as is a rocket motor comprising a case and a solid propellant in the case, the solid propellant comprising the reaction product and an oxidizer. A method of reducing a burn rate of a solid propellant is also disclosed.

A multi-pulse rocket propulsion motor for use with vehicles, such as space vehicles like satellites, rockets, and the like. The propulsion motor is a modular system that is capable of providing a plurality of discrete, controllable propulsion pulses. The propulsion motor can be used for primary propulsion of the vehicle and/or as a maneuvering thruster of the vehicle. The propulsion motor includes a plurality of propellant housings each containing a combustible propellant grain, a discharge plenum defining a plenum volume in communication with the discharge of each propellant housing, and a nozzle downstream from and in fluid communication with the plenum volume.

A multi-pulse rocket propulsion motor for use with vehicles, such as space vehicles like satellites, rockets, and the like. The propulsion motor is a modular system that is capable of providing a plurality of discrete, controllable propulsion pulses. The propulsion motor can be used for primary propulsion of the vehicle and/or as a maneuvering thruster of the vehicle. The propulsion motor includes a plurality of propellant housings each containing a combustible propellant grain, a discharge plenum defining a plenum volume in communication with the discharge of each propellant housing, and a nozzle downstream from and in fluid communication with the plenum volume.