A high density, generally recognized as safe hybrid rocket motor is described which has 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 solid-propellant rocket engine (1) has a casing (2) and a thermal protection (15) internally coating the casing and delimiting a housing (17), which contains a mass of solid propellant (3); the thermal protection has a fixed portion (22) and at least one movable portion (23) that adheres to the mass of solid propellant (3) and can be moved from a back position to a forward position with respect to the fixed portion (22) through a thrust system obtained by pressuring a chamber 31 provided by installing a membrane 32 between the fixed portion 22 and the movable portion 23; the engine is tested by verifying the adhesion of the mass of solid propellant (3) to the movable portion (23) after having moved the movable portion (23) to the forward position by means of a thrust directed from the fixed portion towards the mass of solid propellant (3).

A solid-propellant rocket engine (1) has a casing (2) and a thermal protection (15) internally coating the casing and delimiting a housing (17), which contains a mass of solid propellant (3); the thermal protection has a fixed portion (22) and at least one movable portion (23) that adheres to the mass of solid propellant (3) and can be moved from a back position to a forward position with respect to the fixed portion (22) through a thrust system obtained by pressuring a chamber 31 provided by installing a membrane 32 between the fixed portion 22 and the movable portion 23; the engine is tested by verifying the adhesion of the mass of solid propellant (3) to the movable portion (23) after having moved the movable portion (23) to the forward position by means of a thrust directed from the fixed portion towards the mass of solid propellant (3).

Apparatus, systems, and methods for enhancing solid propellant performance include seeding combusting energetic material, including solid propellant, with microwave energy at a controlled power and duration.

Apparatus, systems, and methods for enhancing solid propellant performance include seeding combusting energetic material, including solid propellant, with microwave energy at a controlled power and duration.

A method for correcting non-rigid thin-walled tubular elements having geometric deficiencies, wherein, following correction, the tubular elements may perform over a wide range of pressure and temperatures, for example as a rocket motor beaker, from about −70 C to about 1000 C. Correction is required to remove asperities, maximize cylindricity, squaring a forward end wall and a rearward end wall, so that the forward end wall of the tube product may be fitted, bonded and sealed to a circular planar element using a labyrinth-joint closure. The method provides uniformity so that both the tubular elements and the circular planar elements are interchangeably uniform in size, shape and performance, and may be readily assembled into non-rigid thin-walled tube products.

A method for correcting non-rigid thin-walled tubular elements having geometric deficiencies, wherein, following correction, the tubular elements may perform over a wide range of pressure and temperatures, for example as a rocket motor beaker, from about −70 C to about 1000 C. Correction is required to remove asperities, maximize cylindricity, squaring a forward end wall and a rearward end wall, so that the forward end wall of the tube product may be fitted, bonded and sealed to a circular planar element using a labyrinth-joint closure. The method provides uniformity so that both the tubular elements and the circular planar elements are interchangeably uniform in size, shape and performance, and may be readily assembled into non-rigid thin-walled tube products.

A method of making a multi-grained fuel grain for a rocket is disclosed, the method comprising the steps of using at least one nozzle to extrude a first propellant in an additive manufacturing process, the first propellant comprising a multi-grained fuel grain, the multi-grained fuel grain forming the at least one void, the at least one void facilitating variation in internal ballistics, forming sensors, said sensors permitting continuous monitoring and continuous modification such that a user controls the ballistics profile of a rocket motor, forming an electrically-controlled second propellant in contact with and operatively coupled to the sensors; and wherein the additive manufacturing process uses at least at least one nozzle to extrude raw materials.

A method of making a multi-grained fuel grain for a rocket is disclosed, the method comprising the steps of using at least one nozzle to extrude a first propellant in an additive manufacturing process, the first propellant comprising a multi-grained fuel grain, the multi-grained fuel grain forming the at least one void, the at least one void facilitating variation in internal ballistics, forming sensors, said sensors permitting continuous monitoring and continuous modification such that a user controls the ballistics profile of a rocket motor, forming an electrically-controlled second propellant in contact with and operatively coupled to the sensors; and wherein the additive manufacturing process uses at least at least one nozzle to extrude raw materials.

A rocket motor propellant including a low molecular weight hydroxyl-terminated polybutadiene (HTPB) polymer and, a high molecular weight isocyanate. In some implementations, a rocket motor propellant hereof is plasticizer free.