A rocket motor has an energetic material between solid fuel (propellent) and a casing that surrounds the solid fuel. The energetic material is configured to be burned along with the solid fuel during normal operation of the rocket motor to produce thrust. The energetic material can also be detonated to cause rupture of the casing. The detonation may be initiated as part of a flight termination process. The detonation may also be initiated as a part of process to prevent as a higher-order reaction, such as in reaction to heating from a fire or other cause. The energetic material may be arranged to function as part of a shaped charge, able to split the casing when detonated. By being located inside the casing, the energetic material does not adversely affect aerodynamics of the flight vehicle of which the rocket motor is a part, such as a missile.

The first solid propellant is formed to have a columnar shape so as for a combustion surface to move to a first direction, and to have an end surface exposed to a combustion space. The surface of first solid propellant except for the end surface is covered with a barrier membrane. The position of combustion surface in the first direction is detected by a position sensor device in an always-on measurement or a fixed-point measurement. Based on the detected result, the consumption amount of the first solid propellant is estimated.

The first solid propellant is formed to have a columnar shape so as for a combustion surface to move to a first direction, and to have an end surface exposed to a combustion space. The surface of first solid propellant except for the end surface is covered with a barrier membrane. The position of combustion surface in the first direction is detected by a position sensor device in an always-on measurement or a fixed-point measurement. Based on the detected result, the consumption amount of the first solid propellant is estimated.

A rocket motor includes at least one inert rod. The inert rod has a groove that extends along the length of the inert rod. The groove may be machined by a lathe, die, and/or CNC machine, such that the groove is configured helically around the rod. A reactive wire is inserted into the groove along the length of the inert rod. The grooved inert rod, and the reactive wire together constitute the burn rate enhancer assembly. The rocket motor is configured such that the burn rate enhancer assembly is inserted into a rocket motor casing. The rocket motor casing is then filled with a burnable propellant grain, the highly loaded grain, which is in a liquid or semi-solid state. The highly loaded grain then cures in the rocket motor casing around the burn rate enhancer assembly.

A readily combustible portion (110) includes a readily combustible exposed surface (111) that is exposed to a flow channel (CA). A combustion-resistant portion (140), which comprises a material that is more resistant to combustion than the readily combustible portion (110), covers an outer surface of the readily combustible portion (110) on the opposite side from the readily combustible exposed surface (111) in a direction orthogonal to a length direction parallel to a direction in which a hybrid rocket is propelled. The combustion-resistant portion (140) includes a thick portion (120) that serves as a stopper that prevents peeling of the readily combustible portion (110) from the combustion-resistant portion (140) in a direction from a starting end surface (100a) toward a terminating end surface (100b).

A readily combustible portion (110) includes a readily combustible exposed surface (111) that is exposed to a flow channel (CA). A combustion-resistant portion (140), which comprises a material that is more resistant to combustion than the readily combustible portion (110), covers an outer surface of the readily combustible portion (110) on the opposite side from the readily combustible exposed surface (111) in a direction orthogonal to a length direction parallel to a direction in which a hybrid rocket is propelled. The combustion-resistant portion (140) includes a thick portion (120) that serves as a stopper that prevents peeling of the readily combustible portion (110) from the combustion-resistant portion (140) in a direction from a starting end surface (100a) toward a terminating end surface (100b).

A solid-propellant gas generator assembly may comprise a bulkhead having an orifice disposed in a housing. The bulkhead may be disposed between a first end and a second end of the housing. The bulkhead and the first end may define a propellant cavity. The bulkhead and the second end may define a pressure chamber. A fast burning solid-propellant may be disposed in the propellant cavity. The solid-propellant gas generator assembly may be configured to replace a slow burning solid-propellant gas generator system in a solid-propellent gas generator system.

A solid propellant rocket motor may comprise a core-burning propellant grain extending along a longitudinal axis of the solid propellant rocket motor between an exhaust end of the solid propellant rocket motor and a forward end of the solid propellant rocket motor, a first burn inhibitor layer surrounding the core-burning propellant grain, an end-burning propellant grain surrounding the first burn inhibitor layer, a second burn inhibitor layer surrounding the end-burning propellant grain, and an aperture at least partially defined by the first burn inhibitor layer. The end-burning propellant grain is ignited by the core-burning propellant grain via the aperture.

A solid propellant rocket motor may comprise a core-burning propellant grain extending along a longitudinal axis of the solid propellant rocket motor between an exhaust end of the solid propellant rocket motor and a forward end of the solid propellant rocket motor, a first burn inhibitor layer surrounding the core-burning propellant grain, an end-burning propellant grain surrounding the first burn inhibitor layer, a second burn inhibitor layer surrounding the end-burning propellant grain, and an aperture at least partially defined by the first burn inhibitor layer. The end-burning propellant grain is ignited by the core-burning propellant grain via the aperture.

A rocket in one example includes separate chambers for storing two thrust grains: an initial thrust grain and a boost thrust grain. The initial thrust grain is stored in a first chamber and the boost thrust grain is stored in a second chamber. The initial thrust grain is ignited separately from the boost thrust grain, such as in a two-stage process where the initial thrust grain is ignited before, or at the same time as, the boost thrust grain. The initial thrust grain has a large surface area (different burn pattern) relative to the boost thrust grain, which causes the initial thrust grain to have a shorter burn time than the boost thrust grain.