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 solid propellant propulsion motor may comprise: a forward propellant grain extending along a longitudinal axis of a motor case between a forward end of the motor case and a first burn inhibitor layer in the motor case; the first burn inhibitor layer disposed axially adjacent to the forward propellant grain; an aft propellant grain disposed axially adjacent to the first burn inhibitor layer; a second burn inhibitor layer disposed axially adjacent to an aft end of the aft propellant grain; and an ablative material layer disposed on a radially inner surface of the aft propellant grain.

A solid propellant propulsion motor may comprise: a forward propellant grain extending along a longitudinal axis of a motor case between a forward end of the motor case and a first burn inhibitor layer in the motor case; the first burn inhibitor layer disposed axially adjacent to the forward propellant grain; an aft propellant grain disposed axially adjacent to the first burn inhibitor layer; a second burn inhibitor layer disposed axially adjacent to an aft end of the aft propellant grain; and an ablative material layer disposed on a radially inner surface of the aft propellant grain.

A method of making a fuel grain for use in a rocket motor, the method comprising blending a first energetic nanoscale metallic compound and a second compound suitable to form a feedstock material for use in an additive manufacturing apparatus, the additive manufacturing apparatus operatively connected to a computing system, that provides additive manufacturing printing instructions to the additive manufacturing apparatus, permitting construction of an autonomously designed and optimized rocket fuel grain section; wherein the stochastic deposition simulation-assisted fuel grain geometries further comprise a plurality of agglutinated layers of solidified fuel grain compound, each layer of the plurality of layers comprising a plurality of blended and radially displaced beads of different radii, said radial displacement optionally optimized via competitive simulation programs, and wherein the system continuously mixes constituent materials in an inline/static mixer, with viscosity controlled via particle size variations, and material is deposited in a controlled atmosphere or vacuum.

A method of making a fuel grain for use in a rocket motor, the method comprising blending a first energetic nanoscale metallic compound and a second compound suitable to form a feedstock material for use in an additive manufacturing apparatus, the additive manufacturing apparatus operatively connected to a computing system, that provides additive manufacturing printing instructions to the additive manufacturing apparatus, permitting construction of an autonomously designed and optimized rocket fuel grain section; wherein the stochastic deposition simulation-assisted fuel grain geometries further comprise a plurality of agglutinated layers of solidified fuel grain compound, each layer of the plurality of layers comprising a plurality of blended and radially displaced beads of different radii, said radial displacement optionally optimized via competitive simulation programs, and wherein the system continuously mixes constituent materials in an inline/static mixer, with viscosity controlled via particle size variations, and material is deposited in a controlled atmosphere or vacuum.

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 motor assembly is provided for use with projectiles, such as munitions, having relatively low length to diameter ratios. The motor assembly has an aerospike nozzle and a casing disposed about the aerospike nozzle, where interior aerospike volume contains propellant and where walls of both the cowl of the casing and of the aerospike nozzle jointly define a combustion chamber.

A motor assembly is provided for use with projectiles, such as munitions, having relatively low length to diameter ratios. The motor assembly has an aerospike nozzle and a casing disposed about the aerospike nozzle, where interior aerospike volume contains propellant and where walls of both the cowl of the casing and of the aerospike nozzle jointly define a combustion chamber.

A rocket motor (20) includes a nozzle (22) and a solid propellant section (24) in communication with the nozzle. The solid propellant section includes a first energetic grain layer (38, 32) that has a top surface and a bottom surface, and a second energetic grain layer (40, 44) that has a top surface and a bottom surface. The second layer is located on top of the first layer. The bottom surface of the second energetic grain layer partially abuts the top surface of the first energetic grain layer, and the bottom surface of the second energetic grain layer and the top surface of the first energetic grain layer define a region (46, 48) therebetween. A powder energetic (49) is disposed in the region.