The terminal portion of a prefabricated skirt is connected to a casing of a thruster body in the vicinity of an end wall thereof using a method including positioning the terminal portion of the skirt with circumferential clearance around the casing of the thruster body in the vicinity of the end wall; keeping the skirt in position relative to the casing of the thruster body; closing both ends of an annular space between the terminal portion of the skirt and the casing of the thruster body; injecting elastomer into the annular space; and curing the elastomer.

A multipulse rocket motor includes a secondary pulse, fired after a primary pulse of the motor, that includes a thermal insulator having channels therein, around a propellant grain of the secondary pulse. The channels provide a way to equalize pressure on the propellant grain of the secondary pulse, to reduce stresses on the propellant grain as the primary pulse is operating. The channels may extend along most or substantially all of a length of the secondary pulse. The channels may be defined by material strips of thermal insulator material evenly circumferentially spaced around the secondary pulse.

A rocket motor comprises at least two propellant grains/grain segments; a case comprising the propellant grains/grain segments, stacked within the case; and a resin for substantially maintaining the grains/grain segments in position within the case. In another aspect, a rocket motor comprises at least two propellant grains/grain segments, each having an aft-end face and a fore-end face. At least two of the propellant grains/grain segments comprise a sleeve having propellant cast therein. The motor further comprises a case comprising the propellant grains/grain segments, stacked within the case, wherein the sleeve of one propellant grain/grain segment is coupled to the sleeve of an adjacent propellant grain/grain segment such that the fore-end face of one grain/grain segment is spaced from the aft-end face of an other grain/grain segment creating a gap therebetween. Methods for making the rocket motors are described.

A rocket motor comprises at least two propellant grains/grain segments; a case comprising the propellant grains/grain segments, stacked within the case; and a resin for substantially maintaining the grains/grain segments in position within the case. In another aspect, a rocket motor comprises at least two propellant grains/grain segments, each having an aft-end face and a fore-end face. At least two of the propellant grains/grain segments comprise a sleeve having propellant cast therein. The motor further comprises a case comprising the propellant grains/grain segments, stacked within the case, wherein the sleeve of one propellant grain/grain segment is coupled to the sleeve of an adjacent propellant grain/grain segment such that the fore-end face of one grain/grain segment is spaced from the aft-end face of an other grain/grain segment creating a gap therebetween. Methods for making the rocket motors are described.

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 solid propellant rocket motor has a tubular casing accommodating a mass of solid propellant material and at least one opening for the space in the casing to communicate with the outside closed by a closing head; the closing head being coupled to the casing by means of one or the other of two blocking portions with different strength both carried by a movement device which can be elastically deformed and operated from the outside.

A solid propellant rocket motor has a tubular casing accommodating a mass of solid propellant material and at least one opening for the space in the casing to communicate with the outside closed by a closing head; the closing head being coupled to the casing by means of one or the other of two blocking portions with different strength both carried by a movement device which can be elastically deformed and operated from the outside.

A thruster has an additively-manufactured housing that includes an integrally-formed nozzle with a burst disk in it. The housing is part of a casing that surrounds and encloses a propellant that is burned to produce pressurized gases that burst the burst disk and produce thrust. The thruster may be placed in a receptacle that defines a recess for receiving the thruster. The receptacle also may be additively manufactured. The thruster and the recess both may be cylindrical, with the housing being closely fit with the cylindrical walls of the receptacle. This may allow some of the structural loads on the housing, such as loads produced by the combustion of the propellant, to be transferred to the adjoining walls of the receptacle. This enables the housing to have less structural strength than if it were to have to contain the pressure from the propellant all on its own.

A thruster has an additively-manufactured housing that includes an integrally-formed nozzle with a burst disk in it. The housing is part of a casing that surrounds and encloses a propellant that is burned to produce pressurized gases that burst the burst disk and produce thrust. The thruster may be placed in a receptacle that defines a recess for receiving the thruster. The receptacle also may be additively manufactured. The thruster and the recess both may be cylindrical, with the housing being closely fit with the cylindrical walls of the receptacle. This may allow some of the structural loads on the housing, such as loads produced by the combustion of the propellant, to be transferred to the adjoining walls of the receptacle. This enables the housing to have less structural strength than if it were to have to contain the pressure from the propellant all on its own.