The application relates to a Ramjet solid fuel having an ignition temperature of less than 400 C., the fuel comprising a bis-(ethylene oxy) methane polysulfide polymer (BMPP) and hydroxyl-terminated polybutadiene (HTPB), the copolymer having a BMPP/HTPB weight ratio of from 1/3 to 3/1; and the fuel comprising at least 85 weight % copolymer. The BMPP comprises from 5 to 8 weight percent mercaptan. Furthermore, the BMPP is selected from

HS(RSS).sub.aCH.sub.2CH((SSR).sub.cCSH)CH.sub.2(SSR).sub.bSHa) where R=(CH.sub.2).sub.2OCH.sub.2O(CH.sub.2).sub.2 and a+b+c<7; and

H(SC.sub.2H.sub.4OCH.sub.2OC.sub.2H4S).sub.nH where n=7.b)

The application relates to a Ramjet solid fuel having an ignition temperature of less than 400 C., the fuel comprising a bis-(ethylene oxy) methane polysulfide polymer (BMPP) and hydroxyl-terminated polybutadiene (HTPB), the copolymer having a BMPP/HTPB weight ratio of from 1/3 to 3/1; and the fuel comprising at least 85 weight % copolymer. The BMPP comprises from 5 to 8 weight percent mercaptan. Furthermore, the BMPP is selected from

HS(RSS).sub.aCH.sub.2CH((SSR).sub.cCSH)CH.sub.2(SSR).sub.bSHa) where R=(CH.sub.2).sub.2OCH.sub.2O(CH.sub.2).sub.2 and a+b+c<7; and

H(SC.sub.2H.sub.4OCH.sub.2OC.sub.2H4S).sub.nH where n=7.b)

The throttleable solid propellant system includes a substantially solid propellant, a shape-altering structure, and an actuation source. The shape-altering structure is at least partially disposed within the substantially solid propellant. The actuation source is to be coupled to the shape-altering structure. The actuation source is to be configured to actuate the shape-altering structure between a first position and a second position. Transitioning the shape-altering structure between the first position and the second position may crack and/or deform the substantially solid propellant. Cracking and/or deforming the substantially solid propellant may increase the burning surface area of the propellant, thereby altering the thrust produced from the throttleable solid propellant system.

The throttleable solid propellant system includes a substantially solid propellant, a shape-altering structure, and an actuation source. The shape-altering structure is at least partially disposed within the substantially solid propellant. The actuation source is to be coupled to the shape-altering structure. The actuation source is to be configured to actuate the shape-altering structure between a first position and a second position. Transitioning the shape-altering structure between the first position and the second position may crack and/or deform the substantially solid propellant. Cracking and/or deforming the substantially solid propellant may increase the burning surface area of the propellant, thereby altering the thrust produced from the throttleable solid propellant system.

An exemplary gas generator driven hydraulic accumulator includes an elongated body having a first end, a second end, and a bore extending axially from a barrier to the second end; a piston slidably disposed in the bore; in use a gas generator located in a chamber between the first end and the barrier; an orifice through the barrier providing fluid communication between the chamber and the bore; in use a hydraulic fluid disposed in the bore between the piston and the second end whereby the hydraulic fluid is exhausted under pressure through a discharge port in response to activation of the gas generator; and in use a one-way flow control device connected in a flow path of the discharge port to permit one-way flow of the hydraulic fluid from the bore and to block return fluid from through the discharge port into the bore.

An exemplary gas generator driven hydraulic accumulator includes an elongated body having a first end, a second end, and a bore extending axially from a barrier to the second end; a piston slidably disposed in the bore; in use a gas generator located in a chamber between the first end and the barrier; an orifice through the barrier providing fluid communication between the chamber and the bore; in use a hydraulic fluid disposed in the bore between the piston and the second end whereby the hydraulic fluid is exhausted under pressure through a discharge port in response to activation of the gas generator; and in use a one-way flow control device connected in a flow path of the discharge port to permit one-way flow of the hydraulic fluid from the bore and to block return fluid from through the discharge port into the bore.

A rocket propellant includes a hydrocarbon blend having a total aromatic compounds content less than 0.5 mass percent, a specific energy of at least 18.4 KBtu/lb, and a mass density of at least 0.8150 grams per cubic centimeter. The propellant, which can be prepared by blending a refined kerosene with an isoparaffin and/or a cycloparaffin, exhibits a high volumetric heat of combustion and excellent thermal stability. This combination of properties is especially useful for fueling reusable launch vehicles employing regenerative cooling of engine components.

An exemplary system for supplying hydraulic pressure to an operational device includes two or more pressure supply devices connected in a pod, the pressure supply devices including an elongated body having an internal bore extending axially from a first end to a discharge end; a gas generator operationally connected at the first end; a piston movably disposed in the internal bore; a hydraulic fluid disposed in the internal bore between the piston and the discharge end, wherein a portion of the hydraulic fluid is exhausted under pressure through a discharge port in response to activation of the gas generator; the operational device in hydraulic connection with the discharge port to receive the exhausted hydraulic fluid.

An exemplary system for supplying hydraulic pressure to an operational device includes two or more pressure supply devices connected in a pod, the pressure supply devices including an elongated body having an internal bore extending axially from a first end to a discharge end; a gas generator operationally connected at the first end; a piston movably disposed in the internal bore; a hydraulic fluid disposed in the internal bore between the piston and the discharge end, wherein a portion of the hydraulic fluid is exhausted under pressure through a discharge port in response to activation of the gas generator; the operational device in hydraulic connection with the discharge port to receive the exhausted hydraulic fluid.

A linear actuator contains a housing having a first end and a second end. A hollow piston is positioned within the housing to slidably engage with an inner wall of the housing. A sealed gas chamber is formed within the hollow piston and contains stored gas for driving the piston upon activation of the actuator.