A precursor composition comprising, before curing, ethylene propylene diene monomer (EPDM), an aramid, and a carbon material comprising carbon nanotubes, graphite, or a combination thereof. A rocket motor including a reaction product of the precursor composition and a method of insulating a rocket motor are also disclosed.

A precursor composition comprising, before curing, ethylene propylene diene monomer (EPDM), an aramid, and a carbon material comprising carbon nanotubes, graphite, or a combination thereof. A rocket motor including a reaction product of the precursor composition and a method of insulating a rocket motor are also disclosed.

A preceramic resin formulation comprising a polycarbosilane preceramic polymer, an organically modified silicon dioxide preceramic polymer, and, optionally, at least one filler. The preceramic resin formulation is formulated to exhibit a viscosity of from about 1,000 cP at about 25° C. to about 5,000 cP at a temperature of about 25° C. The at least one filler comprises first particles having an average mean diameter of less than about 1.0 μm and second particles having an average mean diameter of from about 1.5 μm to about 5 μm. Impregnated fibers comprising the preceramic resin formulation are also disclosed, as is a composite material comprising a reaction product of the polycarbosilane preceramic polymer, organically modified silicon dioxide preceramic polymer, and the at least one filler. Methods of forming a ceramic matrix composite are also disclosed.

An insulation material includes a matrix comprising a reaction product formed from a silicon carbide precursor resin and a silicon dioxide precursor resin. At least one filler, such as hollow glass microspheres and/or carbon fiber is dispersed within the matrix. A rocket motor includes a case, the insulation material within and bonded to the case, and a solid propellant within the case. An insulation precursor includes a silicon carbide precursor resin, a silicon dioxide precursor resin, and the at least one filler. Related methods are also disclosed.

Seals for gimbaling and/or fixed rocket engine nozzles, and associated systems and methods are disclosed. A representative rocket propulsion system includes a rocket engine having an exhaust nozzle, a seal plate carried by the exhaust nozzle, and a seal engaged with the seal plate. The seal includes at least one support, multiple pivotable first flaps, carried by the at least one support and positioned to contact the seal plate, and multiple pivotable second flaps, with an individual second flap positioned to shield a corresponding individual first flap. At least one forcing element is operatively coupled to at least one of the individual first flap or the individual second flap, to apply a pivoting force to the at least one of the individual first flap or the individual second flap.

A hybrid propulsion system includes a housing, at least two electrodes, a solid-grain fuel material, a combustion chamber, an oxidizer port, and a nozzle. The housing has a first end and a second end and defines a cavity. The electrodes extend into the cavity. The fuel material is free of an oxidizer and is positioned in the cavity. The fuel material has a combustion surface and is exposed to the electrodes. The combustion chamber is defined between the combustion surface and the second end. The oxidizer port provides a flow of oxidizer to the combustion chamber. The nozzle is positioned at the second end. Combustion of the fuel material in the combustion chamber may be dominated by radiative heat transfer.

A hybrid propulsion system includes a housing, at least two electrodes, a solid-grain fuel material, a combustion chamber, an oxidizer port, and a nozzle. The housing has a first end and a second end and defines a cavity. The electrodes extend into the cavity. The fuel material is free of an oxidizer and is positioned in the cavity. The fuel material has a combustion surface and is exposed to the electrodes. The combustion chamber is defined between the combustion surface and the second end. The oxidizer port provides a flow of oxidizer to the combustion chamber. The nozzle is positioned at the second end. Combustion of the fuel material in the combustion chamber may be dominated by radiative heat transfer.

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 precursor formulation of a liner comprising a polymer and at least two curatives is disclosed. One of the at least two curatives comprises a curative formulated to preferentially react with the polymer and the other of the at least two curatives comprises a blocked curative formulated to be substantially unreactive with the polymer. A method of lining a rocket motor is also disclosed, as is a rocket motor including the liner.

A separable component assembly is disclosed. The separable component assembly can include a first component having a first interface portion. The separable component assembly can also include a second component coupled to the first component. The second component can have a second interface portion. In addition, the separable component assembly can include a seal disposed between the first and second interface portions. The seal can have a first interface surface associated with the first interface portion. The seal can also have a second interface surface in contact with the second interface portion. Additionally, the seal can have a peel initiator defining a discontinuity in a portion of the second interface surface. Upon separation of the first and second components from one another, the discontinuity can create a stress concentration in the second interface surface that initiates peeling of the second interface surface away from the second interface portion.