A multi-component structure includes a first hybrid metal composite structure, a second hybrid metal composite structure, and a joint structure. The first and second hybrid metal composite structures include layers, each layer comprising a fiber composite material structure including a fiber material dispersed within a matrix material and at least one metal ply located between layers of the layers. The joint structure extends between and connects the first hybrid metal composite structure and the second hybrid metal composite structure. Additionally, the joint structure exerts a clamping force on the first and second hybrid metal composite structures and to reduce gaps between the layers, between the layers and the at least one metal ply, and between the joint structure and the first and second hybrid metal composite structures to less than half a thickness of the at least one metal ply.

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 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.

Piece comprising a first metal part and a second part in organic matrix composite material, wherein the first part has a first connecting portion and the second part has a second connecting portion, the second connecting portion having at least one through-hole, the second connecting portion being totally or partially sandwiched between the first connecting portion and a metal fastening element, the fastening element being fastened on the first part both onto the first connecting portion via the through-hole of the second connecting portion and onto a portion other than the first connecting portion, whereby the first part and the second part are fastened to each other.

Solid rocket motors or ramjets may be provided. Such devices may include a combustion chamber containing at least one fuel, a metal phase alloy film within the combustion chamber, where the metal phase alloy film coupled to the at least one fuel, and an activator operably coupled to the metal phase alloy film, the activator including an electrical activation system, a laser activation system, or an initiator activation system. This allows combined functional features on pulse motors to release inhibitors and ignite solid fuel/propellant. Fast reactions can be achieved by controlling the thickness of the alloys and using multiple layers to achieve the areal energy density. Foils can be rolled and inserted into the fuel/propellant bore. When rolled, it can easily follow the grain bore diameter changes with temperature and provide no additional mechanical loads to the grain.

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.

For producing a dome-shaped element (2) provided with thermal protection for a solid propellant rocket engine, a coupling annular body (4) is arranged in a mold (5) and has a surface (20) that is clean and activated, by an atmospheric-pressure plasma treatment, before depositing a primer layer (26) and an adhesive layer (27) on the surface (20); ablative material is then automatically applied to the adhesive layer and to an area (17) of the mold (5) so as to form a series of superimposed layers (30).

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 ?m and second particles having an average mean diameter of from about 1.5 ?m to about 5 ?m. 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 insulated blast tube includes an insulating layer of a burn resistant material such as phenolic resin formed on an interior surface of the blast tube to provide the necessary erosion and thermal insulation properties to protect the blast tube and a heavy inert gas insulated layer formed in the walls of the blast tube itself to provide the additional thermal insulation properties to protect any non-propulsive sub-systems positioned in the void space around the blast tube. A void space in the walls of the blast tube contains an inert gas such as Argon, Krypton, Xenon or a synthetic inert gas having a density of at least 1.5 kg/m.sup.3 and a thermal conductivity Tcond_gas of no greater than two-thirds the thermal conductivity of air Tcond_air to form the heavy inert gas insulation layer.