Abstract: An inner coating layer for solid-propellant rocket engines, constituted by a material comprising from 45% to 55% wt. of a a cross-linkable, unsaturated-chain polymer base, from 11% to 13% wt. of silica, from 15% to 25% wt. of vulcanizing agents and plasticizers, from 5% to 7% wt. of aramid fiber and from 10% to 15% wt. of microspheres made of a material selected among glass, quartz and nano clay, having diameter lower than 200 ?m, density comprised between 0.30 and 0.34 g/cc and resistance to hydrostatic pressure greater than, or equal to, 4500 psi.

Abstract: 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).

Abstract: 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).

Abstract: 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).

Abstract: An inner coating layer for solid-propellant rocket engines, constituted by a material comprising from 45% to 55% wt. of a a cross-linkable, unsaturated-chain polymer base, from 11% to 13% wt. of silica, from 15% to 25% wt. of vulcanizing agents and plasticizers, from 5% to 7% wt. of aramid fiber and from 10% to 15% wt. of microspheres made of a material selected among glass, quartz and nano clay, having diameter lower than 200 gm, density comprised between 0.30 and 0.34 g/cc and resistance to hydrostatic pressure greater than, or equal to, 4500 psi.

Abstract: 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).