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: 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: 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.

Abstract: A solid propellant rocket motor (1) has a tubular casing (3) accommodating a mass (5) of solid propellant material and at least one opening (10) for the space in the casing (3) to communicate with the outside closed by a closing head (11); the closing head (11) being coupled to the casing (3) by means of one or the other of two blocking portions (28) (21A) with different strength both carried by a movement device (21,35) which can be elastically deformed and operated from the outside.

Abstract: A combustor for a liquid propellent motor has an elongated hollow tubular casing having an inner wall delimiting a combustion chamber for the liquid propellent and an outlet nozzle for the combustion products, and an outer wall, both being coaxial to an axis of the casing; the inner and outer walls being spaced apart from each other in radial direction and delimiting at least one guiding conduit of a cooling fluid therebetween; a plurality of bar-shaped elements extending into the guiding conduit, which form a grid for perturbing the cooling fluid, stiffening the casing and increasing the heat exchange surface; the grid being part of a body made in one piece and of a single material along with the inner and outer walls.

Abstract: In a combustion chamber of a liquid propellant engine, a combustible liquid and an oxidising mixture are fed by means of two different independent and mechanically separate feed pumps and driven by respective turbines which are also independent and mechanically separate from each other; the oxidising mixture generated by a combustible liquid pre-burner passing through one of the turbines; and the heated combustible liquid passing through the other turbine before it is supplied to the combustion chamber; the oxidising mixture, after having passed through the respective turbine, flows into the combustion chamber via an injection plate.

Abstract: The invention provides a system for passively controlling pressure oscillations of hydrodynamic origin in a solid propellant thruster comprising a body containing a charge of solid propellant, the system comprising at least one insert disposed in the thruster body transversely relative to the flow direction of the combustion gases of the solid propellant. The insert has an opening of non-axisymmetric shape so as to generate a three-dimensional effect on the flow and prevent axisymmetric turbulent modes from forming in the thruster. Thus, the control system of the invention serves to break the symmetry of the flow and thus prevents axisymmetric turbulence forming which is the source of instability that the present invention seeks to control. The present system is applicable to existing thrusters.