Solid-propellant rocket engine with inner and outer burner surfaces

A solid-propellant rocket engine, comprising:

• chamber means defining a combustion chamber;
• a support structure connected to said chamber means;
• at least one thrust nozzle at a downstream end of said combustion chamber;
• a two-part grain arranged in said combustion chamber including one part forming an outwardly disposed inner surface burner part and another part forming an inwardly disposed outer surface burner part, said outer surface burner part being connected to said support structure, said outer surface burner part having a cross-section changing over its length and being arranged in a space defined by said inner surface burner part which space corresponds to a shape of said outer surface burner part, said outer surface burner part being axially displaceable relative to said inner surface burner part;
• a thermal barrier arranged at a nozzle side end of said two-part grain, said outer surface burner part being fitted gap-free into said inner surface burner part wherein a circumferential contour formed by a contact surface of said inner surface burner part and said outer surface burner part encloses a cross-section expanding from a front end of said two-part grain to a rear, nozzle-side end of said two-part grain;
• and
• detachable, positive-locking connection means for maintaining said inner surface burner part and said outer surface burner part connected in an inactive state and releasing the connection between said inner surface burner part and said outer surface burner part upon ignition of said two part grain, thereby allowing movement of said outer surface burner part from said inactive position into a rear, active position providing a defined flow gap between said contact surfaces of said two-part grain.