Cleaning device for combustion residues from a rocket engine

A cleaning device for the combustion residues from a rocket engine with a combustion chamber for holding a solid rocket propellant and with a propulsion-gas outlet nozzle which is connected to the end wall of the combustion chamber while leaving free an annular space in which liquid combustion residues from the propellant collect, essentially comprises an arrangement in which at least one tube is fastened to a narrowed portion of the nozzle with the aid of fastening means, one end of the said tube projecting at a defined distance from the end wall of the combustion chamber into the liquid mass formed by the combustion residues and the other end opening at the level of the upper end of the narrowed portion of the nozzle at a point set back slightly from a neck of the nozzle.