SOLID ROCKET MOTOR

PURPOSE:To prevent a loss of energy during the initial turning of a flying vehicle so as to improve performance in the point of a speed and entry height by forming a propellant grain into a shape in which a combustion area is increased by stages. CONSTITUTION:In a solid rocket motor 1, the inside of a cylindrical chamber 2 is charged with a propellant grain 3, and it has a central hole 12, with a circular arc protruded in four directions, and four cavity parts 13, provided in a 90 deg. interval along the outside of a concentric circle 17 detached from this central hole 12, over a machine axial direction of the solid rocket motor 1. An annular insulation 14, which opens the central hole 12 further closes each cavity part 13, is provided in an end face in a tail part side of the propellant grain 3. In the solid rocket motor 1, in the point of time in completion of the initial turning of a flying vehicle, a propellant from the central hole 12 to the concentric circle 17, in contact with the cavity part 13, is completely burned, and following opening of the cavity part 13, by rapidly increasing a combustion area from an internal surface of the cavity part 13, thrust F2 approximate to the maximum thrust is generated.