Abstract: The thrust of a rocket motor can be varied while maintaining efficiency over a range of pressure ratios using a design that allows for changing the relative position of a plug and a combustion chamber exit. The plug or the chamber exit may be attached to an adaptive control system for position modification. The plug may be positioned in a plug nozzle configuration or in an expansion-deflection (ED) configuration. In either configuration, the elongated downstream portion of the plug allows for efficiency over a wide range of pressure ratios, while ability to change plug position with respect to the chamber exit allows adjustment of rocket thrust.

Abstract: The thrust of a rocket motor can be varied while maintaining efficiency over a range of pressure ratios using a design that allows for changing the relative position of a plug and a combustion chamber exit. The plug or the chamber exit may be attached to an adaptive control system for position modification. The plug may be positioned in a plug nozzle configuration or in an expansion-deflection (ED) configuration. In either configuration, the elongated downstream portion of the plug allows for efficiency over a wide range of pressure ratios, while ability to change plug position with respect to the chamber exit allows adjustment of rocket thrust.