Improved Jet Vane Thrust Vector Control for Solid Rocket Motors

JET VANE THRUST VECTOR CONTROL IS ONE OF THE LEAST EXPENSIVE AND LEAST PERFORMANCE-IMPACTING METHODS FOR THRUST VECTOR CONTROL. THIS METHOD UTILIZES VANES SET IN THE MOTOR PLUME TO DEFLECT EXHAUST GASES, CREATING LATERAL THRUST. HOWEVER, THE USE OF HIGH-IMPULSE, HIGH SOLID CONTENT PROPELLANTS COMBINED WITH HIGHER PRESSURE MOTOR OPERATION HAS EXCEEDED THE ABILITY OF CURRENT MATERIALS TO WITHSTAND THE EXHAUST-IMPINGED VANE ENVIRONMENT. EROSION RATES ON W/Mo AND C/C VANES CAN REACH 0.25 TO >1.0"/SECOND, WHICH MUST BE COMPENSATED FOR THROUGH THE USE OF LARGER VANES AND ACTUALORS, WHICH IS OFTEN IMPRACTICAL. IN THIS PHASE I PROGRAM, ULTRAMET PROPOSES TO FABRICATE AND SCREEN TUNGSTEN, RHENIUM-COATED TUNGSTEN, RHENIUM METAL, AND CARBON FIBER-REINFORCED HfC MATRIX COMPOSITE VANES, LEADING TO A ZERO- OR LOW-EROSION JET VANE MATERIAL FOR APPLICATION TO TACTICAL AND LAUNCH VEHICLES. THE MATERIALS SCREENING EFFORT WILL BE CONDUCTED USING INSTRUMENTED SUBSCALE MOTORS WITH VARYING ALUMINUM CONTENT PROPELLANTS FOR WHICH VERIFIED SCALING RELATIONSHIPS HAVE BEEN DERIVED. THIS WILL ALLOW ANALYTICAL DETERMINATION OF FULL-SCALE PERFORMANCE, TO BE VERIFIED DURING PHASE II.