LOW-COST MODULAR SECONDARY-INJECTION THRUST VECTOR CONTROL FOR SOUNDING ROCKETS

ADDITION OF TVC COULD EASILY DOUBLE THE COST OF SOUNDING ROCKETS UNLESS DESIGN FEATURES THAT LIMIT COST GROWTH ARE INCORPORATED. ALSO, THE DESIGN OF THE TVC SUBSYSTEM MUST BE MODULAR AND SELF-CONTAINED SO THAT THE DEVICE CAN BE CONFIGURED FOR INSTALLATION ON 13 OR MORE SOUNDING ROCKET BOOSTERS. INTEGRATED SYSTEMS INC. (ISI) PROPOSED TO DEVELOP A MODULAR, LOW-COST THRUST VECTOR CONTROL AND GUIDANCE SUBSYSTEM FOR SOUNDING ROCKETS BASED UPON USE OF SECONDARY-INJECTION OF HOT GAS AS THE SOLE MEANS OF ACTUATION. MODULAR THRUSTERS DEVELOPED FOR USE ON SDI EXO AND ENDOATMOSPHERIC INTERCEPTORS WILL BE ADOPTED AS THE SECONDARY-INJECTION ACTUATORS. THRUSTER SIZES WILL BE SELECTED TO PROVIDE 2 -3 DEG OF THRUST VECTOR CONTROL SINCE ONLY A SMALL AMOUNT OF CONTROL MARGIN OVER THE ALIGNEMENT UNCERTAINTIES (+ OR - 0.5 DEG MAX) IS NECESSARY TO PROVIDE EFFECTIVE CONTROL AND GUIDANCE IN THE PRESENCE OF ATMOSPHERIC DISTURBANCES. THE PROPOSED TVC DESIGN WILL PROVIDE PITCH, YAW, AND ROLL CONTROL. GUIDANCE OF THE SOUNDING ROCKETS WILL BE ACCOMPLISHED BY FEEDBACK CONTROL OF BODY ATTITUDE OR RATE, EITHER OF WHICH CAN BE SCHEDULED TO CONTROL THE FLIGHT PATH. RATE-CONTROL WILL PROVIDE ACCURATE BALLISTIC TRAJECTORIES, WHEREAS ATTITUDE REFERENCE FROM THE PAYLOAD OR ADDITIONAL SENSORS CAN SUPPORT PITCH, YAW, AND ROLL CONTROL AND GUIDANCE.