PRECISE THRUST ACTUATION BY A MICRO RF ION ENGINE BUSEK PROPOSES TO DEVELOP A RADIO-FREQUENCY DISCHARGE, GR…

Public award description

PRECISE THRUST ACTUATION BY A MICRO RF ION ENGINE BUSEK PROPOSES TO DEVELOP A RADIO-FREQUENCY DISCHARGE, GRIDDED MICRO ION ENGINE THAT PRODUCES N LEVEL OF THRUST PRECISELY ADJUSTABLE OVER A WIDE DYNAMIC THRUST RANGE. RF DISCHARGE WAS CHOSEN TO ELIMINATE THE LIFE-LIMITING INTERNAL CATHODE OF A DC DISCHARGE ION ENGINE. THRUST ACTUATION ON THE ORDER OF 0.03 N RESOLUTION IS PROPOSED WITH A CLOSED-LOOP CONTROL SYSTEM. THIS CONTROLLING SCHEME CAN BE ACHIEVED BY VARYING ONLY ONE PARAMETER: THE RF POWER WITH A FEEDBACK FROM THE BEAM CURRENT. UNIQUELY, THE RF ION ENGINE CAN ALSO PRODUCE ENOUGH THRUST FOR COARSE CONSTELLATION CORRECTIONS OR RECONFIGURATIONS. ARGON WILL BE THE BASE-LINED PROPELLANT TO EASE CONCERNS OF PROPELLANT CONDENSING ON OPTICS OR OTHER CRYOGENIC SURFACES. THIS FEATURE CAN BE CRITICAL FOR CLOSE FORMATION FLYING AS MICRO-THRUSTERS SUCH AS FIELD EMISSION ELECTRIC PROPULSION (FEEP) AND COLLOIDS COULD POTENTIALLY COAT NEIGHBORING SPACECRAFT. THE PROPOSED RF ION ENGINE, COMBINED WITH BUSEK'S SPACE-QUALIFIED CARBON NANOTUBE FIELD EMISSION CATHODE (DEVELOPED FOR THE ST7 DRS MISSION) AS A NEUTRALIZER, WILL CREATE A NEW OPPORTUNITY IN PRECISE THRUST ACTUATION. FURTHER IMPLEMENTATION OF A SIMPLE PROPELLANT FEED SYSTEM AND POWER ELECTRONICS WILL CREATE A COMPACT, LOW POWER, HIGH PERFORMANCE SPACECRAFT PROPULSION SYSTEM.