Propulsion Subsystem (Hall Thrusters)// High specific impulse low propellant expenditure Electrical power required e 2mn where 200 W Hall 100-200W m-mass of spacecraft (129. 4 kg) Thruster Hall thruster u -spacecraft acceleration(m/s) BHT-200-X2B Hal Thruster m -mass flow rate of propellant (kg/s)Specific Impulse :1530s n- thruster efficiency (% Thrust :10.5mN Mass flow rate 0.74mg/s Objective is to minimize electrical Typical Efficiency :42% energy required: Power Input :200W Pdt Figures courtesy of AFoSR Techsat21 Research Review(29 Feb-1 Mar 2000) Space Systems Laboratory Massachusetts Institute of TechnologySpace Systems Laboratory Massachusetts Institute of Technology Propulsion Subsystem (Hall Thrusters) Propulsion Subsystem (Hall Thrusters) • High specific impulse – low propellant expenditure mη m u Pe 2 & 2 2 = where m - mass of spacecraft (129.4 kg) u - spacecraft acceleration (m/s) - mass flow rate of propellant (kg/s) - thruster efficiency (%) m & η BHT-200-X2B Hall Thruster Specific Impulse : 1530 s Thrust : 10.5 mN Mass flow rate : 0.74 mg/s Typical Efficiency : 42% Power Input : 200 W 200 W Hall Thruster * * Figures courtesy of AFOSR Techsat21 Research Review (29 Feb - 1 Mar 2000) • Objective is to minimize electrical energy required: ∫ = f ott J Pedt • Electrical power required: 100 - 200 W Hall Thruster *