Ion propulsion system for stationary-satellite control

The application of ion propulsion to the 3-axes attitude control and station keeping of stationary satellites is discussed. The mission constraints that affect the engine system design, such as velocity increments associated with vernier orbit corrections, magnitude of disturbance torques, and required thrusting directions are presented. An evaluation is made of the tradeoffs between such critical parameters as attitude and station-keeping accuracy, average power utilization, duty cycle, thrust level, and satellite mass and moments of inertia. A preliminary design is given for the ion engine attitude-control and station-keeping system. (A prototype system has been developed and laboratory tested.) Such system parameters as power level, thrust level, specific impulse, and weight are specified.