Results of ten years of operation of electric thrusters within two telecommunication spacecrafts Yamal-200 in geostationary orbit

The paper presents results of operation of electric thrusters onboard two telecommunication spacecrafts Yamal-200 over a period of ten years. It provides a description of propulsion systems and their major components: electric thruster modules, which bring the spacecraft to their stations in the geostationary orbit, provide stationkeeping and attitude control; power supply and control equipment, consisting of the power supply unit and thruster modules automatic control unit. It analyses propulsion system operational modes, peculiarities of operation of thruster modules and power supply and control equipment during steady-state operation, during transient processes - during startup (reaching the nominal power mode) and during surge anode currents that are characteristic of electric thrusters with ceramic discharge chamber. It demonstrates stable operation of propulsion systems over a period of more than ten years with thruster modules accumulating more than 1100 running hours during -2 500 firings. It provides the results of continuous analysis of thruster modules thrust using methods developed by RSC Energia. It demonstrates that the thrust remained unchanged over the ten years of operation.