Method for controlling an ion thruster, and ion thruster system

A method for controlling an ion thruster, the ion thruster comprising an emission electrode, an extraction electrode and a conductive liquid deposited on the emission electrode, the ion thruster being suitable for emitting an ion beam when an electric field is applied to the conductive liquid, the ion beam being suitable for providing the ion thruster with thrust, the thrust depending on an emission current and an ion emission speed, the method includes the following steps:

• delivering the emission current and adjusting the emission current to a setpoint Ic by means of a current generator wherein a number of ions ejected is determined by the setpoint of the emission current;
• when the setpoint Ic of the emission current is reached, adjusting the emission speed by applying an extraction potential Vext to the extraction electrode by means of a voltage generator, so as to bring the emission potential Vem to a predetermined value Vemnpr=Vthresh+Vext, wherein Vthresh is the threshold value of the potential applied to the emission electrode for which the emission current Iem reaches the setpoint Ic
• wherein the current generator and the voltage generator are independent of one another and are each coupled to a controller;
• and
• controlling, via the controller, 1) the current generator, to adjust the setpoint I, and the number of ions ejected and 2) the voltage generator, to adjust the extraction potential and the emission speed, to provide a thrust of the ion thruster.