Air-breathing pulsed plasma thruster with a variable spacing cathode

A method of generating thrust comprising:

• providing a thruster having an inlet, a discharge section in fluid communication with the inlet, a first electrode disposed at least partially in the discharge section, and a plurality of electrode assemblies, each electrode assembly of the plurality of electrode assemblies having a second electrode disposed in the discharge section and an elongate rod extending through a wall of the discharge section, wherein i) the first electrode is anodic and each second electrode is cathodic, or ii) the first electrode is cathodic and each second electrode is anodic:
• controlling a radial position of each electrode assembly by engaging a distal portion of the respective elongate rod of the electrode assembly with an electrode control mechanism configured to move the plurality of electrode assemblies between an inner position wherein each second electrode is located nearer to the first electrode and an outer position wherein each second electrode is located farther from the first electrode;
• inducing a current flow between the first electrode and at least one of the second electrodes with an igniter;
• wherein an ignition circuit connects the first electrode and each second electrode to a first source of electric energy, and connects the igniter to a second source of electric energy through a controllable switch, and the electrode control mechanism is controlled by a processor configured to control a distance between the first electrode and the each second electrode;
• wherein each second electrode is oriented lengthwise parallel to a central axis of the discharge section.