Non-erosive arcjet starting control system and method

Abstract

A non-erosive arcjet starting control system and method are provided in combination with an arcjet thruster which includes an anode, a cathode and a gap defined therebetween. The starting control system and method include the operative steps of, first, actuating a valve in a propellant gas feed path to an opened position thereby permitting flow of propellant gas at a predetermined pressure into the thruster past the gap therein, second, applying to the anode and cathode an electrical potential of a predetermined magnitude being less than that required to generate an electrical arc across the gap through propellant gas at the predetermined flow pressure and, concurrently, actuating the valve to its closed position thereby preventing flow of propellant gas into the thruster past the gap and thereby lowering the flow pressure of the propellant gas in the thruster below the predetermined pressure such that an electrical arc is now generated in the thruster across the gap and, finally, actuating the valve to its opened position thereby permitting propellant gas to flow again at the predetermined pressure into the thruster past the gap and force the electrical arc to move downstream within the thruster so as to minimize erosion in the constrictor. The flow of propellant into the thruster is prevented for only a short period of time.