Abstract
This paper describes water-propellant magnetoplasma dynamic (MPD) thruster. High power
electric propulsion systems attract attention as a next-generation mass transport system. Today, allelectric
satellites, which have no chemical thruster, were launched and will be used as communication satellites. MPD thrusters are one of the most promising electric propulsion devices because of relatively simple structure, high specific impulse and thrust to power ratio. Conventionally, hydrogen, ammonia, and hydrazine propellants were tested for MPD thruster. Hydrogen propellant produced the highest specific impulse though it requires cryogenic cooling and high-pressure tanks for the storage. Ammonia and hydrazine are storable propellant but are deleterious and toxic substances, respectively. Hence, the authors propose to use water as a propellant for MPD thrusters. A coaxial-electrode type prototype was tested to show that 100-kW class waterpropellant MPD produces arc discharge and investigate the correlation between discharge current and voltage.
