Kyushu Univ. Department of Interdisciplinary Engineering Sciences Interdisciplinary Graduate School of Engineering Sciences

Kyushu Univ. Faculty of Engineering Development of Energy Sciences and Engineering

Advanced Space Propulsion Laboratory(Yamamoto Lab)

Advanced Space Propulsion Laboratory(Yamamoto Lab)

Electric Propulsion

An ion thruster is one of the rocket engines, work by pushing ions away from the spacecraft. The action of the ions leaving the thruster causes a reaction that pushes the spacecraft in the opposite direction. Ions, produced in the discharge chamber, can be pushed around by an electric field. A pair of grids in the ion thruster accelerates the ions to very high speed, 30,000-80,000 m/s, and shoots them out of the thruster. Ion thrusters produce high energy transfer efficiency with good specific propellant consumption. Therefore, Ion engines have already been used extensively in space missions, such as Deep space 1, HAYABUSA, and among other missions.


Hall thrusters show considerable promise for satellite station keeping and orbit transfer applications, since they offer an attractive combination of high thrust efficiency, exceeding 50%, with a specific impulse range of 1,000-3,000 s and a higher ion beam density than ion thrusters. This is because Hall thrusters are not space-charge limited.


Currently under development.


TDL (Thruster with Double Layer) is a thruster that accelerates ions using the potential difference between plasma potential and outer space. The concept itself has existed for a long time, but our laboratory aims to adapt it to micro-satellites by using microwave discharge to enable operation with small size and low power. The generation of Double Layer (electric double layer) is also expected, so it is called by this name.


Radio frequency electrothermal thrusters are candidates for propulsion systems in space, since they produced high thrust density and high thrust to power ratio. The physical phenomena governing the operation of the induction plasma is the coupling between the applied radio frequency alternating magnetic field and the eddy currents induced in the plasma. The propellant is heated by an ohmic heating of the eddy currents. Enthalpy of heated propellant converts into axially kinetic energy through the nozzle. There have been many studies about RF thruster.