Busek's ion thrusters utilize an inductively coupled plasma (ICP) source and eliminates the use of internal cathode (life-limiting factor in DC ion engines). Busek's thrusters have been designed to use xenon propellant, but are compatible with a wide range of propellant choices, including argon, hydrogen, iodine, nitrogen and helium gas. Key advantages include fast start-up and rapid thrust response to the input RF power. Busek is also currently developing high-efficiency RF power supply to couple with the thrusters. Busek has developed several prototypes of ion thrusters that offer a wide range of thrusts and specific impulses.