Space Vehicle Electro-dynamic Propulsion

In this final chapter, plasma thrusters based on expansion from low-pressure high-density electromagnetically coupled and wave-excited plasma sources, including a radiofrequency (RF) helicon source, are considered. Associated with these electrodeless and gridless thrusters are plasma-focussing magnetic nozzles and magnetic mirrors, which are also briefly discussed. Developments of plasma thrusters such as magnetoplasmadynamic (MPD) thrusters, self-induced and applied field MPD thrusters, air-breathing electric thrusters, pulsed plasma thrusters and air-breathing PPTs for future space travel are discussed in some detail. This is followed by a detailed discussion of radiofrequency-excited plasma thrusters such as those excited by helicon waves, including the physics of helicon waves, and applications resulting in several design examples of the helicon wave–driven thruster. The chapter is concluded by summarizing recent developments of novel thrusters such as the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) and inertial electrostatic confinement thruster and by providing a summary of helicon wave–excited plasma thrusters.