Thrusters: Pulsed Plasmas
ByIain D. Boyd
Pages 8

A pulsed plasma thruster (PPT) is a simple plasma device in the category of electric propulsion technology used to maneuver vehicles in space. While a variety of PPT designs exist, most are based on the principle of rapidly discharging a capacitor to generate a plasma between two electrodes that are placed within the vicinity of a solid polymer propellant. The discharge current begins to ablate the propellant and subsequently ionizes a fraction of the ablation products. The resulting ions are accelerated via a self-induced Lorentz force creating the desired thrust force. Additional thrust is often provided by hot neutrals through gas dynamic acceleration. As spacecraft propulsion devices, PPTs have many positive attributes such as relative simplicity, robustness, and scalability. However, PPTs also suffer from some challenges such as very low efficiency and potential for damaging the host spacecraft. This entry reviews the basic plasma physics processes that determine PPT operation, discusses issues associated with their poor performance, reviews the development of a variety of PPT devices, discusses the contributions of modeling to better understanding PPT operation, and summarizes the efforts to quantify spacecraft integration issues.