Instrumentation Development for Micro Pulsed Plasma Thruster Experiments

Miniaturized pulsed plasma thrus ters (PPTs) are poised to fulfill a variety of propulsion tasks on future spacecraft ranging from microsats to expansive space structures. Several varieties of micro -PPTs have been successfully designed and fabricated. Evaluation of these devices require s the development of sensitive techniques for measuring thrust and exhaust characteristics. This paper discusses the development of a miniature thrust stand with a resonant frequency around 300 Hz that can capture the shot -by -shot behavior of the micro PP T device. The steps taken to experimentally calibrate the stand and resolve initial discrepancies with analytic models are discussed. Data recorded to date indicate that impulse bit detections as small as 1 ∝N-sec are possible. This paper also briefly discusses some simple time -of -flight techniques used for measuring plume velocity in these devices.