Fiber Optic Sensors for the Study of Spacecraft-Thruster Interactions: Ion Sputtering

The interaction between thruster effluents and spacecraft surfaces has received considerable attention recently. Historically, thruster interaction concerns have focused on self-contamination from non-direct and high angle (measured from the thruster centerline) plume impingement. The growing popularity of distributed networks of cooperative, co-orbiting satellite clusters has brought about an additional need to address direct plume impingement or cross-contamination. Typically, quartz crystal microbalances (QCMs) are used to investigate spacecraft-thruster interactions where the major contamination mechanism is the adsorption of molecular species on critical surfaces. New methods are required to investigate the complex nature of plume impingement from advanced ion electric thrusters where the major interaction is the sputtering of critical surfaces. Additionally, QCMs are limited in that they only provide interaction data at a single point; however, the plume characteristics of a typical ion thruster can vary several orders of magnitude over short distances. Presented as paper 2001-2958 at the AIAA Thermophysics Conference (35th) held in Anaheim, CA on 11-14 June 2001. Prepared in collaboration with the University of Southern California.