<title>Effect Of Bipropellant Plume Exhaust Effluents On Spaceborne Optical Instruments</title>

Abstract

The accuracy, lifetime, and mission effectiveness of a spacecraft is affected adversely by any degradation of sensitive spacecraft surfaces. With a trend towards more sophisticated and complex spacecraft systems capable of performing multimissions over longer time periods, there is increasing concern about the effects of plume contamination. Analytical tools in concert with a good data base are necessary to predict the transport of plume contaminants and their effects on spacecraft surfaces. This paper describes an assessment of bipropellant thrusters, the production and transport of plume contaminants from these thrusters and the use of the JPL Contamination Analysis Program to assess the effects of plume contamination on the Galileo spacecraft.

Environmental Interactions Technology Status

“…The jet emissions tend to be neutral molecules with a small plasma content. While most of this flow leaves the spacecraft vicinity, a small fraction can either strike spacecraft surfaces or redeposit on them, enhancing contamination [283,284]. This contamination source can be significant, even though small amounts of material are ejected during each operation, since these thrusters function over the mission lifetime.…”