Accession Number : ADA258647
Title : Spacecraft Interaction with Ambient and Self-Generated Plasma/Neutral Environment.
Descriptive Note : Final rept. 1 Jul 1990-31 Aug 1992,
Corporate Author : MCDONNELL DOUGLAS SPACE SYSTEMS CO HUNTINGTON BEACH CA DESIGN AND TECHNOLOGY CENTER
Personal Author(s) : Mogstad, Torkil S
Report Date : 31 Aug 1992
Pagination or Media Count : 105
Abstract : This report presents the results of our study of Spacecraft Interaction with Ambient and Self-Generated Plasma/Neutral Environment. Various neutral effluent release scenarios in low Earth orbit were defined and modeled with direct simulation Monte Carlo (DSMC) methods. The simulated environments included H2 venting from an SDI-type chemical power system, and Space Station Freedom (SSF) mono and bipropellant hydrazine thruster plume distributions at high-voltage solar arrays. After the neutral distributions were characterized, various ionization mechanisms (charge exchange, critical velocity ionization effects, photo-ionization) were included to determine the local plasma production. Neutral and ion continuity equations were solved to obtain the local ion distribution in the vicinity of high-voltage surfaces. It was shown that the thruster effluents can generate self-induced neutral and plasma density distributions several orders of magnitude greater than the natural ambient environment. For a bipropellant MMH-N204 thruster firing into the ram, our simulations indicate du the local plasma density may increase as much as four orders of magnitude over the ambient. The effects of these self-induced environments on high-voltage surface arcing were assessed by using a microscopic model of the arcing process developed at MIT. High-voltage surface arcing thresholds, probabilities, and frequencies for current and future space platforms were discussed.
Descriptors : *SPACECRAFT , *INTERACTIONS , *NEUTRAL , *PLASMA DEVICES , *EFFLUENTS , VELOCITY , FREQUENCY , SCENARIOS , STATIONS , ENVIRONMENTS , EARTH ORBITS , MODELS , OXYGEN , SURFACES , HYDROGEN , NITROGEN , MONTE CARLO METHOD , VOLTAGE , ARRAYS , PROBABILITY , CHEMICALS , BIPROPELLANTS , HIGH VOLTAGE , INDUCED ENVIRONMENTS , THRUSTERS , EXCHANGE , SPACE STATIONS , SOLAR ACTIVITY , CONTINUITY , CARBON DIOXIDE , VENTING , REPRODUCTION , EQUATIONS , PLUMES , POWER , IONIZATION , RELEASE , PLATES , PLATFORMS , PROPELLANTS , DISTRIBUTION , HYDRAZINES , PRODUCTION , SIMULATION , IONS , ORBITS , DENSITY
Subject Categories : Organic Chemistry
Plasma Physics and Magnetohydrodynamics
Distribution Statement : APPROVED FOR PUBLIC RELEASE