HR: 0800h
AN: SM41A-1169    [Abstracts]
TI: Spacecraft Surface Charging Application Development for Geosynchronous Orbit
AU: * Hilmer, R V
EM: Robert.Hilmer@Hanscom.af.mil
AF: Air Force Research Laboratory /Space Vehicles Directorate, AFRL/VSBXR 29 Randolph Rd, Hanscom AFB, MA 01731
AU: Cooke, D L
EM: David.Cooke@Hanscom.af.mil
AF: Air Force Research Laboratory /Space Vehicles Directorate, AFRL/VSBXR 29 Randolph Rd, Hanscom AFB, MA 01731
AU: Tautz, M F
EM: Maury.Tautz@Hanscom.af.mil
AF: Radex, Inc., 131 Hartwell Ave , Lexington, MA 02421
AU: Davis, V A
EM: Victoria.A.Davis@saic.com
AF: SAIC, 10260 Campus Point Drive, San Diego, CA 92121
AU: Mandell, M J
EM: Myron.J.Mandell@saic.com
AF: SAIC, 10260 Campus Point Drive, San Diego, CA 92121
AU: Kuharshki, R A
EM: Robert.A.Kuharski@saic.com
AF: SAIC, 10260 Campus Point Drive, San Diego, CA 92121
AB: The development of a geosynchronous spacecraft surface charging application that combines environmental results from the Magnetospheric Specification Model (MSM) with algorithms from the NASCAP-2K surface charging program is described. A previous validation study of the MSM, covering 20-50 keV electrons from the Charge Control System (CCS) on a DSCS III B-7 spacecraft, indicated that the MSM consistently tracked the diurnal and seasonal variations of this energetic portion of the surface charging particle population [Hilmer and Ginet, J. Atmos. and Solar-Terr. Phys., 62, 1275, 2000]. Initial comparisons of on-orbit spacecraft frame charging measurements from CCS with results obtained using MSM output indicated that the MSM produced ion and electron fluxes, as well as evolving electron spectral features, well enough to reproduce geosynchronous spacecraft charging current densities in the two largest of three events studied in the geosynchronous environment. [Hilmer et al., Proc. of 7th SCTC, 23-27 April 2001, ESA SP-476, 235, 2001]. Previously, the assumed particle environments used for NASCAP-2K charging studies were described in terms of worst-case Maxwellian or bi-Maxwellian distributions. In this study we take the next step and use the MSM generated electron and proton fluxes over the full energy range available (~ 1 eV to 200 keV) as direct inputs to the NASCAP-2K charging algorithms. The resulting frame potentials are then compared with the observed DSCS frame potentials at geosynchronous orbit. The comparisons will utilize MSM particle flux output generated using a variety of model input parameters and several simple satellite descriptions including one which roughly approximates features of the DSCS satellite, i.e., the geometrical representation used by Mandell and Cooke [AIAA-2004-986, 42nd AIAA Aerospace Sciences Meeting and Exhibit, Reno, Nevada, Jan. 5-8, 2004].
DE: 2740 Magnetospheric configuration and dynamics
DE: 2753 Numerical modeling
DE: 2764 Plasma sheet
DE: 7855 Spacecraft sheaths, wakes, charging
DE: 7899 General or miscellaneous
SC: SPA-Magnetospheric Physics [SM]
MN: Fall Meeting 2005