Modeling of spacecraft using a modified version of MOLFLUX and comparison with a continuous flux model

David A. Brent; Frederick D. Cottrell; Kelly A. Henderson; Rudy S. Dahbura

doi:10.1117/12.258300

11 November 1996 Modeling of spacecraft using a modified version of MOLFLUX and comparison with a continuous flux model

David A. Brent, Frederick D. Cottrell, Kelly A. Henderson, Rudy S. Dahbura

Proceedings Volume 2864, Optical System Contamination V, and Stray Light and System Optimization; (1996) https://doi.org/10.1117/12.258300
Event: SPIE's 1996 International Symposium on Optical Science, Engineering, and Instrumentation, 1996, Denver, CO, United States

Abstract

The industry-standard, free-molecular contamination code MOLFLUX (molecular flux) developed for NASA has been used for many years by most aerospace contractors to predict on- orbit spacecraft surface contamination levels. Recently, MOLFLUX (version 2.0) which was written for a VAX computer was converted for use on a PC running Windows NT. Both the graphical-user-interface (GUI) menuing portion (written in C) of MOLFLUX), and the physics portion (written in FORTRAN) were fully converted. Subsequent to the conversion task, an effort was initiated to validate the PC version of MOLFLUX for two major spacecraft systems. A new free-molecular contamination code recently developed at TRW, CONFLUX (continuous flux) is being used to validate MOLFLUX. CONFLUX provides a 'nearly-exact' solution to the 'reduced' free- molecular contamination problem by permitting molecules to bounce from surface-to-surface with no bounce limit. CONFLUX is also double-precisioned for higher accuracy. Excellent comparisons have been made between MOLFLUX and CONFLUX on the AXAF and EOS spacecraft systems (discretized into hundreds of surface elements). Both models are also being verified against simple systems having closed-form analytic solutions. In addition the S-cubed environmental work bench (EWB) is being tested on the EOS spacecraft system. All comparisons are still in a preliminary state.

Citation Download Citation

David A. Brent, Frederick D. Cottrell, Kelly A. Henderson, and Rudy S. Dahbura "Modeling of spacecraft using a modified version of MOLFLUX and comparison with a continuous flux model", Proc. SPIE 2864, Optical System Contamination V, and Stray Light and System Optimization, (11 November 1996); https://doi.org/10.1117/12.258300

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