Analyzer for Outgassing Effects of Spacecraft Surfaces 851365
For the analysis of outgassing effects of spacecraft surfaces in vacuum conditions, an analyzer program package was developed as extension of the existing plume impingement model analyzer ERIMA (1)*.
In the geometry section based on the LOHARP-VUFACT routine, the complex spacecraft surfaces are discretized. The view factors from all surface elements to pre-selected surfaces are determined considering special shading techniques In the outgassing analysis section, all surfaces are considered as sources of particle fluxes of a given outgassing rate. The particle fluxes are assumed to follow straight stream lines with the directional dependency of the intensity according to the cosine law.
The particle fluxes impinging on the pre-selected surfaces are determined and summed up considering all surface elements involved and the appropriate view factors and shading factors. The method is also used to calculate the local particle flux density at any location if that location is contained as check point surface in the geometrical model.
The analyzer is used to determine the outgassing induced local mass flow densities and mass fluxes on selected surfaces of a sample case. The spatial mass flow density distribution of various outgassing species is determined at numerous check points in some distance from the spacecraft.