Direct simulation of apex enhancement on the flux onto European Retrievable Carrier

The extended direct simulation Monte Carlo method is employed to model fluxes of meteoroid and space debris onto surfaces of the sun-pointing spacecraft European Retrievable Carrier. Apex enhancement of the Earth motion on flux is considered by including a parameter to describe the anisotropic velocity directionality in the meteoroid distribution. The anisotropy of the measured fluxes onto different surfaces is well explained by this approach, and results are consistent with measured data. Also, the effect of the apex enhancement of the Earth motion on the morphology of the impacts is analyzed, and a good agreement with measured data is achieved. Our simulation allows an estimation of the extent to which the directionality distribution of the meteoroid velocity unit vectors deviates from the isotropic distribution.