Atomic Oxygen (AO) is the main component of the residual atmosphere present at low earth orbit. Multiple reflections can locally enhance or lower erosion rate in case of complex geometry. In a previous work [1], an original geometrical setup was designed in order to expose target surfaces to AO flux with normal incidence or after one reflection. Candidate materials have been selected in view to compare numerical results and experimental results (ground experiment conducted at ESA-ESTEC LEOX facility). After reflection on the inclined samples, the residual fluence coming onto the detector surface (Kapton film) is between 4 and 10 % (depending on material type) of the direct incident fluence. Modeling tools (Atomox module in ESABASE2 and SYSTEMA industrial toolbox) may account for multiple reflections with simplistic approach (ray-tracing) and a set of semi-empirical parameters.

The experimental investigation previously conducted is completed in this present work with profilometry analysis on Kapton film detectors. Comparison with numerical simulations conducted by TAS and ADS with optimization of input parameters allows partly for retrieving the complex-shape eroded areas, the total mass loss and erosion depth level.

Part of this work also aimed at selecting candidate materials for the SESAME experiment (ESA-CNES Euro Material Ageing experiment on-board the Bartolomeo platform of ISS). In particular ONERA provided, with collaboration of the industrial partners and CNES, two flight models (FM) of the 2D and 3D modules (see figure) with RESISTACK AO active sensors [2] (resp. a 2D FM for direct ram AO exposure and a 3D FM for AO effect after reflection). This paper will also disclose associated industrial AO computations outcome for the 3D geometry module and for the planned mission duration. One future goal will be to compare ground vs flight data after the mission return.