Speaker
Description
This paper reports on the degradation of thermo-optical properties of materials used in thermal and power functional surfaces due to lunar dust. A large set of solar cell coverglasses (CVG), radiator coatings such as Optical Solar Reflectors (OSR), Second Surface Mirrors (SSM), or white paints, as well as MLI outer layers are tested after deposit of Lunar Dust Simulant (LDS).
The solar absorptance (alpha) and emissivity (epsilon) parameters are measured for different LDS deposit conditions. The approach proposed here is to accumulate dust with increasing levels of surface coverage (sub-monolayers of LDS with the coverage percentages from 5 to 30 %). The overall objective is to establish the law that governs the evolution of alpha or epsilon with LDS coverage. This evolution law can be plotted versus dust coverage in % or in µg/cm² (from mass measurement).
Then, a temperature investigation is also performed on a sub-set of materials (OSR, SSM and paintings).
The set-up used for dust deposit, thermo-optical measurements and specific test procedures will be described. The measurement test plan will be discussed accounting for the specific contraints linked to the measurement of LDS contaminated samples. Preliminary data on coverglasses, OSR and SSMs with LHS-1 deposit (LDS from Exolith Lab with custom sieve < 100 µm) will be disclosed showing the influence of LDS coverage level on the thermo-optical response of materials.
