Metals are higly variable in their response to the LEO environment. Gold and platinum are nonreactive. Osmium forms a volatile oxide and is rapidly eroded under exposure to atomic oxygen. Silver, which forms a nonprotective oxide, is rapidly eroded. Contamination is a major contributor to exposure effects on metal surfaces.
Absorptance is significantly greater for bare aluminum than for chromic-anodized aluminum.
Emittance is significantly less for aluminum than for chromic-snodized aluminum. The surface properties of both bare aluminum and chromic-anodized aluminum are little changed by exposure to LEO environmental conditions. Magnesium in aluminum alloys is preferentially oxidized relative to aluminum. An oxide coating forms on exposure of copper to atomic oxygen that impedes further oxidation. The oxide coating adversely affects the optical properties of copper.