Low-temperature oxygen-plasma effects on surveyor plasmo-clay coating

The objective was to determine whether the reflectance of the degraded plasmo-clay thermal control coating could be restored by exposing it to an oxygen plasma. An experiment was conducted to determine whether bulk radiation damage would be removed by a reabsorption of oxygen ions into the pigment crystal lattice. Results show that the oxygen plasma treatment can eliminate some of the lunar environment-induced degradation on the plasmo-clay coating. Visual observations of the lunar soil on the surface after plasma treatment indicated that it was still highly absorbent to light. Therefore, part of the residual discoloration could be due to lunar soil.