Radiation Hardened Mirror Coating for Spacecraft And Interceptors

Surface Optics Corporation (SOC), in conjunction with Raytheon Missile Systems and GH-Systems (GHS), has designed and demonstrated by analysis a radiation hardened reflective coating system for interceptor mirrors. The proposed innovation consists of a patented, non-tarnishing silver mirror coating, combined with a carbon-based heat-sink coating. The coating designs may be applied to lightweight substrate materials such as silicon carbide, beryllium or aluminum. In Phase I, hardened coating designs consisting of dielectric and metal layers were optimized using the PUFFTFT survivability analysis code. The survivability analysis predicted a 3x to 5x improvement in X-ray damage tolerance for the new coating designs, compared to a standard protected gold coating design. The coatings were fabricated and subjected to high humidity and acid vapor exposure cycles and showed no significant change in optical performance following these accelerated aging tests. During Phase II, the designs will be refined and the research will be extended to include X-ray exposure tests at the Double Eagle Test Facility.