A Deterministic Approach to the Demonstration of Dimensionally Stable and Survivable VIS/IR CVC-SiC Mirrors for the Space Tracking and Surveillance Sy

MDA, Air Force, and Raytheon are interested in dimensionally stable and survivable SiC substrates and coatings for the Space Tracking and Surveillance System (STSS) Track Sensor Telescope. STSS requirements include: operation in Low Earth Orbit (LEO), surviving a nuclear event, optical performance across the 0.6-12 microns wavebands (specifically VIS/MWIR/LWIR), and operational temperatures from 70-130 K. A legacy VIS/NIR dielectric coated lightweight mirror tested at NASA MSFC reversibly changed the figure of a lightweight ceramic mirror by only 0.5 nm RMS for cyclic testing between 300 and 25 Kelvin, demonstrating the cryogenic-stability of the dielectric coating materials. Under MDA Contract #HQ0006-05-C-7149 performed for Army SMDC, the Principle Investigator successfully designed, manufactured and flash x-ray tested a low emissivity, high-reflectance VIS/NIR/LWIR coating designed from individual elements in the periodic table. A variety of lightweight ceramic mirror substrates were tested. For this project, we propose to design and demonstrate CVC-SiC mirrors with a dimensionally stable (70-130 K) and survivable [space-300 krad (Si) total ionizing dose and nuclear event] VIS/MWIR/LWIR coating, that are traceable to an all SiC STSS cryogenic telescope. In Phase II Trex will work with the government and Raytheon to fully qualify full-scale telescope mirrors and additional coating designs.