Outpost Technologies, Materion, and the University of Alabama (UAH) Center for Applied Optics (CAO) propose a low-cost, stiff, and stable normal-incidence space mirror material that will decrease aerial costs below $500k/m2. Beryllium and silicon carbide (SiC) mirrors are the gold standard in mirror substrate materials given their specific strength, thermal stability, and stiffness. However, their capabilities come at great cost, especially manufacturing complexity and safety-related overhead expenses for a given telescope program. There is a significant performance gap between beryllium and SiC materials and the lower-cost aluminum substrates. This presents problems for telescope programs unable to afford beryllium systems: though science and engineering seek highly capable optical systems, common and less expensive metals such as aluminum 6061 lack the material properties required to deliver required capabilities. Subject matter experts at Outpost technologies and its partnering organizations, Materion and the UAH CAO, have noted that aluminum’s low specific strength/stiffness and high coefficient of thermal expansion have crippled past balloon-based telescope systems due to excessive mass and material limitations. Materion’s SupremEX Metal Matrix Composite (MMC) combines the machinability and low cost of aluminum with the stiffness and thermal performance of silicon carbide, yielding a capable optical mirror substrate material for balloon-based platforms.
Outpost's proposal PI has met with numerous NASA civil servant program managers, system engineers, optics scientists, and diamond turning experts. During these meetings, Alex Few met with a program manager and optics scientist at GSFC who has submitted a balloon based telescope system proposal for a 1-m class IR observatory, called BEGINS. Alex and the PM discussed the BEGINS program needs, mirror specifications, and baseline requirements. This effort is aimed to infuse with the BEGINS program and will continue to update requirements.
The manufacturing efforts to mature the SupremEX MMC product to TRL 5 will open doors for existing optics programs to adopt this technology. Current DOD system use more fragile aluminum substrates on mirror systems commonly failing due to G-loading and vibration loads. The MMC's superior stiffness, thermal stability, and wear resistance will trade well in these DOD applications (tanks, missiles).