Aluminum Metal Matrix Composite UV Mirrors for Small Sats

Outpost, UAH, and EO Solutions will modify the manufacturing and polishing processes developed under Phase I for spherical and aspherical forms, both concave and convex.Ā During Phase I, Outpost and the University of Alabama in HuntsvilleÆs (UAH) Center for Applied Optics (CAO) advanced electrolytic nickel plating and polishing processes to produce highly machinable, polishable optical surface with sub-nanometer surface roughness for Al-MgF2Ācoatings. These processes were designed to be agnostic to surface form and are readily applied to flats and axisymmetric surface forms. Therefore, Outpost and team will also develop prototype concave and convex mirrors for assessment.Ā These mirrors are critical steps towards off-angle parabolic (OAP) forms, which are present on many compact instrument designs, including the GROUP-C/TIP and CIRCE Tri-TIP systems. Outpost aims to develop six (6) lightweighted AlMMC mirrors to evaluate performance in heritage DON systems or a future program. Optical instrument primary and secondary structures may also benefit from AlMMC materials.Ā Outpost has partnered with two large defense contractors and one academic institution to assess AlMMC materials in optical structures and electronics housings in the past 18 months. During these efforts, Outpost has determined that the high strength and CTE properties present mass saving and optical form accuracy improvements over aluminum or plastic components.Ā These benefits are compounded when the mirror substrate materials are similar or equivalent to the structural material. For instance, an AyontEX-13 mirror system mounted to a AyontEX-13 primary structure would benefit from the improvements to strength, stiffness, toughness, as well as the CTE uniformity between mirror and structure. These improvements allow for mass reductions and/or performance improvements without affecting system mass requirements.Ā For instance, the 1U, 1.4 kg Tri-TIP instrument mass could be reduced by 50 to 100 grams with AlMMC mirrors and primary structures. The reduction in mass is a critical design figure of merit for most optical systems, especially those on mass-limited CubeSat platforms. This Phase II effort will produce six (6) flight quality 100 mm-class scan mirrors, six (6) 25.3 mm concave and convex prototypes and assess structural components of DON UV instruments for potential mass savings and optical performance improvements, justifying TRL 5.Ā Further, the prototype designs shall be analyzed to launch and flight dynamic and thermal environments with respect to interface control documents and other system requirements.Ā Once six (6) scan mirror prototypes are delivered, the Customer shall determine candidate prototypes to complete environmental testing and evaluation to justify TRL 6.Ā These tasks aim to prove technical capability and cost benefits of AlMMC materials for small sat UV mirror applications versus conventional aluminum, glass, and composite materials.