Out-of-Oven Fabrication of Lightweight Mirrors for Ground-Based Telescopes via Rapid Printing and In-Situ Curing

The Air Force (USAF) and Space Force (USSF) need a new technique to manufacture custom size/shape mirrors at reduced cost and lighter weight for use in ground-based telescopes to support Space Domain Awareness efforts. Suitable geometries are parabolic or spherical with a figuring of λ/4, λ/10 or better. Currently used materials include fused silica, quartz, and borosilicate glass, which are unable to maintain their shape when viewing at or below the horizon and when used in the desired temperature range (32 °F–100 °F).  Texas Research Institute Austin, Inc. (TRI Austin) will develop, demonstrate, and validate an approach to effectively print low cost, lightweight telescope mirrors without significant need for post processing via FDM, SLA, and DIW. The materials are commercially available, domestically sourced, low cost and lightweight, and ready to be integrated into ground-based telescope systems to mitigate the structural and thermal issues associated with conventional mirrors.  In the Phase I Effort, structural thermoplastic polymers (FDM), photopolymerizable polymers (SLA), and composite thermosetting resins (DIW) will be printed and evaluated geometrically via Foucault testing, AFM scans for surface roughness, and assembled into a telescope. The assembled telescope will be used to image the rings of Saturn for a quality assessment.