Technology for Large Aperture Membrane Optics

The objective of the proposed research is to establish the technical viability of a process that will enable production of cast precision membrane structures of virtually unlimited aperture. Very large membrane structures are required for many concepts currently being considered for space-based large telescopes and other NASA science missions. The current state-of-the-art fabrication process for dual curvature (parabolic) shapes, developed by SRS Technologies, requires a single piece mandrel the size of the final membrane structure. SRS has fabricated precision thin film structures of up to 5 meters in diameter using this method. This technique could probably be extended to manufacture components up to approximately twice this size. However, new technology is required to fabricate very large membrane structures that are needed for many future NASA applications. This effort will result in development of a solvent welding technique to join film sections much more reliably and with much less variation in seam material properties than is achievable at this time. Additionally, new mandrel technology will be developed to enable larger films to be cast on lighter weight, less expensive tools.