SOTER TECHNOLOGY, LLC — National Aeronautics and Space Administration SBIR Phase I: S2.03

Description

Soter Technology is pleased to offer NASA a new technology for manufacturing diffraction limited visible telescope mirror blanks. This technology can support both symmetric primary mirrors and off-axis segments for segmented telescopes. The recurring fabrication cost and cycle time for these mirrors is quite low, once nonrecurring equipment (e.g. the optical test set) has been completed. For example, a 0.25 m diameter mirror with >2 KHz first mode and 19.5 kg/m2 would be fabricated in < 30 days. A 0.75 m diameter mirror with >350 Hz first mode at 21 kg/m2 would be completed in <60 days. The cost of these mirrors (especially at sizes > 1 m) depends strongly on the stiffness requirements, because stiffness drives overall mirror volume. Fabrication costs for the blank and polishing are expected to be between $0.3M/m2 and $0.4 M/m2 for sizes up to 1 m, and <$0.6 M/m2 for sizes up to 2 m. Initial FEA indicates that these mirror blanks will be more thermally stable than ULE mirrors. The goal of these technology is to produce aspheric mirror blanks which can support: - 10 nm RMS global surface figure - 5 nm RMS mid-spatial frequency errors - 1 nm RMS surface roughness This Phase I SBIR will produce and thermo optically test a 100 mm mirror, while applying heat loads representative of those seen by a mirror in a reasonable telescope shroud. In Phase II, this technology will be demonstrated by making a 0.2 m diameter diffraction limited telescope flat field telescope with a 0.2 m diameter primary mirror that is ~20 kg/m2, >400 Hz first mode, 10 nm RMS surface, and has <5 nm RMS midspatial frequency errors.