Lightweight, Segmented, Deployable Silicon Carbide Optical System

SSGPO proposes a segmented, deployable mirror concept that utilizes lightweight, monolithic Silicon Carbide (SiC) mirror segments which can be phased together (tip, tilt, and piston control) to provide a large primary mirror surface. A number of concernshave kept the NGST program from adopting this type of mirror architecture. First, traditional glass optical materials are not stiff enough to support this type of design. Secondly, mirror manufacturing and polishing needs to be very low-cost anddeterministic in order to support the large number of matched mirror segments that would be required for such a configuration. The application of SiC materials addresses the first concern. The SiC material has excellent stiffness and thermal stability,allowing the individual mirror segments to be controlled with fewer degrees of freedom than the current NGST mirror designs. The second concern is addressed by the combination of SSG's SiC slip casting forming process and SSG's Tinsley subsidiary'sComputer Controlled Optical Surfacing (CCOS) process. These processes allow the fabrication of many matched mirror segments in a rapid, low-cost fashion. The work proposed here is based on some previous technology demonstration work done by SSG. Ourtechnical approach has been strengthened by the addition of a number of deployment/latching schemes developed and demonstrated by TRW. In Phase I, we will develop the concept around an application of interest to MDA (i.e.; SBL) to perform a preliminarytechnical assessment of the approach and develop a manufacturing/program plan for implementation in Phase II. Our proposal will benefit from cost sharing from TRW in Phase I, with additional funding allocated for the Phase II effort. The lightweight,deployable optical architecture described will have application to a number of space-based remote sensing, atmospheric observing, and directed energy applications.