Design progression of an all-composite primary mirror for the FIRST Telescope

Composite materials are an ideal choice for the FIRST Telescope, since they provide dimensional stability, excellent stiffness to weight ratios, near zero thermal expansion, and manufacturing flexibility. The most challenging aspect of producing an all-composite FIRST telescope, is the development of the lightweight primary mirror. The design of the primary mirror must satisfy requirements for surface accuracy to operating temperatures of 80 +/- K as well as stiffness and strength considerations during launch.