The primary purpose of this work is to develop and demonstrate technologies to manufacture ultra-low-cost precision optical systems for very large x-ray, UV/optical, or infrared telescopes.
Starfire® RD-730 is a polycarbosilane precursor material that can be converted to a thermally stable silicon carbide by direct pyrolysis. RD-730 is a melt-processable polymer, meaning that it is a solid at room temperature, but can be melted to produce a viscous liquid polymer that can be flowed at temperatures to 100 °C. Using melt processing, T-300 cloth fabrics can be infiltrated with RD-730, which then solidifies and becomes a hard, machinable thermoplastic. T-300 cloth layups with RD-730 in the thermoplastic form will be the new prepreg material. The prepreg in block form can be machined to near-net shape, put in a mold, and re-flowed (re-melted). The molded parts can then be cured (curable above 150 °C) to render a thermoset, which is machinable. The cured polymer matrix composite can then be fired to form a high-temperature, oxidation-resistant, amorphous silicon carbide material.
A 12 × 12 × 0.5 in. (≈30 × 30 × 1.3 cm) vented, lightweight, H-SiC panel was developed that had a density relative to bulk silicon carbide of 11% (89% lightweighting). The H-SiC panel and facesheet stock material were fabricated into ASTM standard coupons and tested at SoRI to obtain basic materials properties data. The materials properties data showed a near-zero coefficient of thermal expansion [CTE, from –320 to +75 °F (≈ –196 to 24 °C) is –0.22 ppm/°C] ceramic matrix composite (CMC) C/SiC material with good strength.
This work was done by Bill Goodman of Trex Enterprises Corporation for Marshall Space Flight Center. NASA is seeking partners to further develop this technology through joint cooperative research and development. For more information about this technology and to explore opportunities, please contact Ronald C. Darty at