Fiber Optic Systems for Light Curing Rigidization of Inflatable Structures

Light (UV and visible) curing composite matrix resins are being explored as an attractive means for rigidizing inflatable spacecraft for large space-deployed structures such as solar sails, radar and communications antennas, radiometers, and solar arrays. Light curing provides a controlled, clean, low power rigidization technology to harden these inflatable spacecraft once they have achieved the required shape. The Phase I program will address the potential use of leaky fiber optics incorporated into the composite structure to provide cure illumination from a diode laser. Fiber optics are a potentially attractive alternative to illumination using LEDs. The advantage is that the fiber optics can be intimately commingled with the composite fibers and matrix resin so that the light located right in the area to be cured. Additionally, a single diode laser can illuminate numerous fiber optics, resulting in a potential weight savings and risk reduction. Matrix chemistry will be formulated to be compatible with the fiber optic illumination system and cure in the space environment using photocurable cationic epoxies. Thermal reversibility of photocured composites and the potential for self repair of misshapen structures will also be addressed. Sample composite tubes will be deployed and rigidized to demonstrate the concept at the end of the Phase I program.