Controlled Rigidization Technology for Inflatable Spacecraft

Large space-deployed structures such as synthetic aperture radars, radiometers, and solar arrays are receiving a great deal of interest by NASA in the Earth Sciences program. These large structures by necessity must be ultra-lightweight and low stored volume. Inflatable or self-deployable approaches that become rigid after they reach the correct shape appear to be a promising approach for fabricating structural members for these applications, such as booms, struts, and trusses. There remains a need for a controlled, clean rigidization technology to harden these inflatable spacecraft once they have achieved the required shape. The Phase I program will address structural and manufacturing requirements for ultralight composite tubes and explore the chemistry of an ultraviolet (UV) light-curing matrix system for rigidizing inflatable space structures. Composite architecture will be selected based on the analytical results. A likely structure will be composed of fine denier yarns woven into an open weave architecture with a [0/¿45] orientation. Matrix chemistry will be formulated to be compatible with long deploy-ment times and cure in the space environment using photocurable cationic epoxies. Previous work on this rigidization on command (ROC) technology has shown that this approach has considerable potential for controlled rigi-dization of inflatable structures. Sample composite tubes will be deployed and rigidized to demonstrate the concept at the end of the Phase I program.