Extremely High Expansion Deployed Structures

Future space-based antenna and optical systems are required for global surveillance and identification of targets in areas denied to traditional airborne assets. For missions from Geosynchronous orbit, the apertures must be on the order of 300-meters in diameter to provide coverage that is both continuous and of sufficient gain and resolution. Existing technology is inadequate to meet the packaging, deployment, and stiffness needs of these revolutionary systems. Foster-Miller will develop a strain energy based, deployable structural system specifically designed to combine very high volumetric expansion during deployment and high specific stiffness of the deployed structure. Using strain energy and hierarchical structural architectures reduces the system mass through the elimination of mechanisms and through greatly increased structural efficiency. The packaging approach reduces complex, composite tubular trusses to a collapsed volume that approaches the bulk material density. Early prototypes have already shown over 110:1 linear expansion as compared to 30:1 for conventional booms. Unlike coiled longeron or inflatable systems, the proposed innovation will use the highest modulus carbon fibers, providing both high stiffness and thermal stability. The Foster-Miller team will develop this core technology and apply it to the needs of extremely large deployable space systems. (P-040030)