Precision Manufacturing of Co-Axially Hybridized Composite Rods for High Performance Deployable Space Structure

Large coilable booms are used to deploy sensors, antennas and other hardware from satellites. These booms are truss-like structures, often 100 feet or more long, constructed from small diameter S-glass/epoxy rods. Booms are designed to be tightly packed for launch. This places severe demands on the structural materials. Rods are currently made by the pultrusion process. KCI proposes to investigate several significant design and manufacturing process advances that could improve boom performance. First, we will investigate use of liquid metal or other non-solid tooling in place of conventional steel dies for consolidation and cure during the processing of rods. Second, we will investigate benefits of material hybridization in specially-controlled geometries to greatly increase the weight-specific axial and bending rigidity of pultruded rods for boom application. Coilable boom performance is closely tied to these structural properties. Finally, we will investigate the possibility of using fiber hybridization to achieve an arbitrary coefficient of thermal expansion in a pultruded composite structure. We will work with AEC, a major fabricator of coilable booms for spacecraft, to estimate performance improvements in typical masts that could be attained by application of KCI's hybrid composite rod technology.