An efficient and scalable manufacturing method for CFRP lattice structures for satellite central tube and large deployable antenna boom applications

CFRP lattice structures, without the skin, offer several benefits with respect to conventional sandwich or monolithic concepts in satellite applications such as mass reduction, accessibility to the interior side and superior thermo-elastic stability. Automated manufacturing process, based on placement or winding, offers opportunities to lower the overall cost of serial products. Despite the apparent simplicity of the process, there is a large variety of manufacturing solutions proposed by industry. This evidences the interest but also an inherent practical difficulty to define a single, definitive process, that is at the same time cheap and suitable for different scales of interest, as well as accounting for flat, single, or even double-curvature shapes. CIRA has developed a specific manufacturing process for grid-stiffened structures based on a combination of rubber tooling, Dry Parallel Robotic Winding (patented) and Resin Liquid Infusion. A variation of this process has been successfully applied to VEGA-C Interstage 2/3. This paper presents the extension of this approach for two applications-promoted by the "CFRP Grid Tubular Structures" ESA ITT project in the framework of Artes 5.1-highly interesting for the space market: an instrument boom segment (a part of a satellite large deployable antenna), and a satellite central tube. Both demonstrators address rather strict requirements and challenging design and manufacturing issues, ranging from a large diameter Central Tube, with stiffness and buckling constraints and thick ribs, to a slender boom segment with stiffness and thermal stability requirements and thin ribs. The two demonstrators have been successfully designed, produced and tested, confirming the efficiency and flexibility of the approach and providing new benchmarks for the space community.