In-Space manufacturing (ISM) is actively being investigated as a method to fabricate large, complex, yet resource efficient structures in orbit. Novel technologies such as fused filament fabrication (FFF) based additive manufacturing (AM) using thermoplastics have been identified as potential sustainable production technology for ISM due to their inherent manufacturing flexibility and low waste generation. Fibre- reinforced composites have been hypothesized to facilitate ISM while simultaneously realising functional structures with strength, modulus and weight advantage. In this study, we proposed and established an adapted FFF process that enables manufacturing of continuous fibre reinforced composite (CFRC) structures in space, beyond the confines of the International Space Station. Using continuous fibre tow and thermoplastic filament as feedstocks, a flexible printing setup was developed. It enables in-situ impregnation and coextrusion of tailored CFRC to directly print composite structures with desired matrix-fibre combination for a specific use case. First, the feasibility of in-situ impregnation and coextrusion process to function in the low-pressure space environment was assessed. The setup was successfully tested in a vacuum chamber using a modified 3D printer, and the impact of low pressure on FFF manufactured CFRC was studied. Initial investigations showed positive results with similar fibre impregnation for the samples produced in low-pressure environment compared to samples manufactured in atmosphere. Next, the viability of the proposed setup to fabricate large, free-form composite structures in the free-floating space environment was evaluated. The proposed coextrusion setup was used to print CFRC trusses in a simulated free-floating environment using the Experimental Lab for Proximity Operations and Space Situational Awareness (ELISSA) air bearing table at the Institute of Space Systems in TU Braunschweig. Combining the reach of a free-flying satellite with the accuracy afforded by a robotic arm in conjunction with coextruding print-head, and using a continuous toolpath, printing of complex, free-standing CFRC structures with sub-millimetre resolution was successfully demonstrated.
Jonckers et al. (Sun,) studied this question.