Manufacturing and Joining of Composite Units for On-Orbit Construction of Large Structures in Space

On-orbit construction eliminates the need to withstand the harsh mechanical environment during the launch phase and is not constrained by the size limitations of a launch vehicle’s fairing. This approach effectively reduces the structural weight of spacecraft and enables the construction of space facilities on scales ranging from hundreds to even thousands of kilometers. Truss-type structures are the primary support structures for large-scale space bodies. Therefore, the 2 key technologies in on-orbit construction are the fabrication of large structural units and the connection between these units. This paper proposes the use of carbon fiber/polyetheretherketone (CF/PEEK) composite prepreg tapes to manufacture composite tubular units through the pultrusion process. The influence of temperature and speed on the mechanical properties of the pultruded tubular units was studied. Additionally, it proposes using 3-dimensionally printed translucent PEEK joints to connect the tubular units, reinforced by laser transmission welding. The effects of welding temperature and speed on the weld strength were analyzed, and the microstructural characteristics of the weld were observed at a microscopic scale. Finally, a parabolic antenna framework was fabricated by cutting CF/PEEK composite tubular units into different lengths, verifying the feasibility of this method for on-orbit construction. This paper offers a valuable technical reference for the advancement of on-orbit construction technology.