In-Space Manufacturing (ISM) is being investigated as a method for producing larger, cheaper, and more capable spacecraft and space stations. One of the most promising manufacturing techniques is additive manufacturing (AM) due to its inherent flexibility and low waste. The feasibility of a free-flying small spacecraft to manufacture large structures using a robotic arm with an AM end effector has been examined. These large structures would aid the construction of a large space station or spacecraft. Using the Experimental Lab for Proximity Operations and Space Situational Awareness (ELISSA) at the Institute of Space Systems at TU Braunschweig, a process has been designed and tested which is capable of producing structures with arbitrary length. This process was demonstrated by manufacturing support free truss elements of unlimited length using a free-floating mobile robot. Avenues for further extending the process to produce structures of any size in 3D space are discussed.

Large scale additive manufacturing (LSAM) refers to the fabrication of structures that exceed the build volume of conventional additive manufacturing setups. This can be used for in-space manufacturing (ISM), facilitating the production of large functional structures in space which cannot fit within the payload fairing of a launcher system. In this paper, a new approach for a continuous fabrication process of structural elements is presented, combining the reach of a free-flying satellite and a robotic arm, utilizing a fused filament fabrication (FFF) 3D-printing setup. A motion planning algorithm was developed which calculates energy-efficient movement trajectories based on a truss design input combined with the movement constraints of the satellite and robotic arm. Using this printing paradigm, a long support-free truss was manufactured. This approach was further elevated by extending the truss structure along the second planar axis, thus facilitating the manufacture of structures larger than generally possible through a layer-by-layer approach. Subsequently, combining the segmented and continuous printing approach, a planar truss structure was produced.