Description: Branch Technology proposes using its lightweight, material-efficient, truss-producing additive manufacturing technology called "Freeform" 3D printing as inspiration for the challenge of assembling a tall truss-based tower for power generation and communications on the lunar surface. Branch has developed the capability to autonomously deposit and solidify printed material in free space without supports, creating a lightweight and geometrically optimized truss or lattice structure called the BranchMatrixTM that creates structural, volumetric geometries with minimal amounts of material. With reimagined deployment concepts and mechanical hardware for the relevant structure size and lunar environment, this fabrication process could be adapted to larger scale trusses, including the potential for lunar surface construction of a power/communications tower. In this project, Branch proposes to (1) identify a portfolio of viable approaches for constructing or assembling a lunar truss tower inspired by Freeform 3D printing, (2) create an initial design iteration concept for each approach, downselect the best approach and (3a) begin design of a robotic tool/end-effector and (3b) begin design of the tower structure and deployment/assembly sequence, (4) optimize the tower's structural design with Freeform 3D printing principles to minimize material usage and maximize strength, (5) incorporate potential tower outfitting strategies into the design, and (6) produce a 1/10th-scale demonstration tower based on the downselected design. The technology that enables this lunar infrastructure could be deployed for other lunar surface use-cases, as well as for structural fabrication and geometric optimization projects for terrestrial use — whether for spanning elements, bridge or trussing members, or building construction. The funds requested in this SBIR Phase I proposal will enable the preliminary design and demonstration objectives described above.

Benefits: Enabling a long-term presence on the Moon will require substantial infrastructure on the lunar surface, including the ability to autonomously construct, erect, or assemble towers that can protrude from the surface of the Moon far enough to capture communications signals and take advantage of solar irradiation for power generation. Branch Technology's Freeform 3D printing technique is a viable source of inspiration to look to as NASA seeks to build such structures on the Moon. Branch invented structural Freeform 3D printing and has used it to produce many of the world's largest and most significant 3D printed structures and construction projects. Its nature as a truss-building additive manufacturing technique lends itself particularly well to the development of a truss-based tall tower because the mechanisms and automation software to produce parts are already developed with consideration for truss pathplans, grid structures, and associated traverse kinematics. If adapted to larger truss modules and for operation on the lunar surface, autonomous Freeform 3D printing and/or part assembly could enable the production of a tall truss tower for communications and power generation. In addition, because of the difficulty of transporting feedstock materials to the Moon or harvesting usable feedstock resources from the lunar environment, material efficiency is critical — in either case. Freeform 3D printing fundamentally asks a different question than traditional additive manufacturing techniques — not "How much can be 3D printed?", but "How little?". This approach is a step-change shift in mindset for fabrication methods and will create a higher chance of mission success on the lunar surface as astronauts and robots work together to stretch the materials available to them as far as possible. Freeform 3D printing could also serve as inspiration in designing methods to produce other aspects of lunar infrastructure, from habitats and revetments to solar arrays or landing pads.Branch Technology is already the only known entity in the world to have commercialized multiple code compliant product lines for commercial construction projects. Primarily focused on the market for exterior cladding of commercial buildings, Branch's products include ventilated rainscreens, prefabricated megapanel wall panels, and sculptural and artistic installations. However, as adaptations to the company's manufacturing technology are achieved through projects like this for structural tower design, Branch's products could be certified for code compliance in other areas of terrestrial infrastructure. The lightweight, custom-geometry structures that Branch can produce could be apt candidates for applications like bridge construction, power tower construction, or other civil engineering jobs that require optimized topologies for maximum structural efficiency. Branch has chosen to initially focus on the exterior cladding market within the construction sector because of the combination of lower barrier-to-entry and high-value-add that its products encounter in this submarket. With additional development for an application like a tall lunar tower, Branch expects its innovations to become applicable to a much wider range of construction and infrastructure projects where a premium is placed on achieving a high strength-to-weight ratio.