Qualification of 3D-Printed Titanium Volume-Optimized Propulsion Tanks for Small Satellites

The current state of the art for small satellite chemical propellant tanks is limited in design customization, is expensive, and is volumetrically inefficient within the cuboid volumes of small satellite buses. Space Dynamics Laboratory and Velo3D Inc. partnered to develop propulsion tank technology that solves these challenges using metal additive manufacturing (AM). We designed, analyzed, built, heat-treated, post-machined, precision cleaned, and qualification tested a titanium 6A14V volume-optimized 3D-printed propulsion tank with an integral printed propellant management device (PMD). They are rated for a maximum expected operating pressure of 400 psi. These tanks are 3D-printed in the desired cuboid mission geometries with significantly faster lead times, yielding a much lower cost while improving delta-V per size envelope. This project focused on half ESPA satellite sized tanks, compatible with hydrazine or green propellant, with a scalable methodology to execute any size from 1U to full ESPA. The qualification testing results, processes developed, lessons learned, and key takeaways for the industry are presented. Additionally, this paper outlines a roadmap for the industry showing the pre- and post-printing processing steps needed for success in metal AM for propulsion tanks, referencing the applicable industry standards. We performed a thorough specimen testing campaign and share the results. Finally, we also designed, analyzed, 3D-printed, and heat treated a full ESPA sized propulsion tank with integral printed PMD. This work demonstrates the viability of metal volume-optimized AM tanks for small satellite propulsion and the processes required to be successful in future projects.