Addditive-manufactured Low-Cost Upper-stage Propellant (ALCUP) Tank

An Additive-manufactured, Low-Cost, Upper-stage Propellant (ALCUP) tank architecture is proposed that integrates different AM techniques to produce a scalable, modular tank architecture which allows for incorporation of different tank features required to retain mission flexibility, while utilizing advanced concepts to decrease inert fraction. The innovative design and manufacturing technique utilizes the large build platform of current wire-fed Electron Beam Additive Manufacturing (EBAM) platforms to create axisymmetric preforms that can then be Electron Beam welded to powder-bed fabricated components used to provide complete tank specification. Advanced high strength-to-weight materials are being incorporated to further decrease structural mass density while topology optimization is being used to incorporate mechanical load-bearing elements into the baseline design to further decrease inert mass. A series of proof-of-concept tests are proposed to demonstrate the feasibility of using the EBAM machine to EB weld the different tank components, produced with the different AM techniques, together to form an upper stage tank assembly. An optimized isogrid panel is also being created to demonstrate the idea of directly incorporating stiffening elements into upper stage propellant tanks to realize the concept of tanks-as-structure. Finally, a series of corrosion and compatibility tests are proposed to demonstrate a wide range of propellant viability. Approved for Public Release | 18-MDA-9817 (23 Oct 18)