Europa clipper vault shielding optimization approach

In the effort to further understanding of the Jovian moon Europa, a Jet Propulsion Laboratory (JPL) and Applied Physics Laboratory (APL) joint team are developing the Europa Clipper spacecraft concept that would provide multiple flybys of Europa during its tour. During the flyby maneuvers, the proposed Europa Clipper spacecraft would be required to operate within the high radiation environment. In order to protect the sensitive electronics of the spacecraft, the current radiation protection approach is to locate these electronics within a radiation vault. This paper documents the study performed addressing the construction and geometry of this electronics radiation vault. The method of development incorporated analytical base panels of various thicknesses comprised of standard aerospace materials (aluminum and titanium). These panels were then subjected to a range of seed loads in order to create a preliminary rib pattern. Panels where the baseline thickness is not adequate to provide the necessary shielding will then have additional shielding applied in the form of Tantalum sheet added to either the internal or external faces in order to account for the capability differences. Further vetting of the panel geometries will then take into account factors such as manufacturability, flexibility to late shielding requirement changes, assembly mass, and additional design requirements finally selecting a baseline configuration to be implemented in the flight design. Detailed analysis will be performed for an idealized panel which will not be required to support any additional components; however aspects such as harness pass-through, thermal impacts, and accessibility will be addressed.