Key questions surrounding the origin and evolution of Titan and the Saturnian system in which it resides remain following the Cassini-Huygens mission. In-situ measurements performed at key locations on the body are a highly effective way to address these questions, and the aerial-aquatic platform proposed in this report serves to deliver unprecedented access to Titan's northern surface lakes, allowing an understanding of the hydrocarbon cycle, the potential for habitability in the environment and the chemical processes that occur at the surface. The proposed heavier-than-air flight and plunge-diving aquatic landing spacecraft, ASTrAEUS, is supported by the modelling of the conditions which can be expected on Titan's surface lakes using multiphysics fluid-structure interaction (FSI) CFD simulations with a coupled meshfree smoothed-particle hydrodynamics (SPH) and finite element method (FEM) approach in LS-DYNA.