Methods and Quantitative Analysis for Explicit Simulation of Soft Landing on Asteroids

This thesis defines and implements a workflow for the finite element analysis of the landing of a 10 kg 6U CubeSat platform on the surface of an asteroid such as Apophis, with scientific objectives. The explicit solver Dytran was employed, well-suited for simulating highly nonlinear, short-duration dynamic events. An introductory review of the main asteroid types and past space missions provided the reference data. Based on this, a simplified CAD model of the lander was developed, discretized into finite elements, and processed in Patran to assign boundary conditions and material properties. The analysis was initially performed on a nominal scenario, representative of the most probable mission conditions, and subsequently extended through a sensitivity analysis. This explored uncertain parameters including asteroid mechanical properties (Young’s modulus, Poisson ratio, bulk density, Pressure-Crush Factor curve), descent velocity (ranging from 1 cm s−1 to 50 cm s−1), and surface inclination. The study further compared the Shock Response Spectrum (SRS) generated during landing with those of three commercial launch vehicles (Falcon 9, Vega C, and Ariane 6), to evaluate the relative severity of the loads. Results indicate that the landing is structurally feasible, with stresses remaining below material limits even in the most demanding scenarios. The descent velocity is identified as the key parameter, significantly affecting post-impact dynamics and overall mission reliability.