Assessment of hybrid Macroscopic/State-to-State model for numerical simulation of Ice Giant orbit insertion

In the current emerging of New Space Economy, space exploration is becoming a priority for the scientific community, for Space Agencies, and for industries. In this field, while gas giants (Jupiter and Saturn) have been explored thanks to NASA space missions, the study of ice giants (Uranus and Neptune) remains an open issue. ESA and NASA are carrying out extensive researches to devise affordable strategies in order to reach these planets in a reasonable time. Specifically, a critical issue in planet exploration is the atmospheric entry phase, due to the extremely challenging flight conditions experienced by the space vehicle. This paper illustrates a numerical investigation of entry and aerocapture maneuvers for ice giant orbit insertion. A comparison between the full State-to-State kinetic model and the proposed hybrid macroscopic model, coherently derived from state-specific dynamical data, is presented in detail. Two different flow regimes are analyzed: a low enthalpy flow, characterized by molecular dissociation, and a high enthalpy flow, where ionization and radiation become relevant. • Hybrid State-to-State/macroscopic model for H2/He mixtures is assessed. • Low free stream enthalpy does not induce ionization. • Charged species molar fractions are relevant by increasing the free stream enthalpy.