Master thesis and internship[BR]- Master's thesis : Simulation of Deep Space Missions: Integrating Solar System Planets and Small Celestial Bodies with Fine Gravitational Field Modeling[BR]- Internship

Abstract

This thesis presents a comprehensive approach to enhancing the existing patrimony of SPACEBEL’s physical models for deep space mission simulations. This thesis focuses on two critical areas: the integration of both large and small celestial bodies into mission simulations and the accurate modeling of gravitational fields for small celestial bodies with complex shapes.

The first part addresses the accurate integration of celestial bodies, including both large entities like planets and smaller ones such as asteroids and comets. It focuses on predicting their ephemerides using Chebyshev polynomial interpolation, which provides efficient and precise results over extended mission timescales. Additionally, models were developed for defining and managing reference frames and calculating the spheres of influence (SOI) of celestial bodies, which are crucial for accurate mission simulation and optimising computational time. These models ensure consistent and precise simulations across different reference frames and help define regions where gravitational influences need to be considered. These models have been validated through their application to several well-known missions, including Voyager 2’s journey through the solar system and the Hera mission to the Didymos binary asteroid system. These validations demonstrate the practical utility of the models in enhancing the accuracy of mission simulations, thereby supporting SPACEBEL’s goals in deep space mission simulation software development.

The second part of the thesis explores the precise modeling of gravitational fields for irregularly shaped celestial bodies, such as those in the Didymos-Dimorphos binary system. In this thesis, the polyhedron method was employed. This approach models a celestial body’s shape using polyhedral facets, offering a more accurate representation of its gravitational field. Validation of this approach was carried out by comparing the gravitational field results at the surface of several asteroids with known data. The results show that the polyhedron model provides a more detailed and realistic gravitational field, which is crucial for mission scenarios involving close proximity operations and landings. Additionally, this part of the thesis explores the implications of these gravitational models for spacecraft trajectory propagation in such complex dynamical environments. The findings offer valuable insights into the precision needed for deep space missions simulation, particularly when dealing with the complex gravitational fields of irregular bodies.

Overall, the models developed in this thesis offer valuable advancements for SPACEBEL’s patrimony of physical models, providing enhanced tools for future deep space mission simulation.