Cislunar Trajectory Design in Realistic Ephemeris Model

Abstract

Realistic models and the development of efficient techniques for space trajectory design are essential with the increasing global interest and activities in space missions in the cislunar and lunar regions. As Brazil starts to collaborate and develop its own lunar missions, being the first South American country to sign the Artemis Accords, it is essential to have the expertise in realistic, time-dependent dynamical models capable of providing operational-ready trajectories for upcoming cislunar missions. The search for new trajectories that facilitate or lower the cost of a space flight can have a huge impact. In this scenario, preliminary solutions are usually obtained by exploiting the abundant diversity of dynamical structures provided by the circular restricted three-body problem (CRTBP), given that it models in a very good first approximation the nonlinearity in the phase space of the subsystem of interest. However, although the CRTBP serves as an excellent preliminary design model, the solutions it provides are only approximations of the real multi-body dynamics. Therefore, they must be refined to more realistic models that consider planetary ephemerides, taking into account additional perturbative forces and eliminating approximations assumed in an ideal model. This process of refinement can be tackled in different ways and will certainly change the original trajectory of the CRTBP, raising or lowering the fuel cost, changing the duration of the flight, or even the final destination of the spacecraft. Therefore, the objective of this project is to obtain a reliable methodology for transitioning the trajectories from the CRTBP system to realistic ephemeris models and proficiency in navigating the complex dynamical structures of the Moon vicinity.