Dedicated Mission to the Sun-Earth Saddle Point: a Feasibility Assessment

Gravitational Saddle Points are points in space where the net gravitational acceleration of solar system bodies cancels. Certain gravitational theories, motivated by the still unresolved Dark Matter problem, predict potentially verifiable deviations from General Relativity around these points. A dedicated mission to one of these points may be an attractive proposition, if feasible. In this paper, a scientific test case is built to set the requirements for that mission, then periodic orbits through the Sun-Earth Saddle Point, necessary to collect relevant data, are sought. The periodic orbits survey is made using a systematic approach, firstly addressing it in the circular restricted three-body problem with the Sun and the Earth as main bodies: first attempt trajectories are sought through a grid search and then refined using a simple shooting, differential correction scheme. Stability is evaluated and a classification is made. Restricted four body problem adding the Moon is used as middle complexity model in order to find quasi-periodic orbits. These are refined in a full ephemeris high-fidelity n-body model. Results show different solutions with diverse characteristics and properties.