Stable low-altitude polar orbits around Europa

Resumo

In this paper, a search for low-altitude orbits around Europa is performed. An emphasis is given in frozen orbits. These orbits are used in the planning of aerospace activities to be conducted around this planetary satellite, with respect to the stability of orbits of artificial satellites. The study considers orbits of artificial satellites around Europa under the influence of the third-body perturbation (the gravitational attraction of Jupiter) and the polygenic perturbations. These last ones occur due to forces such as the non-uniform distribution of mass (J2 and J3) of the main (central) body. A simplified dynamic model for these perturbations is used. The Lagrange planetary equations, which compose a system of nonlinear differential equations, are used to describe the orbital motion of the artificial satellite around Europa. The equations of motion are developed in closed form to avoid expansions in power series. Low-altitude polar orbits and frozen orbits with long lifetimes were found. This study can be used for planning of future space missions which seek to visit Europa and other planetary satellites.