Phase space structure for three-dimensional motion around Europa

The dynamics of an orbiter close to a planetary satellite is known to be unstable from a wide range of inclinations emcompassing polar orbits. Taking the Jupiter-Europa system as our model, we use numerically determined periodic orbits to investigate the stability of motion over three dimensional space for this problem. We found that the change in the stability is produced by a bifurcation in phase space: At a certain critical inclination, almost circular periodic orbits change their stability character to instability and new families of (stable) eccentric orbits appear.