On the Design of an Enceladus Science Orbit

Recent Cassini discoveries have quickly thrust Enceladus into the science spotlight. Unfortunately, the low Enceladus mass and its proximity to Saturn lead to extreme instabilities when considering typical near polar science orbits. Here we find that the usual doubly averaged techniques are invalid for realistic Enceladus orbits. Further, it is shown that a dependence on the low order averaging assumptions leads to overly conservative conclusions regarding stability boundaries. Instead, we rely on the results of global searches for periodic orbits in the unaveraged model and demonstrate long term stable orbits with altitudes near 200 km and inclinations approaching 65 degrees. Prior studies imply the maximum stable inclination is near 45 degrees.