Hi Alexander!no, I did no further investigation about this issue...the strange fact is that the data I set for Pan contain a 0 degrees inclination for the orbit (orbit_Inclination=0.0), so I can't explain why the satellite doesn't orbit Saturn in a steady, fixed orbit along the equatorial plane.what you can see is that the orbit oscillates up and down in time as if it were inclined by a small amount of degrees. It sounds as the rings themselves oscillate as if they were inclined to the equatorial plane: this fact is really new to me, as I never heard about it. Rings should have an ascending node and an inclination to the equatorial plane. I can't explain such a strange behavior, without thinking about a small bug in the orbit algorithm... I wonder what should happen creating a completely new and fictitius object in the solar system with at least one satellite, with easy and convenient orbital parameters: once angain a 0 degrees inclination and other simple values. And also a synchronous orbit and rotation then after landing on the satellite it'd be interesting to see the movements of the planet and verify its steadiness in time...This is a common practice for programs as Celestia, but unfortunately this is not updated since a lot of time... what do you think about this "experiment" ? Pierluigi On Sunday, May 22, 2016 12:07 PM, Alexander Wolf