This software is free to use for educational purposes.
This software effectively solves the 4-body problem in Earth-Centered-Inertial (ECI) coordinates to determine satellite orbits with Earth, lunar, and solar gravity included.
Since lunar orbit perturbations due to the Sun are included, as well as Earth bulge perturbations, we believe that it can also be used for both Earth-centric space mission and lunar orbit space mission design. However, it has not yet been certified for operational use.




















