Paper: https://www.sciencedirect.com/science/article/pii/S0019103523001410 Eqs. 58–60 Should connect to: https://github.com/FormingWorlds/PROTEUS/blob/8eccd9782f318565013b1a579e26252249831f1b/src/proteus/orbit/wrapper.py#L140 Create new file in `/orbit` module to define orbital dynamics functions