It's actually extraordinarily difficult to get a DNN model to accurately predict planetary motion over arbitrary time horizons. RNNs have a tendency to either decay or blow-up.
The only way I know to make neural nets work well for this problem is to build in lots of physics into the model architecture, e.g., conservation of energy:
https://arxiv.org/abs/1906.01563
The only way I know to make neural nets work well for this problem is to build in lots of physics into the model architecture, e.g., conservation of energy: https://arxiv.org/abs/1906.01563