Improve Spatial prediction performance

[gwbres]

Spatial state prediction

Following the latest developments (#23 and #25), new features arise and offer forward and backwards prediction of the spatial state. But the current performance is very poor (around +/- 100km errors), most likely due to an invalid spacecraft model, but possibly other problems too.

To see the performance, run the following test. The testbench therefore does not verify the performance, it only verifies that we can deploy

cargo test --all-features -- --nocapture forward_spatial_prop

@ChristopherRabotin any suggestions what might be wrong ? the spacecraft model is designed in spacecraft_model_iter

[ChristopherRabotin]

I will be happy to take a look and see what the error source could be. 100 km is pretty large indeed. I'll post my findings here, along with a git patch when I have a better result.