Feature/thrust guide

[gaffarelj]

This is the first version of the thrust guide, which can probably be already useful to P&O students as-is.

The more complex part of the guide on how to use rotational dynamics to define the thrust orientation, and how to use the thrust orientation from aerodynamic guidance, is still to be added later on.

[DominicDirkx]

Nice work on the guide Jeremie! I've made a bunch of small modifications, but overall I think we can push this soon. A few points:

• A Python user is typically not exposed to the settings classes, and I replaced this with links/references to the settings factory functions. This is how we're also approached this in other parts of the guide
• I like the idea of putting notes inside the code blocks, this makes it much more flexible for future C++ extensions
• I'm not sure the combined aero/thrust part at the end is right (which say something about the design....). If you use thrust_direction_from_state_guidance, the body inertial orientation gets defined, as the thrust direction in a body-fixed frame is defined by the thrust magnitude settings. If you subsequently define the angle of attack through aerodynamic guidance, I think this will override the original orientation. I propose that we leave this part out for now until we can discuss this in more detail. The rest of the guide can be merged as far as I'm concerned. Well done!

[gaffarelj]

Thank you for your review, and for your improvements.

Concerning the aero/thrust part and example: I have tested this scenario with my (in progress) rocket ascent code. From what I could see, the aerodynamic angles and thrust orientation are kept separate. Changing the angle of attack from a sine wave to constant values of 0 and -45deg induced changes in the aerodynamic acceleration, but kept the trajectory more or less the same. I conclude from this that the thrust orientation was not impacted and that both of the orientations were kept separate.

But if you wish, I could still remove this part and wait that things get more confusion-free regarding orientations.

[DominicDirkx]

Since I'm not quite sure why/how this works the way it does, I think it's best that we remove it for now. This type of mess is also a clear reason why we should refactor the whole orientation part :)

[gaffarelj]

Perfect, I commented this part out, and just merged this pull request. The thrust guide is now available on tudat-space here.

@FilippoOggionni as we discussed on Slack, feel free to send me comments on this guide if you wish.

[gaffarelj]

Thanks a lot for the comments and commits you made to this guide @FilippoOggionni! I have overall incorporated all of your comments from above, I have removed all of the smaller code snippets (I kept the more important ones), and I have added these to the API docs (still to be built later on).

[FilippoOggionni]

No worries, it looks great! Awesome job 🚀

[DominicDirkx]

Awesome, thanks!