This is a long-shot question:
- User Experience SE users can draw Balsamiq mockups in their questions and answers.
- Electrical Engineering SE users can draw schematics.
- Maths and physics sites can use MathJax (I suppose it's the easiest thing to do since MathJax is free) - already covered here (Writing equations (Mathjax and alternatives)).
I wonder if Space Exploration SE could provide its users with the ability to edit/draw orbits within posts.
Note: Cesium works:
There is an implementation of SGP4 algorithm to be used with Cesium: https://github.com/koansys/isat
Old ideas transferred from a comment:
The first implementation idea that I have right now revolves around letting the user experiment with setting parameters for a simple (cough) D3 graph of the Earth and a single sat around it.