Nice! Reminds me of this amazing (for the time) book which taught me a ton about the topic when I was in my first year at uni learning c++ https://books.google.at/books/about/Flights_of_Fantasy.html?...
This will go nicely with "Methods of Orbit Determination for the Micro Computer" (1991) which published by AFIT and has some incredibly useful simulation content...with examples in BASIC