toy Common LISP orbit simulator
Probably it's not a very good N-Body simulation, but at least the planets are no longer typically going off to infinity like they were in earlier instances of the code. Many Bothans, etc.
There's a surprising amount of, uh, estimation going on. I mean you calculate the expected orbit velocity for a circle and the transfer ellipse, dutifully apply the necessary thrust, and... the satellite never gets there. Almost. So then you fudge the numbers a bit, maybe put in a "let me know if it gets out this far?" check and then fudge some more. And that's just a 2-body system!
Meanwhile, the pros:
https://www.quantamagazine.org/new-math-shows-when-solar-systems-become-unstable-20230516/
New math!