In my book there are occasional battles between space ships or fleets which can span hours due to the distances involved. Most of the combat is done using missiles which can accelerate at e.g. 750g with enough fuel for 30 minutes, which means they have a range of about 40 lightseconds. Ships move with 200g and are pretty much constantly accelerating in various directions to change their momentum.
This becomes fairly complicated over time, because I have to keep the momentum of all ships and missiles in mind when calculating things like time to impact, distances and all of that. I'm currently doing all the calculations manually, which is extremely tedious and time consuming, not to mention error prone.
I've tried to find a tool where I can say "Ship A is at X,Y,Z and is accelerating at A gravities. Here is Ship B. Now step through it second by second, occasionally changing the vectors or adding new objects (missiles)." I have yet to find a tool like that and if I program it myself, I don't have time to write the book.
Does anyone know a tool (free or not) I can use to simulate my space combat?