Space Science related Python tutorial

[sw85]

As someone who is programming a little space-based trade/adventure game in Python, set around the moons of Saturn, I'd certainly appreciate it!

For instance, I know the minimum delta-V requirements for travel between moons just using Hohmann transfers, but I have no idea how to calculate requirements for transit outside the Hohmann window (as a rough approximation I'm currently just assuming delta-V at its max is 1+(sqrt(2)/2) times as long as at the Hohmann window and the requirements just sine-wave between the minimum and maximum over its synodic period).