Orbital navigation is mainly done by transferring from one orbit to another, contrary to how we drive on Earth, where we simply accelerate and turn the wheel into the direction we want to go.
Because of the target-audience, everything is very simplified. The goal is to intersect a randomly placed satellite without running out of fuel. The height of the satellite is unknown, and to match position, the student must understand how you overtake an object even if you are in the correct orbit yourself.
If you are interested in how to simulate newtonian gravity, have a look at this page (in danish).
See also my real-time satellite tracker and the planetarium on the front page.