Are you talking about trying to compute an optimal path, potentially containing an arbitrary number of thrusts in any direction?
Yes something like that. However I'm not sure there is a single optimal path. You could probably optimize for fuel consumption, speed or some combination of the two.
If you did it without thrusts, it seems like a problem more suited to global optimization techniques than graph algorithms.
I'm not sure what you mean. If you use no trusts you would end up where gravity wants to take you. Perhaps you meant an initial burn and then no thrusts after? However I'm guessing you would need to apply thrusters at the end to at least put you in orbit assuming you weren't using the atmosphere slow you down.
Could be fun though. The problem I find with games involving gravity like that is that they're too damn hard. It's nearly impossible to stop yourself crashing into a planet.
Yes that's kind of my motivation. Apollo 11 landing aside, in real life I'm sure computers are used for space navigation. I want to simplify it to where the player just tells the game where he wants to go, and maybe selects from a few possible routs, like a low fuel rout or fast route.