The problem: An autonomous ship starts at the outskirts of a solar system, and wants to move to a moving target, which is one of the planets. There are also many other planets moving at the same time, and these should be considered the only obstacles. I want to find the optimal path to the target. To keep it simple, the world is 2D, and the planets are moving in uniform circular motion around the sun as opposed to how planets actually behave. Also, assume the ship knows pretty much everything about the world. Most importantly, the location, speed, and orbit radius of every planet.
With complete knowledge, this seems conceptually simple. For any planet and any time, you can find its location by doing some fairly simple math. But how would you apply this to pathfinding? Would it be just to pathfind in 3 dimensions: x, y, and t? In theory this makes sense, but I think working that out to an actual solution would involve a lot of complications. Is it really as simple as 'setup a* on a grid with x,y,t values'?