I've been doing some searches in google and on the boards and haven't been able to find anything. I have been able to find a lot of "random system generators" that'll give me stars, planets, and their relative distances and such, but I haven't been able to find any mapping tools that will give me a good 2D/3D map of those systems. It doesn't have to generate the maps randomly. In fact, I'd rather just be able to input planets sizes/types/distances and star info and generate the map that way. Bonus points for one that can be set up to move.
I tend to prefer "show don't tell" when I'm running, and it would be nice to have a map of the Pact Worlds or other systems to put up on the screen whenever we're playing (especially early on or entering a new system). The map in the book is nice, and some of the random generators have stuff that help with new system, but nothing I've found does a good job to show the scale or how those bodies move over time.
I have people I can work with to build what I'm looking for, but I'd rather not re-invent the wheel if there is anything out there I just haven't found yet.
Universe Sandbox might be what you're looking for. Among other things, you can create star systems.
I gave up on trying to recreate the Pact Worlds with it, but theoretically you could do that too.
It's pretty fun to play around with. You can change the stats of planets, you can see what our solar system would be like with a different star, etc.