Wow that roughing pass tool path looks really busy, lots of red move lines all over the place.
I don’t know why it would cut down the just the sun like that…
So these are multiple STL files you combined into a singe one for import?
My guess is that there is some kind of flaw or artifact in the merged STL file that is choking VCarve?
Lots of home made stl files that I get from sties like thingverse are screwed up in some way. Open holes, inverted faces (inside out), etc. For the most part VCarve ignores these errors or automatically corrects them on import.
I would try opening the stl file in a error checking app and see if there are problems. (there may be something up with the original sun file)
I use NetFabb Basic (free) to do this. There is a web based version you can try:
https://service.netfabb.com/
FYI: One trick I use to try to keep some of tool moves to a minimum on 3D carves is to create a custom outline. I have found that if you trace a 3d object, the offset that path you have a larger curve you can manually smooth out. So that it will do the whole object in a single continuous path.
(I will try to make up some example pics to illustrate this better)