Idea for a 3D piece/installation

I began to think a bit more about making something experiential, like a sculpture to represent the solar system as mentioned in the last post, but I'm realising that time is running out and I've never built anything before, so to attempting to build something at this stage is not very smart. I'll have to abandon the idea. These were a couple of the sketches I made for this idea though:

The bottom image shows an installation that would require an insane amount of space in order to make accurately. Not very feasible.