Ingame prefab saving and manipulation

so, i am working a a planet builder thing and i want to save the created object to reuse it later by adding it to an GameObject[] so i can spawn it when necessary .in my script, i have a Object variable (var object : GameObject;...)wich is created using primitives, how could i save it as a prefab(in the project view in a spceific folder)through JavaScript?

Then, how do i add objects to, for example, GameObject[] through JS ? thank you in advance. :)