After trying some stuff and looking at the source code of mods (especially this one : https://github.com/JPLRepo/TarsierSpaceTechnology ) I managed to get it somewhat working. It seems to work if you set the parent of the GameObject to one of the (scaled version) bodies GameObjects. obj = GameObject.CreatePrimitive(PrimitiveType.Sphere); obj.layer = 10; float scale = 2f*(float)bodiesByName["Kerbin"].Radius / ScaledSpace.ScaleFactor; obj.transform.localScale = scale * Vector3.one; obj.transfor