A method and apparatus provides cube-shaped satellite primary structures, each comprised of six identical, or nearly identical, rectangular truss panels and internal struts. The struts, all adjustable in length, connect, and are directed between all cube opposite corners and all cube opposite panel centers. All struts meet at the cube center where they attach rigidly to either a block called the “nucleus fitting” or to a hollow sphere. Each strut attaches to either a ball-socket corner fitting located at the interior corner of the cube, or to a ball-socket panel center fitting located at the panel center interior to the cube.