Magnetic ropes can be tied in nuclear knots
The Insane Math Of Knot Theory at https://www.youtube.com/watch?v=8DBhTXM_Br4
Magnetic ropes can be tied in nuclear knots, not orbits but closed paths. One can make permanent fuels with no mass, and when you snip at pre-weakens links, it gives up the energy cleanly, leaving no matter at all. With careful planning a macroscopic rope can be made that can swing a starship from earth to orbit. Knots are not everything, but they are something. One reason I am trying to get all humans to share all knowledge is there are practically infinite many useful connections that fall out quickly when even a few thousand start working as one. Think what 8.2 Billion can be capable of, with lossless memory to help keep track of things.