Near Force-Free Space Elevator by Magnetic Inflation

The mass of a planetary-scale high-temperature superconducting ring (HTS ring) scales approximately as the supercurrent: M.ring ~ I.ring. However, the radial-lift force scales approximately as the square of the current: F.lift ~ (I.ring)^2. As current increases, a point is reached in which the weight of the ring is exceeded by the radial magnetic lift force, and the ring begins to rise into orbit. Notionally, the HTS ring lies as a loop of folds, akin to an empty, loosely-laid firehose. As current is pumped into the HTS ring, the Lorentz self-force (magnetic tension) pushes the folds of the current-ring apart. As the current increases, so too does the lifting force until F.lift ≳ F.gravity. The unanchored portion of the ring rises, and the folds straighten. As the ring rises, gravity weakens, and the lift-current can be decreased. As the ring reaches low orbit, or areostationary orbit, or beyond, the lift force and centrifugal force balance the gravitational force. For situations where moons (such as Phobos and Deimos) would periodically obstruct the elevator, notionally, control moment gyros (CMGs) could be placed along the ring to cyclically store and release magnetic energy from the elevator ring, thus allowing for a gentle deflation and inflation of the ring so as to avoid collision with orbiting bodies. Notionally, such rings not only provide a transportation system from the surface to and from areostationary orbit, but, secondly, it can also propulsively detach space vessels located on the ring portion that extends further than areostationary orbit. Thirdly, such superconducting rings generate a global magnetic field that can instantiate an artificial magnetopause (MP) for protecting nascent atmospheres (such as at Mars) and to mitigate cosmic radiation (such as at Luna, other moons, space stations, and Mars). Fourthly, such an elevator-ring could connect Pluto and its moon Charon as Charon’s orbit is effectively circular and areostationary, and Charon is tidally locked to Pluto.