Control Strategies Utilizing the Physics of Flux-Pinned Interfaces for Spacecraft

Abstract

Flux-Pinned Interfaces are a developing technology for spacecraft that exploit flux pinning, a phenomenon in superconducting physics, to manipulate the dynamics between two spacecraft modules. Flux pinning occurs in certain types of superconductors which, when cooled below their critical temperature, will resist changes to the distribution of magnetic flux that was present during the temperature transition. The resulting physics passively “pins” a magnetic field source in a six-degree-of-freedom equilibrium relative to the superconductor. By placing a magnetic array on one spacecraft module and a superconductor with this capability on another, it is possible to exploit these passive physics to augment technologies for close-proximity spacecraft operations such as rendezvous, docking, and formation flying. This paper investigates the use of the nonlinearities and specific physics in the flux pinning connection to develop efficient control strategies that will allow spacecraft operators to alter the equilibrium of a flux-pinned space system. Specifically, the dynamic model for flux-pinned spacecraft is presented, a set of design principles for actuators are examined with simulation plots to demonstrate the system response to various stimuli, and two potential control strategies are presented. The paper concludes with an assessment of the actuation strategies and potential advantages and disadvantages that each has to offer in the context of actual spacecraft operations.