Doctoral Research

Spacecraft as Reconfigurable Kinematic Mechanisms

Magnetic fields pinned to superconductors only experience pinning forces in directions associated with a gradient in that field. For example, the cylindrical permanent magnet in the photo at left has a cylindrically symmetric field, so it is free to rotate about its axis. The intuition here is that spinning the magnet does not change the magnetic field distribution inside the superconductor. For spacecraft interfaces, we probably want flux pinning to act in all six rigid-body degrees of freedom, but the freedom to move a pinned superconductor along a symmetry in the magnetic field is something that we think we could take advantage of to produce flux-pinned joints.

Flux-pinned joints

On left, a cylidrically symmetric field with one degree of freedom; at right, an asymmetric field with stiffness in all six rigid-body degrees of freedom.

In fact, we could arrange for many kinds of magnetic field symmetry - rotational and translational. We could also use electromagnets to turn introduce or break selected symmetries. A spacecraft consisting of flux-pinned modules could then use these "toggle-able" symmetries to reconfigure itself. Such a spacecraft might be able to take advantage of ambient forces in the space environment to drive the reconfiguration. It would control the reconfiguration process by altering the kinematic degrees of freedom in its joints.

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