Eddy-Current Actuation


As the pace of space exploration increases, spacecraft will need to complete more tasks that require physical interactions with resident space objects: inspection, on-orbit repair or repurposing, and docking, to name a few.

Eddy-current actuators could enable an inspection vehicle to maneuver near the ISS without fuel.

Eddy-current actuators could enable an inspection vehicle to maneuver near the ISS without fuel.

Force interaction between a spacecraft and any other object has always been inherently risky. At present, non-cooperative interactions – interactions not anticipated in the target’s design – require direct physical contact, either through linkages, wires, or simple grapplers. While these methods are effectual, they are risky: a grappler may apply excessive force and damage the target, or unanticipated dynamics of the target may result in a catastrophic collision. Actuators utilizing magnetic eddy currents offer a solution to this problem.

How does it work?

Maxwell’s equations show that a time-varying magnetic field will induce an electric current in a conductor. This induced current, known as an “eddy current”, experiences a force caused by the same magnetic field that generated it. Unlike magnetic attraction caused by static fields, eddy currents can be formed in any conductor, including the aluminum skin of most man-made objects in space. The idea of this project is to use these forces to create 6-DOF actuation forces.