Newly developed magnetic devices are used to create an interface between adjacent mirror segments so that once assembled, aligned, and phased, the multiple segments will behave functionally equivalent to a monolithic aperture mirror. One embodiment might be a kinematic interface that is reversible so that any number of segments can be pre-assembled, aligned, and phased to facilitate fabrication operations, and then disassembled and reassembled, aligned, and phased in space for operation.

The interface mechanism has sufficient stiffness, force, and stability to maintain phasing. The key to producing an interface is the correlated magnetic surface. While conventional magnets are only constrained in one direction — the direction defined by their point of contact (they are in contact and cannot get any closer) — correlated magnets can be designed to have constraints in multiple degrees of freedom. Additionally, correlated magnetic surfaces can be designed to have a limited range of action.

Finally, via the use of electromagnets, the rate of closure or separation of correlated magnetic surfaces can be controlled. Once the interface is established, mechanisms will adjust the segment alignment relative to each other to establish phasing. Once phasing is established, the correlated magnetic surfaces have sufficient axial and lateral force to maintain that alignment in the microgravity environment of space. Additionally, beyond providing a hard interface, the axial and lateral force (spring constants) of the correlated magnetic surfaces can be designed to provide a very stiff or very soft interface. The net effect is similar to a kinematic mechanical flexure system, a tuned dampener, or shock absorber.

This work was done by H. Stahl of Marshall Space Flight Center. For more information, contact Sammy Nabors, MSFC Commercialization Assistance Lead, at This email address is being protected from spambots. You need JavaScript enabled to view it.. MFS-32917-1

NASA Tech Briefs Magazine

This article first appeared in the February, 2012 issue of NASA Tech Briefs Magazine.

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