Superconductors could help spacecraft hover

The cold of space
The cold of space is enough to make the superconductors work--although for spacecraft inside the orbit of Mars, the superconductors will have to be shaded from direct sunlight in order to maintain their grip. With proper design, however, it should be possible to pull together and latch freestanding space modules without physical tethers, by rotating solar shades to provide solar heating and cooling that activates and controls the magnetic pinning functions.

Peck and his colleagues since 2005 have experimented with magnetic superconducting building blocks that self-assemble without physically touching. The initial funding for the Cornell project was under NASA's Institute for Advanced Concepts, where Peck first showed how rotational and translational degrees of freedom could be fixed with magnetic flux pinning.

"We can place them in close proximity and let the magnets do the rest, never actually having to physically touch each other and without requiring power to maintain their positions and orientations," said Peck.

To perform micro-positioning functions, Peck plans to include tiny electromagnets that can be turned on and off to exactly position two modules, after which all the electromagnets could be powered down to lock the assembly into place.

"We believe that flux pinning can be used to assemble spacecraft in a reliable, safe and permanent way, but without all the pitfalls associated with mechanical components," said Peck.

By funding Peck's work, NASA hopes to chuck traditional single-spacecraft architectures in favor of clusters of wirelessly interconnected spacecraft modules--each able to contribute a unique capability to the cluster. These interconnected modules would travel in a loose formation to create a virtual spacecraft capable of delivering more than the sum of its parts.

"The biggest advantage of our approach to building such distributed, modular spacecraft is that if you have a power failure, the spacecraft does not start falling apart--all the components would remain in their relative locations despite any loss of power," said Peck.

Peck's current test bed resembles an airair hockey table that simulates weightlessness for pint-size modules. But within six months, he pledges to have a new test bed that will be capable of testing (on Earth) satellite-size modules pinned into position using superconductors and magnets. He predicts that the first in-space test will be to hold together the components of a simple communications satellite that are launched piecemeal, then assembled with magnetic pinning.