Protecting hundreds of low-Earth-orbit satellites from destruction seems a laudable idea, and the US Pentagon wants to do just that. But the scheme could backfire, by shutting down civilian and military communications and impairing Global Positioning System signals.

The Pentagon is concerned that a high-altitude nuclear explosion or an intense solar storm could fill near-Earth space with charged particles, crippling the operation of many satellites. It has proposed a plan called “radiation belt remediation” to clean it up.

The idea is to orbit satellites that would direct very low frequency radio waves at 20 kilohertz into areas filled with charged particles. That would create wave-particle interactions that encourage particles to precipitate and fall into the upper atmosphere, where they would do little damage to other satellites in low-Earth orbit.

However, a study by Craig Rodger at the University of Otago in New Zealand, and colleagues, has revealed this could affect the electrical properties of the part of the upper atmosphere called the ionosphere, which in turn could severely disrupt radio and GPS transmissions.

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Hecht, Jeff. "Pentagon's satellite-saving plan could backfire." New Scientist. August 15, 2006.