Space storms—squalls of high-speed electrons unleashed by giant eruptions on the sun—threaten our growing fleet of GPS, communications, and imaging satellites. But electrical engineer Umran Inan of Stanford University says he has figured out how to control the weather in space and keep our technology safe.
Solar electrons cause trouble when they collide with Earth's magnetic field and get trapped in the magnetosphere, a vast envelope of charged particles surrounding our planet. These bottled-up electrons can disrupt, degrade, or even destroy the sensitive electrical equipment inside a satellite. Inan became intrigued by a natural process that can clear out the magnetosphere: Bursts of lightning generate low-frequency radio waves that drive the electrons toward Earth's poles, where they escape harmlessly into the atmosphere. He determined to find a way to do the same thing deliberately.
Pages of calculations later, Inan determined that an orbiting transmitter emitting just 13 watts of low-frequency radio power could mimic the effects of lighting and cut the damage to satellite components within its vicinity by half. A fleet of 10 such transmitters could safeguard most satellites in low-Earth orbit. "This type of system is going to become an absolute necessity," Inan says. "A series of really severe storms or a nuclear detonation could effectively wipe out our communications system."
