If scientists gets their way, the first line of defense Earth will have against dangerous space storms will be dust. No, that's not a weird threat to destroy something; he wants to use dust-sized spacecraft to keep us safe.
The miniature spacecraft measure 1 centimeter-square, and weigh less 7.5 milligrams. They were designed by Mason Peck and Justin Atchison of Cornell University in New York, and modeled after dust particles that surround the sun; Peck and Atchison imagine that a "swarm" of the Smart Dust craft could monitor solar winds without affecting them in orbit around the sun. The first prototypes will be launched later this year.
Smart dust could give early warning of space storms [New Scientist]