The radiation belts around Earth are loaded with dangerous protons and electrons that can damage spacecraft. Now researchers are launching experiments to see if they can clear away the high-energy particles that pose the hazard by blasting them with radio waves.When humans began exploring space, the first major find was the Van Allen radiation belts, doughnut-shaped zones of magnetically trapped, highly energetic charged particles. The Van Allen belts consist mainly of two rings: The inner belt starts roughly 1000 kilometers above Earth’s surface and extends up to 9600 km, while the outer belt stretches from about 13 500 to 58...