(AP) NASA has launched twin satellites to study Earth's radiation belts.
An unmanned rocket blasted off early Thursday from Cape Canaveral, carrying the Radiation Belt Storm Probes. It's the first time two spacecraft will orbit in tandem amid the harsh, hazardous radiation belts of Earth. The extra tough satellites are designed to withstand an onslaught of cosmic rays over the next two years.
Scientists expect the $686 million mission to shed light on how the sun affects the Van Allen radiation belts. The goal is to improve space weather forecasting. Solar storms can cripple satellites, endanger astronauts in orbit and disrupt communications on the ground.
It took three tries for NASA to launch the spacecraft.