The Radiation Belt Storm Probe mission (RBSP) will explore the Van Allen Radiation Belts in the Earth's magnetosphere. The charge particles in these regions can be hazardous to both spacecraft and astronauts. Project Scientist David Sibeck explains the how the mission will explore space weather -- changes in Earth's space environment caused by the sun -- that can disable satellites, create power grid failures and disrupt GPS service. The mission also will allow researchers to understand fundamental radiation and particle acceleration processes throughout the universe.The 2-year mission is scheduled to launch no earlier than 4:08 a.m. Thursday, Aug. 23 from Cape Canaveral Air Force Station in Florida. The twin probes will lift off on a United Launch Alliance Atlas V rocket.