WASHINGTON  - Nasa launched two satellites into space to explore the belts of radioactive particles orbiting the Earth, in a mission that is the first of its kind. The twin spacecraft will spend the next two-yr exploring the so-called Van Allen belt that is filled with highly-charged particles and at times poses a danger to communications, GPS satellites and even human spaceflight. “Scientists will learn in unprecedented detail how the radiation belts are populated with charged particles, what causes them to change and how these processes affect the upper reaches of the atmosphere around Earth,” said John Grunsfeld, a Nasa’s Science Mission Directorate official.

 associate administrator for . “The information collected from these probes will benefit the public by allowing us to better protect our satellites and understand how space weather affects communications and technology on Earth.” The satellites - buttressed with protective plating - blasted into orbit from Cape Canaveral Air Force Station in Florida aboard an Atlas V 401 rocket. Nasa’s latest mission comes just weeks after the space agency landed its $2.5 billion Mars Science Laboratory and Curiosity rover on the surface of the Red Planet, breaking new ground in US-led exploration of an alien world.