Officials at NASA announce that the two identical Radiation Belt Storm Probes (RBSP) were successfully launched into orbit today, August 30, from the Eastern Range of the Cape Canaveral Air Force Station (CCAFS), in Florida.
The robotic spacecraft were launched aboard a United launch Alliance (ULA) Atlas V delivery system, with a Centaur upper stage. Takeoff occurred at 4:05 am EDT (0805 GMT), at the very beginning of today's 20-minute launch window.
At the time of writing, 1 hour and 30 minutes of the mission had elapsed. Later today, the Centaurus stage will carry out a series of maneuvers meant to take it in the position required to launch the vehicles.
RBSP will fly in formation above the planet, and investigate the mysterious Van Allen radiation belts. The mission is expected to boost our understanding of space weather, and the factors that control it.