The engines ignite under the United Launch Alliance Atlas V rocket at 4:05 a.m. EDT lifting NASA's Radiation Belt Storm Probes, or RBSP, off Space Launch Complex 41 on Cape Canaveral Air Force Station in Florida.
RBSP will explore changes in Earth's space environment caused by the sun -- known as "space weather" -- that can disable satellites, create power-grid failures and disrupt GPS service. The mission also will provide data on the fundamental radiation and particle acceleration processes throughout the universe. For more information on RBSP, visit http://www.nasa.gov/rbsp. Photo credit: NASA/Rusty Backer