Liftoff marks the 50th Evolved Expendable Launch Vehicle mission
A United Launch Alliance Atlas V rocket blasts off from Cape Canaveral Air Force Station, Fla., June 20, 2012, with a national security payload for the National Reconnaissance Office. This is the 61st launch for ULA and marks the 50th successful launch of an Atlas V and Delta IV Evolved Expendable Launch Vehicle. (United Launch Alliance photo/Pat Corkery)