What may be a first-of-its-kind U.S. spy satellite lifted off atop an Atlas V rocket from Cape Canaveral Air Force Station.
[PHOTOS: Atlas V rocket set to launch from Cape]
The launch came after a more than two-week delay because of damage to an Air Force tracking radar, which is needed to ensure public safety during the flight.
It will be the second Atlas V from the Cape this year and ULA's 81st launch overall.
"I am proud of the persistence and focus of the launch team, the wing, NRO, ULA and other mission partners, to make this launch happen," said Brig. Gen. Nina Armango, 45th Space Wing commander. "Our entire team worked together flawlessly once again to ensure mission success."
The NRO also does not discuss what it is launching.