At 6:13 a.m., the NROL-85 satellite took off from Vandenberg Space Force Base on a SpaceX Falcon 9 rocket.
Vandenberg stated in a statement that it was the first time the NRO had reused a SpaceX rocket booster.
The Falcon's initial stage flew back to the seaside base northwest Los Angeles.
NRO described the NROL 85 satellite as a "critical national safety payload."
It was one of three launches that SpaceX awarded to the Air Force in 2019 at a fixed price of $297 millions.
The NRO is the government agency responsible for developing, building and launching U.S. satellites. These satellites provide intelligence data to senior policymakers, intelligence community, and the Defense Department.