A classified satellite for the US National Reconnaissance Office was launched on Saturday aboard a United Launch Alliance Delta 4 Heavy rocket.
The NROL-91 spy satellite lifted off at 3:25 p.m. from Vandenberg Space Force Base in Santa Barbara County, California.
It was the last launch of a Delta 4 from the west coast. Additional launches are planned from Florida before the Deltas are replaced by ULA’s next-generation Vulcan Centaur rockets.
The Delta IV Heavy configuration was first launched in December 2004. It was the 387th flight of a Delta rocket since 1960 and the 95th and final launch from Vandenberg.
The National Reconnaissance Office is the government agency responsible for developing, building, launching and maintaining US spy satellites that provide intelligence data to policy makers, the intelligence community and the Department of Defense.