Air Force ground controllers have activated service aboard the newest Global Positioning System satellite, achieving that milestone for the final spacecraft in a dozen built in a manufacturing batch to update the constellation.

The most powerful variants of the Atlas 5 and Delta 4 rockets have been purchased by the Air Force to launch intelligence-gathering spacecraft for the U.S. government, and NASA has bought an Atlas 5 to deploy a critical polar-orbiting weather satellite.

United Launch Alliance has selected Orbital ATK to provide solid rocket boosters for the company’s next-generation Vulcan launcher, and will switch the workhorse Atlas 5 to the new booster supplier by the end of 2018, officials said Tuesday.