Beginning its fourth launch campaign of the year, the Atlas 5 rocket program has started stacking the vehicle that will boost a satellite 11,000 miles high for the Global Positioning System.

The bronze first stage of United Launch Alliance’s next Atlas 5 rocket arrived at its Cape Canaveral launch pad Friday, where it will be joined by five solid-fueled boosters, a Centaur upper stage and a U.S. Air Force communications satellite in the coming weeks ahead of liftoff set for June 27.

A Boeing-built communications satellite lifted off at 7:21 p.m. EDT (2321 GMT) Monday on top of a SpaceX Falcon 9 rocket from NASA’s Kennedy Space Center in Florida. The spacecraft will add to Inmarsat’s Global Xpress network linking airplanes, ships and other mobile terminals with broadband Internet and data services.