Ground crews finished the initial build-up of the last “single stick” medium-lift variant of United Launch Alliance’s Delta 4 rocket on its launch pad at Cape Canaveral last week in preparation for liftoff with a GPS navigation satellite July 25.

As the internal investigation continues into the first stage performance trouble on the last Atlas 5 rocket launch, the next mission on the manifest has slipped to May 27.

The last flight of the single-core variant of United Launch Alliance’s Delta 4 rocket lifted off at 9:06 a.m. EDT (1306 GMT) Thursday from Cape Canaveral Air Force Station, Florida. The 207-foot-tall launcher carried a GPS navigation satellite into orbit for the U.S. Air Force.