United Launch Alliance have successfully launched an Atlas V rocket in it's heaviest configuration, the 551. The rocket lifted off at 04:15 UTC, October 17th 2018 from Space Launch Complex 41, Cape Canaveral in Florida placing the AEHF-4 satellite in orbit for the US Air Force.
This was the 79th Atlas V rocket launch and the 4th Advanced Extremely High Frequency satellite to be launched.