Live coverage: Falcon 9 disintegrates after launch

A United Launch Alliance Atlas 5 rocket blasted off at 6:18 a.m. EDT (1018 GMT).to deploy the Navy’s fourth MUOS satellite that will expand coverage to encompass the globe with mobile communications.

Orbital ATK’s Antares rocket will deliver the commercial Cygnus supply ship to an orbit with an altitude between 117 miles (189 kilometers) and 184 miles (296 kilometers) within about nine minutes of liftoff Saturday from Virginia’s Eastern Shore.

SpaceX’s first Falcon Heavy rocket was loaded with propellants Saturday at Kennedy Space Center’s launch pad 39A, as engineers make progress preparing for a hold-down engine firing, and eventually liftoff of the huge commercial launcher.