SpaceX launched what has been a top secret mission just before dusk on Sunday, not releasing the contents of its payload and changing its original mission name.

Updates from the SpaceX launch of the Optus-X mission, which launched late Sunday from Kennedy Space Center Pad 39A.

While neither company has released details, an advisory by the Federal Aviation Administration (FAA) shows that the Optus-X satellite is set to liftoff atop a Falcon 9 during a window open from from 4:29-6:57 p.m. EST. The launch will be from Cape Canaveral Space Launch Complex 40, and travel on a due-east trajectory.