Live coverage: SpaceX supply ship returns to Earth

Passing a major pre-flight milestone ahead of a launch and landing planned early Sunday, a SpaceX Falcon 9 rocket ignited its main engines Wednesday for a hold-down firing at Cape Canaveral.

The Falcon Heavy rocket was lowered to the horizontal position before sunrise Friday morning after less than a day standing at the launch pad.

SpaceX’s first Crew Dragon spacecraft, a capsule designed to eventually carry astronauts on treks to the International Space Station, has arrived at Cape Canaveral to begin preparations for launch on an unpiloted test flight later this year.