Spacebus 4000B2

SpaceX’s launch team loaded liquid propellants into the company’s first upgraded Falcon 9 Block 5 rocket Friday at the Kennedy Space Center in Florida, and the countdown rehearsal culminated in a brief ignition of the launcher’s nine Merlin main engines on the launch pad.

SpaceX’s first Falcon 9 Block 5 rocket, sporting changes to make the booster easier to reuse, rolled out of its hangar and up the ramp to launch pad 39A at NASA’s Kennedy Space Center on Thursday ahead of a planned hold-down engine firing.