Live coverage: SpaceX finally launches Falcon 9 rocket

A Falcon 9 rocket is again standing upright on launch pad 39A at NASA’s Kennedy Space Center in Florida after ground teams lowered the booster Friday to swap out mice heading to the International Space Station for medical experiments.

The Falcon Heavy is lifted upright at launch pad 39A at the Kennedy Space Center on April 10, 2019, in this time-lapse video.

SpaceX is counting down to liftoff Saturday of a Falcon 9 rocket with a commercial cargo craft heading for the International Space Station after engineers replaced a component in an upper stage steering system that grounded the launcher Tuesday.