Video: Alice Bowman, New Horizons mission operations manager, previews Ultima Thule flyby (members only)

A SpaceX Falcon 9 rocket sporting human-rating upgrades such as new composite pressurant tanks briefly ignited its nine Merlin engines Thursday afternoon on a launch pad at NASA’s Kennedy Space Center in Florida, and SpaceX later declared the pre-launch milestone complete in preparation for a critical test flight with a commercial crew capsule as soon as late February.

The chief executive of Axiom Space says agreements with NASA, SpaceX, and fare-paying passengers should be finalized in the coming weeks for the launch of the first all-private crew to the International Space Station in October 2021, and former NASA astronaut Michael Lopez-Alegria is set to command the mission.

A United Launch Alliance Atlas 5 rocket emerged from its vertical hangar Tuesday for the 1,800-foot journey to pad 41 at Cape Canaveral Air Force Station, moving into position for liftoff Thursday with NASA’s Mars 2020 Perseverance rover.