SpaceX's Falcon 9 rocket lifted off at 7:03 p.m. ET (2303 GMT) from NASA's Kennedy Space Center in Florida carrying four astronauts who will replace Wilmore and Williams, both of whom are veteran NASA astronauts and retired U.

SpaceX launched another batch of Starlink satellites into orbit, a little more than 12 hours after the private company teamed up with NASA to send four astronauts to the International Space Station -- also from Florida.