A SpaceX capsule carrying four private citizens splashed down off the coast of Florida before dawn 3:36 a.m. ET on Sunday morning, ending a historic mission that included the world’s first all-civilian spacewalk. A SpaceX capsule carrying four private citizens splashed down off the coast of Florida before dawn 3:36 a.m. ET on Sunday morning, ending a historic mission that included the world’s first all-civilian spacewalk. NBC News Science