SpaceX's Crew Dragon capsule, carrying four private citizens, plunged through Earth's atmosphere Saturday night and splashed down off Florida's east coast, completing the company's first all-civilian mission in space. The Inspiration4 crew, which included billionaire mission funder Jared Isaacman, geoscientist Sian Proctor, physician assistant Haley Arceneaux, and data engineer Chris Sembroski, became the first to spend time in Earth orbit without any professionally trained astronauts.