By Steve Gorman (Reuters) -The first all-private team of astronauts ever launched to the International Space Station (ISS) were welcomed aboard the orbiting research platform on Saturday to begin a weeklong science mission hailed as a milestone in commercial spaceflight. Their arrival came about 21 hours after the four-man team representing Houston-based startup company Axiom Space Inc lifted off on Friday from NASA’s Kennedy Space Center, riding atop a SpaceX-launched Falcon 9 rocket. The Crew Dragon capsule lofted into orbit by the rocket docked with the ISS at about 8:30 a.m. EDT (1230 GMT)…