Four space tourists are back on Earth after orbiting over the north and south poles. Their SpaceX capsule splashed down in the Pacific off the Southern California coast on Friday. Bitcoin investor Chun Wang bought the 3 1/2-day flight for an undisclosed price. He invited along a Norwegian filmmaker, a German robotics researcher and an Australian polar guide. The four rocketed into a polar orbit earlier this week from NASA’s Kennedy Space Center in Florida. Their capsule was outfitted with a domed window that provided stunning 360-degree views of the poles.