WASHINGTON, April 4 (Reuters) – A team of four private astronauts safely returned to Earth on Friday inside a SpaceX Crew Dragon capsule, concluding an approximately four-day journey in space that followed a groundbreaking polar route—an unprecedented mission for a fully private team organized by Elon Musk’s aerospace company. The crew launched Monday night from Florida and spent their time orbiting Earth from pole to pole, a unique flight path that brought them over polar ice approximately