NASA astronauts Butch Wilmore (L) and Suni Williams are seen before boarding Boeing's Starliner spacecraft at Cape Canaveral Space Force Station in Florida, the United States, June 5, 2024. (Joel Kowsky/NASA/Handout via Xinhua)

NASA astronauts Suni Williams and Butch Wilmore, who have been stranded at the International Space Station (ISS) since last June, started journey back to Earth aboard SpaceX's Dragon spacecraft early Tuesday.