NASA astronauts Suni Williams and Butch Wilmore have departed from the International Space Station (ISS) after an extended stay of nine months.Williams and Wilmore were originally scheduled for an eight-day stay but were stuck on the ISS due to technical problems with their return spacecraft.They left the ISS inside a SpaceX Crew Dragon spacecraft and are expected to splash down off the coast of Florida later today.During their extended stay, the astronauts contributed to scientific research and expressed their unique perspective on living in space.