SpaceX returned four astronauts from the International Space Station on Sunday, making the first US crew splashdown in darkness since the Apollo 8 moonshot. The Dragon capsule parachuted into the Gulf of Mexico off the coast of Panama City, Florida, just before 3 am, ending the second astronaut flight for Elon Musk s company. It was an express trip home, lasting just 6 1/2 hours. The astronauts, three American and one Japanese, flew back in the same capsule named Resilience in which they launched from NASA s Kennedy Space Center in November. Their 167-day mission is the longest for astronauts launching from the US The previous record of 84 days was set by NASA s final Skylab station crew in 1974.