LOS ANGELES, March 18 (Xinhua) -- NASA astronauts Suni Williams and Butch Wilmore, who had been stranded at the International Space Station (ISS) since last June, returned to Earth Tuesday afternoon.

The duo astronauts returned home with their fellow Crew-9 astronauts, NASA astronaut Nick Hague and Roscosmos cosmonaut Aleksandr Gorbunov, on SpaceX's Dragon spacecraft.

The spacecraft splashed down off Florida's coast at 5:57 p.m. Tuesday Eastern Time (2157 GMT), according to NASA live broadcast.

The crew undocked with the ISS early on Tuesday to start an about 17-hour journey home. The spacecraft completed multiple orbit-lowering maneuvers, and re-entered Earth's atmosphere before a parachute-supported splashdown off Florida's coast.

A recovery ship moved into position to hoist Dragon onto the main deck with the Crew-9 crew members inside, and teams on the ship secured Dragon to ensure the spacecraft's safe recovery.

After the hatch was opened, the four astronauts egressed the capsule one by one with the help of medical personnel. Medical teams will evaluate the crew's health, which is routine after astronauts return from space, according to NASA.

The crew splashed down one day earlier than NASA had targeted due to favorable conditions forecast for the evening of Tuesday, according to the space agency, which expressed concerns about weather conditions later in the week.

Williams and Wilmore had been stuck in space since last June due to technical problems of Boeing's Starliner which took them to the ISS, including helium leaks and propulsion issues. The duo astronauts were initially scheduled for an eight-day mission in space, but were stranded at the ISS for over nine months.

The Crew-9 astronauts returned home following the arrival of new mission Crew-10 astronauts at the ISS, including NASA astronauts Anne McClain and Nichole Ayers, Japan Aerospace Exploration Agency astronaut Takuya Onishi, and Roscosmos cosmonaut Kirill Peskov.

NASA said Crew-9 astronauts have completed more than 900 hours of research between more than 150 unique scientific experiments and technology demonstrations during their stay aboard the orbiting laboratory.