Three astronauts and one cosmonaut have returned to Earth after nearly eight months on the International Space Station (ISS), which was extended by Boeing's capsule trouble and Hurricane Milton.

A SpaceX capsule carrying the crew parachuted into the Gulf of Mexico off the coast of Florida before dawn on Friday, local time, after undocking from the ISS earlier in the week.

The three Americans and one Russian on board should have returned two months ago, but their voyage was stalled by safety concerns linked to Boeing's new Starliner astronaut capsule.

The plans were then delayed further when Hurricane Milton made landfall in Florida earlier this month, followed by another two weeks of high wind and rough seas.

SpaceX launched the four crew — NASA's Matthew Dominick, Michael Barratt and Jeanette Epps, and Russia's Alexander Grebenkin — into orbit in March. 

Mr Barratt, who was the only space veteran going into the mission, said support teams on Earth had "to replan, retool and kind of redo everything right along with us … And helped us to roll with all those punches".

The astronauts' replacements are the two Starliner test pilots, Butch Wilmore and Suni Williams, whose own mission was extended from eight days to eight months, and two other astronauts launched by SpaceX four weeks ago.

Mr Wilmore and Ms Williams were not able to join the SpaceX capsule destined for Earth because they were not assigned to the spacecraft, according to a CNN report.

The pair are expected to return to Earth aboard SpaceX's next mission spacecraft. 

That will mean the four astronauts still on the ISS will remain in space until February 2025.

ABC/wires