Two NASA astronauts are due to return to Earth with a rare splashdown off Florida, the first splashdown for 45 years.
Bob Behnken and Doug Hurley left the International Space Station in the early hours of this morning for the final and most important part of their SpaceX test flight on the Crew Dragon.
They are aiming to land their capsule by parachute in the Gulf of Mexico near Pensacola in west Florida.
NASA has forecast favourable weather for their arrival despite the approach of Hurricane Isaias, which weakened to a tropical storm on Saturday, but was expected to regain hurricane strength when it hit the state.
Flight controllers will be watching the storm closely after it caused flooding and landslides on Thursday in the Dominican Republic and Puerto Rico.
Separation confirmed. Dragon performing 4 departure burns to move away from the @Space_Station pic.twitter.com/ea14fozdO8
— SpaceX (@SpaceX) August 1, 2020
Mr Hurley and Mr Behnken launched from the Kennedy Space Center on May 30th, making Elon Musk's SpaceX the first private company to send people into orbit.
It was also NASA's first crewed mission from home soil in nine years.
Space station commander Chris Cassidy, who will remain on board with two Russians until October, said: "We're a little sad to see them go."
The next SpaceX flight is at the end of September, while rival Boeing is expected to launch its first crew next year.
Since 2011, the US had previously relied on Russian rockets to get astronauts to the space station.
Reporting by IRN
