WASHINGTON: The astronauts on the historic private space mission Polaris Dawn splashed down near the southern tip of Florida early Sunday, after a five-day voyage that included the world’s first-ever commercial spacewalk, reported German news agency (dpa).

The SpaceX Crew Dragon capsule carrying the four astronauts touched down in the Gulf of Mexico at around 3.30 am (0730 GMT), mission controllers said.

Billionaire tech entrepreneur Jared Isaacman led the chartered flight, in coordination with SpaceX founder Elon Musk, who remained on the ground.

Isaacman, along with private astronauts Scott “Kidd” Poteet, Sarah Gillis and Anna Menon, lifted off aboard a Crew Dragon spacecraft with a Falcon 9 rocket from Cape Canaveral in Florida on Tuesday.

The Crew Dragon ascended to an altitude of about 1,400 kilometres – higher than any other crewed flight since the Apollo moon missions of the early 1970s and more than three times the altitude of the International Space Station.

The riskiest part of the endeavour followed on Thursday, when Isaacman, followed by Gillis, performed the world’s first commercial spacewalks.

The amateur astronauts did not float freely in space during the walk, which lasted about 20 minutes for both Isaacman and Gillis. They remained holding onto a specialised ladder leading out of the capsule.

As the Crew Dragon has no airlock, unlike the International Space Station, all four crew members – including ex-jet pilot Poteet and SpaceX employee Menon – had to put on spacesuits. With the hatch open, they were exposed to the vacuum of space, and there was no breathable air in the cabin.

- Bernama, dpa