The first-ever spacewalk by private civilians has been successfully attempted, with four passengers on board SpaceX’s Polaris Dawn mission being subjected to outer space conditions for about one hour.

The four-person crew will now start their journey back down to Earth on board the spacecraft, with a splashdown expected off the Gulf of Mexico on Saturday.

How did the spacewalk go?

The first-ever commercial spacewalk was delayed for about two and a half hours, with the spacewalk starting at about 10:50 GMT after the hatch of the spacecraft was opened.

Before heading out, the pressure inside the capsule was slowly altered as part of the “pre-breathing” process that prepares the astronauts’ bodies. When the hatch was opened, the spacecraft was travelling at an elliptical orbit of 736km (457 miles) above the surface of the Earth at a speed of more than 25,000km/h (at least 15,500mph).

As billionaire mission commander Jared Isaacman opened the hatch and stepped up to transmit the first view of the planet from outside, the SpaceX crew on Earth erupted into cheers. He began limb movements which he had memorised beforehand to test out mobility in outer space.

After a number of minutes with his body partially outside the hatch, the 41-year-old Isaacman withdrew and was replaced by SpaceX engineer Sarah Gillis, 30, who went through similar motions, turning side to side and flexing her limbs to see how the new spacesuit, designed to protect the crew from the harsh vacuum, would hold up.

US SpaceX engineer Sarah Gillis emerges via the hatch from the Dragon spacecraft, during the first private spacewalk performed by the crew of the SpaceX Polaris Dawn mission [Polaris Program/AFP]

They were the only ones to go through the hatch, secured by a 12-foot (3.6-metre) tether linked to the spacecraft. They used Skywalker, a hatch structure with hand-held mobility assistance hardware developed by the company, but neither fully exited the hatch.