As tech billionaire Jared Isaacman emerged from a capsule in space and looked down at planet Earth, his first observation triggered an eruption of cheering in the control room.

The tycoon had just made history on Thursday (US time) as the first civilian to perform a spacewalk, a dangerous endeavour until now reserved for professional astronauts.

“Back at home, we all have a lot of work to do,” said Isaacman, as he soared above the South Pacific.

“But from here, it sure looks like a perfect world.”

The historic spacewalk was the main focus of a five-day flight funded by Isaacman and Elon Musk’s company SpaceX.

It was the culmination of years of development geared towards settling Mars and other planets.

SpaceX engineer Sarah Gillis also popped out of the Crew Dragon capsule once Isaacman was safely back inside.

This spacewalk was simple and quick – less than two hours – compared with similar walks of up to eight hours for astronauts repairing the International Space Station.

Jared Isaacman was bobbing around more so than walking in space. Photo: SpaceX

Isaacman emerged first from the hatch, joining a small elite group of spacewalkers; previously it has included only professional astronauts from a dozen countries.

All four on board donned new SpaceX spacewalking suits they were testing, which protected them from the harsh vacuum they were exposed to once the hatch was opened.

They launched on Tuesday from Florida, rocketing further from earth than anyone since NASA’s moonwalkers.

The orbit was reduced by half – to 740 kilometres – for the walk.

This first spacewalking test involved more stretching than walking, with Isaacman flexing his arms and legs to see how his spacesuit held up.

The hatch sported a walker-like structure for support.

After about 10 minutes outside, Isaacman was replaced by SpaceX engineer Sarah Gillis to go through the same motions.

Gillis bobbed up and down in weightlessness, no higher than her knees out of the capsule, as she twisted her arms and sent reports back to Mission Control.

More and more wealthy passengers are plunking down huge sums for rides aboard private rockets to experience a few minutes of weightlessness, while others have spent tens of millions to stay in space for days or even weeks.

Space experts say it is inevitable that some will seek the thrill of spacewalking, deemed one of the most dangerous parts of spaceflight but also the most soul-stirring.

This operation had little room for error, and there were a few glitches.

Isaacman had to manually pull the hatch open instead of pushing a button on board, and Gillis reported seeing bulges in the hatch seal before heading out.

Scott “Kidd” Poteet, a former Air Force Thunderbird pilot, and SpaceX engineer Anna Menon stayed strapped to their seats to monitor from inside.

All four had intensive training before the trip.

Mission controllers announced the spacewalk complete from company headquarters in Hawthorne, California, after an hour and 46 minutes.

It went by “in the blink of an eye”, SpaceX commentator Kate Tice said.

NASA administrator Bill Nelson congratulated the team and SpaceX for “a giant leap forward for the commercial space industry and NASA’s long-term goal to build a vibrant US space economy”.

Isaacman, 41, CEO and founder of the Shift4 credit card-processing company, has declined to disclose how much he invested in the flight. It was the first of three flights in a program he dubbed Polaris; this one was called Polaris Dawn.

On SpaceX’s inaugural private flight in 2021, contest winners and a cancer survivor were among those on board.

Until Thursday, only 263 people had done a spacewalk, representing 12 countries.

The Soviet Union’s Alexei Leonov kicked it off in 1965 followed a few months later by NASA’s Ed White.

-with AAP