The first privately-funded spacewalk is set to take pace by a group of astronauts who will leave a SpaceX capsule in the company's riskiest mission yet.

A billionaire entrepreneur, a retired military fighter pilot and two SpaceX employees have been orbiting Earth aboard Crew Dragon since Tuesday's pre-dawn launch from Florida of the Polaris Dawn mission.

It is the Elon Musk-led company's latest and riskiest bid to push the boundaries of commercial spaceflight.

The event is being livestreamed with two astronauts set to venture outside Crew Dragon while two stay inside.

The capsule, at an altitude of 700 km (435 miles), will be completely depressurised, and the whole crew will rely on their slim, SpaceX-developed spacesuits for oxygen.

Jared Isaacman, 41, a pilot and the billionaire founder of electronic payments company Shift4, is bankrolling the Polaris mission, as he did his Inspiration4 flight with SpaceX in 2021.

The others in Polaris include mission pilot Scott Poteet, 50, a retired U.S. Air Force lieutenant colonel, and SpaceX employees Sarah Gillis, 30, and Anna Menon, 38, both senior engineers.

Good morning, and welcome to the Standard's live blog.

We'll be bringing you all the latest updates from the first private spacewalk in history, which is set to take place.

A group of astronauts who will leave a SpaceX capsule, testing a new line of spacesuits in the company's riskiest mission yet, pushing the boundaries of commercial spaceflight.