More than 435 miles (700km) above our heads, the crew of SpaceX’s Polaris Dawn mission have made history as they completed the world’s first private spacewalk.

Shortly before midday today, billionaire Jared Isaacman became the first ever non-professional astronaut to step out into the vaccum of space. 

‘Back home we have a lot of work to do, but from here Earth sure looks like a perfect world,’ said Isaacman as he stepped out into space. 

SpaceX employee Sarah Gillis followed shortly afterwards as she exited the safety of the capsule and embarked on her own spacewalk.  

Isaacman and mission specialist Sarah Gillis have both now completed their spacewalks and returned to their spacecraft.

At 11:17 BST the spacewalk officially began as pure oxygen from the spacecraft started to flow into the astronaut’s suits. 

The crew, consiting of billionaire Jared Issacman, former airforce commander Scott ‘Kidd’ Poteet, and SpaceX employees Sarah Gillis and Anna Menon, then faced a nervewracking half-hour wait. 

All four members of the crew underwent suit checks, ensuring that the helmet’s heads-up display functions and that there were no air leaks.

With leak checks complete, the crew were given pure oxygen to breathe as they waited for the pressure inside the capsule to fall.

At 11:43 BST Isaacman received the go-ahead to start opening the spaceship and began to tug on the hatch to loosen any resistance and vent the last of the remaining atmosphere. 

Just minutes later, Isaacman opened the hatch to space and pulled himself out into the void – becoming the first non-professional astronaut to undertake a spacewalk. 

Once outside the craft, Isaacman tested the mobility of the EVA suit as he stood on the specially fitted ‘Skywalker’ platform.

This is the first time that SpaceX’s new extravehicular activity (EVA) suits have been tested outside a laboratory setting so the company was keen to see how they would stand up to the rigours of space.

Isaacman spent a little over 10 minutes outside of the vehicle running through a set of pre-planned movements designed to test the limits of the EVA suit.

The billionaire-turned-astronaut practised turning, raising himself, and reaching his arms up away from the spacecraft.

However, at no point during the spacewalk did Isaacman float freely as he remained in contact with the handles or foot loops of the platform the entire time. 

Having concluded his mobility tests, Isaacman reentered the Dragon capsule and mission specialist Gillan exited the capsule and completed the same set of movements. 

As she exited the craft, Gillan informed mission control that some of the seals around the hatch were ‘bulging’ due to the pressure change.

However, these changes were expected and Gillan was able to push these back into position before exiting.

After ten minutes out in the vacuum of space, Gillan returned to the spacecraft and the crew sealed the door behind her. 

With the hatch closed, air returned to the Dragon capsule slowly bringing the pressure back up to safe levels. 

‘Pressure indicates good seal,’ mission control told the astronauts. 

At 13:00 BST mission control confirmed that EVA had concluded, bringing the first ever commercial spacewalk to a close. 

After a final round of safety checks, the crew will then be able to remove their EVA suits and move around the cabin.  

Earlier today, SpaceX confirmed that the four-hour window for the spacewalk would take place at 05:58 ET (10:58 BST).

‘On Thursday, September 12 the Polaris Dawn crew will attempt the first-ever spacewalk – also known as an extravehicular activity (EVA) – from Dragon,’ it explained. 

‘The EVA is targeted to start at 5:58 a.m. ET. If needed, a backup opportunity is available on Friday, September 13.’

The spacewalk had been pushed back from the original time of 07:23 BST (02:23 ET) although SpaceX did not state the reason for the delay. 

The successful conclusion for this mission is a major leap forward for SpaceX’s ambitions in commercial spaceflight. 

Previously only state-backed space agencies have sent astronauts on spacewalks due to the extremely high risks involved.

Floating beyond the protective walls of a spacecraft is considered to be one of the most dangerous tasks an astronaut can undertake.

In this case, that risk was only heightened by the fact that none of the crew except for Isaacman had ever been in space before.

Unlike the EVA suits used by NASA’s astronauts, the SpaceX suits only get their life support through an umbilical connecting to the ship rather than from a built-in system.

While this makes the suits far more mobile, it also means that the 12-foot (3.7m) umbilical will be the only thing preventing the spacewalkers from drifting off or asphyxiating. 

Mission pilot and former Air Force commander Scott Poteet and medical officer Anna Menon remained seated the entire time to monitor the vitals of the two spacewalkers. 

Since the Dragon spacecraft does not have an airlock, the entire craft needed to be depressurized at once so Poteet and Menon also had to wear EVA suits during the spacewalk. 

That exposed all four crew members to the harsh conditions of low orbit and broke the current record for most people simultaneously in the vacuum of space. 

Some of the biggest risks faced by the crew came from the extreme changes in pressure between the sealed Dragon capsule and the vacuum of space outside.

As the cabin vents its pressure into space, astronauts can experience symptoms like you might feel while rising quickly in a plane. 

However, the consequences can be far more severe since, just like deep-sea divers, when astronauts enter the vacuum of space the sudden drop in pressure can cause dissolved nitrogen in the blood to expand into bubbles.

These bubbles can cause a condition called decompression sickness, otherwise known as the Bends, which can be fatal in severe cases.

To avoid decompression sickness the Polaris Dawn crew have spent the last two days going through a pre-breath procedure by breathing a high-oxygen gas mix to purge their blood of Nitrogen. 

This is significantly longer than the two hours normally taken by astronauts on the ISS before spacewalks.

In the last half hour before exiting the vehicle, the Polaris Dawn crew moved onto a pure oxygen mixture to purge the last of the nitrogen from their bloodstreams.  

On social media, commenters shared their excitement and well-wishes for the crew before the start of the spacewalk.

One commenter wrote on X, formerly Twitter, ‘Let’s go!! Praying for a safe spacewalk for Polaris dawn.’

Another commenter wrote: Absolutely breathtaking. Another achievement!’

‘Humanity once again reaching out towards the stars’, another commenter said.

SpaceX CEO Elon Musk, meanwhile, shared a simple excited statement, writing: ‘Spacewalk!!’ 

Some commenters also shared their amazement at the technological advancements behind this impressive feat.

One commenter wrote on X: ‘History in the making on so many fronts.. let’s go. Godspeed and good luck to all the Astronauts!’

‘Amazing technical accomplishment to get crystal clear video and audio back to earth. Much better than 50 years ago,’ another wrote.  

The Polaris Dawn mission launched from the Kennedy Space Centre in Florida on September 10 at 5:23 am ET after days of delay due to weather and a helium leak.

Yesterday, the SpaceX Dragon Crew spacecraft carried its crew to an altitude of 870 miles (1,400 km) above Earth – the highest any human has been since NASA’s Apollo missions. 

At that altitude, the Dragon capsule briefly entered Earth’s Van Allen Belt – a region where magnetic fields trap highly radiating charged particles.

Entering the Van Allen Belt means the crew received a hefty dose of space radiation, getting as much in a few hours as they would in 20 years on the Earth by one estimate.  

NASA has noted that it is crucial ‘to fly through this region quickly to limit exposure to radiation,’ since high doses of space radiation can increase astronauts’ long-term risk of cancer by damaging cellular DNA.

By stepping out beyond the protection of the spacecraft, Isaacman and Gillan will once again expose themselves to harmful radiation, albeit in a far smaller dose.   

While in space, the crew’s sole protection will be SpaceX’s new EVA suits.

These suits have been designed using thermally resistant materials borrowed from the Dragon’s trunk section and includes a ‘Faraday’ layer which insulates the astronaut from any electrical fields.

The new helmets also include a ‘heads-up display’ (HUD) and a camera which can stream video to Earth via the Dragon spacecraft.

While in space, Polaris Dawn will also conduct nearly 40 scientific experiments some of which will measure the harmful effects of exposure to radiation.

These also include testing contact lenses embedded with microelectronics to continuously monitor changes in eye pressure and shape.

The Polaris Dawn crew will also take the opportunity to trial SpaceX’s latest laser-based communication system nicknamed the ‘Plug and Play-ser’. 

They will attempt to communicate between the spaceship and Starlink – SpaceX’s more than 6,000-strong constellation of internet satellites, in a bid to boost space communication speeds.

This mission also marks an important landmark for SpaceX’s goal of making the Dragon spacecraft the go-to option for orbital flights.

The same Dragon used for this mission is the exact same craft used by Isaacman on the Inspiration4 mission and on NASA’s Crew 1 mission.  

After six days in space, the mission will conclude with a splashdown off the coast of Florida.