The billionaire rocketman who made the first private spacewalk on the SpaceX Polaris Dawn mission is back on earth after splashing down off the coast of Florida today.    

Jared Isaacman, 41, led the four-member team who landed in the ocean at 3.37am, a webcast of the splashdown showed, with a recovery team deploying in the pre-dawn darkness to retrieve the Dragon spacecraft and crew.

The capsule was lifted from the water and onto the recovery vessel half an hour later.

After brief medical checks, a smiling and waving SpaceX engineer Anna Menon was the first of the crew to exit, followed by engineer Sarah Gillis, pilot Scott Poteet and commander Isaacman. A helicopter was due to transport them to land.

The team launched on Tuesday from the Kennedy Space Center, quickly journeying deeper into the cosmos than any humans in the past half century as they ventured into the dangerous Van Allen radiation belt.

Tech entrepreneur Jared Isaacman (centre) smiles as he gets out of the capsule upon his return

Tech entrepreneur Jared Isaacman (centre) smiles as he gets out of the capsule upon his return

The four-member crew including Isaacman (third left) seated in the capsule

The four-member crew including Isaacman (third left) seated in the capsule

The space capsule floating in the Gulf of Mexico near Florida's Dry Tortugas upon returning to Earth

The space capsule floating in the Gulf of Mexico near Florida's Dry Tortugas upon returning to Earth

The space capsule landing in the Gulf of Mexico near Florida's Dry Tortugas upon returning to Earth

The space capsule landing in the Gulf of Mexico near Florida's Dry Tortugas upon returning to Earth

The SpaceX Crew Dragon Resilience spacecraft is seen as it lands

The SpaceX Crew Dragon Resilience spacecraft is seen as it lands

They hit a peak altitude of 870 miles - more than three times higher than the International Space Station and the furthest humans had ever travelled from Earth since the Apollo missions to the Moon.

On Thursday, with their Dragon spacecraft's orbit brought down to 434 miles, Isaacman swung open the hatch and climbed out into the void, gripping a structure called 'Skywalker' as a breathtaking view of Earth unfolded before him.

'SpaceX, back at home we all have a lot of work to do, but from here, Earth sure looks like a perfect world,' he told mission control in Hawthorne, California, where teams erupted in applause.

He went back inside after a few minutes and was replaced by a second astronaut, SpaceX engineer Gillis, who, like Isaacman, performed a series of mobility tests on SpaceX's next-generation suits.

Since Dragon doesn't have an airlock, the entire crew was exposed to the vacuum of space. Mission pilot Poteet and SpaceX engineer Menon remained strapped in throughout as they monitored vital support systems.

It marked a 'giant leap forward' for the commercial space industry, said NASA chief Bill Nelson, as well as another triumphant achievement for SpaceX.

US Mission Specialist Anna Menon reacting as she gets out of the capsule upon returning to Earth

US Mission Specialist Anna Menon reacting as she gets out of the capsule upon returning to Earth

Crew working next to the space capsule after it landed in the Gulf of Mexico near Florida's Dry Tortugas upon returning to Earth

Crew working next to the space capsule after it landed in the Gulf of Mexico near Florida's Dry Tortugas upon returning to Earth

The capsule (centre) carrying tech entrepreneur Jared Isaacman with his crew

The capsule (centre) carrying tech entrepreneur Jared Isaacman with his crew

The space capsule splashing in the Gulf of Mexico near Florida's Dry Tortugas upon returning to Earth

The space capsule splashing in the Gulf of Mexico near Florida's Dry Tortugas upon returning to Earth

Tech entrepreneur Jared Isaacman, center, reacts as he gets out of its capsule upon his return with his crew

Tech entrepreneur Jared Isaacman, center, reacts as he gets out of its capsule upon his return with his crew

The space capsule floating in the Gulf of Mexico near Florida's Dry Tortugas upon returning to Earth

The space capsule floating in the Gulf of Mexico near Florida's Dry Tortugas upon returning to Earth

Although the company was only founded in 2002, it has outpaced its legacy competitors thanks in large part to founder Elon Musk's vast fortune and zeal to begin the colonisation of Mars. 

Since completing their extravehicular activity, the crew have continued to carry out roughly 40 science experiments, such as inserting endoscopic cameras through their noses and into their throats to image their airways and better understand the impact of long-duration space missions on human health.

They also demonstrated connectivity with SpaceX's Starlink internet satellite constellation by sending back to ground control a high-resolution video of Gillis playing 'Rey's Theme' by 'Star Wars' composer John Williams, on the violin.

Polaris Dawn is the first of three missions under the Polaris programme, a collaboration between Isaacman and SpaceX.

Financial terms of the partnership remain under wraps but Isaacman, the founder and CEO of Shift4 Payments, reportedly poured $200million of his own money into leading the 2021 all-civilian SpaceX Inspiration4 orbital mission.

The final Polaris mission aims to be the first crewed flight of SpaceX's Starship, a prototype next-generation rocket that is key to Musk's interplanetary ambitions.