The billionaire businessman smiled as he headed back to the planet surface after feeling the thrill of weightlessness for several minutes on Sunday afternoon.

The launch was hailed a “landmark moment” for the billionaire businessman, as well as the whole commercial space industry.

Take-off had been delayed by about 90 minutes on Sunday due to the weather overnight at Spaceport America in New Mexico, in the US.

But video streamed live online showed the spacecraft being carried up into the atmosphere by its mothership before being released so it could power up to highs of 250,000 feet.

Branson and his crew reached speeds of Mach 3 on their way to the edge of space.

After a short spell during which they experienced weightlessness, the craft then pointed downwards and made its way back to the ground.

On the return flight, Branson hailed the “experience of a lifetime” and the “hard, hard work” that went into the flight.

Out on the runway, he was greeted with cheers and hugs as he walked back to the spaceport.

Later, he told a press conference: “Like most kids I have dreamt of this moment since I was a kid but honestly nothing could prepare you for the view of Earth from space.

“The whole thing was just magical.”

He also paid tribute to scientist Stephen Hawking, who he said it was an “honour” to know.

Branson is the first owner-astronaut to take part in a mission, beating Amazon founder Jeff Bezos, who plans to reach space in his own rocket through his Blue Origin company.

On the ground, Michael Colglazier, chief executive of Virgin Galactic, said: “This is a landmark moment for Virgin Galactic.

“It’s a landmark moment for the new commercial space industry and it certainly is a landmark moment for our founder Richard Branson.”

He said the company’s work on Sunday was dedicated to “opening up space to all”.

Tourists are expected to pay $A334,000 for a spaceflight on Virgin Galactic, which includes four minutes of zero gravity.

The gleaming white spaceplane took off attached to the underside of a specially designed twin-fuselage carrier jet VMS Eve – named for Branson’s late mother, separating from the mothership at an altitude of 50,000 feet. Unity’s rocket engine ignited to send the spaceplane streaking straight upward to the blackness of space some 88km high, where the crew experienced about four minutes of microgravity.

Virgin has plans for two further test flights of the spaceplane in the months ahead before beginning regular commercial operation in 2022.

The Swiss-based investment bank UBS has estimated the potential value of the space tourism market reaching $US3 billion ($A4 billion) annually by 2030.

Proving rocket travel safe for the general public is key, given the inherent dangers of spaceflight.

An earlier prototype of the Virgin Galactic rocket plane crashed during a test flight over California’s Mojave Desert in 2014, killing one pilot and seriously injuring another.

His ride-along upstages rival Bezos, in what has been popularised as the “billionaire space race”.

Bezos has been planning to fly aboard his own suborbital rocketship, the New Shepard, later this month.

Branson, a week away from his 71st birthday, has insisted he and Bezos are friendly rivals and not engaged in a personal contest to beat one another into space.

Bezos posted a message on Instagram on Saturday wishing Branson and his team good luck and “a successful and safe flight”, but nonetheless there has been some public rancour between the two.

Blue Origin has disparaged Virgin Galactic as falling short of a true spaceflight experience, saying that unlike Unity, Bezos’s New Shepard tops the 100km-mark, called the Kármán line, set by an international aeronautics body as defining the boundary between Earth’s atmosphere and space.

However, US space agency NASA and the US Air Force both define an astronaut as anyone who has flown higher than 80km.