Jeff Bezos, the world's richest man, has soared about 107km above the Texas desert aboard his company Blue Origin's New Shepard launch vehicle and returned safely to earth, a historic suborbital flight that helps to inaugurate a new era of private commercial space tourism.
"Best day ever," Bezos said after the space capsule touched down, kicking up a cloud of dust on the desert floor.
The 57-year-old US billionaire, wearing a blue flight suit and donning a cowboy hat, was joined by three crewmates for a trip to the edge of space lasting about 10 minutes and 20 seconds.
After landing and exiting the space capsule, Bezos and the other crew members exchanged hugs and popped champagne, spraying each other.
"Astronaut Bezos in my seat - happy, happy, happy," Bezos said in response to a mission control status check after the crew members buckled back in aboard New Shepard's capsule following a few minutes of weightlessness in space.
Bezos, founder of ecommerce company Amazon.com, and his brother Mark Bezos, a private equity executive, were joined by two others.
Pioneering female aviator Wally Funk, 82, and recent high school graduate Oliver Daemen, 18, become the oldest and youngest people to reach space.
The fully autonomous 18.3-metres-tall gleaming white spacecraft, with a blue feather design on its side, ignited its BE-3 engines for a lift-off from Blue Origin's Launch Site One facility about 32km outside the rural town of Van Horn.
There were generally clear skies with a few patchy clouds on a cool morning for the launch.
The flight came nine days after Briton Richard Branson was aboard his competing space tourism company Virgin Galactic's successful inaugural suborbital flight from New Mexico.
Bezos gave a thumbs-up sign from inside the capsule after landing on the desert floor.
He stepped out to cheers from family members and Blue Origin employees and gave high-fives to some of the roughly two dozen people on hand.
He founded Blue Origin two decades ago.
This was the company's first crewed flight to space.
New Shepard was designed to hurtle at speeds upwards of 3540km per hour to an altitude reaching the so-called Karman line - 100 km - set by an international aeronautics body as defining the boundary between earth's atmosphere and space.
After the capsule separated from the booster, the crew unbuckled for the few minutes of weightlessness.
The capsule then returned to earth under parachutes, using a retro-thrust system that expelled a "pillow of air" for a soft landing.
The mission was part of a fiercely competitive battle between Bezos' Blue Origin and Branson's Virgin Galactic to tap a potentially lucrative space tourism market the Swiss bank UBS estimates will be worth $US3 billion ($A4.1 billion) annually in a decade.
Before the flight, Bezos and the other passengers climbed into an SUV vehicle for a short drive to the launch pad, then walked up a tower and got aboard the spacecraft.
Each passenger rang a shiny bell before boarding the craft's capsule.
Branson got to space first but Bezos flew higher - Virgin Galactic managed an altitude of 86km - in what experts called the world's first unpiloted space flight with an all-civilian crews.
The flight coincides with the anniversary of Neil Armstrong and Edwin "Buzz" Aldrin becoming the first humans to walk on the moon on July 20, 1969.
New Shepard is named for Alan Shepard, who in 1961 became the first US astronaut in space.
Funk was one of the so-called Mercury 13 group of women who trained to become NASA astronauts in the early 1960s but was passed over because of her gender.
Daemen, Blue Origin's first paying customer, is set to study physics and innovation management at a college in the Netherlands.
His father, who heads investment management firm Somerset Capital Partners, was on site to watch his son fly to space.
New Shepard is a rocket-and-capsule combo that cannot be piloted from inside the spacecraft.
It is completely computer-flown and had none of Blue Origin's staff astronauts or trained personnel onboard.
Virgin Galactic used a space plane with a pair of pilots onboard.
The reusable Blue Origin booster had previously flown twice to space.
Another billionaire tech mogul, Elon Musk, plans to send an all-civilian crew on a several-day orbital mission on his Crew Dragon capsule in September.
On Twitter, Musk wished the Blue Origin crew "best of luck" hours before the launch.
Blue Origin aims for the first of two more passenger flights this year to happen in September or October.
Australian Associated Press