Saudi Arabia’s first astronauts in decades rocketed towards the International Space Station on a chartered multimillion-pound flight on Sunday.
SpaceX launched the ticket-holding crew, led by a retired Nasa astronaut now working for the company that arranged the trip.
Also on board was a US businessman who now owns a sports car racing team.
The four should reach the space station in their capsule on Monday – they will spend just over a week there before returning home with a splashdown off the Florida coast.
Sponsored by the Saudi Arabian government, Rayyanah Barnawi, a stem cell researcher, became the first woman from the kingdom to go to space.
She was joined by Ali al-Qarni, a fighter pilot with the royal Saudi air force.
They are the first from their country to travel in a rocket since a Saudi prince launched aboard the shuttle Discovery in 1985.
In a quirk of timing, they will be greeted at the station by an astronaut from the United Arab Emirates.
“This is a dream come true for everyone,” Ms Barnawi said before the flight. “Just being able to understand that this is possible. If me and Ali can do it, then they can do it, too.”
Completing the visiting crew is John Shoffner, former driver and owner of a sports car racing team that competes in Europe, and chaperone Peggy Whitson, the station’s first female commander who holds the US record for most accumulated time in space – 665 days and counting.
It is the second private flight to the space station organised by Houston-based Axiom Space.
The first was last year by three businessmen, with another retired Nasa astronaut.
The company plans to start adding its own rooms to the station in another few years, eventually removing them to form a stand-alone outpost available for hire.
Axiom will not say how much Mr Shoffner and Saudi Arabia are paying for the planned 10-day mission. The company had previously cited a ticket price of 55 million dollars (£44 million) each.
Nasa’s latest price list shows per-person, per-day charges of 2,000 dollars (£1,600) for food and up to 1,500 dollars (£1,200) for sleeping bags and other gear.
Need to get your stuff to the space station in advance? Figure roughly 10,000 dollars (£8,000) per pound and the same fee for trashing it afterwards. Need your items back intact? Double the price.
At least the email and video links are free.
The guests will have access to most of the station as they conduct experiments, photograph Earth and chat with schoolchildren back home, demonstrating how kites fly in space when attached to a fan.
After decades of shunning space tourism, Nasa now embraces it with two private missions planned a year. The Russian Space Agency has been doing it, off and on, for decades.
“Our job is to expand what we do in low-Earth orbit across the globe,” said Nasa’s space station programme manager Joel Montalbano.