Virgin Galactic’s first fully crewed flight to the edge of space has been delayed due to the weather.
Billionaire businessman Sir Richard Branson, the company’s owner, is due to test the “private astronaut experience” on Sunday.
Launch preparations have been pushed back by 90 minutes due to weather overnight at Spaceport America.
The launch time from New Mexico is now set for 3.30pm UK time.
Sir Richard will become 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.
Tourists are expected to pay 250,000 US dollars (£180,000) for a spaceflight on Virgin Galactic, which includes four minutes of zero gravity.
The Sunday Times newspaper reported that Elon Musk – who owns rival exploration company SpaceX – has paid for a seat on a future Virgin voyage.
Mr Musk paid a 10,000-dollar (£7,000) deposit to reserve a seat but no date for his flight has been specified.
Sir Richard confirmed the purchase in an interview with the newspaper, saying he might reciprocate by booking a ticket on a SpaceX flight in the future.
“Elon’s a friend and maybe I’ll travel on one of his ships one day,” he said.
Amid what has been dubbed the billionaires’ space race, SpaceX has launched dozens of rockets, including manned flights, but Mr Musk himself has not yet flown on any.
The company is due to launch its first fully private spaceflight in the autumn.