More than 7,000 people have said they will pay to fly into space in one of entrepreneur Richard Branson's space ships - which have yet to be built.
Sir Richard's family will be first on board the space ship.
The space adventurers had pledged a total of £805m to go 110km (70 miles) above the Earth, Sir Richard said.
The 54-year-old has put £74m into his Virgin Galactic plan, adding to the £115,000 each passenger will have to pay for the expected take-off in 2008.
They will experience weightlessness and see the curvature of the Earth.
Sir Richard said he was overwhelmed by the response.
"We are extremely pleased because it just means in a sense that the gamble we took seems to have paid off," he said.
"We have committed $100m (£60m) and we have had a tremendous take-up. All indicators are that the risk was worth taking.
"Market research suggested that there were that sort of number of people willing to agree to that sort of price."
The first flight will be reserved for Sir Richard and his family.
Its scheduled lift-off will be in 2008 to coincide with the Virgin boss's father Ted, 86, turning 90.
"My dad has put his hand up and will be 90 at the time, my kids definitely want to come and if there is room for my mum she will come, too," said Sir Richard.
If his father joined the flight, he would the oldest person ever to fly in space, beating John Glenn who travelled aged 77 in 2001.
Sir Richard hopes that eventually the spacecraft will launch from various stations around the world, including Europe.
"If we can make it a success, then I hope we can lower the price so that more people can realise their dream and go into space."
Among those keen to travel at three times the speed of sound are Star Trek star William Shatner and Dave Navarro, the former Red Hot Chili Peppers guitarist.
One unidentified Hollywood director has also booked an entire ship and hopes to be among the first up in space.
The journey, in either five- or nine-seaters, will last about 3.5 hours and passengers will be weightless for at least six minutes.