For £110,000, Branson offers his passengers a voyage into space

Strapped in, flat on their backs, passengers will accelerate - within 25 seconds - to 2,500mph. For no more than five minutes they will float about, 80 miles above planet Earth. Lavatory and in-flight drinks? Not a chance. And the price for this brief excursion? £110,000.

Sir Richard Branson, the master of combining publicity coups with redrawing aeronautical boundaries, unveiled his latest project to redefine air travel yesterday - the first commercial space flights. By 2007, the British billionaire plans to offer five wealthy space tourists at a time the chance to fly on a new fleet of rocket-powered craft on three-hour trips that will take them into space - but stop short of entering into orbit.

Mr Branson announced the venture - to be named Virgin Galactic - after signing a £14m deal at the weekend to use technology perfected by the California-based team which made the first privately funded flight into space this summer with their craft, SpaceShipOne.

Mr Branson said he hoped to add a space hotel to his portfolio within his lifetime and even broached the subject of flights to the moon. At the launch of the project at the Royal Aeronautical Society in London, Sir Richard said: "For years I have dreamt of seeing the beauty of our planet from space, experiencing true weightlessness.

"I hope with the launch of Virgin Galactic that, some day, children around the world will wonder why we ever thought that space travel was just a dream we read about in books or watched - with longing - in Hollywood movies." The attempt will be paid for by Sir Richard and the Microsoft co-founder Paul Allen, who also funded SpaceShipOne.

Work will start by the end of the year on VSS (Virgin Space Ship) Enterprise, the first of the new "space liners" to be built with a total investment of £60m. After being carried to a height of 50,000ft by a launch aircraft, the spaceship will fire its rocket for 90 seconds, accelerating to a speed of 2,500mph. It will spend five minutes of weightlessness at the height of its trajectory before changing its wing pattern to glide back to its launch site in the Mojave Desert in south-west of the US.

The spacecraft, hoped to be the first of five, will be built in California at the base of Burt Rutan, the aviation engineer who built SpaceShipOne. It was this bulbous, futuristic craft, powered by a mixture of solid rubber propellant and liquid nitrous oxide, or laughing gas, that achieved the first privately funded manned flight into space in June. It flew 100km above the earth using the new low-cost technology.

But it is only likely to be as safe as early commercial airliners. The only previous space tourists have been a handful of billionaires who paid the Russian government for the privilege. With plans for further "space ports" first in Florida, then Australia and Britain, Mr Branson plans reinvest profits from the early flights to cut the cost and make space tourism more widely available.