The "spaceships" are designed to carry a maximum of eight people

The Virgin spaceships are designed to carry six passengers and two pilots to an altitude of about 140km on a sub-orbital space flight.

Tickets on a Virgin Galactic flight are expected to cost £100,000 ($190,000).

The mock-up of the spacecraft was unveiled at the Javits exhibition centre in New York on Thursday.

The Virgin craft are based on the design of SpaceShipOne, built by aviation pioneer Burt Rutan, which became the first privately built vehicle to reach space in 2004.

SpaceShipOne made three flights to altitudes just greater than 100km - the edge of the Earth's atmosphere - claiming the prestigious Ansari X-Prize.

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The rocket plane was first carried to a launch altitude of 15km (50,000ft) by an aircraft, or mothership, called White Knight.

It was then released and ignited its rocket engine, which propelled it through the atmosphere.

Sir Richard tested a passenger seat inside the mock-up

Virgin Group has contracted Rutan's company Scaled Composites to design and build the passenger spaceship and its mothership. Virgin Galactic will own and operate at least five spaceships and two motherships.

The passenger flights, which could begin in 2009, will take off from a $225m (£127m) facility called Spaceport America in the New Mexico desert.

Will Whitehorn, president of Virgin Galactic, said the firm was in negotiations over a reality TV show.

In the show, contestants would compete to win a place on a space flight, the Press Association reported.

Mr Whitehorn said: "The indications are that we can create a show that would give people the chance to go into space. It would be a cross between Dr Who, Star Trek and the Krypton Factor."

Virgin Galactic is one of several private firms vying to open up public access to space.