British entrepreneur Sir Richard Branson's space tourism project was inspired by a Tv show fan more than 20 years ago.

Branson's Virgin Galactic aims to offer tourists the chance to holiday in space by taking them into Earth's orbit, and celebrities including Justin Bieber and Lady Gaga have already booked tickets for some of the earliest flights.

The businessman is hoping to launch the first shuttle later this year (14) but he first began considering a space mission during a chat with a viewer who called in to British Tv show Going Live! in 1988.

Branson tells U.K. chat show host Jonathan Ross, "You never know what sparks things off in your mind but as a result of that show (Going Live!) we registered the name Virgin Galactic Airways. Over the next decade I started travelling around the world meeting technicians and engineers to see if we could find a genius who could build a spaceship that could take you and me into space.

"I think it's going to be the beginning of a whole new era of space travel. Initially we're going to be giving people a taste of space. It's going to be absolutely magnificent. People will become astronauts, they'll be able to experience zero gravity. They'll be able to check the world is really round and they'll have the ride of a lifetime."