Private sector companies are already taking bookings for the ultimate trip, although the tourist space vehicles have not yet been built.

Teymoor Nabili looks at the possibility of holidays in space

A $10m prize is on offer to the first private team that to build and fly a re-usable spaceship capable of carrying three individuals on a sub-orbital flight.

The X-Prize Foundation is offering the prize to "stimulate the development of commercial space tourism".

Foundation President Peter Diamandis said: "If you don't want to spend a decade training or if you aren't qualified to be an astronaut how can you get the chance to fly.

"We have to develop a private sector. The competition's purpose is to encourage entrepreneurs and rocket scientists to build vehicles that will take us into space."

Space passengers

Nasa is also encouraging private investment in the tourism space race.

Nasa pioneers were an elite band

"It will allow us to invest our funding in our real mission to expand knowledge of the earth, the universe and the solar system," Alan Ladwig, a senior advisor at the space agency said.

While Nasa has proven the final frontier can be reached, the challenge for the private sector is to make space flights economical.

One option being looked at is to develop jets that fly to the edge of the atmosphere and jettison a passenger capsule out of the earth's gravitational field.

Companies such as Space Adventures and Zegrahm Space Voyages have taken about 100 bookings for any future flights.

Space Adventures President Mike McDowell said: "It is going to stay with people who have disposable income.

"But there are people looking at ways to open up space travel to those without $100,000."