Richard Garriott, one of the world's first ever private space tourists, believes space travel will become affordable for a lot more people "in the next decade or two."

The video gaming billionaire, who in 2008 became the sixth private astronaut to live aboard the International Space Station, says the cost of space travel is already dropping very fast. 

Therefore, he argues, a lot more people will be able to travel - and maybe even work - in space once the price of a journey drops below a million dollars.

Garriott co-founded Space Adventures, a company that offers space flights for private citizens. The son of former NASA astronaut Owen Garriott, he has been a leader in civilian and commercial space travel as an investor and board member of institutions such as the X-Prize Foundation and Planetary Resources. In response to questions from students across the USA and UK, Garriott developed more than 30 educational video clips about life in space ranging from fluid dynamics in microgravity to useful items found on the ISS.