British billionaire Sir Richard Branson's commercial space flight company Virgin Galactic is now accepting the digital currency Bitcoin as a way for tourists to buy a ticket into space

The Virgin Group founder, who has invested in Bitcoins and other forms of virtual "cash" such as Clinkle and Square, made the announcement on Friday.

"While the world of travel is rapidly advancing, the world of payments is changing fast too,"Branson said Friday in a blog post. "Virgin Galatic is a company looking into the future, so is Bitcoin. So it makes sense we would offer Bitcoin as a way to pay for your journey to space."

Created in 2009, a Bitcoin is a cryptography-based digital currency which advocates say is counterfeit-proof. It is considered a decentralized currency, meaning it is not backed by any single financial institution.

The value of a Bitcoin is determined by the number of units in circulation. Its value has appreciated rapidly over the last few years, with growth fueled by views that a virtual currency can become an alternative to traditional methods of payment.

According to Branson, a single Bitcoin was valued at less than $10 two years ago. But earlier this week, the value of one Bitcoin reached $900.

"Bitcoins aren't yet formally recognized by governments as a currency but with some regulation, I hope that it will become more widely accepted," Branson said.

Who would pay for a ticket with Bitcoin?

A ticket to outer space aboard Virgin Galatic costs US$250,000. Branson said a "future astronaut," a female flight attendant from Hawaii, has already purchased her space travel ticket using Bitcoins.