Billionaire entrepreneur Sir Richard Branson announced on CNBC's "Squawk Box" Friday that his commercial space flight venture will accept bitcoin as payment. He called it "a new exciting currency." Virgin Galactic accepted its first purchase with bitcoin from a flight attendant in Hawaii. Branson—an early bitcoin investor himself—said the woman made "quite lot of money getting into bitcoin early on." He said she paid in bitcoin, which was transferred into actual dollars "so there's a fixed price ... [and] we can actually pay her money back, if she changes her mind about going to space in a few months." If Virgin Galactic didn't have a refund policy, it might be willing to take the risk on a pure bitcoin transaction, he said. The cost in U.S. dollars to book a space flight is $250,000. (Read more: Bitcoin accepted by university in Cyprus)

Branson did the interview from his private island in the Caribbean, Necker Island, where the rebuilding project of his luxury home is now complete. The previous one burned down two years ago. "It's rebuilt. It's beautiful," he said. "We've actually got 30 astronauts who signed up to go to space here at the moment."

Before the CNBC interview, Branson tweeted: Want to spend your #bitcoins? How about a ticket to space! Will discuss today live on @SquawkCNBC @virgingalactic

Many bitcoin users are the type of people who will buy tickets for space travel, Branson told CNBC via a Skype video connection with a cellphone for audio pressed to his ear. "Virgin Galactic is a bold entrepreneurial technology. It's driving a revolution. And bitcoin is doing just the same when it comes to inventing a new currency."

"I think the fact that there's going to be a limited number of bitcoins out there and it will ultimately be capped—unlike normal currencies where governments can print more currencies—gives it a sense of security," he said, but acknowledged the risk. "There have been spikes and lows. But I think one day it will settle at a price that, I personally believe, is higher than the price today." For bitcoin's latest price, (click here.) (Read more: Winklevosses: Bitcoin worth at least 100 times more)