Thursday’s test, the fourth so far by Virgin Galactic, carried two pilots and a passenger dummy on a spacecraft more than 50 miles into the air, high enough to meet the Federal Aviation Administration’s definition of space. Afterward, Branson was asked on CNBC when the company would start ferrying human passengers.

Branson said that SpaceShipTwo would first be examined to see if changes are needed before facing a few more rounds of tests. “Then we will move the operation to a space port in New Mexico,” he said. “Then I will then go up, and we’ll do another set of tests. If every box is ticked we will start to be able to take members of the public up.”

In the past, Branson noted, his timing estimates have erred on the side of the optimistic. “I always get these estimates wrong. It’s been 14 years to get to this stage. I thought it would be seven,” he said. “But I would hope sometime in the middle of next year, I’ll be going up and quite soon after that members of the public will go up.”

The cost of a trip on a Virgin Galactic spacecraft has been estimated to be between $200,000 and $250,000. In the interview, CEO George Whitesides said that the price for early trips might be higher than that range, although the company hopes it will eventually be lower in the longer term.

To accommodate more passengers, Virgin Galactic is building two more spaceships. Branson said all three may be taking humans to space “in the not too distant future.”