BBC News Published image captionBezos and the Blue Origin team may not qualify as astronauts In a move that pours cold water on the dreams of a few billionaire space explorers, the US has tightened its definition of the word "astronaut". New Federal Aviation Administration (FAA) rules say astronaut hopefuls must be part of the flight crew and make contributions to space flight safety. That means Jeff Bezos and Sir Richard Branson may not yet be astronauts in the eyes of the US government. These are the first changes since the FAA wings programme began in 2004. The Commercial Astronaut Wings programme updates were announced on Tuesday - the same day that Amazon's Mr Bezos flew aboard a Blue Origin rocket to the edge of space.