The idea of flying tourists into space goes back to the 1980s, when NASA and the Space Transportation Association appointed a panel to examine the possibilities. I was a member of their steering committee. The panel concluded that there was a viable market for space tourism — if launchers and spacecraft of suitable safety and reliability could be developed. Several companies are now chasing that goal. The leader among them is Virgin Galactic, a company that brought together Sir Richard Branson, the British entrepreneur who founded Virgin Airways, and Burt Rutan, designer of record-breaking, innovative aircraft.