Will space tourism really lift off?

In the autumn of 2004, Richard Branson hosted a press conference at the Royal Aeronautical Society in London. It was conceived to launch his space tourism venture Virgin Galactic – and proclaim the dawn of a new era that would “bring the dream of space travel for many millions closer to reality”.

“Within five years, Virgin Galactic will have created over 3,000 new astronauts,” proclaimed the ebullient billionaire. Twenty years later, the company has flown only 37 people to space,…