I. The Unthinkable
Commercial passenger service to space is a difficult proposition. To succeed, it has to contend with the pull of gravity, violent rocketpropelled accelerations, heavy vibrations, supersonic speeds and shock waves, vertical climbs, the lethality of the outside environment, and the problems of deceleration and heating during re-entry into the atmosphere. It has to do this safely, reliably, repeatedly, and perhaps profitably, while carrying ordinary passengers in ordinary clothes, who, if they are traveling point-to-point, will want to bring along ordinary luggage as well.
We are far from that now. But by last fall, Virgin Galactic, a self-described “spaceline” founded by the flamboyant British entrepreneur Richard Branson and based in Mojave, California, was nearing the moment when it could offer rides to as many as six passengers at…