It’s been a busy couple of months for Virgin Galactic, Sir Richard Branson’s space tourism venture. WhiteKnightTwo — the mothership that will launch Virgin Galactic’s tourist spaceship, SpaceShipTwo — made its maiden flight from California’s Mojave Air and Space Port December 21. On December 17, 2003, the jet-powered WhiteKnightOne lifted SpaceShipOne to 50,000 feet, where it then rocketed into suborbital space. SpaceShipOne received the Ansari X...

Once upon a time, barnstorming over the countryside in a biplane was sufficiently thrilling and expensive for the idle rich. Then, the only thing that would do was taking a steamer to Africa to blast away at lions for the season. Then there was (and remains) the curious habit of paying a small fortune for the privilege of expiring on Mt. Everest from hypothermia, oxygen deprivation, or stumbling into a crevasse. Much later, attempting to circumnavigate...