The idea of space tourism -- which already was a costly, risky adventure – now is pushed back by a dramatic test flight crash. A rocket-powered passenger plane called SpaceShipTwo broke apart at an altitude of 45,000 feet near the start of an Oct. 31 flight over California's Mojave Desert, killing the co-pilot and seriously injuring the pilot.

"We are determined to find out what went wrong," says Richard Branson, a British billionaire who heads Virgin Galactic, a company that wants to take rich tourists on short flights into space. "We would love to finish what we started." Two months ago, he voiced hope that flights would begin next spring. A second six-passenger space plane is being built, but aerial tests may await a year-long inquiry by the National Transportation Safety Board. That's a new role for federal investigators who typically respond to situations involving trains, vehicles or regular planes. The board helped look into the loss of U.S. space shuttles in 1986 and 2003, but never before took the lead in investigating a manned space launch.

Company says: "In the early days of aviation, there were incidents, and then aviation became very safe. . . . We do understand the risks involved, and we are not going to push on blindly. We're going to learn from what went wrong, discover how we can improve safety and performance, and then move forward." – Richard Branson, head of Virgin Galactic

Science author says: "Criticism of 'space tourism' today echoes the scoffing of a century ago that greeted the arrival of powered flight. . . . Many experts of the day were certain that flight, however interesting, was destined to be not much more than a rich man's hobby with no practical value." – Sam Howe Verhovek, book writer

Aviation writer says: "What to many must have seemed the prospect of a spectacular joy ride is now better appreciated as a thrill from the very edge of what is safely attainable." – Clive Irving at thedailybeast.com