Private space flight: Oops...

"ROCKETS are tricky," quipped Elon Musk, the founder of SpaceX, a firm that builds and launches them, just after one of his blew up. That thought will surely have crossed minds at Orbital Sciences, another such company, whose latest mission exploded spectacularly on October 28th, 11 seconds after it took off from the Wallops Flight Facility in Virginia. The mission-control staff themselves sent it a self-destruct order when something was clearly amiss.SpaceX and Orbital are the only American out...