> And, remarkably, it also went on to fly into space more than a dozen times. Only twice, according to the standard everyone else uses. Saying the X-15 has bee

> And, remarkably, it also went on to fly into space more than a dozen times. Only twice, according to the standard everyone else uses. Saying the X-15 has been to space a dozen times is like weighing yourself in kilograms to make the number smaller. Certainly helps the ego of those Air Force pilots, and Blue Origin, though!