There's an old joke about the man who asks his neighbor to turn down the loud, raucous noise emitting from her stereo."What's the matter, are you a music hater?" "No," he replies, "I'm a music lover." I'm reminded of this by the calls of some over the years to end the space-shuttle program, even (perhaps especially) by people who are frustrated by our lack of progress in space. In the wake of the latest tragedy, the calls will undoubtedly grow louder, but in many cases, even if correct, they will be for the wrong reasons, and may not lead to...