I don't care what Websters (or whoever made your dictionary) says, the miltary definitions make distinct differences between artillery projectiles, rockets, and missiles. A missile is a guided and non-ballistic. The projectile pictured is neither.
And therein lies one of the problems with the 'conservative' movement. Facts don't matter. The original post rallied around the point that the NY Times was wrong. When in fact, from the very definition of English, they weren't. They used the correct definition of the word. As a non-military person, they used the word that best fit according to the dictionary. But Webster's, Oxford, American Standard, they're all wrong. They just have to be. Or else the whole point of the original poster was wrong (not to mention somewhat idiotic). And we can't have that.....
But we'll just get around to redefining all the words in the dictionary to fit your world view shall we?