Does it really matter if fins are swept forward or back? After looking at the pix of the CSXT booster and seeing the reverse sweep fins I've been wondering if there was any technical reason for the shape. Or was it just cosmetic? Since the thing went supersonic I guess the shape could be an aerodynamic aid of some kind. But the fin tip seems to be the least supported part of the structure and a little vibration would be a very big problem at those speeds. Anyone care to clear up this point? Some of my toys are going to go mach+ "soon" and it'd be good to know this stuff towards that time.