Just some info: Transonic/supersonic and near-speed-of-sound aerodynamics differ from traditional low velocity aerodynamics (I think the threshold is approximately 0.25Vs, so up to 1/4 of the speed of sound, I am a bit rusty on that). After that point you can't ignore compressibility phenomena, meaning that the density is no longer a constant, but also becomes a variable. You may be able to reduce drag by going very high in the atmosphere where the air is very thin (10^-6). Speed of sound also is an equation of the density and the temperature.