@edenceover is probably referring mainly to the boost-glide vehicles that are moving at up to mach 20 ... through atmosphere. The air-breathing cruise missile t

@edenceover is probably referring mainly to the boost-glide vehicles that are moving at up to mach 20 ... through atmosphere. The air-breathing cruise missile type designs go slower (only mach 6-ish) but at that speed you can have a sane discussion about guidance. This rocket-guidance problem, by the way, is where the Black-Scholes model came from.