In this paper, unlike other developments in missile guidance which rely on
solving a system of coupled nonlinear differential equations, an innovative
approach is presented for studying tactical missile guidance. The moving o
rthogonal coordinate system of classical geometric curve theory is similar
to the stability axis system used in atmospheric flight mechanics. Based on
this similarity, the Frenet-Serret formula of classical geometric curve th
eory together,vith the concept of a pseudomissile pointing velocity vector
are used to analyze and design a missile guidance law The capture capabilit
y of this guidance law is qualitatively studied by comparing the rotations
of the velocity vectors of missile and target relative to the line of sight
vector. Sufficient initial conditions for capture are found by following s
equences of engagement geometry with different initial conditions.