Instability of Spinning Projectiles During Terminal Guidance

We examine the criteria for dynamic stability of a spinning projectile subjected to steady horizontal and vertical side forces applied at the nose; such forces could, for example, be generated by canards mounted on a roll-stabilized nose. The problem requires an extension of standard aeroballistic theory which yields intersting new information on stability. It is found that the precessional and nutational modes can become unstable, depending on the magnitude and direction of the applied side force. Results of numerical simulations which confirm these conclusions are given.