Flight Data Analysis and Electromechanical Simulation of Sounding Rocket Stability.

The post-burnout angular motions of three divergent NIRO sounding rocket flights have been examined using rigid body energy techniques previously developed. Two of these flights exhibited roll-pitch lock-in through burnout and for several seconds after. All exhibited a rapid initial increase in coning angle followed by an actual decrease and a later more gradual divergence consistent with increased altitude. The rigid body kinetic energy histories show a double peaked character which implies that energy is temporarily stored internally such as in structural deformation. The magnitude of the energy in transverse motion is small enough so that de-spun damping of reasonable weight penalty is feasible. The previous study indicated that coning divergence of a spin-stabilized sounding rocket could be eliminated by the use of a passive de-spun rotor stabilization system. Author