Investigation of factors which contribute to mallaunch of free rockets

Abstract : The simulation of the motion of a single-round launcher/rocket system during launch, transition to free flight, and free flight of the rocket is considered. A simple physical model for the system is described. The model consists of an arbitrary rigid-body launcher, with 3 deg of rotational freedom, and an arbitrary rigid-body rocket, which is attached to the launcher during the spin-up (if applicable), detent, and guidance phases by 'springs.' These springs are intended to model the flexibility and damping characteristics of the rocket's shoes or the interface between the rocket and the tube of a tube-type launcher. The model also includes the effects of thrust malalignment, tipoff, variable thrust, and spin torque programs and friction. Using modern vector/ matrix algebra, the vector equations are converted to matrix equations, amenable to digital programming and solution. Results of preliminary simulation runs made using a computer code written to perform the required numerical integration are presented and discussed.