Stage separation dynamic analysis of upper stage of a multistage launch vehicle using retro rockets

This paper presents in brief the formulation used for the studies of lateral and longitudinal dynamics associated with separation and pull out of an ongoing functional stage from the spent stage of a multistage launch vehicle using retro rockets as jettisoning system. A fourth-order Runge-Kutta method is employed to solve the governing nonlinear differential equations of motion to obtain the state vectors of the separating bodies. A statistical method is adapted to account for the off nominal design parameters of the bodies undergoing separation and the jettisoning system. The tolerances in magnitude of the pull out time, relative velocity, lateral gap and longitudinal clearances between the separating bodies were used to find out the nonoccurrence of collision between the separating bodies. This procedure helps in designing and adapting a suitable jettisoning system to achieve collision free separation of multistage launch vehicle stages.