Simple method for performance evaluation of multistage rockets

► A multistage rocket with realistic structural, propulsive, and aerodynamic data is considered. ► A simple, easy-to-implement method for performance evaluation is proposed. ► For the first two stages an iterative process combined with an optimization routine is used. ► For the upper stage the analytical conditions for optimality are employed in conjunction with a swarming optimizer. ► The numerical results are presented for three three-dimensional cases.