A swarm intelligence based approach has been used for design optimization of a single stage solid propellant small sounding rocket. The selected sounding rocket (SR) is capable of placing a small payload of 20 kg to an apogee of 100 km altitude. This optimization approach combines the advantage of a particle swarm optimization (PSO) to find the optimum. The aerodynamic, trajectory, propulsion and mass model were implemented in a Matlab environment, and a multi feasible design was applied to integrate the modules. It is shown that the proposed optimization approach was able to find a rapid convergence of the optimal solution with acceptable precision.