Multidisciplinary Design Optimization (MDO) of a two-stage Small Solid Propellant Launch Vehicle (SSPLV) by simulated annealing (SA) Method is investigated. Propulsion, weight, aerodynamic (geometry) and 3degree of freedom (3DOF) trajectory simulation disciplines are used in an appropriate combination. Suitable design variables, technological-functional constraints and minimum launch weight objective function are considered. To handle constraints augmentation of constraints to cost using penalty coefficients are used. Results are compared with gradient-base method that shows the ability of SA to escape local optimums.