Missile systems require optimal trajectory planning to maximize range and efficiency while ensuring mission success. This study focuses on the optimization of key design parameters, such as cruise speed, cruise altitude, and fuel consumption, using heuristic optimization techniques. A three-degree-of-freedom (3DOF) missile model is employed to simulate realistic flight dynamics. Three heuristic optimization techniques—Particle Swarm Optimization (PSO), Genetic Algorithm (GA), and PSO with Gradient Descent (PSO-GD) are evaluated based on convergence speed, solution accuracy, and computational efficiency. The results provide insights into the trade-offs between these methods, guiding the selection of the most effective optimization approach for missile design applications.