Abstract: The attitude control of a rigid spacecraft with two momentum wheel actuators is discussed. The control problem of the system can be converted to a nonholonomic constraint motion planning problem of a drift-free system with non angular momentum. A particle swarm optimization (PSO) algorithm of a spacecraft attitude motion planning with two momentum wheel actuators is proposed by using optimal control method and the spline approximation technique. The optimal controls are smooth and the initial values and terminal values are zeros, so the wheels can be controlled easily by controlling servomotors. The effectiveness of the approach is shown by a numerical simulation.