  The purpose of this paper is to present an application of the State Dependent
Riccati Equation (SDRE) method to satellite attitude control where the
satellite kinematics is modeled by Modified Rodriguez Parameters (MRP). The
SDRE methodology is applicable on special forms of nonlinear systems where
satellite model is one of the candidates. It is not easy to find an analytical
solution from the SDRE. Thus point wise solutions are interpolated with respect
to the operating conditions. The point wise solutions are obtained from the
MATLAB algorithms which are derived from the positive definite solutions of the
SDRE. The global stability analysis is difficult due to the nature of the
methodology. The resultant attitude controllers outside the breakpoints (the
selected operating conditions for interpolation) are suboptimal. The
performance of the designs is examined by simulations on MATLAB - Simulink
environment. The simulation results show that, the designed attitude
controllers are working satisfactorily even in the presence of inertial
uncertainties.
