The present invention provides a method for the attitude control of
satellites in elliptic orbits or satellites initially placed in circular
orbits perturbed to elliptic orbits due to environmental disturbances.
The method relies on the application of solar radiation pressure to
provide the desired torque for the satellite attitude control. The
satellite is equipped with two-oppositely placed light-weight solar
panels extending away from the satellite along a predetermined direction
(satellite body fixed Y-axis). By rotating one of these solar panels or
both of them through desired angles about their axis using the respective
driver motors as per the simple open-loop control law, the torque about
the satellite axis is developed to achieve the desired attitude
performance. The open-loop control law is derived using an analytical
approach to neutralize the excitation caused by eccentricity and it is
implemented via analog logic based on the information of sun angle and
satellite position provided by the sensors. The present invention
significantly improves the performance of the satellite by a factor of
more than 20 times approximately in general and it only requires the
rotation of the solar panels by fraction of a degree for particular
system parameters. Thus, the semi-passive nature of the present invention
makes it attractive for future space applications.