High area-to-mass ratio space objects at geosynchronous orbits pose a threat to operational satellites because of the difficulty to track them from Earth. This paper develops an in-orbit on-board algorithm for tracking high area-to-mass ratio space objects. The design utilizes relative motion dynamics and a simplified stereo-camera measurement model to estimate the tracked object's position and velocity, as well as its solar radiation pressure coefficient. An underlying assumption is the dominance of the solar radiation pressure perturbation. Two scenarios are examined: similar orbits and crossing orbits. The simulation results show that the tracking algorithm estimates the tracked object position, velocity, and solar radiation pressure coefficient in both scenarios with high accuracy. The simulations show that although shape information is lost in the measurement model, the solar radiation pressure coefficient can still be estimated.