Description: A method is propsed to develop a sensor fusion process for blending GPS/IMU/EO data for fault tolerant rendezvous and docking of spacecraft. The methodology takes advantage of analytic redundancy between the GPS and EO sensor technology. Using advanced fault detection, identification, and reconfiguration (FDIR) technology, the method will guarantee navigation functionality in the presence of failures in either the GPS or the EO sytsem guaranteeing safety of operations in the safety critical docking operation.