This thesis examines the damage induced by proton radiation on the Sinclair Interplanetary S3S star tracker. The star tracker is made from commercial othe shelve (COTS) components, which are not speci cally designed for use within a radiation environment. The detector was irradiated with high energy protons of 100MeV to a 9krad total ionizing dose (TID). After high temperature annealing process, the sensor was analysed for functionality and image quality. Immediate responses to the radiation include the rise in dark current and the creation of hot pixels. The combination of the damage introduced false detections of stars from the matching algorithm. By adjusting image correction parameters, which includes the raw threshold and the size of the point spread function (PSF), false detections were reduced. Finally we examine ways of detecting hot pixels from the irradiated unit.