High Accuracy Star Sensor for Indian Regional Navigational Satellite Segment “NAVIC”

ISRO has successfully launched series of satellites for Indian Regional Navigation Satellite Segment named as NAVIC, which consists of a constellation of SEVEN satellites launched into Geo Stationary (GEO) and Geo Synchronous (GSO) orbits. The pointing and thermal management of the payload require continuous attitude steering of the satellites. This requires autonomous attitude determination and control. To meet these requirements a new MPP CCD based high accuracy low mass star sensor with an accuracy of 10” with an update rate of 8Hz was designed and developed. This paper describes about the design aspects of the Star sensor flown on-board NAVIC satellites and its performance.