The A-STR from Leonardo is an Autonomous Star Tracker that is designed for satellites used in LEO and GEO orbits. It has an accuracy of 8.25-11.1 arcsec and an update rate of 4-10 Hz. This star tracker has a mass of 3.55 Kg. It has a tracking rate of up to 2 deg/sec and a field of view of 16.4 x 16.4 deg. This star tracker requires a DC supply of 20-50 V and has a power consumption of up to 13.5 W. It supports the RS-422 interface and has a high-performance MPP CCD detector that can be used in extremely accurate pointing space telescopes and agile satellites. This MIL-STD-1553B certified star tracker measures 195 x 175 x 290.5 mm and is ideal for telecommunication geostationary satellites, earth observation satellites, scientific satellites, and for interplanetary missions/probes applications.