Strategically Radiation-Hardened Star Tracker

ABSTRACT: We propose a new radiation-hardened star tracker system which will provide high-precision performance while meeting all radiation requirements listed in the solicitation. It has a baffle, focal-plane arrays, microprocessor, memory and power supply. The key component is a high-performance microprocessor fabricated using the Micro-RDC rad-hard Structured ASIC process. This is a low cost solution to implement the rad-hard microprocessor and communication interfaces including Space Wire, I2C, and USB. In addition, the system will include a rad-hard memory and CMOS active pixel sensor (APS). The system has a simple architecture with a small number of components. The star tracker will have total ionizing dose (TID) tolerance greater than 1 Mrad (Si). The performance degradation of the star tracker at 300 krad(Si) will be less than 30%. The star tracker will have an inertial pointing measurement error of less than 1 arc-second. The star tracker can continue to operate at track rate slew up to 2 degrees per second. The"lost in space"feature will be included, too. BENEFIT: The target market of the radiation hardened star tracker includes all satellite or space applications that need attitude information, especially these satellites required to work for long time in radiation environment or following a high dose rate event. For general commercial satellite, the radiation hardened star tracker can extend the life time of whole system and work more robustly in some harsh space environments, such as"space storm"when Sun activity peaks. The proposed star tracker has the advantage of high radiation tolerance, high accuracy and low power. Comparing to existing start trackers, our star tracker is competent for high reliability and long term space applications, especially for military satellites. In addition, the radiation hardened computing part can be used in all space applications that needs low power, high performance and radiation tolerance. The application is much wider than the star tracker.