The technical key parameters of the APS based star sensor are the low mass budget with <1.5kg (at 5V power supply), the low power consumption with <5W and the attitude quaternion accuracy of <1arcsec (1sigma) at 10Hz update rate. These data define a new level of compactness compared to state-of-the-art CCD-based star sensors for the GEO telecom market (>18 years life time).
The improvements in dimensions and performance are realized with the replacement of the CCD detector by the APS detector technology (STAR 1000, HAS). The mass and envelope benefit is based on the very high functional integration of the APS detectors. The whole analogue read-out and sampling electronics is placed on the detector chip. This saves PCB area compared to CCD-based systems. The parts count for an APS based star sensor is reduced accordingly. Along with that, the unit costs are reduced and the system reliability is increased.
Based on its very compact design, outstanding reliability and attractive price, the ASTRO APS is a star sensor for both LEO and GEO applications.
A Flight Model of ASTRO APS will be integrated on the European large telecom satellite AlphaSat for demonstration of its outstanding capabilities.