The Stellar Attitude Rate Measurement Unit (STARMU) helps control a satellite’s position, using stars as reference points. It is a radiation-hardened integrated stellar-inertial attitude determination system for pointing and stabilization of satellites. The fault tolerant system supports 15-year missions.

The architecture entails independent star trackers and rate sensor channels for continuous output of inertial attitude and body rates. Typical short term (2 hr) pointing accuracy is better than 4.5 src-sec (3 sigma) with gyro in-run bias better than 1 deg/hr over 1 hr. The I/O interface is Mil-Std-1553B. Primary power options include 28V and 70Vdc.