The ESRO I Attitude Measurement System

A system for measuring the attitude of a small scientific satellite is described. It consists of a magnetic aspect system and a solar aspect system, and has been flown successfully on two missions. The development was aimed at achieving maximum precision while observing the severe restrictions natural in a small satellite. The result is a set of instruments differing in several respects from previously existing hardware. The flight results have proved very interesting and are expected to yield useful technological experience.