Abstract:The problem of attitude stability of dual spin sate11ites with flexible appendages is studied in this paper. The model of the flexible dual spin satellite consists of a semirigid platform with a semirigid axisymmetric rotor and n flexible appendages attached to it. The relative energy function of the system is selected as a Liapunov function in terms of the attitude angles and mode coordinates,and the attitude stability criteria is obtained by using the Liapunov stability theorem.