Abstract Improved dual spin turn which is applicable to the initial attitude acquisition of the initially spin-unstable momentum-biased 3-axially stabilized spacecraft is proposed. It has been believed that the dual spin turn method can not be applied to the initially spin-unstable spacecrafts without implementing some active nutation control. However, the improved dual spin turn method proposed for the initial attitude acquisition of the initially spin-unstable space-craft requires no active control loop, instead the reaction wheel rotated at the specified constant speed around the initial spin axis of the spacecraft. The analytical and the geometrical analysis for the validity of the method is shown and also the computer simulation results demonstrate the validity of the method.