This paper deals with polymer actuators using carbon nanotube bucky-gel, or CNT actuators for use in space. CNT actuators are composed of a pair of CNT bucky-gel electrode films and an ionic liquid polymer electrolyte membrane. When a voltage is applied to the electrodes the CNT actuators bend due to movement of the ionic liquid. This actuator type is studied in order to confirm its operating principles and methods of fabrication, and to improve its displacement characteristics, producible stress and responsiveness. The paper reports the results of this study with emphasis on the displacement characteristics.