In the last fifteen years a series of Electroactive Polymers (EAP) materials have emerged that exhibit a significant shape or size change in response to electrical stimulation. These materials have the closest response similarity to biological muscles enabling to engineer novel capabilities that were considered until recently science fiction ideas. Initially, EAP received relatively little attention due to their limited actuation capability. Recent progress led to dramatic improvements in the capability of these materials and efforts are underway to address the many challenges that are hampering the practical application of these materials. Various novel mechanisms and devices were already demonstrated including robot fish, catheter steering element, robotic arm, gripper, loudspeaker, active diaphragm, and dust-wiper. For developers of future planetary mechanisms the flexibility, fracture toughness, low mass and low power requirements of these materials are offering numerous advantages. This paper provides background about these materials and it includes a review of the state of the art, challenges and potential applications of these materials for future space missions.