1 Gyroscope technologies for space applications M. N. Armenise, C. Ciminelli, F. De Leonardis, R. Diana, V. Passaro, F. Peluso Optoelectronics Laboratory, Dipartimento di Elettrotecnica ed Elettronica, Politecnico di Bari Via Orabona n.4, 70125 Bari, Italy, e-mail: armenise@poliba.it Abstract In this paper a review of the gyroscope technologies for space applications is reported. For each technological approach the principle of operation, advantages and disadvantages are discussed. Also, some future trends are predicted. 1. Introduction Guidance, navigation and control systems both in aircrafts and spacecrafts require gyroscopes to maintain orientation in flight even in case of undesired interference. In particular, the measurement of the angular motion of a satellite in the space is essential for the control and stabilization of its attitude. Systems employing a gyroscope include the control and processing electronics to provide the most direct method for sensing inertial angular velocity. Navigation systems, including also land transport vehicles, require gyroscopes with a sensitivity as low as 10-100°/s, attitude and heading reference systems in the airplanes use 1°/s gyroscopes, while precision inertial navigation systems [1], such us military airplanes and ships, spacecrafts and satellites, need a sensitivity value as high as 0.01-0.001°/s. This paper presents a review of gyroscope devices [2]. The main technological categories are described in detail. For each of them, the operating principle, device structures, fabrication technology, specifications, open issues related to the design, packaging and interface electronics are discussed. A comparison among the performances allowed by the different technologies is also presented together with an indication of the future trends for the development of high – performance gyroscope, devoted to space applications.