STU-2A, a 3U CubeSat developed by Shanghai Engineering Center for Microsatellites, along with the other two 2U CubeSats and one MicroSat, has been sent into a 481km sun-synchronous orbit by CZ-11 launch vehicle with its maiden journey. As the first batch of CubeSats in China that is made in accordance with CubeSat standard, the 2.9kg satellite is featured with the on-board CMOS color camera for taking pictures of polar glacier, Gamalink for Cubesats Networking, MEMS based cold-gas micropropulsion for attitude/orbit maneuver and formation flight and precise ADCS module for technology demonstration. The ADCS module, equipped with two 3-axis magnetometers, 1 fine Sun sensor, five coarse Sun sensors, one three-axis MEMS gyro, one Nano-scaled star tracker, three magnetic coils and three reaction wheels, would provide three-axis stabilization and maneuver capability. Combining the attitude sensors, TRAID and unscented Kalman Filter (UKF) algorithms are adopted to determine the attitude knowledge. Some attitude control modes, such as damping control, Sun-pointing, magnetic-based nadir pointing, momentum-biased stabilization and reaction wheels-based control, are designed to achieve the prefect attitude.In-Orbit data received by ground station verified the performance of ADCS of STU-2A
