63 rd International Astronautical Congress, Naples, Italy. Copyright ©2012 by the International Astronautical Federation. All rights reserved. IAC-12-B4.6B.7 Page 1 of 9 IAC-12-B4.6B.7 HIGHLY INTEGRATED, LOW VOLUME AND MASS ADCS SUBSYSTEM FOR PICOSATELLITES Dr. Stefano Redi SSBV Space and Ground Systems, United Kingdom, sre@ssbv.com Mr. Vincenzo Capuano University of Rome “La Sapienza”, Italy, vincenzo_capuano@tiscali.it Mr. Samir A. Rawashdeh University of Kentucky, United States, sar@ieee.org Mr. Alexander Finch SSBV Space and Ground Systems, United Kingdom, a.finch@ssbv.com Dr. Massimiliano Pastena SSBV Space and Ground Systems, United Kingdom, M.Pastena@ssbv.com Mr. James Barrington-Brown SSBV Space and Ground Systems, United Kingdom, J.Barrington-Brown@ssbv.com This paper introduces the recent activities at SSBV Space and Ground Systems in the field of attitude determination and control (ADCS) for picosatellites. In particular the paper focuses on the design and development of an ADCS subsystem suitable for cubesat missions from 1U to 6U. The design presented integrates 1 magnetometer, 6 sun sensors, GPS, three metal core Torquerods, 3 axes MEMS gyros, momentum wheel and a stellar gyro in order to provide a complete solution for high accuracy 3 axis pointing. The system also integrates an autonomous intelligence which implements the attitude determination and control laws reducing the computational effort required by the main computer that is only responsible for the choice of a specific spacecraft attitude to be reached or maintained. The modular design is extremely compact allowing a very small size. The whole subsystem fits in the volume of two PC 104 employed as a standard for CubeSat applications, significantly reducing the overall mass. The extensive use of off the shelf components and sensors previously developed at SSBV also contributes to the reduction of the power consumption. Furthermore the paper introduces the results obtained from the test campaign currently under development at SSBV. The results obtained show that for cubesats up to 3U the pointing accuracy that can be achieved is better than 1 deg while for 4U and 6U cubesats the pointing accuracy is around 2.8 deg. The ADCS design is one of the latest products developed at SSBV, and it constitutes the most recent result of the activities of this company in the field of small satellites, which since beginning of operations in 2008 has been providing attitude control sub-systems for customers in USA, Europe, India, Taiwan and Indonesia. The ADCS board is due to fly in the next Techdemosat mission scheduled for the first quarter of 2013. I. INTRODUCTION The past 15 years have seen a rapid increase in the number of missions involving picosatellites and nanosatellites. The survey presented in [1] provides an overview of these projects, describing the main technologies employed and the main missions objectives. The results of this survey, based on a database developed by Delft University of Technology, demonstrate that since 1997, an increasing number of academic institutions, government bodies but also private companies have been investing resources in the design and development of this type of satellites. In particular the CubeSat standard, introduced in 1999 by California Polytechnic University and Stanford University [2] has represented a significant milestones in this field and it has triggered the success of pico and nano satellites. Most of developers belong to Academia with applications spanning from technology demonstration (majority) to scientific measurements and communications. However recent interest has also been shown by private organizations for possible commercial applications attracted by the shorter development time and the reduced cost. This interest demonstrates the potential that these missions can have in the near future, mainly driven by improvement in electronics miniaturisation and growing access to space. However challenging applications like for example earth imaging, military reconnaissance or even formation flight require accuracies in the determination and control of the spacecraft attitude that are beyond the