This book describes the development and design of a unique combined data and power management infrastructure for small satellites. This new edition became necessary because in the frame of the systems impressive evolution from an academic prototype to one of todays most advanced core avionics, many elements were upgraded to their next technology generation and diverse new components complement the upgraded design. All elements are presented in updated respectively new chapters. This modular infrastructure was selected by the Swiss start-up ClearSpace SA for ESAs first mission ClearSpace-1 to remove space debris. Furthermore it is the baseline for the Thai national satellite development program and is used by an increasing number of universities worldwide for research studies.