The Orsted Star Imager, comprises the functionality of an advanced stellar compass (ASC), i.e. it is able to autonomously solve 'the lost in space' attitude problem, as well as determine the attitude with high precision in the matter of seconds. The autonomy makes for a high capability for error rejection and faulty recovery, as well as graceful degradation at radiation, false object or thermal loads. The instrument was developed from concept to flight model within 3 years. The instrument surpasses the initial specifications for all parameters. For precision, computational speed and fault detection and recovery by orders of magnitude. This was accomplished, by the use of advanced high level integrated chips in the design, along with a design philosophy of maximum autonomy at all levels. This approach necessitates a prototyping facility, capable of extensive component screening. This screening addresses topics such as chip technology and thermo-mechanical propeties, as well as radiation sensitivity. The purpose of this facility is to reduce costs, by generating early information concerning whether specific components have the ability to survive space environs. This paper describes the development philosophy and the development process. Starting with the system specifications and its derived design drivers. Via the design process, iteration levels and the specifications and capability of the prototyping facility. Ending with the final system design. During this, actual choices of IC- levels and system flexibility are addressed.