A major concern when dealing with test, validation and in-flight fault diagnosis of On-Board Software, whose complexity is continuously increasing, thanks notably to the increased computational power provided by modern microprocessors, is the level of observability that is provided to software and hardware engineers. In general terms, the more observability is provided to the engineering teams, the easier it is to diagnose an anomaly. Classical observability mechanisms are not enough to provide the needed observability of nowadays avionics systems. 

The main objective of this activity was to propose ways of increasing the flight software observability capabilities and complementing current testing techniques thanks to enhanced mechanisms provided by modern microprocessors and operating systems. The outcomes of this activity were therefore: an state of the art of existing observability mechanisms, a list of proposals on how to use the identified observability mechanisms during testing but also during the operation of the satellite, as well as recommendations to enhanced current development, integration and testing of on-board computers.