Galileo Safety and Dependability Programme for Safety of Life Applications
Brown, Andrew; Watts, Nigel
European Space Agency
A key objective of the Galileo Program is to enable critical Safety of Life applications to exist based upon the usage of the Signal In Space, produced by the Galileo System and operated by a Galileo operator.
The usage of Galileo within Safety of Life applications all over the world enforces the need for certification of the system by external bodies. However, since the individual certification requirements are not yet fully known, the current Galileo safety analyses need to anticipate almost any eventuality.
To this end very stringent performance and safety requirements have been applied to the system in terms of integrity, continuity, availability, single point failures etc. and a rigorous set of analyses performed, including RAMS & Performance modelling, on the system design to identify feared events. These feared events are then either eliminated from the design or suitable mitigations implemented. This is an iterative process that continues from the conceptual design stage through to the Critical Design Review and beyond.
The EGNOS project, which is the precursor to Galileo, faced many similar problems to those on Galileo in terms of the implementation of a safety & dependability programme that would facilitate the eventual certification of the system. Now in the final stages of defining how, and by whom, that system will be certified for Safety of Life applications the lessons learnt from the EGNOS project have been, and will continue to be, injected into the Galileo programme.
It is clear that a major input will be required from the ESA Galileo project in terms of documentation to demonstrate that the system has been designed and built to meet the stringent performance and safety requirements. This documentation must be provided in a truly transparent form to facilitate incorporation into future certification submissions.
This paper will report on the methodology adopted by the ESA Galileo Project to provide the required inputs to enable the eventual certification of the system, and will illustrate how the Galileo approach to systems design and management is used to demonstrate compliance to the system performance and safety requirements.