Autonomous systems are intended to operate without human intervention over prolonged time periods, perceive their operating environment, and adapt to changes – while pursuing defined goals or generating new ones. The perception functions process the inputs of various sensors and generate an internal model of the operating environment. By relying on this model, the decision functions plan and execute the actions required to achieve the goals of the mission. To achieve safety for an autonomous system, the engineers should ensure that the perception functions can sufficiently accurately build the model of the environment, i.e., perception and establishing a context for prediction are reliable. They also seek to ensure that the planned actions are safe, i.e., decisions do not result in actions that endanger humans or other agents in the operating environment.