Benefits of using functional safety in commercial space applications

Abstract

According to IEC61508 functional safety is relevant whenever a product or system contains electrical, electronic or programmable electronic elements that perform safety-critical functions. It is used in many areas of technology such as, process industry (e.g., energy sector), automotive (transport sector), mechanical engineering, or aviation. This article will compare the approaches and concepts of Functional Safety based on IEC61508 and ISO26262 with the RAMS (Reliability, availability, maintainability and safety) approaches of the space industry, in particular with the Fault Detection Isolation and Recovery (FDIR) approach. The paper will provide an insight into the possibilities of minimizing risk at the component level, especially for complex integrated circuits. Traditionally, the space industry has focused on qualifying the components used for the extreme environmental parameters and the typically very long duration of use in space. However, as ICs (Integrated Circuit) have become very complex, there is significantly increased risk of systematic failures that can occur during the development of the component itself and also by the designer using it for development the actual circuit board assembly. In addition, the cost of components is a major factor in the development of satellite constellations due to higher volumes, so a trade-off between qualification and affordability must be found. The presentation will show how systematic faults in other market sectors can be avoided as far as possible and how so-called random faults can be detected as quickly as possible and their effects ideally eliminated or at least minimized with the help of appropriate performance features of the semiconductor products, such as ECC (Error Correction Code), lock-step, or BIST (Built-in Self Test). The successful mission of the Mars Rotorcraft Ingenuity from JPL (NASA) provides an insight into the practical application of a functional safety concept in a space application. This paper is intended as a suggestion on how to make the best use of existing features of semiconductor products developed for functional safety in other market sectors also for space applications.