SPAAS: Software Product Assurance for Autonomy on-board Spacecraft

The project objectives were to investigate dedicated software product assurance measures to support autonomous functions both for nominal spacecraft operations and for fault detection, identification and recovery management, i.e., how to ensure safety and dependability of autonomous space software and especially of software in charge of autonomous functions dedicated to the spacecraft safety and dependability management. Special attention was put on software product assurance for advanced autonomy techniques (artificial intelligence, self learning techniques, etc.). The project was split in two phases. The first phase investigated the lessons learnt from autonomous nonspace applications, the software product assurance requirements and then methods, tools and procedures, for autonomous space systems. Special autonomy software safety aspects were then investigated and an implementation plan was elaborated for the second phase. The main results highlighted on the one hand the necessity to cope with residual faults during execution (fault tolerance), and on the other hand the interest of intensive simulation-based testing before actual operations. The second phase was dedicated to the definition of software functions (on-board and in the ground system) for the safety of spacecraft with autonomy, and to their implementation and assessment through a pilot application. Two components were developed and experimented, in line with the results of phase 1: • An on-board component (the “safety bag”) for monitoring on-line of safety properties; • A ground based component (the “plausibility checker”) for complementary extensive validation of interpreted procedures. Deliverables: Phase 1: • Technical Note 1 “Lessons learned from autonomous non-space applications” • Technical Note 2 “Software product assurance requirements for autonomous space applications” • Technical Note 3 “Software product assurance methodology for the development of autonomous space systems” • Technical Note 4 “How to ensure safe decisions in autonomous space systems: candidate techniques for autonomy on-board spacecraft” • Technical Note 5 “Plan for implementing assurance software for autonomy functions” • Phase 1 final presentation slides Phase 2: • Technical Note 6: “Experimentation of SPAAS reusable components” • Technical Note 7: “Identification, collection and assessment of certification requirements” • Software data packages (on-board: “safety bag” and ground: “plausibility checker”): code, associated files and documentation • Final presentation slides • Final Report (this document), abstract The work described in this report was done under ESA contract. Responsibility for the contents resides in the author or organisation that prepared it. Name of author: Jean-Paul Blanquart (EADS Astrium SAS) NAME OF ESA STUDY MANAGER: Maria Hernek DIV: TEC-QQS DIRECTORATE: D-TEC ESA BUDGET HEADING: 061 * Sections to be completed by ESA SPAAS/FRP 2004-4-21 Page 3 of 32