ScOSA - Application Development for a High-Performance Space Qualified Onboard Computing Platform

摘要

Future onboard computing applications require significantly greater computing performance than is currently provided by standard space qualified onboard computers. Examples of such applications include onboard data analysis and (rendezvous) navigation tasks. Therefore, the German Aerospace Center is currently developing Scalable On-board Computing for Space Avionics.(ScOSA). The aim of the ScOSA onboard computing platform is to deliver high performance, reliability, scalability and cost-efficiency. To reach these properties, a distributed computing platform approach is used, by which reliable radiation hardened computing nodes (LEON3's) are combined with several high performance computing nodes (Xilinx Zynq), connected over a high-bandwidth SpaceWire network. The execution platform consists of a distributed task-based framework. In this paper, the architecture, features and capabilities of the ScOSA onboard computing platform are presented from an application developer's view. A brief summary of the design goals and the general hardware and software architecture of the ScOSA system will be introduced. This is followed by a description of the programming model and the application interface, with a focus on how the distributed nature of the ScOSA system is handled. It will also be shown how an existing application can be integrated in the ScOSA system. The main part of this paper will focus on the computing performance attainable from the ScOSA platform. There will be a comparison of the computing performance of an example application executed on the ScOSA system versus a standard PC. It will also be demonstrated how the performance of an application can be improved by adapting it to the distributed computing architecture of the ScOSA platform. Furthermore, a short overview of the failure detection and recovery features of the ScOSA platform are described and how they can be integrated into an application.