Operations System vs. Operating System: Towards a Ground System Supporting Satellite Application Programming

The term operating system refers to a software component, which traditionally controls the resources and the processes of a computer, and by providing the appropriate interfaces allows for the implementation of custom user applications. This is a common definition, working very well for ordinary computer systems. Yet, what if the operating system and a corresponding application are physically separated, because the computer is within a satellite in space, while the user program is executed on ground? Then, capabilities must be created to connect both, which is of course complicated by the natural boundaries in satellite communication, for example the limited satellite contact times. Over the past decades, several systems have been developed, which are capable of managing satellite resources and the mission schedule from ground. Although this covers quite well the purpose of an operating system, other terms have evolved in this domain: operations system, ground system, mission control system, ground data handling, etc. The problem though is, those systems primarily focus on the exchange of data and satellite TM/TC, rather than the actual control process. This creates an artificial barrier between ground and space, which harms the development capabilities for ground based satellite applications. This paper introduces a novel approach for an operations system architecture, which can be considered as a ground extension of the satellite’s operating system. This approach shall not break with the existing conventions and definitions, especially in terms of operating systems, but shall introduce a new view on satellite operations. In a layered, functional software architecture, the operating system is the lowest layer between the hardware and the application. Through the definition of the appropriate interfaces in the ground system, a software architecture can be created that actively supports outsourcing parts of the satellite control process to ground. The proposed approach has great potential for various applications in satellite operations. It supports the implementation of automatic system control processes, the implementation of custom payload applications, and the integration of respective activities into the satellite schedule. As applications and operators interact with a verified schedule, and operations is thus no longer limited to low-level commanding, the approach further reduces the risk of the mission being jeopardized by human mistake.