Down To Earth Systems Engineering: The forgotten ground segment
- Paper number
IAC-06-D1.5.04
- Author
Dr. Ed Chester, SciSys GmbH / ESA-ESOC, Germany
- Year
2006
- Abstract
Systems engineering involves dealing with a project, a system, at the level at which it operates. The system perspective is concerned with the behaviour and interfaces rather than implementation details, and engineering a given instance of a system is typically much more complex than the sum of its parts precisely because we are concerned with overall behaviour. Systems engineering is an integral aspect of spacecraft engineering throughout the mission lifecycle – systems engineers are architects and designers in a project up to phase B, they are testers, reviewers and modellers in phases C and D, and they are operators in phase E. However, the ground segment that enables a mission to be conducted is surprisingly devoid of systems engineers.
It has specialists in networking, in computing, in security. It has a flight operations team extremely familiar with the spacecraft they are responsible for, but they take the ground segment for granted. It has technicians and maintenance teams responsible for components, subsystems, elements and their reliability and availability. Ground segments vary much less than spacecraft do and employ high degrees of re-use, and so systems engineering as a discipline is rarely applied. As current and future missions place ever higher demands on the ground segment in terms of volume of data delivery, timeliness and security, we will find that overall system behaviour of the ground deserves and requires detailed consideration.
The present paper summarises 2 years of work in leveraging the principles of systems engineering in a contemporary ESA mission ground segment, describes how the elements of the ground segment were abstracted, and the end-to-end data-flow modelled. The fundamentals of the “ground as a system” are identified, and we detail how the resulting model was used to define the operational architecture, the systems-level validation planning, detailed test planning, interface coverage analysis, and requirements traceability. The paper concludes with lessons learned, and summarises the next steps in making the “ground as a system” model more broadly applicable and available to other projects.
- Abstract document
- Manuscript document
IAC-06-D1.5.04.pdf (🔒 authorized access only).
To get the manuscript, please contact IAF Secretariat.