Replacing the TDP-1 Mission Planning System – more than just another Technical Demonstration Project

Kurzfassung

After over seven years of successful operations, end of last year it was decided to replace the existing TDP-1Mission Planning System (MPS) at the German Space Operations Center (GSOC) by a completely new MPS implementation based on the novel generic Reactive Planning framework. With the MPS being the core component within a well-proven ground segment this meant a huge step including not-neglectable risks with respect to the effort to guarantee continuous reliability. The paper at hand describes why we still performed this migration as such a decision of course requires more good reasons than a list of change requests by the customer. It introduces both the old and the new system, including their setup and design approaches. It critically discusses design and implementation of the previous, Plato-based system before giving an overview and some details of the solutions included in the new software. This has been implemented based on the Reactive Planning framework which we developed at GSOC in the last years and which shall serve as the basis for all our future Mission Planning Systems. After the almost finalized preparation of the MPS for an upcoming complex Earth-observation mission, EnMAP, the TDP-1 laser communication coordinating MPS became the second implementation based on the framework and now is the first one operational since some weeks. The migration provided numerous benefits for the future TDP-1 maintenance and was a very valuable experience to make the Reactive Planning framework even more robust and generic as it led to a number of improvements that will be inherited by the other and all future systems based on it. The lessons learnt comprise for instance how an iterative DevOps approach with a close cooperation with the other subsystems and the customer as well as a thorough multi-level testing approach enabled the successful replacement of the MPS in the last months, and furthermore, after the thorough discussion of the previous approach, remind to be always open-minded to and prepared for software development technology evolutions.