Tobias Göttfert

The joint TerraSAR-X / TanDEM-X mission planning system

This paper recalls the essential system requirements and elements for the joint TerraSAR-X / TanDEM-X mission planning system. Its commissioning approach, tests and results are described in detail.

Onboard Planning and Scheduling Autonomy withinthe Scope of the FireBird Mission

For most low orbiting earth observation satellite missions, the timeline is generated on- ground and during dedicated uplink sessions the corresponding tele-commands are sent to the spacecraft. Bene�ts of this approach are easy maintainability of the complex planning software and quick response times to customer input. However this approach has two major drawbacks: On the one hand the spacecraft behavior is not completely predictable in terms of constraining resources, which means that even detailed modeling requires margins for the on-board resources within the on-ground scheduling algorithms. On the other hand, the reaction time to onboard detected events includes at least the two upcoming ground station contacts, since data downlink and evaluation, (re-)planning and tele-command uplink have to be awaited before the spacecraft can perform new activities. This paper describes the �nal design and use cases of VAMOS, an experiment of DLR/GSOC, which will be part of the FireBird mission. VAMOS consists of a combined onboard / on-ground planning system, which resolves the above mentioned drawbacks by supplying limited onboard autonomy to the satellite, retaining the bene�ts of a ground based planning system as far as possible.

The Incremental Planning System—GSOC's Next- Generation Mission Planning Framework

The paper at hand presents the new generic framework for automated planning and scheduling in future mission planning systems developed at GSOC (German Space Operations Center). It evolved from the experiences made in past and current projects and the evaluation of internal and external requirements for upcoming projects. In customary systems such as the one used within GSOC’s TerraSAR-X/TanDEM-X mission, succeeding planning runs to combine all collected input to a consistent, conflict-free command timeline take place at fix, dedicated points in time, e.g. twice a day. In contrast and as a main difference, with the new system each new input is processed immediately and so a consistent up-to-date timeline is maintained at all times. We show that this approach provides a set of important advantages and new possibilities for spacecraft commanding and user satisfaction. For example, uplink schedules can be flexibly modified due to short-term notifications, or up-to-date, extensive information about the planning state is always available, which means that conflicts can be seen before finally submitting a new request and, if applicable, can be resolved by selecting a suggested solution scenario. The presented system constitutes a generic tool suite which is scalable in performance critical areas, which is configurable to various mission scenarios and which defines a dedicated set of interfaces, specifying the functionality that remains to be implemented by each individual project. The declared goal is that all upcoming GSOC missions will benefit from using the Incremental Planning framework in terms of cost reduction, implementation duration and system robustness.

The TerraSAR-X/TanDEM-X Mission Planning System: Realizing new Customer Visions by Applying new Upgrade Strategies

The history of the TerraSAR-X and TanDEM-X mission planning system is briefly presented. In addition to the not trivial demands of the first years, special attention is given to the challenges of recent years. Here the TanDEM-X science phase, conducted between 2014 and 2016, is the most prominent feature. It is shown how agile software engineering methods can help to keep the already achieved system robustness, and how further enhancements can easily be incorporated.

Operating and Evolving the EDRS Payload and Link Management System

Based on its Plato scheduling library, GSOC has developed the scheduling components for controlling the EDRS-A and EDRS-C payloads, called Link Management System. This paper reports on the operational experience gained from almost two years of EDRS-A operations and the improvements that have been made to the codebase. The necessary changes for EDRS-C are highlighted. Finally, thoughts and recommendations for future ground segment engineering are given.

RootVis telemetry Analysis framework

A commonality of all space missions is the need to receive, process, archive, and analyze on-board telemetry of the spacecrafts involved. For long-running missions, the amount of data that needs to be preserved can reach hundreds of gigabytes. At the German Space Operations Center (GSOC), the RootVis framework is under development; it shall allow to process the full telemetry dataset of the GSOC satellite missions for analysis of the long-term behavior of the spacecraft. Typically each mission has slightly di�erent concepts of analysis, visualization and format of its telemetry, so RootVis was conceptualized as a modular telemetry visualization tool. It is built around the core telemetry archive in the �le format of the ROOT data analysis library, which|thanks to its e�cient serialization| enables high performance data access. Thus, it is possible to handle large data sets with billions of data points in short time for all current and future GSOC missions.