A Holistic Control Center for the Operation of PUS-Based Optical Communication CubeSat Technology Demonstration Missions at the German Aerospace Center

Kurzfassung

CubeSats have evolved from simple technology demonstrators to important assets for space utilization to fulfill a myriad of complex goals. In contrast to small launch expenses, CubeSat operation costs are often higher due to their limited space-to-ground communication capabilities. The recent emergence of European Committee Space Standards -Packet Utilization Standard (ECSS PUS) compliant CubeSat platforms allows the use of traditional ground segment infrastructure rather than adding dedicated mission control software for each new CubeSat. Apart from the idea of saving operations costs, these systems are, however, often overloaded with features, many of which are not applicable to CubeSat operations. Modern nanosatellite missions tend to carry numerous increasingly complex scientific and commercial payloads to be operated by various research and commercial entities that wish to operate them from their own premises. However, today's mission control systems require much effort to deploy network infrastructure and adapt operational software to the needs of such missions. Serious drawbacks during operations preparation, planning, and AIT (Assembly, Integration, and Testing in the context of operations) and operation execution, such as delocalized operations in-situ, limited interoperability- and multi-user/client capabilities, to name just a few, take ample time to meet the desired requirements of the stakeholders and customers of such missions. CubeSats, relying on optical space-to-ground communication systems, are particularly susceptible to cloudy weather conditions. This susceptibility brings up the need for a flexible and resilient mission control system to change the optical teleport quickly. Yet, current operation systems also do not have enough automation capabilities to operate single optical communication CubeSats or CubeSat fleets cost-efficiently with only few personnel. As a result, the operational costs tend to be at least as high as those of conventional satellites, which is out of proportion compared to their low launch costs. In those regards, a more flexible system is needed, which would be better suited for proper mission operations of optical communication CubeSats. In the following, we propose a system architecture to allow reconfiguration of established operational technologies and infrastructures to better fit into the active context of state-of-the-art optical communication CubeSat mission design, planning, and operational execution. The proposed architecture outfits the design of a Holistic CubeSat Control Centre (HC3), developed as a scalable service-based ground segment for the preparation and execution of CubeSat operations using established operation services and ground segment infrastructure from the German Space Operations Center (GSOC) but utilized in a delocalized fashion that enables multiple missions to be operated by multiple operating entities. Also, multiple entities can simultaneously cooperate on the same mission in that same delocalized frame, using newly developed software and existing software solutions running on virtual machines inside a virtual network in a cloud. This operational concept is most likely to become the new operation standard at GSOC shortly. The proposed Holistic CubeSat Control Centre will be applied in a simplified setup onto a German CubeSat Technology Demonstration Mission, intended to be launched in Spring 2024. Three different operations centers will operate this CubeSat: The German Space Operations Center (GSOC); the FH Aachen Space Operations Facility (FHASOF); German Orbital Systems (GOS) on behalf of the Responsive Space Cluster Competence Center (RSC³), and the Institute of Communication and Navigation (DLR-KN) as the principal investigator. All operation entities will operate within the HC3 frame from their respective locations. This use case will be used as a risk mitigation and validation tool of the proposed system for the operation of the CubeISL Mission, which is intended to be launched in winter 2025. CubeISL consists of two 6U-CubeSats which will be used to investigate the performance of space-to ground and inter-satellite laser link of an optical communication terminal subsystem (D.N. Amanor, 2018), developed at the Institute of Communication and Navigation (DLR-KN) in close cooperation with the company TESAT.