Adopting the federated satellite systems paradigm for earth observation: An architecting framework

Federated Satellite Systems (FSS) are a novel space mission architecture concept that proposes the ad-hoc exchange of resources between independent, heterogeneous space missions. By adopting a cooperation approach, missions can benefit from on-demand access to resources such as downlink bandwidth or data processing. This is of particular interest for data-intensive Low Earth orbit Earth Observation (EO) missions, which suffer from short ground station passes and may generate large amounts of instrument data. As the state-of-the-art mission data downlink systems are reaching practical limits, peaking at 800 Mbps in X-band, we need alternative approaches to this communications bottleneck. FSS is a potential reliever, networked approach to space missions, which requires the addition of inter-satellite link capabilities on some of the participant spacecraft. The costs and benefits of this approach, its adoption strategies and long-term dynamics need to be carefully assessed not only mission by mission, but also from the perspective of the open systems of systems FSS represents. This paper presents a preliminary architecting framework to explore the implementation strategies, synergistic effects and global trade-offs of FSS and applies it to an EO case study. This adds a new analysis perspective to previous work that focused on the design impacts of joining the federation from the point of view of a single mission. In this work, a multi-stakeholder, 17 EO missions portfolio is assessed in the light of the framework. Multiple options to increase the value delivery of the full portfolio through federating the missions are discussed. In particular, we show that the overall value of the portfolio, in terms of EO utility and data throughput, can be increased by 8% at a cost of 3000 kg worth of communications equipment to be distributed among the 17 missions. This is an average of 170 kg per mission. Pending further analysis, this outlines the potential of cooperative approaches to space missions.