Mission High Reactivity in Decentralized Architectures for Space Systems

The Saint Exupéry Technological Research Institute (IRT) is an accelerator for science, technological research and transfer to the aeronautics and space industries for the development of innovative solutions that are safe, robust, certifiable and sustainable.

We offer on our sites in Toulouse, Bordeaux, Sophia Antipolis an integrated collaborative environment made up of engineers, researchers, experts and doctoral students from industrial and academic backgrounds for research projects and R&T services backed by technological platforms around 4 areas: advanced manufacturing technologies, greener technologies, methods & tools for the development of complex systems and smart technologies.

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Toulouse

IRT Saint Exupéry is the main tenant of building B612, Toulouse Aerospace's innovation center, occupying 10,900 m² of the 24,000 m² available. Located in the Montaudran district, at the heart of a rich and rapidly changing ecosystem, the B612 is home to the major players in innovation: U-Space, Airbus OneWeb satellites, ANITI, ESSP, Aerospace Valley and Capgemini.

3 reasons to join us:

• Take part in innovative research projects, at the service of French technological research and for the benefit of industry established on national and European territory.
• Living your passion for technology, giving yourself the freedom to innovate and developing your pioneering and team spirit
• Evolve in a collaborative and multicultural environment, working alongside collaborators from academic research or industry: researchers, doctoral students, engineers, technicians, etc.

This postdoctoral project is the result of a collaboration between the Centre National d'Etudes Spatiales (CNES) and the Institute of Technological Research Saint Exupéry (IRT Saint Exupéry). The successful candidate will be employed by CNES. The primary location is the IRT Site in Toulouse or Nice.

About the Centre National d'Etudes Spatiales (CNES)

CNES is the public institution responsible for proposing and implementing France's space policy. Through its innovative activities, CNES plays a major role within the European space sector and is a leading player in major international programs.

As an incubator of projects and a laboratory for new ideas, CNES's mission is to continue inventing the space sector of tomorrow by offering unique career paths. Working at CNES means joining 2,350 employees in a cutting-edge field firmly oriented toward the future and innovation.

Space systems are increasingly required to support urgent and unpredictable user needs, ranging from military operations to scientific observations. Traditional architectures rely heavily on ground segments for mission planning, scheduling, and data downlinking. While robust, these centralized approaches introduce significant delays in mission responsiveness due to communication constraints, limited contact windows, and the inherent latency of human-in-the-loop decision-making.

An alternative paradigm is to move towards decentralized architectures where satellites within a constellation autonomously process user requests, schedule acquisitions, and determine optimal data download and delivery strategies. In this model, urgent requests are directly submitted by end-users on the ground (direct tasking) or even generated dynamically by the constellation itself (dynamic targeting). The satellites then collaboratively identify the most suitable platform for task execution based on criteria such as visibility, resource availability, and global responsiveness.

This postdoctoral research subject aims to provide the foundations for such architectures, identifying key technological enablers and assessing their feasibility in different mission contexts.

Technological Challenges

Several technological barriers must be addressed to enable fully decentralized satellite constellations:

1. Autonomous Scheduling and Tasking:

The constellation must embed onboard algorithms capable of prioritizing urgent requests over routine operations. This requires adaptive scheduling techniques that consider visibility windows, satellite health, resource constraints, and downlink opportunities. Recent advances in distributed planning for constellations highlight the potential of decomposition-based or learning-based approaches to handle large-scale autonomy [1,2].

1. Inter-Satellite Communication:

A responsive decentralized system requires low-latency communication between satellites to exchange tasking information and negotiate responsibilities. The heterogeneity of satellite platforms and payloads adds complexity to this problem.

1. Dynamic Targeting:

In addition to user-driven requests, the system should be able to generate tasking internally (e.g., anomaly detection, event-triggered acquisition). Robust onboard planning methods are essential to dynamically reallocate resources in such cases [3,4].

1. Resource Management and Optimization:

Balancing urgent tasking with ongoing routine missions (e.g., systematic acquisitions) requires strategies that allow graceful interruption or rescheduling of low-priority tasks without compromising system efficiency.

1. System Reliability and Security:

A fully autonomous, decentralized system must include mechanisms to guarantee mission reliability, fault tolerance, and cyber-resilience, particularly in defense-related applications.

Proposed Work Plan

To address these challenges, the study can be structured into three main phases.

Phase 1 – Architectural Analysis:

Define reference scenarios across defense, Earth observation, and exploration missions.

Characterize requirements in terms of responsiveness metrics (acquisition delay, information age).

Assess trade-offs between fully decentralized, partially decentralized, and hybrid architectures.

Phase 2 – Technological Enablers:

Investigate onboard autonomous scheduling algorithms suitable for real-time operation.

Analyze inter-satellite communication protocols for coordination and decision-making.

(optional) Explore methods for integrating dynamic targeting triggered by satellite observations.

Evaluate security, reliability, and fault-tolerance strategies in decentralized systems.

Phase 3 – Simulation and Validation:

Develop a simulation framework to model heterogeneous constellations and user request flows.

Benchmark performance of decentralized scheduling against centralized approaches.

Validate responsiveness gains in representative mission scenarios (e.g., urgent tactical imaging, rapid astronomical event monitoring, planetary exploration).

PhD holder in Aerospace Systems Engineering, Embedded Systems or Applied Mathematics. Experience in satellite mission planning and scheduling is a valuable asset.