Atheras Analytics awarded ESA contract to tackle satellite interference in crowded skies

Atheras Analytics SAS has signed a contract with the European Space Agency (ESA) to develop an advanced simulation tool aimed at ensuring the harmonious coexistence of next-generation satellite constellations. The nine-month project is titled “ENGEOS - Evolution of the NGSO and GSO Co-Existence Framework”.

The project directly addresses one of the most pressing challenges in modern space communications: the increasing risk of signal interference between legacy Geostationary (GSO) satellites and the new wave of thousands of Non-Geostationary (NGSO) satellites in Low Earth Orbit (LEO) and Medium Earth Orbit (MEO). While these new NGSO mega-constellations, operated by companies like SpaceX, OneWeb, and Amazon, promise to deliver low-latency, high-speed internet globally, they share radio frequency spectrum with GSO satellites that provide critical services, from broadcasting to secure communications.

To manage this, the International Telecommunication Union (ITU) has established a regulatory framework based on Equivalent Power Flux-Density (EPFD) limits, which cap the acceptable level of interference from NGSO systems into GSO networks. However, the unprecedented scale and complexity of new constellations are pushing the existing analytical models to their limits.

Under the contract, Atheras Analytics will develop a sophisticated “System Simulator for EPFD Evaluation Tool”. This software will provide ESA with a powerful new capability to go beyond static regulatory checks and conduct dynamic, system-level simulations. The tool will assess the real-world impact of NGSO interference on GSO system performance, such as its effects on service availability and data throughput. Crucially, the simulator is designed to assess the effect of changing the current EPFD limits, providing data-driven insights into how varying these international regulations could impact GSO services and whether they could be modified to accommodate future systems. It will allow for the analysis of a wide range of operational scenarios, including large LEO constellations with thousands of satellites and MEO systems with tens of satellites.

Pantelis-Daniel Arapoglou, Technical Officer of the project at ESA said: “As the number of operational NGSO constellations increase, there is increasing pressure to review the regulations that govern the co-existence of GEO with NGSO systems, including the EPFD limits. The present activity by Atheras Analytics will build a sophisticated simulation tool that is meant to quantify the impact of various EPFD masks on actual system performance, thereby bridging the regulatory world with the operational one.”

David Gibbons, CEO at Atheras Analytics commented: “This is a pivotal project and an opportunity to address a challenge that could severely impact satellites in GSO if it is not managed at an early stage. The rapid increase in the deployment of NGSO satellites is set to continue, so it is vital that a system is developed to take control and ensure that users of GSO satellites, that often provide mission critical services, are unaffected by RF interference from satellites in LEO. We are looking forward to taking on this project and we thank ESA for the opportunity.”

The new simulator will incorporate various methodologies, including the ITU's standard "Worst-Case Geometry" approach as well as more comprehensive full simulation and Monte Carlo methods to capture a complete statistical picture of the interference risk. This will provide regulators and operators with a more nuanced understanding needed to refine coexistence strategies.

The work will culminate in a set of recommendations and a final report, with the aim of providing valuable input for ESA’s contributions to future ITU World Radiocommunication Conferences.