Manchester University Develops New Tool to Tackle Orbital Congestion and Satellite Collision Risk

A Proactive Approach to a Crowded Sky

As the number of satellites in Earth’s orbit grows at an unprecedented rate, the risk of collisions and the proliferation of space debris have become critical challenges for the space industry. In response, researchers at The University of Manchester have developed a novel modeling framework designed to integrate collision risk directly into the early stages of satellite mission design. This tool allows mission planners to balance performance requirements, such as high-resolution imaging, with the long-term safety and sustainability of the orbital environment, addressing what experts call a looming space traffic crisis.

The Core of the Innovation: Integrating Risk and Performance

Traditionally, mission performance and collision risk have been assessed separately, with safety considerations often addressed late in the development process. The Manchester tool revolutionizes this approach by linking mission objectives-like image resolution and coverage area-with key risk factors such as satellite size, mass, constellation density, and the amount of debris in different orbits. This concurrent evaluation enables designers to foresee the trade-offs between data quality and safety from the very beginning, selecting parameters that minimize the chances of an accident.

Addressing the “Space Sustainability Paradox”

The new tool directly confronts what lead author John Mackintosh, a PhD researcher at the university, terms the “space sustainability paradox.” This refers to the irony that using satellites to solve environmental and social problems on Earth-like monitoring climate change or managing resources for the UN’s Sustainable Development Goals-could inadvertently harm the long-term viability of the space environment itself. By embedding collision risk into the initial design phase, the framework promotes more responsible mission planning.

“By integrating collision risk into early mission design, we ensure Earth-observation missions can be planned more responsibly, balancing data quality with the need to protect the orbital environment,” Mackintosh stated.

Key Findings and Industry Context

The model has already yielded important insights. For instance, the researchers found that collision risk is not solely dependent on debris density. Satellite size is a dominant factor; for a satellite providing 0.5-meter resolution imagery, the highest collision probability is between 850 and 950 kilometers altitude, which is about 50 km higher than the peak of debris concentration, because larger optics are needed at that height. Furthermore, while higher orbits require fewer satellites for coverage, these larger satellites carry a much greater individual collision risk.

This development comes at a critical time. The number of active satellites has surged from around 1,200 in 2013 to nearly 12,000 today, with projections suggesting over 100,000 by the end of the decade. This orbital congestion is increasing the frequency of avoidance maneuvers, with some estimates suggesting SpaceX’s Starlink satellites may need to perform a million maneuvers every six months by 2028 if current trends continue. The European Space Agency’s 2025 report confirms that even if all launches stopped today, the amount of space debris would continue to grow due to existing objects colliding and fragmenting-a scenario known as the Kessler syndrome.

A Look to the Future of Space Traffic Management

The University of Manchester’s tool is a significant step forward in a broader, global effort to establish a comprehensive Space Traffic Management (STM) system. Currently, the lack of an internationally agreed-upon framework creates operational risks and vulnerabilities. Dr. Ciara McGrath, a Lecturer in Aerospace Systems at the university, emphasized the tool’s practical value: “As satellite use continues to grow, our method offers a practical way to ensure that space remains safe, sustainable and usable for generations to come.” The framework is adaptable and could be expanded to include other environmental impacts, such as how long debris remains in orbit and the effects of satellite re-entry. This proactive design philosophy is essential for preventing our vital orbital highways from becoming unusable fields of debris.