The growing congestion of Earth’s orbit poses an increasing threat to the satellites that provide critical data for addressing global challenges. Researchers at The University of Manchester have developed a new modeling approach to mitigate this risk, integrating collision probability into the initial design phase of Earth-observation missions. The tool, detailed in the journal Advances in Space Research, aims to balance the need for high-quality data with the long-term sustainability of the space environment.
The Space Sustainability Paradox
Currently, approximately 11,800 active satellites orbit Earth, a number projected to exceed 100,000 by the end of the decade. This rapid proliferation increases the likelihood of collisions, generating substantial amounts of space debris. These collisions not only threaten operational satellites and crewed missions but also jeopardize access to key orbital regions. The University of Manchester team frames this challenge as a “space sustainability paradox,” highlighting the risk that efforts to leverage satellites for solving problems on Earth could ultimately compromise the viability of space-based infrastructure.
“Our research addresses what is described as a ‘space sustainability paradox’, the risk that using satellites to solve environmental and social challenges on Earth could ultimately undermine the long-term sustainability of space itself,” explained John Mackintosh, a PhD researcher at The University of Manchester and lead author of the study.
Integrating Collision Risk into Mission Design
The new model represents a shift in how Earth-observation missions are conceived. Traditionally, mission design has focused primarily on achieving specific data quality and coverage objectives. The Manchester team’s framework introduces collision risk as a fundamental consideration from the outset. By linking mission objectives directly to collision probability, designers can make informed trade-offs between data performance and orbital safety.
The research revealed a nuanced understanding of collision risk. It’s not simply concentrated in areas with the highest debris density. Satellite size also plays a significant role. Larger satellites present a greater collision cross-section, increasing their vulnerability and the potential for generating debris in the event of a collision. This finding underscores the importance of considering satellite dimensions alongside orbital parameters when assessing risk.
Supporting the Sustainable Development Goals
Earth-observation satellites are increasingly vital for monitoring progress towards the United Nations’ 17 Sustainable Development Goals (SDGs). They provide critical data on land use, urban development, ecosystems, and disaster response. High-resolution imagery, in particular, is essential for many applications supporting these goals. However, the increasing risk of collisions threatens the continued availability of this data.
The new tool is intended to help ensure that these vital data streams remain accessible. By enabling more responsible mission planning, it aims to balance the benefits of Earth observation with the need to protect the orbital environment. The framework allows for a more holistic assessment of mission feasibility, considering not only technical and scientific requirements but also the potential impact on space sustainability.
Beyond Debris Mitigation: A Proactive Approach
While existing efforts to address space debris often focus on tracking and removing existing objects, the University of Manchester’s approach is fundamentally proactive. Rather than reacting to the consequences of collisions, it seeks to prevent them by influencing mission design. This preventative strategy is crucial for long-term sustainability, as removing debris is a costly and technically challenging undertaking.
The model’s integration of collision risk into early design stages allows for exploration of alternative orbital configurations, satellite designs, and operational strategies that minimize risk without significantly compromising data quality. This could involve selecting orbits with lower debris density, employing collision avoidance maneuvers, or designing satellites with features that reduce their collision cross-section.
Mackintosh emphasized the importance of this integrated approach: “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.”
The development of this tool represents a significant step towards ensuring the long-term viability of Earth-observation capabilities, allowing these critical assets to continue supporting efforts to address some of the world’s most pressing challenges.
