The Space Sustainability Paradox: Can Satellites Save Earth Without Destroying Orbit?
Earth-observation satellites are increasingly vital for tracking progress towards the United Nations’ 17 Sustainable Development Goals (SDGs). These eyes in the sky provide crucial data on everything from land use and urban development to ecosystem health and disaster response. But, a growing body of research, including fresh work from The University of Manchester, highlights a critical challenge: the very tools we rely on to monitor and protect our planet could be jeopardizing the long-term sustainability of space itself.
The Rising Risk of Space Debris
The core of the issue lies in the increasing number of satellites orbiting Earth. As more are launched, the risk of collisions – and the creation of space debris – rises exponentially. Even small fragments of debris traveling at high speeds can cause significant damage to operational satellites, potentially creating a cascading effect known as the Kessler Syndrome, rendering certain orbits unusable.
Researchers at The University of Manchester have been investigating how to balance the need for comprehensive Earth observation with the imperative to maintain a safe orbital environment. Their work focuses on linking mission requirements – specifically image resolution and coverage – with satellite size and the total number of satellites deployed.
Size Matters: A Trade-off Between Coverage and Collision Risk
The study revealed a key trade-off: the size of each satellite directly impacts the probability of collisions. Larger satellites, while potentially offering broader coverage, also present a greater individual collision risk. Conversely, smaller satellites require a larger constellation to achieve the same level of coverage, increasing the overall number of objects in orbit and, the risk of collisions.
Interestingly, the research also found that higher orbits, while requiring fewer satellites for coverage, carry a greater individual collision risk due to the larger size of the satellites operating at those altitudes.
“Our research addresses what is described as a ‘space sustainability paradox’,” explains John Mackintosh, a PhD researcher at The University of Manchester and lead author of the study, “the risk that using satellites to solve environmental and social challenges on Earth could ultimately undermine the long-term sustainability of space itself.”
The University of Manchester’s Leading Role in SDG Research
The University of Manchester is recognized globally for its commitment to the UN SDGs. It’s the only university in the world to consistently rank in the top ten for social and environmental impact in the Times Higher Education Impact Rankings, currently holding the number two position worldwide (2025 rankings). The university also features in the top 10 of the 2025 QS World University Sustainability Rankings.
Beyond this new research, the University contributes significantly to SDG-related research, having produced 21,571 research publications across all 17 SDGs over the past five years – representing 4% of the UK’s total research output on these goals. Its research beacons – advanced materials, biotechnology, cancer, energy and global inequalities – are all focused on tackling global challenges.
What’s Next for Space Sustainability?
Addressing the space sustainability paradox requires a multi-faceted approach. This includes:
- Improved Space Traffic Management: Developing more sophisticated systems for tracking and managing satellites and debris.
- Debris Removal Technologies: Investing in technologies to actively remove existing debris from orbit.
- Sustainable Satellite Design: Designing satellites with finish-of-life plans that ensure responsible deorbiting.
- International Collaboration: Establishing international norms and regulations to govern space activities and promote responsible behavior.
The University of Manchester’s work underscores the urgency of these efforts. As our reliance on space-based technologies grows, ensuring the long-term sustainability of the orbital environment is paramount.
FAQ
Q: What are the UN Sustainable Development Goals?
A: The 17 SDGs are a collection of global goals set by the United Nations to address the world’s most pressing challenges, including poverty, hunger, climate change, and inequality.
Q: What is space debris?
A: Space debris consists of defunct satellites, fragments from collisions, and other man-made objects orbiting Earth. Even small pieces can pose a significant threat to operational spacecraft.
Q: What is the Kessler Syndrome?
A: The Kessler Syndrome is a hypothetical scenario in which the density of objects in low Earth orbit is so high that collisions between them become inevitable, creating a cascading effect that renders certain orbits unusable.
Q: How is The University of Manchester contributing to sustainability?
A: The University of Manchester is a global leader in sustainability research and education, ranking highly in international sustainability rankings and contributing significantly to research across all 17 SDGs.
Did you know? The University of Manchester is the only university in the world to rank in the top ten for social and environmental impact in every year of the Times Higher Education Impact Rankings.
Pro Tip: Stay informed about space sustainability initiatives by following organizations like the United Nations Office for Outer Space Affairs (UNOOSA).
What are your thoughts on the future of space sustainability? Share your comments below and let’s continue the conversation!
