A bold step forward to protect space: a new design approach could dramatically cut collision risks for Earth-observation satellites while still delivering essential data for global challenges.
Researchers from The University of Manchester have developed a novel method for planning Earth-observation missions that aims to keep the space environment safer as satellite activity grows, all while continuing to support crucial tasks like monitoring climate change, food production, supply chains, and environmental health.
Earth-observation satellites are increasingly relied upon to help meet the United Nations’ 17 Sustainable Development Goals (SDGs). They provide vital data on land use, urban growth, ecosystems, and disaster response. Yet the rapid expansion of satellite missions is crowding the skies and creating new hazards, raising the risk of in-space collisions and the generation of long-lasting debris.
There are currently about 11,800 active satellites in orbit, with some forecasts suggesting this could exceed 100,000 by the end of the decade. When satellites collide or debris is produced, large quantities of fragments can threaten spacecraft, astronauts, and the long-term usability of key orbital regions.
The researchers’ model ties collision risk to mission objectives at the very start of the design process. This integrated view helps ensure Earth-observation missions balance high-quality data with the need to keep orbital environments safer, as described in Advances in Space Research (doi: 10.1016/j.asr.2026.01.019).
Lead author John Mackintosh, a PhD researcher at The University of Manchester, explains the concept as a response to what he calls a “space sustainability paradox”: using satellites to tackle Earth’s problems should not come at the expense of space sustainability itself. By factoring collision risk into early-stage design, missions can be planned more responsibly and in harmony with orbital safety.
Many SDG-related applications demand very high-resolution imagery. Achieving this detail often means operating at lower altitudes, which narrows the field of view. Alternatively, to maintain a wide view from higher altitudes, satellites must be larger and heavier to carry bigger optical systems, increasing exposure to debris and the likelihood and potential severity of collisions.
The new framework allows performance requirements, such as desired image resolution and coverage, to be considered alongside factors like satellite size, mass, constellation size, and debris levels across different low Earth orbit bands. Designers can explore how various choices impact both data quality and collision risk in a single, coordinated analysis.
Using the model, the researchers discovered that collision risk isn’t determined only by where debris concentration is highest. The size of the satellite itself plays a major role. For instance, a satellite built to deliver 0.5‑meter resolution imagery showed its peak collision probability at an altitude between roughly 850 and 950 kilometers, about 50 kilometers higher than the maximum debris density.
The study also notes that higher orbits, while needing fewer satellites to achieve global coverage, impose greater individual collision risk because the satellites are larger. In contrast, lower orbits require more satellites but each can be smaller and less hazardous.
Dr. Ciara McGrath, a Lecturer in Aerospace Systems at The University of Manchester, remarked: “As satellite usage grows, our method provides a practical way to keep space safe, sustainable, and usable for future generations while still delivering the data needed to address the world’s most urgent challenges.”
Professor Katharine Smith, a Space Technology expert at Manchester, added that the approach could be adapted to other Earth-observation systems and expanded to incorporate more detailed space-environment impacts. Future work could model how long debris fragments stay in orbit, the likelihood of collisions with other satellites, and the broader environmental effects of satellite re-entry. This would help mission designers evaluate trade-offs across the full sustainability picture.
This research appears in Advances in Space Research under the title Collision risk from performance requirements in Earth observation mission design (DOI: 10.1016/j.asr.2026.01.019).
Public release notes: this material reflects the authors’ views and may be edited for clarity and length. Original publication: Mirage News.
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