Space Sustainability and Orbital Debris Management

Space sustainability encompasses the responsible use, exploration and utilisation of near-Earth space to ensure long-term accessibility and safety. Central to this endeavour is the management of orbital debris, which comprises defunct satellites, spent rocket stages and fragments arising from collisions or explosions. As the number of active satellites and launch campaigns has grown exponentially, so too has the population of debris, raising the risk of cascade collisions known as the Kessler syndrome. Effective sustainability strategies integrate technical, regulatory and environmental considerations, aiming to limit new debris generation, enhance tracking capabilities, and enable timely removal of malfunctioning or end-of-life objects. Advancements in sensor networks and space situational awareness tools support more accurate orbital predictions, while emerging deorbiting and active removal techniques promise to mitigate long-term collision risk. International cooperation, harmonised standards and novel policy frameworks are essential to balance commercial ambitions, scientific interests and the preservation of the orbital environment for future generations.

Research from Nature Portfolio

Recent observational campaigns have quantified the optical impact of large communications satellites, demonstrating that prototype constellation platforms can reach apparent magnitudes far brighter than existing guidelines recommend. These findings underscore the need for satellite operators and astronomers to collaborate on surface treatments and operational manoeuvres that reduce stray light, in order to safeguard ground-based optical facilities. In parallel, analyses of mega-constellation deployments have revealed that rapidly increasing satellite densities in low Earth orbit may significantly elevate collision probabilities and contribute novel sources of high-altitude alumina through re-entry. Modelling work has shown that without stricter post-mission disposal standards and coordinated orbital “traffic management”, untracked fragments could soon precipitate regular on-orbit collisions, threatening both functional spacecraft and the broader space environment. These studies call for an urgent regulatory overhaul that embeds debris mitigation requirements into constellation licensing processes and international treaty frameworks.

Space Sustainability and Orbital Debris Management publication trend

The graph below shows the total number of articles in space sustainability and orbital debris management across all publications each year (not limited to Nature Index journals).

Technical terms

Orbital debris: Man-made, non-functional objects in Earth orbit including defunct spacecraft, spent launch stages and fragmentation remnants.

Low Earth orbit (LEO): The region of space within approximately 2,000 km of Earth’s surface, hosting the majority of operational satellites and debris.

Space situational awareness (SSA): The capability to detect, track and predict the trajectories of objects in space to assess collision risks and support operational planning.

Active debris removal (ADR): Techniques and missions designed to capture and deorbit large debris objects, thereby reducing long-term collision probability.

Glint: A brief, intense flash of reflected sunlight observed when tumbling debris passes through an optical telescope’s field of view.

References

1. The high optical brightness of the BlueWalker 3 satellite. Nature (2023).
2. Expected Impact of Glints from Space Debris in the LSST. The Astrophysical Journal Letters (2024).
3. The space sustainability paradox. Journal of Cleaner Production (2023).
4. Satellite mega-constellations create risks in Low Earth Orbit, the atmosphere and on Earth. Scientific Reports (2021).
5. Orbital Debris Threat for Space Sustainability and Way Forward (Review Article). IEEE Access (2020).