Large Satellite Constellations: Perspectives and Challenges (2026)

The rapid expansion of large satellite constellations, particularly in low Earth orbits (LEO), marks a turning point in humanity’s relationship with near-Earth space. Propelled by the NewSpace era, characterised by private innovation, reusable launchers, and digital integration, tens of thousands of satellites are being deployed in LEO and medium-Earth orbits (MEO) to deliver global broadband access and real-time Earth observation. These advances promise transformative benefits for society, including universal Internet/communication coverage (there are about three billion people without coverage today), enhanced Internet/communication resilience, integration of communications and sensing, and, more generally, the potential for a space-based extension of the Internet.
Large constellations also pose unprecedented challenges and risks that need to be mitigated in the short term. (a) Reflected sunlight from satellites and radio emissions directed towards Earth are disrupting optical and radio astronomy. (b) The growing density of spacecraft is increasing the risk of collisions and debris generation, potentially rendering key orbital regions unusable. (c) The rising rate of rocket launches increases the risks of debris surviving re-entry and potentially causing injuries or damage to air traffic or on the ground. It also augments the injections of chemicals and particulates into the upper atmosphere, with consequences that are not well understood.