Low Earth orbit satellite proliferation and congestion

The proliferation of satellite constellations in Low Earth orbit (LEO) is driving both scientific advancement and increased orbital congestion.

Initially, the Starlink network, operated by SpaceX, has been utilized for more than just internet services. Astronomer Tony Phillips has implemented a “planetary barometer” method, which uses the atmospheric drag experienced by Starlink satellites to measure changes in Earth’s upper atmosphere and track density changes caused by solar energy.

However, the rapid deployment of these networks has led to unprecedented congestion in LEO. As of late September 2026, there are over 31,300 cataloged objects in orbit, including approximately 15,700 active satellites and between 3,000 and 4,000 defunct devices. SpaceX’s Starlink constellation remains the dominant presence, accounting for nearly 70% of all operational spacecraft with over 11,000 active satellites. This growth, fueled by projects such as Amazon’s Kuiper and China’s Qianfan, marks a significant increase from 2019 levels.

In October 2026, Starlink identified undisclosed satellite maneuvers by other operators as a primary collision risk. The company reported encountering conjunctions with approximately 650 unique maneuvering third-party satellites in 2026, noting that only about half of those operators shared ephemeris data. Starlink observed roughly 164,000 conjunctions over a six-month period where the closest approach occurred within four hours of an unannounced maneuver. To mitigate these risks, Starlink is advocating for industry-wide transparency, urging operators to share predicted trajectories and planned maneuvers to prevent a “false sense of security” caused by a lack of high-accuracy post-maneuver information.