Tam Do, University of Western Ontario; Peter Brown, University of Western Ontario; Denis Vida, University of Western Ontario
https://doi.org/10.64861/WSMB2379
Keywords: Satellites, Space Debris, Meteors, Optical Cameras, Re-Entries
Abstract:
Since the beginning of the decade, approximately 10,000 satellites have been launched into low-Earth orbit (LEO). Many of these are part of the Starlink constellation which have re-entry lifetimes of about five years. As the first Starlink satellites were launched in 2019, the first generation of Starlink satellites are now starting to re-enter Earth’s atmosphere. With the number of satellite re-entries predicted to continue rising, there is an urgent need to both validate re-entry models used to predict the amount of surviving mass reaching the ground, as well as quantify the environmental impact of re-entries. _x000D_
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Optical measurements of human-made debris re-entries has historically been limited to isolated cases, either serendipitously captured by optical instruments searching for other objects or through dedicated campaigns focused on re-entries of larger objects. Opportunistic re-entry observations, such as the Starlink-1353 satellite re-entry over Hokkaido Island in 2023, provide detailed measurements of fragmentation morphology and brightness evolution as the satellite ablates while still moving at orbital velocities. Ground-based optical meteor networks are a source of re-entry data as they are designed to monitor large time-area products of the atmosphere for bright meteors. Reports of serendipitous re-entry observations have been published by the Spanish Meteor Network, Desert Fireball Network, All-Sky Meteor Orbit System, AllSky7 Fireball Network, and Global Meteor Network (GMN). Most of these observations have been of larger objects, usually larger spacecraft and upper rocket stages. However, a critical gap remains in the systematic, continuous optical monitoring of re-entries, particularly those of smaller objects._x000D_
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In this study, we perform the first large-scale systematic global survey of satellite re-entries using the GMN, a global network of over 1600 cameras. Our goal is to create a comprehensive catalogue of un-cued ground-based optical observations of re-entries to characterize the population of re-entering spacecraft/debris with emphases on ablation behaviour with height. This survey has sky coverage of approximately 3% of Earth’s total atmospheric area at 100 km altitudes with at least 2 camera stations, at spatial scales of tens of metres and sensitivity to re-entries for objects as small as a few tens of centimetres. Between January 2019 and July 2026, the GMN’s automated data processing pipeline rejected and archived ~9300 events with velocities consistent with geocentric orbits. The majority of these events are likely natural meteors observed late in their flight such that they decelerated below escape speed. Examining the distribution of in atmosphere speeds and apparent entry angle, we found an apparent excess in events with low velocities and shallow entry angles. Using this speed-entry angle selection, we identified 26 meteor-like events with observed in-atmosphere velocities ranging from 5.5 km/s to 10.3 km/s, all entering the atmosphere at very low entry angles (less than 3 degrees from horizontal). While we cannot a priori rule out some of these as being decelerated meteors, we were able to correlate 20 of the 26 events with Two-Line Elements (TLE) sets from the SPACE-TRACK catalogue, suggesting the majority are truly re-entries. Of the events we were able to correlate with known re-entered objects, nine were associated with Tracking and Impact Prediction Services (TIPS) messages posted within the same general timeframe, while the rest were associated solely by propagating the observed trajectory backwards/forwards in time and matching its orbit to the TLE orbits of catalogued satellites/debris. We find several re-entries with no TIPS predictions which we could confidently associate with re-entering CubeSats having radar cross sections (RCS) of order 0.1 m2, demonstrating the GMN’s ability to detect and characterize re-entries for objects as small as ~10 cm in size. Extrapolation of the re-entry brightness of the smallest event in our dataset suggests that the GMN may be able to record the optical signature from re-entering objects as small as just a few cm in size, provided the material properties are conducive to light production. These results demonstrate the utility of a global optical meteor network as a powerful, continuous Space Domain Awareness asset for persistent, un-cued monitoring of satellite and space debris re-entries._x000D_
Date of Conference: September 15-18, 2026
Track: Space Debris