Subashree Balakrishnan, Digantara; Bhanu Chandana Gunti, Digantara; Gautham Ganesan, Digantara; Thamim Ansari, Digantara
https://doi.org/10.64861/UINO8545
Keywords: Space Situational Awareness, Space Domain Awareness, Low Earth Orbit (LEO) debris , CZ-6A fragmentation , Radar debris detection , Beam-park observations , EISCAT UHF radar , Radar Cross Section (RCS) , Catalog correlation
Abstract:
The continued growth of the space debris population in Low Earth Orbit (LEO) necessitates measurement-driven characterization to support safety of flight and space traffic management. The fragmentation of the CZ-6A rocket body in Low Earth Orbit (LEO) during 2022/2024 produced a substantial debris population in this heavily utilized orbital regime, increasing collision risk to operational spacecraft and complicating space domain awareness activities. Public reporting and 18th SDS Space-Track catalog documented hundreds of trackable fragments following the breakup; however, quantitative characterization of the full debris population, particularly objects below standard tracking thresholds, remains limited. _x000D_
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This study presents independent radar detections of fragments associated with the breakup, derived from processing raw IQ data collected by the EISCAT UHF radar. The collection campaign consisted of six EISCAT beam-park sessions, each lasting four hours and covering the 200–2000 km altitude range, conducted on 05 May 2025, 10 May 2025, and 20 May 2025. By utilizing scientific radar measurements, the work demonstrates the capability to detect and characterize debris populations beyond those represented in publicly available catalog. _x000D_
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Custom signal processing of radar data enabled identification of discrete Resident Space Objects (RSO) detection events and the estimation of Radar Cross Section (RCS) for individual fragments. The processing chain included data conditioning, systematic extraction of object signals from background noise and clutter, and formation of high-confidence tracklets. Each detection was compiled into a standardized, time-tagged measurement record that enabled systematic object correlation and characterization. These measurements were used to infer RCS across a range extending below the nominal detection limits of conventional surveillance networks. _x000D_
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The analyzed dataset comprises more than 1000 detections obtained over a cumulative 24-hour observation period. Many of these detections were recorded at altitudes spanning approximately 650–950 km, consistent with the CZ-6A breakup region. A subset of these detections was positively associated with the catalogued objects maintained by the Space-Track database, enabling validation of detection attribution. While this process also provides a benchmark for assessing catalog completeness, it also revealed that a significant population of detections failed to correlate with any catalogued RSOs. These previously uncatalogued fragments were systematically isolated to evaluate the full extent of the debris cloud, including objects typically below standard tracking thresholds. Following this identification phase, detection rates, spatial distribution, and Radar Cross-Section (RCS) statistics were evaluated to characterize the physical properties and orbital behavior of the observed population. _x000D_
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The inferred RCS distribution suggests that many of these objects occupy size regimes that pose operational hazards to spacecraft yet remain difficult to track routinely. Variations in detection frequency and estimated fragment size further suggest differential orbital evolution among debris pieces, consistent with dispersion expected from a breakup in LEO. The results demonstrate that processing raw radar measurements can yield independent, high-resolution characterization of debris populations, providing insight into the completeness and limitations of existing surveillance catalogs. Such measurements are particularly valuable for assessing the hazardous small debris environment that contributes disproportionately to collision risk but is underrepresented in tracking data. _x000D_
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The study also illustrates the potential role of scientific radar facilities in supporting operational space surveillance by providing sensitivity to smaller objects and enabling post event assessment. These findings support improved conjunction risk evaluation and satellite maneuver planning by highlighting the presence of debris not captured in routine catalogs. More broadly, the work contributes to understanding the evolution of debris clouds in congested orbital regimes. The approach demonstrated here may be applied to future fragmentation events to enable timely characterization of emerging debris hazards and to support mitigation strategies aimed at preserving the long-term sustainability of LEO. _x000D_
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Date of Conference: September 15-18, 2026
Track: Space Debris