Reentry and disintegration dynamics of space debris tracked using seismic data.

The risks posed by reentering space debris continue to grow as Earth's orbit becomes more crowded. Currently, responses to uncontrolled reentries are hampered by an inability to reliably track spacecraft once they are burning up within the atmosphere, meaning that debris fallout locations are poorly predicted. We have demonstrated a minimum-gradient fit seismic inversion methodology that allows in-atmosphere debris trajectory, speed, altitude, descent angle, size, and fragmentation pattern to be discerned relatively quickly. We tested this methodology on open-source data from the 2024 reentry of Shenzhou-15, deriving a location significantly south of the predicted track. Observations of cascading, multiplicative fragmentation offer insight into debris disintegration dynamics, with clear implications for space situational awareness and debris hazard mitigation.