Mikolaj Kruzynski, Polish Space Agency; Tomasz Zubowicz, Polish Space Agency; Krzysztof Arminski, Polish Space Agency; Mikolaj Karawacki, Polish Space Agency; Marcin Teofilewicz, Polish Space Agency; Edwin Wnuk, Polish Space Agency; Zygmunt Aniol, Polish Space Agency; Tymoteusz Trocki, Polish Space Agency
Keywords: re-entry
Abstract:
Space Traffic Management (STM) has a key role in ensuring the safety of space operations and the sustainable use of near-Earth space. It becomes crucial in an environment of rapidly increasing numbers of satellites and orbital debris. As such, active STM involves monitoring object trajectories, implementing avoidance maneuvers and controlling deorbit. The latter is essential both for protection of satellite infrastructure, to ensure the reliability of space services and to minimize threats to Earth from uncontrolled re-entry of objects into the atmosphere. This demands international cooperation, the standardization of procedures, and the development of regulations on the responsibility for orbital objects. In this context, STM emerges as a key element in ensuring the long-term stability of space operations and the protection of space as a global resource.
Managing the end-of-life phase of satellites requires accurate prediction of their behavior prior to atmospheric re-entry. This facilitates the orderly removal of inactive objects. In the event of uncontrolled re-entry, it is critical to accurately determine the trajectory of such an object. This enables the implementation of safety measures, such as notifications of possible hazard, implementation of evacuations, or protective measures for critical infrastructure.
Modern monitoring methods for the process are based on global ground-based radar systems with a comparatively modest contribution from optical observations and space-based elements. As such, these systems are used to conduct intensive measurements and observations with a special focus on the last 30-60 days before the anticipated deorbiting. With these data, a joint parameter and state estimation of the object is carried out to characterize its orbit, during which time it evolves rapidly. Based on the updated object information and the factors influencing the perturbation of its motion, prediction of its trajectory and the point of atmospheric re-entry is performed. The process is subject to uncertainty owing to the accuracy of the forecast of atmospheric factors and their frequent deviation from the expected realizations. Also, the orientation of the object and its structural integrity are of considerable importance. These elements, given the technical difficulties of observing the object in the last phase of its movement, contribute to the complexity of estimating the exact time and location of the fall, and the resulting uncertainty.
The Polish STM system which is under development is based on both own resources and access to data within the framework of international cooperation mainly with the US and EU. The Polish Space Agency (POLSA), scientific institutions and the private sector, manages a distributed, global, network of telescopes that enable effective tracking of objects in low Earth orbit (LEO), as confirmed by published research results. In this context, the Polish government, industry, and scientific institutions are focusing on the development of optical observation technologies.
This article outlines the process elements and results of monitoring of a space object subject to the uncontrolled atmospheric re-entry, which occurred in February 2025 with a point of fall on the territory of Poland. Classic data, i.e. elements of the orbit before entering the atmosphere, as well as non-standard data, such as recordings by random observers, were collected and analyzed, and on this basis a probable description of the course of the event was made.
Date of Conference: September 16-19, 2025
Track: Space Domain Awareness