Jiri Silha, Comenius University Bratislava; Daniela Bartková, Comenius University Bratislava; Juraj Toth, Comenius University Bratislava; Tomáš Paulech, Comenius University Bratislava; Matej Zigo, Astros Solutions s.r.o.; Tobias Lips, Hyperschall Technologie Göttingen GmbH; Patrik Kärräng, Hyperschall Technologie Göttingen GmbH; Stefan Loehle, Institute for Space Systems, University of Stuttgart; Clemens Müller, Institute for Space Systems, University of Stuttgart; Fabian Zander, University of Southern Queensland; Byrenn Birch, University of Southern Queensland; Ranjith Ravichandran, University of Southern Queensland; Gerard Armstrong, University of Southern Queensland; Beatriz Jilete, GMV for ESA (Space Safety Programme/Space Debris Office); Stijn Lemmens, ESA/ESOC Space Debris Office
Keywords: re-entry, airborn, observation, modeling
Abstract:
Airborne campaigns are commonly used to monitor spacecraft, cargo ships, upper stages, or other compact space objects as they demise in the atmosphere. The objective is to investigate the physics of the disintegration and fragmentation processes that accompany these objects during the final stages of their lifecycle. While re-entries are becoming increasingly common phenomena, the processes related to them – such as parent body breakup, ablation, fragment cloud formation, and, consequently, the survivability of the fragments and their impact locations – are still not well understood. One way to improve our knowledge is to collect data on such events using various methods, including direct imaging, spectroscopy, and narrow-band photometry.
A daylight airborne campaign organized by European Space Agency was conducted on September 8, 2024, to observe the re-entry of the Salsa satellite, one of four satellites from the former ESA space weather Cluster mission. Salsa, with its highly eccentric orbit, was a suitable observation target because a sufficiently precise prediction of its entry location was possible, allowing for an airborne observation. Furthermore, the Cluster satellite re-entered at high speed, making it only the second such object observed after the WT1190F entry in 2015. This target selection also provides an opportunity for repeated experiments, focusing on the re-entry of the remaining three Cluster satellites in October 2025 and in August/September 2026. A team of nine researchers from four institutions across three countries deployed 26 scientific instruments on board to detect the event.
In our work, we focus on event reconstruction, crucial event timestamps, and object dynamics based on measurements acquired by Comenius University instruments, specifically using a DMK 33UX183 20 MP with Sony IMX183 1” CMOS camera equipped with Tamron C-Mount,1.1″, F1.8, 16 mm lens and M55 K filter (770 nm) meant to detect the potassium (K) element. A total of 15 seconds of footage was recorded, during which several bright flashes were identified. These flashes could potentially be linked to high-energy events, such as fragmentations. Furthermore, we reduced the data using available calibration measurements to extract the position of the object on sky, as well as its brightness. As a reference object used has been Moon which was present in the field of view of the camera during the data acquisition. We reconstruct the dynamics of the object and, consequently, the fragment cloud using the available footage, along with the plane’s pointing direction and telemetry data. The extracted data were then compared to high-fidelity simulations conducted using the ESA SCARAB model.
We will present the overall mission and its preparation, the instrumentation used, data acquired, reconstructed event and comparison with the re-entry model. Presented will be plans for future campaigns including another Cluster satellites as well as ESA DRACO mission.
The airborne observation mission ‘ROSIE-Salsa’ is a joint effort of academic partners from the Comenius University in Bratislava (CUB), University of Stuttgart (IRS/HEFDiG) – science lead, the University of Southern Queensland (UniSQ) – mission lead and industrial partners from Hypersonic Technology Göttingen (HTG) – event predictions & modelling and Astros Solutions – mission coordinator, in close cooperation with ESA.
Date of Conference: September 16-19, 2025
Track: Space Domain Awareness