EU SST closely monitors re-entry of space object ZQ-3 R/B

Re-entry window evolution of object ZQ-3 R/B as of 2 February 2026. Estimated window: 2026-01-30 14:05:13 UTC ±30 minutes.

The EU Space Surveillance and Tracking (EU SST) Operations Centres have actively monitored the re-entry into Earth's atmosphere of the space object ZQ-3 R/B, the second stage of a launch vehicle that could have had a dummy payload attached. The EU SST network of contributing sensors closely followed the object, and its sensors narrowed down its re-entry window to 30 January.

Latest update: 2026-02-02 17:30 UTC+1

Based on EU SST analysis and external information, EU SST confirms that object ZQ-3 R/B has decayed. The estimated re-entry window is 2026-01-30 14:05 UTC ±30 minutes. The point of re-entry into the atmosphere and the entire analysis may be affected by uncertainties in the available information on the object's mass, structure and shape.

Due to its inclination of approximately 56.94 degrees, the object could re-enter within a latitude band of ±57 degrees, covering a vast area of the Earth's surface, although most of it is ocean or uninhabited. The Italian Operations Centre, responsible for the EU SST Re-entry Analysis service, worked to narrow down the possible re-entry location and time. As the re-entry approached, the predictions became more accurate, but uncertainties remained due to the object's uncontrolled nature.

The EU SST contributing sensors played a crucial role in observing the object and providing data for analysis, and EU SST used this data to produce the best possible estimation for the expected re-entry location and time.

Map of the whole ground track. Yellow lines: ground track before the centre of the re-entry window. Green lines: ground track after the centre of the re-entry window. Red: overflights inside European countries and overseas territories. Note: the possible re-entry locations lied anywhere along the yellow and green lines. The re-entry point was considered to be at an altitude of 80 km. — Map of the whole ground track.
Yellow lines: ground track before the centre of the re-entry window. Green lines: ground track after the centre of the re-entry window. Red: overflights inside European countries and overseas territories.
Note: the possible re-entry locations lied anywhere along the yellow and green lines. The re-entry point was considered to be at an altitude of 80 km.

The ZQ-3 R/B was quite a sizable object deserving careful monitoring, with an estimated total mass of 11 tonnes and an estimated length of 12-13 m. Its maiden launch on 3 December 2025 seemingly included a dummy payload, which could have remained attached to the second stage of the launcher. The object had been decaying since then, apparently uncontrolled.

Passage of ZQ-3 R/B taken with the T2 telescope of the EU SST contributing sensor CASSINI-TANDEM, 0.09s exposures. Loiano Astronomical Station managed by INAF-OAS (Italy). Image credit: INAF-OAS. — Passage of ZQ-3 R/B taken with the T2 telescope of the EU SST contributing sensor CASSINI-TANDEM, 0.09s exposures. Loiano Astronomical Station managed by INAF-OAS (Italy).
Image credit: INAF-OAS.

ZQ 3 R/B at ~190 km altitude captured by the EU SST contributing sensor POLON-CHILE on 30 January 2026 at 00:43:35 UTC. Image credit: POLSA — ZQ 3 R/B at ~190 km altitude captured by the EU SST contributing sensor POLON-CHILE on 30 January 2026 at 00:43:35 UTC.
Image credit: POLSA

The EU SST Operations Centres will continue to provide the latest information on this event, and this article will be updated accordingly.