ESA's ERS-2 satellite began to come apart earlier than predicted

The European Space Agency's ERS-2 satellite has re-entered the Earth's atmosphere. While no damage to property was reported, some impressive shots were taken of the spacecraft starting to buckle as it approached re-entry.

The images were taken by the German Fraunhofer Institute for High Energy Physics and Radar Techniques and show the ERS-2 satellite breaking apart earlier than scientists had anticipated.

Fraunhofer FHR was commissioned by ESA and the joint Space Situational Awareness Centre to track the final orbits of ERS-2. The spacecraft was monitered using the Tracking and Imaging Radar (TIRA), and the resulting images showed the changes in the spacecraft's structure as it descended.

The final images of the tumbling satellite were captured on February 21, approximately ten orbits before re-entry. The solar array is clearly coming loose from the body of the spacecraft.

"In our data," said Felix Rosebrock, radar expert at Fraunhofer FHR, "we can see a clear bend in the solar panels on the one hand, and artifacts that could be caused by rapid uncontrolled 'fluttering' on the other hand."

ESA said: "When predicting a satellite’s reentry trajectory, experts treat it as one rigid object until almost the very end. If ERS-2's solar array was loose and moving independently a day early, it may have caused the satellite to interact with the atmosphere in ways we did not expect."

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The upshot is that predicting the time and location of ERS-2's re-entry became more difficult. As it was, ESA put the entry time at approximately 1717 UTC on February 21, 2024. The satellite completed its atmospheric entry over the North Pacific Ocean, breaking into pieces as it reached an altitude of approximately 80 kilometers.

Evidence of the break-up starting earlier will be helpful for scientists predicting what will happen to the next veteran satellite headed for a similar "natural" re-entry.

Many of ESA's current missions have been designed with a controlled re-entry in mind, however, the agency has several elderly satellites that predate the Zero Debris approach. The imagery of ERS-2's final hours will, therefore, be helpful in predictions for the upcoming re-entry of the Cluster spacecraft, the first of which – Salsa – is due to enter over the South Pacific Ocean in September. ®