30 Years in Orbit: ESA's ERS-2 Satellite Successfully Reenters Earth's Atmosphere

Monday - March 4 2024, 16:06 UTC - 8 months ago

Naerly 30 years after its launch, ESA's ERS-2 satellite successfully reentered Earth's atmosphere. Its final moments were tracked by Germany's Fraunhofer Institute, which discovered the unexpected detachment of its solar array. This may have affected the satellite's reentry trajectory and could help improve predictions for future natural reentries.

After nearly 30 years in orbit and a hugely successful mission, ESA's ERS-2 satellite has reentered Earth's atmosphere. The final moments of the satellite's reentry were captured by Germany's Fraunhofer Institute for High Frequency Physics and Radar Techniques FHR, providing valuable data for improving satellite reentry predictions.

ERS-2 was launched on April 21, 1995 as part of the European Remote Sensing (ERS) Program. Originally planned for a 5-year mission, the satellite far exceeded expectations and remained in orbit for nearly 30 years, making important contributions to studies of Earth's oceans, ice sheets, and land surfaces. The ERS program also included ERS-1, which was launched in 1991 and operated until 2000.

Despite its long time in orbit, predicting the exact time and location of ERS-2's reentry was made more difficult by the lack of recent observations of the satellite. However, the Tracking and Imaging Radar (TIRA) at Fraunhofer Institute was able to track ERS-2 in its final moments, providing crucial data for understanding its reentry trajectory. By comparing images from multiple tracking sessions, it was discovered that ERS-2's solar array was already coming loose and no longer firmly attached to the rest of the satellite the day before reentry. This unexpected detachment may have caused the satellite to interact with the atmosphere in unexpected ways, challenging the way experts treat satellites as one rigid object during reentry predictions.

Further analysis of the data is currently underway, and it is possible that the buckling of the solar array may have contributed to ERS-2's reentry taking place slightly later than predicted. If this is the case, the research could help improve forecasts of future natural reentries. ESA expresses thanks to Fraunhofer Institute for High Frequency Physics and Radar Techniques FHR and their space observation radar TIRA, in collaboration with the German Space Situational Awareness Center, GSSAC, for their assistance in tracking ERS-2's final moments. It should also be noted that the color in the TIRA images represents radar echo intensity and not temperature.