On Wednesday, February 21, 2024, at approximately 18:17 CET (17:17 UTC), the European Space Agency’s (ESA) ERS-2 satellite completed its descent into the Earth’s atmosphere over the North Pacific Ocean. No reports of damage to property have been received following the event.
Launched nearly three decades ago on April 21, 1995, ESA’s ERS-2 satellite, alongside its predecessor ERS-1, has been instrumental in gathering extensive data on various aspects of Earth’s environment. These satellites have significantly advanced our comprehension of Earth’s land surfaces, ocean temperatures, ozone layer, and polar ice extent, thereby revolutionizing our understanding of the Earth system. Moreover, they played a crucial role in monitoring and responding to natural disasters.
Simonetta Cheli, ESA’s Director of Earth Observation Programmes, emphasized the transformative impact of the ERS satellites, stating that they have provided unprecedented insights into our planet’s dynamics, atmospheric chemistry, ocean behaviors, and the consequences of human activity on the environment. This wealth of data has opened new avenues for scientific research and practical applications.
Despite exceeding its planned operational lifespan of three years by a significant margin, ESA made the decision to decommission ERS-2 in 2011 due to increasing concerns about the proliferation of space debris and its potential threat to ongoing and future space missions.
Over the years, the satellite’s orbit had been gradually decaying, culminating in its reentry into Earth’s atmosphere on February 21, 2024, when it reached an altitude of approximately 80 km. This critical altitude subjected the satellite to substantial atmospheric drag, leading to its breakup into smaller pieces.
An international effort, involving organizations such as the Inter-Agency Space Debris Coordination Committee and ESA’s Space Debris Office, closely monitored the reentry process to ensure safety and mitigate any potential risks.
Tim Flohrer, Head of ESA’s Space Debris Office, explained that uncontrolled atmospheric reentry has been a common practice for disposing of satellites at the end of their operational lifespan. While such reentries have occurred regularly over the history of spaceflight, instances of resulting damage or injuries have been extremely rare.
ERS-2’s reentry was classified as “natural,” meaning that all remaining fuel had been depleted during the deorbiting process to minimize the risk of malfunction. Consequently, the descent of the satellite was solely driven by atmospheric drag, making its trajectory difficult to predict accurately beforehand.
Despite the historical prevalence of natural reentries, ESA is now committed to a “Zero Debris” approach, striving for the long-term sustainability of space activities by minimizing the creation of space debris and ensuring controlled reentries for satellites at the end of their missions. This approach aims to guide future space endeavors towards safer and more environmentally conscious practices.