ESA's ERS-2 Satellite Retires: Decommissioned Spacecraft Nears Earth's Atmosphere, Prompting Minimal Risk Concerns

In the coming weeks, the European Space Agency's (ESA) European Remote Sensing 2 (ERS-2), is poised to reenter Earth's atmosphere. Launched in 1995, the ERS-2 satellite was decommissioned over a decade ago after it had exhausted its fuel reserves. As per ESA, the reentry is expected around mid-February.

ERS-2's 16-Year Legacy of Scientific Advancements and Satellite Innovation

During its 16-year operational span, ERS-2 provided groundbreaking insights into Earth and climate change, leaving a substantial data legacy that continues to drive scientific advancements. This mission not only advanced science but also paved the way for contemporary satellites, establishing ESA's leading role in Earth observation.

Launched in 1995 as the successor to ERS-1, the ERS-2 satellite marked the pinnacle of sophistication in Earth observation satellites during its launch period. In 2011, ESA concluded the operational life of ERS-2 and began the deorbiting process, setting the stage for its imminent reentry into Earth's atmosphere for natural disintegration.

Both ERS satellites, equipped with advanced instruments like imaging synthetic aperture radar, radar altimeter, and other powerful sensors, played crucial roles in measuring ocean-surface temperature, winds at sea, and atmospheric ozone.

They significantly contributed to understanding various Earth phenomena, including polar ice reduction, changing land surfaces, sea-level rise, warming oceans, and atmospheric chemistry. Additionally, these satellites played a vital role in monitoring natural disasters such as severe floods and earthquakes in remote regions.

The groundbreaking technologies pioneered by ERS laid the foundation for subsequent missions, including the successful Envisat mission, MetOp weather satellites, the Earth Explorer scientific research missions, and the Copernicus Sentinels, along with numerous national satellite missions.

For instance, ERS-2's radar technology paved the way for the Copernicus Sentinel-1 mission, while its radar altimeter influenced the sensor on the CryoSat Earth Explorer mission, monitoring changes in ice thickness. The ERS radiometer's legacy continues through its version of Copernicus Sentinel-3.

The Global Ozone Monitoring Experiment (GOME) on ERS-2 foreshadowed subsequent instruments like Sciamachy on Envisat and GOME-2 on MetOp. ERS-2's launch preceded widespread awareness of climate change, yet its missions provided crucial data that aided scientists in comprehending human-induced impacts on the planet.

ERS-2's contributions are evident in thousands of scientific papers, and thanks to ESA's Heritage Space Programme, inactive satellites' data remains valuable and continues to improve, offering ongoing insights into our evolving world and the associated risks.

ERS-2 Satellite's Landing Location Still Unpredictable

After 13 years of orbital decay primarily driven by solar activity, the satellite is expected to naturally reenter Earth's atmosphere around mid-February.

The exact landing location of the ESA's sizable ERS-2 satellite remains unpredictable due to the natural nature of its reentry process. As the satellite descends, closely monitored by the ESA's Space Debris Office, predictions on when and where it will begin burning up remain challenging.

The ESA, in adherence to space debris mitigation requirements, conducted ERS-2's disposal to minimize the generation of space debris. Although the descent appears largely uncontrolled, it is deemed a preferable outcome compared to the potential threat it could pose to future space exploration endeavors, given the increasing presence of space debris in Earth's orbit.

Despite the uncertainty, a FAQ about the upcoming reentry emphasizes that the satellite, beyond potentially becoming space debris, has contributed significantly by amassing valuable data on Earth's polar ice, changing land surfaces, sea-level rise, warming oceans, and atmospheric chemistry. ERS-2, operational until its mission completion in 2011, underwent altitude reduction and passivation to mitigate collision risks with other satellites.