NEW DELHI: A defunct Earth-observing satellite descended from orbit Wednesday and safely disintegrated over the Pacific.
The European Remote Sensing 2 satellite, known as ERS-2, made its reentry halfway between Hawaii and Alaska. The European Space Agency confirmed the end of the 5,000-pound (2,300-kilogram) spacecraft.
There were no reports of damage or injuries.It was anticipated that most of the satellite would incinerate upon reentry.
The ERS-2 was launched in 1995 and decommissioned in 2011. To prevent collisions with other satellites, mission controllers promptly reduced its orbit, depleting its fuel. Subsequently, natural orbital decay led to its reentry, which was unguided, rendering the exact reentry location unpredictable.
“Gone, but not forgotten,” ESA stated on X, formerly Twitter. “ERS-2 has left behind a significant legacy of data that continues to benefit scientific research.”
Its precursor, ERS-1, which ceased functioning years ago, is still in orbit.
Why it was hard to track as it fell to Earth
The European Space Agency indicated that pinpointing the exact location of the satellite’s reentry into Earth’s atmosphere would be challenging due to “how difficult it is to forecast the density of the air through which the satellite is passing.” However, they noted that as the time of reentry approached, their predictions became increasingly accurate.
Predicting satellite reentry locations is difficult due to several factors:
Atmospheric Variability: The Earth’s atmosphere is constantly changing in density and composition, influenced by solar activity, seasonal variations, and weather conditions. These changes affect the drag on a satellite, making it hard to accurately forecast when and where it will descend.
Orbital Decay Uncertainty: As satellites lose altitude, they encounter increased atmospheric drag, leading to orbital decay. The rate of this decay is not constant and can be unpredictable due to varying atmospheric conditions.
Satellite Orientation and Configuration: The orientation and physical configuration of the satellite, such as its size, shape, and materials, can affect how it interacts with atmospheric particles, altering its speed and trajectory.
Limited Tracking Data: Although there are systems in place to track satellites, gaps in coverage or data can lead to uncertainties in predicting the exact time and location of reentry.
High-Speed Travel: Satellites reenter the Earth’s atmosphere at very high speeds. Small errors in speed or position can lead to large discrepancies in reentry location predictions.
Fragmentation and Breakup: As a satellite reenters the atmosphere, it may break apart due to the intense heat and pressure. Predicting the exact path of multiple fragments is more complex than predicting a single object.
(With inputs from agencies)
The European Remote Sensing 2 satellite, known as ERS-2, made its reentry halfway between Hawaii and Alaska. The European Space Agency confirmed the end of the 5,000-pound (2,300-kilogram) spacecraft.
There were no reports of damage or injuries.It was anticipated that most of the satellite would incinerate upon reentry.
The ERS-2 was launched in 1995 and decommissioned in 2011. To prevent collisions with other satellites, mission controllers promptly reduced its orbit, depleting its fuel. Subsequently, natural orbital decay led to its reentry, which was unguided, rendering the exact reentry location unpredictable.
“Gone, but not forgotten,” ESA stated on X, formerly Twitter. “ERS-2 has left behind a significant legacy of data that continues to benefit scientific research.”
Its precursor, ERS-1, which ceased functioning years ago, is still in orbit.
Why it was hard to track as it fell to Earth
The European Space Agency indicated that pinpointing the exact location of the satellite’s reentry into Earth’s atmosphere would be challenging due to “how difficult it is to forecast the density of the air through which the satellite is passing.” However, they noted that as the time of reentry approached, their predictions became increasingly accurate.
Predicting satellite reentry locations is difficult due to several factors:
Atmospheric Variability: The Earth’s atmosphere is constantly changing in density and composition, influenced by solar activity, seasonal variations, and weather conditions. These changes affect the drag on a satellite, making it hard to accurately forecast when and where it will descend.
Orbital Decay Uncertainty: As satellites lose altitude, they encounter increased atmospheric drag, leading to orbital decay. The rate of this decay is not constant and can be unpredictable due to varying atmospheric conditions.
Satellite Orientation and Configuration: The orientation and physical configuration of the satellite, such as its size, shape, and materials, can affect how it interacts with atmospheric particles, altering its speed and trajectory.
Limited Tracking Data: Although there are systems in place to track satellites, gaps in coverage or data can lead to uncertainties in predicting the exact time and location of reentry.
High-Speed Travel: Satellites reenter the Earth’s atmosphere at very high speeds. Small errors in speed or position can lead to large discrepancies in reentry location predictions.
Fragmentation and Breakup: As a satellite reenters the atmosphere, it may break apart due to the intense heat and pressure. Predicting the exact path of multiple fragments is more complex than predicting a single object.
(With inputs from agencies)
