By Jacob King
A bus-sized satellite re-entered Earth’s atmosphere over the North Pacific Ocean on Wednesday, February 21, 2024. This occurred after the European Space Agency lost communications and control of the ERS-2 satellite during its 13-year deorbiting campaign, but no damage to property has been reported according to the ESA.
ERS-2 was approximately the size of a school bus, weighing 5,547 pounds when full of fuel according to space.com. Upon its reentry to earth, the satellite weighed in at around 5,057 pounds. Even though this may seem like a large object, objects of this size such as space junk or debris re entering Earth’s atmosphere is not unusual and occurs every few weeks according to space.com.
“We see objects similar in size or larger to ERS-2 reentering the atmosphere multiple times each year,” Tim Flohrer, Head of ESA’s Space Debris Office, said. “In the 67 years of spaceflight, thousands of tons of artificial space objects have reentered the atmosphere. Pieces that make it to the surface have only very rarely caused any damage and there has never been a confirmed report of a human injury.”
In 2011, the ESA decided to return the satellite to earth in response to growing concern over long-term hazards that orbital debris poses to current and future space exploration. Since then, ERS-2’s altitude had been steadily declining. On February 21, 2024, the satellite reached a critical altitude of about 50 miles. Here, the atmospheric drag is so strong that it began to break the satellite into pieces according to the ESA.
During the deorbiting process, all the remaining fuel was depleted in order to reduce risks of internal malfunctions. As a result, the satellite could not be controlled meaning the only thing controlling the satellite was atmospheric drag. Finally at approximately 12:17 pm ET on February 21, the satellite reentered Earth’s atmosphere and burned above a remote patch of the North Pacific Ocean between Alaska and Hawaii according to Live Science.
Due to when it was constructed, natural reentry was the only option for ERS-2, but the ESA hopes to do away with this type of reentry.
“Natural reentries are no longer the gold standard in space sustainability,” the ESA said. “By implementing the ‘ESA Zero Debris approach,’ the agency is committed to ensuring the long-term sustainability of space activities by mitigating the creation of space debris wherever possible and ensuring the safest possible reentry of satellites at the end of their lives.”
The satellite was launched on April 21, 1995, and during its nearly 30-year long mission it, along with its twin ERS-1 satellite, gathered information on Earth’s land surfaces, ocean temperatures, ozone layer and polar ice extent that helped scientists get a greater understanding of the Earth system.
“The ERS satellites have provided a stream of data which has changed our view of the world in which we live,” Simonetta Cheli, ESA’s Director of Earth Observation Programs, said. “They have provided us with new insights on our planet, the chemistry of our atmosphere, the behavior of our oceans, and the effects of mankind’s activity on our environment – creating new opportunities for scientific research and applications.”
ERS satellites also set the stage for many successor missions dedicated to studying our ever changing world. Some predecessor satellites include Envisat, MetOp weather satellites, the ESA’s Earth Explorer scientific research missions and the Copernicus Sentinels, as well as many others.
