Space debris: “grandfather satellite” ERS-2 scheduled to fall to Earth

Europe's pioneering satellite is set to fall to Earth within hours.

ERS-2 was a state-of-the-art observational platform when it launched in 1995, building on the technology now routinely used to monitor the planet.

The European Space Agency (Esa) says most of the two-tonne satellite will burn up during its fall.

Although sturdier components may be able to withstand the intense heating that occurs during high-speed dives, these pieces are less likely to impact populated areas and cause damage.

Although it could land almost anywhere on Earth, most of the Earth's surface is covered by ocean, so any debris left on the surface would most likely be lost at sea.

“And it's worth emphasizing that none of the elements that can re-enter the atmosphere (and reach the surface) are radioactive or toxic,” said Mirko Albani of Aether's Earth Observation Ground Division. Stated.

The agency launched two nearly identical Earth Remote Sensing (ERS) satellites in the 1990s. They were the most sophisticated planetary observers of their time, carrying an array of instruments to track changes in land, sea, and air.

They monitored floods, measured surface temperatures on continents and oceans, tracked the movement of ice fields, and sensed ground warping during earthquakes.

And ERS-2 specifically introduced new capabilities to assess the Earth's protective ozone layer.

“That's right,” said Dr. Ralph Cody. “In terms of technology, you can draw a direct line from ERS to the European Copernicus/Sentinel satellites that monitor the Earth today. ERS is where it all started,” Airbus' Earth Observation Business Development Manager told BBC News told.

Dr. Ruth Mottram is a glaciologist at the Danish Meteorological Institute. She recalled the revolution that ERS brought to her own discipline.

“When I was a college student in the '90s, we were told that the ice sheets were so cold and stable that they wouldn't change much. By the time we saw the changes that we expected, It will take several decades.'' “This is thought to be a result of climate change, and ERS has actually shown that this is not true and that major changes are already occurring.''

ERS-2 was the first of the duo to return home. Initially installed at 780 km above Earth, engineers lowered the altitude to 570 km using the final fuel reserves in 2011. The upper atmosphere would then drag the spacecraft in, and it was expected to be destroyed in about 15 years.

This forecast also holds true on Wednesday afternoon (Greenwich Mean Time).

It's hard to say exactly when and where. Much depends on the density of the upper atmosphere, which is influenced by solar activity.

What we can say with certainty is that reentry will occur between 82 degrees north and 82 degrees south. This is due to the range of the satellite's orbit around the Earth.

Debris impacting the planet may include internal panels and some metal parts such as fuel and pressure tanks.

The element most likely to pass through the atmosphere in some form is the antenna of a synthetic aperture radar system manufactured in the United Kingdom. The antenna is a carbon fiber construction that can withstand high temperatures.

When ERS-2 was launched, space debris mitigation guidelines were further relaxed. It was deemed permissible to bring back surplus spacecraft within 25 years of their end of service.

ESA's new Zero Debris Charter recommends that the disposal grace period not exceed five years. And that future satellite will be launched with the necessary fuel and the ability to deorbit propulsively in a short period of time.

The rationale is clear. With so many satellites now being launched into orbit, the likelihood of collisions is increasing. ERS-1 suddenly failed before technicians could lower its altitude. It is still over 700km above Earth. At that height, it could take 100 years to fall naturally.

The American company SpaceX, which operates most of the functional satellites currently in orbit (more than 5,400), recently announced that 100 of its satellites have been removed due to the discovery of defects that “may increase the likelihood of failure in the future.” announced that it would crash. They want to remove the spacecraft before problems arise and make their work even more difficult.

They say, “The accumulation of giant derelict objects in low Earth orbit continues unabated, with 28% of the current long-lived giant derelict objects remaining in orbit since the turn of the century.

“These uncontrollable clusters of mass pose the greatest debris generation potential for the thousands of newly deployed satellites powering the world's space economy.”