Pioneering 2-ton satellite will fall to Earth this Wednesday – 02/21/2024 – Science

A pioneering European satellite is expected to fall to Earth in the coming hours.

ERS-2 was a cutting-edge observation platform when it launched in 1995 — and it helped forge technologies that are now routinely used to monitor the planet.

The device’s activity has gradually declined since it ceased operations in 2011.

Now, the apparatus will undergo an uncontrolled and violent “dive” into the atmosphere this Wednesday (21).

The European Space Agency (ESA) says most of the two-ton satellite will burn and fall apart during descent.

It is possible that some larger and more robust pieces can withstand the intense heating generated during the high-speed fall, but the chances of these fragments reaching populated areas and causing damage are minimal, experts guarantee.

These pieces of satellite could land almost anywhere in the world — but with most of the Earth’s surface covered by the ocean, any debris that survives friction will likely be lost at sea.

“And it’s worth highlighting that none of the elements that can enter the atmosphere (and reach the surface) are radioactive or toxic,” said scientist Mirko Albani, from ESA’s Earth Observation Department.

ESA launched two almost identical Earth remote sensing satellites — known by the acronym ERS — in the 1990s.

Both made the most sophisticated planetary observations at the time and carried a suite of instruments to monitor changes occurring on land, in the oceans and in the air.

The devices monitored floods, measured continental and ocean surface temperatures, tracked the movement of ice fields, and observed ground deformation during earthquakes.

ERS-2, specifically, introduced a new possibility of evaluating the ozone layer that protects the Earth.

The pair of satellites have been described as the “grandfathers of Earth observation in Europe”.

“In terms of technology, it is possible to draw a direct line from the ERS to the European Copernicus/Sentinel satellites that monitor the planet today”, says Ralph Cordey, Development Manager for the Earth Observation Sector at Airbus.

“The ERS was where it all started,” he added.

ERS-2 is the first of the pair to return home. It was originally 780 km above Earth, and engineers used final fuel reserves in 2011 to reduce its altitude to 570 km.

The expectation was that the upper layer of the atmosphere would drag the spacecraft to destruction in about 15 years.

According to scientists, this is exactly what should happen this Wednesday, 13 years after the reduction in altitude.

The satellite should collapse between the end of the morning and the afternoon, Brasília time, this Wednesday (21).

It is difficult to determine precisely when and where it will fall. This varies depending on the density of the upper atmosphere, which in turn is influenced by solar activity.

What can be said with certainty is that reentry will occur between 82 degrees North and South, as this was the extent of the satellite’s orbit around the Earth.

ESA space debris experts calculate that little material from ERS-2 will resist friction and reach the Earth’s surface.

Fragments that could reach the surface include internal panels and some metal parts, such as fuel tanks.

The element most likely to pass through the atmosphere in some way is the antenna of the radar system, which was built in the United Kingdom.

The antenna has a carbon fiber construction capable of tolerating high temperatures.

When ERS-2 was launched, mitigation guidelines on space debris were much more flexible. Bringing home a spacecraft 25 years after the end of operations was considered acceptable.

ESA’s new Zero Waste Charter recommends that the grace period for disposing of these objects should not exceed five years. And future satellites will be launched with the necessary fuel and the ability to leave orbit through propulsion in a short space of time.

The reason is obvious: with so many satellites in orbit, the potential for collisions has increased considerably.

ERS-1, for example, suddenly failed before engineers could lower its altitude.

This device is still more than 700 km above Earth. At that point, it could take a hundred years for it to fall off naturally.

The American company SpaceX, which operates most of the functional satellites currently in orbit — there are more than 5,400 — recently announced that it would shoot down 100 of them after discovering a flaw that “could increase the likelihood of failures in the future.”

The company wants to remove the objects before any problems make the task more difficult.

Last week, the Secure World Foundation, an advocacy group for the sustainable use of space, and LeoLabs, a US company that tracks space debris, issued an urgent statement on the need to remove devices in orbit that no longer work.

“The accumulation of derelict objects in low Earth orbit remains the same; 28% of today’s massive derelict long-lived objects have been left in orbit since the turn of the century,” says the text.

“These clusters represent the greatest debris-generating potential for the thousands of recently deployed satellites that power the global space economy,” the statement concludes.