A European satellite will crash to Earth on Wednesday. Are there risks to humans?

The European satellite ERS-2, which ended its Earth observation mission 13 years ago, will be almost completely destroyed on Wednesday, when it descends through the Earth's atmosphere, without risk to humans, according to the latest forecasts of the European Space Agency (ESA). AFP reported on Monday, quoted by Agerpres.

The process of de-orbiting the satellite to be destroyed upon re-entry into the atmosphere began in 2011, to avoid the situation in which this satellite could become a source of orbital debris that would endanger active satellites and the International Space Station ( ISS).

The satellite crashes naturally, not being directed in any way

The satellite will enter the Earth's lower atmosphere at 11:14 GMT on Wednesday, with a margin of error of +/- 15 hours, ESA's European Space Operations Center (ESOC) announced. This margin of error, which a week ago was +/- 48 hours, is explained by the fact that the satellite falls naturally, under the influence of the gravitational force, not being directed in any way.

ERS-2 is going to cross the upper layers of the atmosphere where it will lose its speed more or less, it being very difficult to predict the area on the globe where its remains could fall that will not be completely destroyed by friction with the atmospheric layers.

Most of the ERS-2 satellite's 2.3 tons should burn up when it reaches the lower atmosphere on Wednesday, at an altitude of about 80 km.

“It is estimated that the largest fragment of the satellite that can reach the ground would be 52 kg“, said last week Henri Laur, from the Earth Observation Directorate within ESA.

Risks below 1 in 100 billion to strike people

The probability of satellite debris hitting a person on the ground is less than 1 in 100 billion, according to information published on the ESA blog dedicated to this mission. In other words, the risk is 65,000 times lower than that of being struck by lightning.

An object with a mass similar to the ERS-2 satellite is destroyed in the atmosphere, on average, once every one to two weeks, according to the ESA.

The monitoring of the satellite during its last days in space is carried out by ESOC, with European, German and American institutional partners.

ERS-2, one of the pioneering Earth observation satellites, was launched in 1995 and placed in an orbit at an altitude of almost 800 kilometers. In 2011, at the end of its mission, ESA lowered it into an orbit at an altitude of about 500 kilometers to allow a natural and gradual fall back to Earth.

If it had been left in its original orbit, its collapse would have lasted between 100 and 200 years. Left without internal power (batteries or fuels), ERS-2 would have raised significant risks of producing space debris that would endanger the other functional satellites.

A million debris from satellites or rockets

In July 2023, the European satellite Aeolus crashed to Earth in a controlled manner, from an orbit (300 km) lower than that of ERS-2. Its remains fell into the Atlantic Ocean.

According to ESA estimates, there are currently approximately one million pieces of debris from satellites or rockets larger than one centimeter in Earth's orbit, large enough to “disable” another spacecraft on impact.