ESA report shows significant increase in space debris in Earth’s orbit

25 Apr 2022

An illustration to show the number of satellites orbiting Earth. Image: NASA

The ESA estimates that there are 1m pieces of debris in Earth’s orbit that could impact or destroy a spacecraft but are too small to be individually tracked.

A new report from the European Space Agency (ESA) highlights how crowded space is getting, with concerns raised about the growing level of space debris and satellites in Earth’s orbit.

The ESA’s latest Space Environment Report says that more than 30,000 pieces of space debris have been spotted and are being regularly tracked by space surveillance networks.

There were 10,000 catalogued debris objects surrounding Earth at the end of 2003 and the agency’s estimated total figure of dangerous debris is now significantly higher.

According to NASA, space debris is mostly human-generated objects. It includes pieces of spacecrafts and flecks of paint, parts of rockets, satellites that have stopped working and fragments resulting from explosions in orbit.

The ESA has previously stated that objects in the 1cm to 10cm size range could pose a threat, as they are too small to track but can impact or even destroy a spacecraft they hit.

Based on statistical models, the ESA now estimates that there are likely 1m pieces of space debris in orbit that range from 1cm to 10cm in size, with an estimated 36,500 objects larger than 10cm.

More debris, more satellites

While the amount of space debris has risen, the ESA report notes that Earth’s low orbit is also getting more crowded with satellites.

The number of satellite launches from private companies has significantly increased in recent years, while the average size of satellites is getting smaller. The number of satellite constellations, or groups of satellites working together as a system, has also increased.

“Many of these constellations are launched to provide communication services around the globe,” the ESA said in a statement. “They have great benefits, but will pose a challenge to long-term sustainability.”

The number of collision alerts experienced by satellites is also on the rise. The ESA said that collision alerts with other satellites are increasing at low altitudes, while the risk of encountering space debris grows at higher altitudes.

“Not all alerts require evasive action,” the ESA added. “But as the number of alerts increases, it will become impossible for spacecraft operators to respond to them all manually.”

In 2020, two defunct satellites racing across the sky at around 53,000kph narrowly missed smashing into each other.

One fear highlighted by the ESA is the risk of Kessler Syndrome in the long term. This is a scenario where the amount of objects in space create a cascading effect – with more collisions creating more debris, which causes even more collisions.

The ESA said that certain low-Earth orbits could become “entirely inhospitable”.

In February, the European Commission proposed a Space Traffic Management system alongside a proposed €6bn satellite system.

“Space has become more crowded than ever, increasing the complexity and the risks related to space operations,” high representative of the union for foreign affairs and security policy, Josep Borrell, said at the time.

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Leigh Mc Gowran is a journalist with Silicon Republic