Explainer: What is space debris and why countries in the Global South are more at risk?

The vastness of space is not as empty as it once was. Over the years, human activity has turned low Earth orbit into a congested highway clogged with abandoned satellites, discarded rocket stages, and crash debris. These particles of debris, generally known as “space junk,” pose an increasing risk to countries in the Global South, astronauts, the space industry, and critical satellite operations.

What is Space Junk?

Space junk is any man-made item in orbit around Earth that is no longer usable. It is also known as orbital debris or space rubbish. This may include:

Defunct satellites: They are those that are no longer functioning due to age or malfunction.

Rocket stages: Are rocket components that are discarded during launches.

Fragmentation Debris: Pieces of spacecraft or satellites that have separated due to collisions, explosions, or degradation.

Mission-Related Debris: Items discarded during missions, such as tools or components.

The growing problem

Since the launch of Sputnik 1 in 1957, space operations have grown at a rapid pace, resulting in the development of space debris.  There are about 170 million bits of space trash left behind following missions, however NASA reports that just 27,000 pieces of orbital debris have been detected by the Department of Defense’s global Space Surveillance Network (SSN). However, millions of tiny particles, too small to be detected but large enough to cause harm, also populate Earth’s orbit.

Why is space junk a threat?

A study conducted by experts at the University of British Columbia in Vancouver discovered that, under current practices, if a typical rocket re-entry spreads debris across a 10 m2 area, there is a 1 in 10 chance that one or more casualties will occur over the next ten years.

They also stated that persons living in the global south were at a larger danger, with errant pieces three times more likely to land at Jakarta, Dhaka, and Lagos latitudes than in New York, Beijing, or Moscow.

Collision risks

One of the most serious risks posed by space debris is the possibility of collisions with operating satellites and spacecraft. Even little debris, travelling at speeds of up to 28,000 km/h (17,500 mph), can inflict substantial harm. The 2009 collision of the Iridium 33 and Kosmos 2251 satellites, which resulted in hundreds of new debris particles, is a harsh reminder of this risk.

The second occurred in January 2007, when China used an outdated Fengyun meteorological satellite to test an anti-satellite weapon.

Additionally, two sites that have grown alarmingly congested were recommended by experts.

Impact on Space Missions

Space garbage endangers human safety and undermines the success of space operations. The International Space Station (ISS) often performs movements to avoid colliding with debris. The fear of a collision can cause mission delays, higher expenses, and threaten crew members’ lives.

Threat to satellites

Satellites play an important role in communication, weather forecasting, navigation, and Earth observation. A collision with space debris could impair these services, causing substantial economic and societal consequences. The loss of important satellites might jeopardise disaster response, global communications, and military operations.

The Kessler Syndrome

The Kessler Syndrome, suggested by NASA scientist Donald Kessler in 1978, outlines a scenario in which the density of objects in low Earth orbit is high enough that collisions between them generate a cascade effect, resulting in further trash. This self-perpetuating loop could make certain orbits unsuitable for satellites or space research, significantly limiting humanity’s ability to use space.

Mitigation Strategies

Addressing the space debris problem necessitates international collaboration and creative solutions.

There are efforts underway to create systems capable of removing junk from orbit. Robotic arms, nets, harpoons, and lasers are among the concepts proposed for capturing and destroying defunct satellites and trash in space.

Improved Tracking and Collision Avoidance

Improved tracking of space debris enables more accurate collision prediction and avoidance. Organisations such as the United States Space Surveillance Network (SSN) and the European Space Agency (ESA) are strengthening their ability to track and predict debris courses.

Regulations and Best Practices

International rules and regulations are being created to reduce the generation of fresh debris. These include designing satellites and rockets with end-of-life disposal plans, such as controlled reentry or transfer to cemetery orbits, as well as assuring compliance with space debris reduction guidelines.

Reusability and Sustainable Design

Reducing the quantity of items launched into space can be accomplished by encouraging the use of reusable rockets and creating satellites with longer operating lifetimes. Space junk generation can be reduced with the use of sustainable design techniques.

The operation of vital satellite equipment and the future of space exploration are both threatened by the growing problem of space debris. Adhering to best standards in space mission design and execution, technical innovation, and coordinated worldwide efforts are all necessary to address this challenge. Maintaining the sustainability of Earth’s orbit is essential for the growth and safety of space activities, as humanity’s dependence on space-based services grows.