The number of satellites orbiting the Earth has never been higher, and neither has the amount of space debris. These objects (also called orbital debris and space junk) come from obsolete satellites, spent rocket stages, and in-space collisions, and contribute to an increasingly risky orbital environment.
Understanding how much debris is orbiting Earth and how long this space debris stays in orbit is key to recognizing the threats and potential solutions.
How Many Space Debris Objects Are Currently in Orbit?
According to the European Space Agency (ESA), there are currently over 40,000 pieces of debris larger than 10 cm being tracked and cataloged. Some pieces are as big as a refrigerator.
Additionally, tens of millions of smaller fragments sized from 1 mm to 10 cm are hurtling through space at incredibly high speeds. These space debris objects range from tiny paint chips to shards of satellites created by collisions.
The Growing Numbers of Space Debris in Orbit
How many space debris objects are currently in orbit has increased dramatically since the start of the space age. There are now more than 10,000 functioning satellites in orbit, and each time a new satellite launches, the risk of creating more debris grows.
The worst-ever satellite collision occurred in 2009 when the American Iridium-33 commercial satellite collided with the defunct Russian Cosmos-2251 military communications satellite. This incident created at least two thousand debris fragments.
The sheer volume of space debris means space agencies, enterprises and startups need to take proactive measures if they want to secure the future of space missions.
The Threat to Satellites and Space Stations
Space debris travels at speeds of up to 28,000 km/h, which means even small fragments are capable of causing catastrophic damage to spacecraft. Active satellites being used for global communication, navigation, and scientific research face a significant risk from these high-speed projectiles.
There are many examples of this risk. The International Space Station (ISS) regularly has to maneuver to avoid collisions with debris. In the first half of 2024, SpaceX’s Starlink satellites maneuvered nearly 50,000 times to avoid collisions. And also in 2024, a NASA satellite and an obsolete Russian spy satellite came within 20 meters of colliding with each other. These incidents prove the dangers of an orbital environment overcrowded with space debris.
How Much Debris Is Orbiting Earth?
Assessing how much debris is orbiting Earth is crucial for understanding the potential hazards. Not all space debris objects are tracked, so it is impossible to know the exact number, but space agencies generate estimates based on statistical models.
Understanding the Density of Space Debris in Low Earth Orbit
The majority of space debris is in Low Earth Orbit (LEO), which includes Earth-centered orbits with an altitude of 2,000 km or less. LEO is heavily populated with operational satellites and the ISS, making debris particularly dangerous.
Here is a breakdown of space debris density according to the ESA:
40,500 objects greater than 10 cm
1,100,000 objects from greater than 1 cm to 10 cm
130 million objects from greater than 1 mm to 1 cm
Higher orbits, such as Geostationary Orbit (GEO), also contain debris, but at a lower density. Debris in these orbits can stay there for centuries however and also contribute to long-term safety risks.
Risks Posed to Communication and Observation Systems
Space debris poses a serious risk to communication satellites, which play a vital role in our lives back on Earth. Communication satellites are used for broadcasting, internet connectivity, and weather forecasting. Even a minor impact with a small piece of debris could lead to costly damage or complete satellite failures.
Earth observation satellites are also at risk. These spacecraft provide important data for climate research, disaster response, and agricultural planning. Damage to these satellites could disrupt essential services and delay scientific advancements.
How Long Does Space Debris Stay in Orbit?
Does space debris always stay in orbit around the Earth? Will it eventually disintegrate or get out or orbit?
Factors Affecting Space Debris Longevity
How long space debris stays in orbit depends on various factors, including the object’s altitude, size, and atmospheric conditions.
Low Earth Orbit (LEO) Debris: Objects at lower altitudes (below 600 km) are more likely to re-enter Earth’s atmosphere and burn up within a few years due to atmospheric drag. However, debris above 800 km can remain in orbit for decades or even centuries.
Medium Earth Orbit (MEO) and Geostationary Orbit (GEO) Debris: Space debris in these regions experiences little atmospheric drag, meaning pieces could remain for thousands of years unless actively removed.
Impacts of Long-Lasting Debris on Space Operations
Space debris accumulation creates long-term challenges for space exploration and satellite launches. As debris builds up, the likelihood of chain reactions in which in-space collisions create even more debris becomes a serious concern.
This hypothetical phenomenon, known as Kessler Syndrome, could eventually leave certain orbits unusable. It’s a scenario that would limit future space missions and commercial satellite operations.
Addressing the Critical Threat of Space Debris
Solving the space debris problem requires a combination of technological innovation, international cooperation, and sustainable space practices.
Emerging Technologies for Debris Removal
Removing existing space debris is crucial to reversing this crisis. To combat the growing threat, governmental space agencies, private companies and space startups are developing innovative debris removal technologies:
Harpoon and Net Capture Systems: Designed to trap and retrieve large debris objects for controlled deorbiting.
Laser Ablation: Ground-based or space-based lasers that can change the trajectory of small debris, so it gradually burns up in the atmosphere.
Magnetic Removal Technology: Powerful magnets or electromagnets attract and capture space debris, allowing for controlled deorbiting or disposal.
Robotic Arms and Claws: Certain missions are developing robotic arms or claws to grab and remove large pieces of debris from orbit.
To learn about the companies behind the development of active debris removal technology, check out this article: How Businesses Are Capturing and Mitigating Space Debris
International Collaboration for Space Sustainability
Mitigating space debris also requires coordinated global efforts. Organizations such as the United Nations Office for Outer Space Affairs (UNOOSA) and the Inter-Agency Space Debris Coordination Committee (IADC) actively work on international guidelines to promote responsible satellite design and disposal practices.
Some key initiatives include:
End-of-life deorbiting plans for satellites
Designing more sustainable satellites
Encouraging active debris removal technologies
As we humans increase our reliance on space-based technology, the threat of space debris becomes even more urgent. But if we take proactive measures now, we can ensure that Earth’s orbit remains a safe and accessible space for future explorers, scientists, and industries.
