Space debris in low Earth orbit poses an increasing challenge. Space-faring nations are seeking technical solutions to manage and mitigate these risks.
The growing amount of space debris in low Earth orbit (LEO) threatens the safety of satellites and crewed missions. With over 8,000 satellites in orbit and millions of fragments of debris, the risk of collisions is increasing. Major space-faring nations, including the United States, China, and Russia, are actively seeking solutions to monitor and alleviate this problem. However, there is still no consensus on the methods to adopt, who will be responsible for implementation, or how it will be funded.
Proliferation of Space Debris in Low Earth Orbit
Since the launch of the first Sputnik satellite by the Soviet Union in 1957, space has become increasingly crowded. By the end of 2022, there were about 8,261 satellites in orbit, with only 58% of them still active. This means that over 3,400 inactive satellites are orbiting the Earth, adding to the space debris problem.
Debris is not limited to inactive satellites. Upper stages of launch vehicles, tools lost by astronauts, and fragments resulting from collisions or explosions also contribute to the issue. It is estimated that there are more than 500,000 objects over 10 cm in orbit that can be tracked from Earth. Additionally, there are about 130 million fragments smaller than 1 cm, which are difficult to detect but can cause significant damage due to their high velocity, reaching speeds of up to 28,000 km/h.
The exponential growth in the number of satellites, particularly with constellations like SpaceX’s Starlink, which plans to deploy up to 42,000 satellites, exacerbates the problem. In 2020, over 1,000 satellites were launched, compared to just 120 in 2010. This increase raises the risk of collisions, potentially generating even more debris in a phenomenon known as the Kessler Syndrome.
Risks for Space Operations and Infrastructure
Space debris poses a threat to operational satellites, crewed missions, and infrastructure like the International Space Station (ISS). An object as small as 1 cm can cause significant damage if it impacts. For example, in 2016, a small piece of debris created a 7 mm hole in one of the ISS windows.
Collisions with debris can result in the loss of costly satellites. The French satellite Cerise was damaged in 1996 after colliding with a fragment from an Ariane rocket. Financial consequences are significant: the average cost of a telecommunications satellite can exceed €200 million, not including launch costs.
Operators now must conduct avoidance maneuvers, consuming fuel and reducing satellite lifespan. The European Space Agency (ESA) performs an average of 12 avoidance maneuvers per year. These actions require constant debris monitoring and coordination among international operators.
Monitoring and Tracking of Space Debris
Several nations have established space surveillance systems to track debris. The United States has the Space Surveillance Network, which can track more than 22,000 objects over 10 cm. Russia, China, and Europe also have their own tracking capabilities.
Space debris management requires international collaboration to share data and coordinate efforts. The United Nations Committee on the Peaceful Uses of Outer Space works on guidelines to mitigate debris, but these are not legally binding.
Emerging technologies, such as high-resolution radars and optical telescopes, enhance detection capabilities. For example, the European Space Fence project aims to detect objects as small as 2 cm. However, detection alone does not remove debris, underscoring the need for active removal solutions.
Technical Solutions for Reducing Debris
Several technologies are under development to actively remove space debris. These include:
- Debris-catching satellites: Devices like the RemoveDEBRIS from the University of Surrey use nets or harpoons to capture debris and direct it toward the atmosphere for controlled disintegration.
- Space tugs: Satellites like Northrop Grumman’s MEV-1 can dock with defunct satellites to move them to graveyard orbits or bring them back into the atmosphere.
- Laser technology: Ground-based stations could use lasers to alter the trajectory of small debris, causing it to descend into orbits where it would burn up.
However, these solutions are costly and present technical and legal challenges. The cost of a cleaning mission can reach several tens of millions of euros, and the use of technologies like lasers raises concerns about militarization of space.
Legal Framework and Funding for Operations
The lack of a binding international legal framework complicates space debris management. The 1967 Outer Space Treaty and subsequent agreements do not provide specific mechanisms for debris cleanup. Moreover, the questions of responsibility and funding remain open.
Commercial operators are reluctant to invest in cleanup solutions without financial or regulatory incentives. Some propose the implementation of launch fees or taxes to fund a cleanup fund. Others suggest international standards obligating operators to deorbit their satellites at the end of their life.
Consequences for the Future of Space Missions
If no significant action is taken, the risk of collisions could render certain orbits unusable. This would have consequences for satellite-dependent services, such as communications, GPS navigation, and Earth observation.
Ambitious projects, such as crewed missions to the Moon or Mars, could be compromised. Space agencies might have to rethink their plans or develop additional protection technologies, increasing costs and delays.
The international community recognizes the urgency of the situation, but implementing effective solutions requires global cooperation and substantial investments. The coming years will be crucial to ensure the sustainability of space activities.
Ongoing Innovations and Research
Research is underway to develop materials and satellite designs that minimize debris production. For example, using self-destructing materials or clean propulsion systems can reduce the environmental impact of satellites.
Startups and innovative companies are playing an increasing role. Firms like Astroscale in Japan are working on demonstration missions for debris capture and removal. International consortia and public-private partnerships are also being explored to share costs and knowledge.
War Wings Daily is an independant magazine.