Space Debris and Space Sustainability
Published on 23 Feb 2025
Space debris, often referred to as space junk, comprises non-functional human-made objects in orbit around Earth, posing significant risks to operational satellites and spacecraft.
Current Situation and Implications
Volume of Debris: It is estimated that there are over 500,000 pieces of debris larger than 1 mm and about 34,000 pieces larger than 10 cm in orbit.
Collision Risks: Space debris travels at speeds of up to 28,000 km/h, posing a significant risk of collision with operational satellites and the International Space Station (ISS).
Threat to Space Operations: Increased debris raises the risk of collisions, which can lead to more debris generation, creating a cascading effect known as the Kessler Syndrome.
Challenges to Space Sustainability
Space Debris: The rapid increase in satellite launches, particularly from projects like SpaceX's Starlink, contributes significantly to the debris problem.
Example: Kessler Syndrome describes a scenario where collisions create more debris, leading to a cascading effect that could render certain orbits unusable.
Limited Space Resources: As the number of satellites increases, competition for orbital slots and radio frequencies intensifies, necessitating fair resource allocation to prevent conflicts.
Example: In 2020, India and China filed protests with the International Telecommunication Union over each other's satellite filings.
Space Traffic Management: The growing number of satellites requires effective traffic management systems to avoid collisions and ensure safe operations.
Example: European Space Agency (ESA) had to perform a "collision avoidance manoeuvre" to move one of its Earth observation satellites to ensure it would not collide with a Starlink satellite.
Space Weather: Solar flares and geomagnetic storms can disrupt satellite operations and terrestrial communications, posing additional risks to sustainability.
Environment impact: Rocket launches release pollutants into the atmosphere, impacting both the environment and climate.
Example: A study published in the Journal of Astrophysics in 2021 found that the Starlink satellites could contribute to climate change by trapping heat in the atmosphere.
Initiatives on Space Sustainability
National Initiatives
Project NETRA: Launched by ISRO to monitor space debris and protect space assets.
Zero Debris Mission: ISRO's PSLV-C58/XPoSat mission achieved a milestone by leaving zero debris in Earth's orbit.
Global Initiatives
COPUOS Guidelines: The United Nations Committee on the Peaceful Uses of Outer Space adopted guidelines in 2019 to ensure the long-term sustainability of outer space activities.
Outer Space Treaty (1967): This treaty emphasizes the peaceful use of outer space and includes provisions related to space debris and the return of space objects to Earth.
Active Debris Removal (ADR): Technologies are being developed to capture and remove debris from orbit using nets, harpoons, or robotic arms.
Example: Remove DEBRIS mission aims to demonstrate these technologies.
International Cooperation: Initiatives like the Zero Debris Charter aim to set global standards for the development of effective mitigation.