Context: The world is increasing its reliance on space technology for vital functions like climate monitoring. However, it gives rise to the concerns about satellite interference and the accumulation of orbital debris.
Relevance of the Topic: Mains - Environmental consequences of space activities and what are the barriers in achieving space sustainability.
Key Environmental Consequences of Space Activities:
- Exacerbating Global Warming:
- Every rocket launch releases carbon dioxide, black carbon, and water vapour into the atmosphere. Black carbon absorbs sunlight 500-times more effectively than carbon dioxide.
- Satellites also use propulsion systems to adjust their location and orientation in orbit, and their emissions amplify global warming. As commercial space ventures become more common, the cumulative impact of these emissions will worsen.
- Depletion of Ozone:
- Rocket propellants (especially those using chlorine-based chemicals) deplete the ozone layer at high altitudes.
- This increases the exposure to ultraviolet radiation on the ground as well as disrupts atmospheric circulation, both of which affect the global climate.
- Metallic Ash:
- When satellites burn up in the atmosphere at the end of their missions, they release "satellite ash" into the middle layers of Earth's atmosphere. This metallic ash can harm the atmosphere and potentially alter the climate.
- Energy Intensive Processes:
- The production of satellites demands energy-intensive processes involving metals and composite materials, whose extraction and preparation have large carbon footprints.
- The rise of extracting valuable (on the earth) minerals from asteroids could lead to increased industrial activity both in space and on the ground.
- Dangers of Orbital Debris:
- As of September 2024, over 19,590 satellites have been launched, with 13,230 still in orbit of which 10,200 are functional. Non-functional objects in Earth's orbit contribute to pollution and can disrupt scientific research by interfering with data collection and radio waves.
- These risks significantly impact mission costs and pose severe threats to human-crewed missions (such as the International Space Station).
Barriers to Space Sustainability:
- No specific international regulations: Space activities currently fall outside international sustainability instruments like the Paris Agreement. Without clear guidelines, the unchecked growth of emissions and debris will harm Earth's climate and increase barriers to future space exploration.
- Lack of regulation for Space Debris: Currently, there are no international space laws pertaining to Low Earth Orbit (LEO) debris.
- Lack of binding provisions: The principles of the Outer Space Treaty lack binding provisions to regulate countries' exploration and use of outer space (including the Moon and other celestial bodies), thus limiting its effectiveness.
Way Forward:
- Establish Enforceable Standards:
- The UN Office for Outer Space Affairs should set standards for governing activities in outer space.
- Governments should set domestic standards for emissions from rockets and satellites.
- International cooperation through bodies like the Committee on the Peaceful Use of Outer Space (COPUOS) is necessary to create enforceable standards for emissions and debris management.
- Reusable Rockets: Such as developed by SpaceX and Blue Origin reduce manufacturing waste and lower costs by allowing engineers to reuse rocket components in multiple missions.
- But the reusable parts are often heavier, which increases fuel consumption. These also have limited applicability for high-orbit missions, requiring costly refurbishments.
- Cleaner fuels: Such as liquid hydrogen or biofuels can minimise harmful emissions during lift-offs.
- However, hydrogen is currently produced using non-renewable energy, which negates its environmental benefits.
- Designing satellites with Biodegradable materials: That naturally disintegrate during re-entry can prevent long-term debris accumulation.
- These materials currently lack the durability required for the extreme conditions of space. High development costs and limited adoption further slow progress.
- Autonomous Debris Removal (ADR) technologies: Such as robotic arms and laser systems also offer hope for cleaning up orbital debris.
- They are currently expensive as well as need more legal clarity before they can begin to operate safely.
- Global Traffic System: To monitor satellites and debris in real time could reduce collisions and optimise orbit use.
- Resistance to data sharing, including due to security and commercial concerns, and the lack of a unified international authority hinder its development.
Policy and technical measures on a global scale are necessary to ensure that space is a safe, sustainable, and accessible domain for all.