Climate Footprint of Space Exploration

The growing reliance on space technologies for climate monitoring and other critical functions has heightened concerns about the environmental impact of space activities, particularly satellite interference and orbital debris.

Background

• According to the European Space Agency, as of September 2024, there had been around 6,740 rocket launches since 1957 that placed 19,590 satellites in orbit. 
• Around 13,230 are still in space and of them 10,200 are still functional.

Enroll now for UPSC Online Course

About Climate Footprint

• A climate footprint refers to the total amount of greenhouse gases (GHGs) emitted into the atmosphere as a result of human activities.
• It is a measure of how much a particular activity, product, or organisation contributes to global warming and climate change.

Environmental Impact of Space Activities

• Emissions of Greenhouse Gases: Every rocket launch emits carbon dioxide, black carbon, and water vapor, contributing to global warming.
  • Black Carbon’s Role: Black carbon absorbs sunlight 500 times more effectively than carbon dioxide, significantly amplifying the warming effect.
  • Growing Commercial Launches: Increased frequency of rocket launches intensifies these emissions, exacerbating their cumulative impact on the climate.
• Ozone Layer Depletion: Rocket propellants, especially those using chlorine-based chemicals, deplete the ozone layer at high altitudes, leading to increased ultraviolet radiation exposure on Earth.
  • Ozone depletion affects atmospheric circulation, contributing to global climate changes.
• Harmful Satellite Debris: When satellites burn up in the atmosphere at the end of their missions, they release “satellite ash” in the middle atmospheric layers.
  • This metallic ash could disrupt atmospheric composition and alter climate patterns.
• Carbon Footprint of Satellite Production and Operations
  • Energy-Intensive Manufacturing: Satellite production involves energy-heavy processes requiring metals and composite materials, resulting in significant carbon emissions.
  • In-Orbit Emissions: Satellite propulsion systems emit gases while adjusting location and orientation, adding to atmospheric pollution.
• Future Concerns with Space Mining: Space mining, such as extracting minerals from asteroids, could lead to intensified industrial activities both in space and on Earth.
  • Though not yet operational, space mining could have profound ecological consequences in the future.

About Orbital Debris

• Definition: Orbital debris, or space junk, includes defunct satellites, spent rocket stages, and fragments from satellite break-ups in low Earth orbit (LEO).
• Scale of the Problem
  • Fragmentation Events: Over 650 fragmentation events (break-ups, explosions, and collisions) have been recorded.
  • Mass of Space Objects: The total mass of all objects in orbit exceeds 13,000 tonnes.
  • High-Speed Movement: Debris can travel at speeds of up to 29,000 km/hr, making even tiny fragments highly destructive.
• Orbital Space as a Limited Resource
  • Pollution in Space: Non-functional objects in orbit occupy valuable space, constituting a form of pollution similar to that on Earth.
  • Risk Amplification: The growing number of non-functional objects increases the likelihood of collisions, creating more debris in a cascading effect.
• Risks to Satellites and Space Missions
  • Satellite Damage: High-speed collisions can destroy satellite components critical for communication, navigation, and climate monitoring.
  • Increased Costs: Operators must invest in shielding technologies.
    • Costly manoeuvres are required to avoid collisions, raising mission expenses.
  • Threat to the International Space Station (ISS): The ISS frequently adjusts its orbit to avoid collisions with debris, highlighting the risks to human missions.
• Interference with Scientific Data Collection
  • Impact on Earth Observation: Orbital debris interferes with data collection for disaster tracking, weather monitoring, and other Earth-related observations.
  • Radio Signal Disruption: Debris can interfere with radio waves, hampering the efficiency of scientific studies.

Check Out UPSC CSE Books From PW Store

Barriers to Space-Sector Sustainability

• Absence of Clear Guidelines: The space sector lacks comprehensive international regulations to control emissions and manage debris.
  • Without standards, emissions from rockets and satellites risk becoming overlooked contributors to global warming.
• Outside Global Agreements: Space activities currently fall outside international sustainability instruments like the Paris Agreement

• Overcrowding of Low Earth Orbit (LEO): The rising number of satellites and debris in LEO increases collision risks, making missions more expensive and complex.
  • Overcrowding diminishes space’s potential as a shared global resource, restricting equitable access.
• Insufficient International Cooperation: Collaboration through organizations like the Committee on the Peaceful Use of Outer Space (COPUOS) is essential to establish binding and enforceable sustainability standards.
  • Without unified action, sustainability challenges in space remain unresolved.
    • The Committee on the Peaceful Uses of Outer Space (COPUOS) is a United Nations body established in 1959 to promote international cooperation in the peaceful use of outer space.
• Non Binding provisions of the Outer Space Treaty (1967): The Outer Space Treaty promotes responsible use of space but lacks binding clauses to address environmental concerns.
  • The Outer Space Treaty serves as the foundation of international space law, promoting peaceful uses of outer space and banning the placement of weapons in space.

Measures To Make Space Exploration More Sustainable

• Adoption of Reusable Rockets: Reusable rockets like those by SpaceX and Blue Origin lower manufacturing waste and reduce costs by enabling multiple uses of rocket components.
  • However, associated challenges include:
    • Heavier reusable components increase fuel consumption.
    • Limited applicability for high-orbit missions.
    • Wear-and-tear necessitates costly refurbishments, making scalability a challenge.
• Transition to Cleaner Fuels like liquid hydrogen and/or biofuels: Cleaner alternatives like liquid hydrogen and biofuels can reduce harmful emissions during launches.
  • However, Hydrogen production relies heavily on non-renewable energy, negating its environmental benefits.
  • Cryogenic fuels, though efficient, are expensive and complex to handle, limiting their accessibility to smaller operators.
  • Electric propulsion offers a low-emission alternative, ideal for in-orbit manoeuvres.
    • However, its low thrust restricts its use to specific missions like in-orbit manoeuvres.
• Use of Biodegradable Satellite Materials: Designing satellites with biodegradable materials could prevent long-term debris accumulation by allowing natural disintegration during re-entry.
  • However, current materials lack the durability needed for extreme space conditions.
    • High development costs and limited adoption slow progress.
• Deployment of Autonomous Debris Removal (ADR) Technologies: Robotic arms and laser systems can help clean up orbital debris.
  • Challenges: High operational costs and Legal and regulatory uncertainty hinders safe and widespread deployment.
• Establishment of a Global Traffic System: A global system for real-time monitoring of satellites and debris can optimise orbit use and reduce collisions.
  • However, resistance to data-sharing, including due to security and commercial concerns, and the lack of a unified international authority hinders its establishment.
• Global Cooperation: International cooperation through bodies like the Committee on the Peaceful Use of Outer Space (COPUOS) is necessary to create enforceable standards in this context.

Enroll now for UPSC Online Classes

Way Forward

• International Collaboration: Binding agreements via bodies like COPUOS can standardise emission limits, debris mitigation measures, and data-sharing protocols.
• Prioritising Green Technologies: Governments and private entities can focus funding on:
  • Advanced propulsion systems.
  • ADR technologies.
  • Biodegradable satellite materials.
• Incentives for Sustainable Practices: Financial rewards, subsidies, or penalties can nudge private players toward adopting sustainable technologies and practices.

Conclusion

Space technology plays a crucial role in climate monitoring and disaster management. However, rising environmental costs, both for Earth’s atmosphere and outer space, require immediate attention and coordinated global action.