Rocket Re-entry Triggers Atmospheric Pollution

Syllabus: GS3/ Science and Technology

Context

• A recent study has found that the re-entry of rockets such as the Falcon 9 is altering the chemistry of the upper atmosphere, leading to a tenfold surge in lithium atoms.

Atmospheric Pollution from Space Activity

• Satellites and rockets contain aluminum alloys and Lithium-ion batteries. During re-entry these materials burn and vaporize, releasing metals into mesosphere and lower thermosphere (MLT region).
• Dangers of Space debris: They are defined as all non-functional, man-made objects, including fragments and elements thereof, in Earth orbit or re-entering into Earth’s atmosphere.
  • According to NASA, debris can travel at speeds of up to 18,000 mph, which is 10 times faster than the speed of a bullet.

What are the concerns?

• Impact on Atmospheric Chemistry: Artificial metals alter the natural composition of upper atmospheric layers. Natural space dust contributes negligible lithium (~80 g/day), while rockets inject significantly higher amounts.

• Kessler Syndrome: It is a theoretical scenario in which a cascade of collisions between artificial objects in low Earth orbit leads to a rapidly increasing amount of space debris, making the use of near-Earth space impossible for an extended period of time.
• Threat to Ozone Layer: Metal particles may trigger chemical reactions that can degrade ozone, affecting protection from harmful ultraviolet radiation.
• Climate Implications: Changes in atmospheric composition may affect radiative balance and heat retention properties. This can have long-term implications for climate systems.

International agreements on space debris

• The Space Liability Convention of 1972: It defines responsibility in case a space object causes harm.
  • The treaty says that “a launching State shall be absolutely liable to pay compensation for damage caused by its space objects on the surface of the earth or to aircraft, and liable for damage due to its faults in space. 
• Zero Debris Charter: Twelve nations and the European Space Agency (ESA) have signed the Zero Debris Charter at the ESA/EU Space Council. It aims to become debris neutral in space by 2030.

Missions on Removing Space Debris

• RemoveDebris mission: It is the European Space Agency’s debris removal demonstration mission in the low Earth orbit (LEO) that aims to test and validate multiple active debris removal technologies.
• Space Debris Removal System (SDRS): It is a proposed mission by the Russian Space Agency (Roscosmos) to demonstrate the feasibility of removing space debris from low Earth orbit.

Steps taken by India

• Project NETRA (Network for space object Tracking and Analysis), an early warning system, was initiated by ISRO to help detect space hazards to Indian satellites.
  • The project is expected to give India its own capability in space situational awareness (SSA), something that other space powers already have.
  • The SSA is used to predict threats from debris to Indian satellites.
• The ISRO System for Safe and Sustainable Operations Management (IS4OM) was established in 2022 to continually monitor objects posing collision threats and to mitigate the risk posed by space debris.

Way Ahead

• The detection of a lithium plume from a single rocket re-entry highlights a previously overlooked dimension of space activity which is its atmospheric footprint. 
• As the scale of space operations expands rapidly, proactive monitoring, sustainable design, and global regulatory efforts will be essential to prevent long-term disruption of Earth’s atmospheric system

Source: TH