Protecting Astronauts from Deadly Space Debris

Syllabus: GS3/Science and Technology

Context

• The rapid expansion of satellite launches and commercial space activity has intensified the threat posed by Micrometeoroids and Orbital Debris (MMOD), raising serious concerns for astronaut safety and long-term sustainability of Earth’s orbits.

What is Micrometeoroids and Orbital Debris (MMOD)?

• MMOD refers to the natural and human-made particles moving at very high speeds in Earth’s orbital environment that pose a collision risk to spacecraft and astronauts.
  • Micrometeoroids: Naturally occurring, extremely small particles originating mainly from asteroid belt collisions and comets, travelling at velocities of 11–72 km/s.
  • Orbital Debris: Human-made objects such as defunct satellites, rocket fragments and collision remnants, typically moving at around 10 km/s.

Dangers of space debris

• 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.
• The International Space Station has experienced damage from a two-inch piece of space junk striking one of its components in 2021.
• 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.

What are the MMOD Protection Measures

• Debris Avoidance Manoeuvres (DAM): Objects larger than 10 cm are continuously tracked.
  • When collision probability rises, spacecraft perform orbital adjustments using onboard thrusters.
• Whipple Shields: It forms the primary line of defence against MMOD and consists of multiple layers of materials such as aluminium, Kevlar and carbon fibre separated by air gaps.
  • It shatters incoming debris and disperse its energy over a larger area, preventing damage to the main spacecraft wall.

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.
• Absence of law: However, there is no law against space junk crashing back to earth.

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.
• Cleanup Mission: It is China National Space Administration’s (CNSA) to demonstrate the feasibility of cleaning up space debris using a combination of active and passive methods.

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.

Source: TH