What is space junk?

• Space junk, or space debris, is any piece of machinery or debris left by humans in space.
• It can refer to big objects such as dead satellites that have failed or been left in orbit at the end of their mission. 
• It can also refer to smaller things, like bits of debris or paint flecks that have fallen off a rocket.

What is kessler syndrome?

• This is a concept suggested by NASA scientist Donald Kessler in 1978, which states that if there is too much space junk in orbit, it might cause a chain reaction in which more and more objects crash, creating additional space junk in the process, until Earth’s orbit becomes useless — a Domino Effect.
• For the previous two decades, 12 fragmentation incidents have occurred per year.

India’s measures against space debris

1. Space Situational Awareness (SSA): 

• SSA deals with the comprehensive knowledge of the space environment, assessment of any threats to space activities and the implementation of necessary mitigation measures to safeguard the space assets. 
• SSA plays a crucial role in ensuring safe and sustainable space activities complying with domestic and international guidelines, standards and other norms.

2. Project NETRA (Network for space object Tracking and Analysis):

• Under the Network for Space Objects Tracking and Analysis (NETRA) project, ISRO is building up its orbital debris tracking capability by putting up many observational facilities: connected radars, telescopes, data processing units and a control centre.
• They can spot, track and catalogue objects as small as 10 cm, up to a range of 3,400 km and equal to a space orbit of around 2,000 km.

• The initiative would provide India with its own space situational awareness capabilities, which is used to predict dangers to Indian satellites from debris.

3. International Space Debris Coordination Centre:

• India hosts the International Space Debris Coordination Centre (ISDCC) in Bengaluru, which serves as a hub for sharing information and coordinating efforts related to space debris research and mitigation.

4. Space Debris Removal Technology: 

• ISRO has been researching and developing technologies for space debris removal. One such technology is the Electrodynamic Debris Eliminator (EDDE), which aims to capture and deorbit space debris using an electrodynamic tether system. This technology is being explored as a potential solution to actively remove debris from space.

5. Space Debris Mitigation Guidelines:

• ISRO has formulated Space Debris Mitigation Guidelines that outline best practices and procedures to reduce the generation of space debris during the launch and operation of satellites. 
• These guidelines include measures such as designing satellites to minimize debris generation, adopting end-of-life disposal strategies, and promoting space situational awareness.

Why in News?

• A large object found on the shores of western Australia recently has been confirmed to be the debris of an ISRO rocket.

What could be done?

• After a spacecraft’s mission is over, it can be moved to a more secure orbit. That is, a high-altitude “graveyard orbit” over low-Earth space.
• Carrying out ‘collision avoidance manoeuvres’ to avoid space debris.
• A recent study proposes using powerful laser pulses from a high-efficiency fiber laser to shoot down the debris. The pulses would knock objects into the Earth’s atmosphere, where they would burn up. 
• Reusable spacecraft can be developed.
• Creating spaceships that can endure the harsh conditions of space without dissolving.