ISRO to step up tracking of space debris


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    • With space junk posing an increasing threat to Indian assets in space, ISRO is building up its orbital debris tracking capability by deploying new radars and optical telescopes under the NETRA project. 
      • The government has given the go-ahead for the deployment of the radar, which will be capable of detecting and tracking objects 10 cm and above in size.

    ‘Project NETRA’

    • ISRO has initiated a Rs 400 crore project, called Project NETRA (Network for space object Tracking and Analysis), an early warning system that would 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.
    • SSA also serves as a warning system against missiles or a space attack against India.
    • India’s SSA would be the first for low-earth orbits or LEO. Under NETRA, the agency plans on putting up a number of observational facilities, including connected radars, telescopes, data processing units and a control centre.
    • The eventual goal for NETRA would be to capture the geostationary orbit, which is reportedly seen at 36,000 kilometers, where communication satellites operate.
      • A high-precision, long-range telescope in Leh and a radar in the North East are also being planned.

    What is Space Debris? 

    • Most Space debris comprises human-generated objects, such as pieces of spacecraft, tiny flecks of paint from a spacecraft, parts of rockets, satellites that are no longer working, or explosions of objects in orbit flying around in space at high speeds.
    • Hurtling at an average speed of 27,000 kmph in LEO, these objects pose a very real threat as collisions involving even centimetre-sized fragments can be lethal to satellites.

    Implications of Space Debris

    • Cascading impacts: Any damage, even minor, to the operational space assets will have cascading impacts on many vital systems including communication, finance, power, transportation, time scheduling and critical defence related aspects.
    • Many state-of-the-art defence technologies such as drones, guided missiles, intelligence data collections, encrypted communications and navigation would be limited or can become inoperable with functionally crippled satellite systems.
    • The growing usage of a large constellation of satellites, the growth of private sector investment in space exploration, the on-orbit breakup and collisions (like Iridium-Cosmos collision) and the anti-satellite testing leaving thousands of fragments in the orbits are all contributing to the spurt in the space debris population.

    Ways to clean Space Debris

    • To tackle this problem, several companies around the world have come up with novel solutions:
    • Removing dead satellites from orbit and dragging them back into the atmosphere, where they will burn up. To do this-

    o    Use a harpoon to grab a satellite; 

    o    Catching it in a huge net;

    o    Using magnets to grab it;

    o    Firing lasers to heat up the satellite; 

    o    Execute a collision avoidance manoeuvre;

    o    Increasing its atmospheric drag so that it falls out of orbit.

    • However, these methods are only useful for large satellites orbiting Earth. There isn’t a way to pick up smaller pieces of debris such as bits of paint and metal.
    • There are international guidelines for getting rid of old satellites and rockets from the Inter-Agency Space Debris Coordination Committee (IADC). 
    • By making sure that satellites are removed from orbit in a reasonable amount of time once they are no longer active, we can mitigate the problem of space junk in the future.

    Challenges in Space Debris Removal

    • ISRO officials say the volume of debris is likely to go up in the coming years with the increase in space missions globally.
    • Globally, 2021 saw the highest space object-to-launch ratio.
      • In other words, more space objects are placed in orbit per launch.
      • In 2020, 522 objects were placed in space with 102 launches compared to 1,860 objects in 135 launches in 2021.
    • Unfortunately, there is an explosion risk in removing more dangerous objects.
    • The issue of property rights; one can’t grab a satellite or rocket that belongs to another country without their permission. 
    • It is hard to eliminate space debris as there are huge chances of creating more junk while doing it.
    • Most satellite operators require hours or days to plan and execute a collision-avoidance maneuver

    Way Forward

    • Spacefaring nations must minimize the risks to people and property on Earth of re-entries of space objects and maximize transparency regarding those operations.
    • It is critical that all spacefaring nations and commercial entities act responsibly and transparently in space to ensure the safety, stability, security and long-term sustainability of outer space activities.
    • The high-accuracy assessment and prediction tools are essential for reducing risk to current systems and future launches.
    • Space Debris Monitoring and Space Traffic Management
      • Space traffic management is a crucial area that requires attention since the satellites in orbit can come in the way of each other
      • Thus, Space Debris management and monitoring play a crucial role as many countries are becoming players. 
      • Space debris monitoring removal has an estimated market revenue of around 2.7 billion dollars in the 2020s.
    • Space junk is no one countries’ responsibility, but the responsibility of every spacefaring country
    • The problem of managing space debris is both an international challenge and an opportunity to preserve the space environment for future space exploration missions.

    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.
    • Satellites orbiting the Earth being susceptible to collision from other space objects, it is essential to analyze the close approach of all space objects to detect collision threats well in advance.
    • Whenever a critical collision threat is identified for a spacecraft, an evasive manoeuvre known as Collision Avoidance manoeuvre (CAM) needs to be performed to mitigate the collision risk. 
    • The essentially global nature of space activities makes data sharing and collaboration very important for SSA, especially in the context of collision avoidance. 
    • Because in case a close approach event involves two operational assets, the exchange of relevant information through coordination and collaboration between the concerned agencies helps to improve the accuracy of close approach analysis.

    Source: TH