SPACE DEBRIS – SCI & TECH
News:
● On March 7, 2023, the Indian Space Research Organisation (ISRO) successfully carried out a controlled re-entry for the decommissioned Megha-Tropiques-1 (MT1).
Megha Tropiques- 1 Satellite:
● The satellite is an Indo-French joint satellite mission, launched more than a decade ago, was designed to study clouds in the tropical regions of the world. It was expected to make a final impact in the Pacific Ocean.
Objective:
● Its objective is to comprehend the life cycle of convective systems that influence tropical weather and climate, as well as their role in the associated energy and moisture budget of the tropical atmosphere.
Features:
● It provides scientific data on the contribution of the water cycle to the tropical atmosphere, including information on condensed water in clouds, water vapour in the atmosphere, precipitation, and evaporation.
● The Megha-Tropiques satellite, with its circular orbit inclined 20 degrees to the equator, is a one-of-a-kind climate research satellite that should also help scientists refine prediction models.
● The Megha-Tropiques has day, night, and all-weather viewing capabilities; it passes over India nearly a dozen times per day, providing scientists with an almost real-time assessment of cloud evolution.
About Space debris:
● Space junk is any piece of machinery or debris left by humans in space, principally in Earth orbit.
● These include dead satellites, fragments of rocket bodies and spacecraft etc.
● Currently, an estimated 14,000 objects including satellites and space debris are crowding low-Earth orbit.
● 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.
Current situation of Space debris:
● The surging number of rocket launches and the increasing number of payloads carried in recent years have made the space junk problem acute, especially after private companies such as SpaceX launched thousands of satellites to provide Internet access.
● In 2022, over 2,160 objects were launched into space, about 300 more than 2021 and 900 more than 2020.
● The number of satellites in space crossed the 10,000-mark in 2023. This includes active satellites as well as defunct ones which are still orbiting Earth.
● The number of fragmentation debris is hurtling towards the 14,000-mark.
● While satellite launches are the reason for the rise in rocket bodies orbiting Earth, fragmented debris are mostly a consequence of collisions and Anti-Satellite (ASAT) missile tests.
○ India's Mission Shakti:
■ The programme was sanctioned in 2017. On 27 March 2019, India successfully conducted an ASAT test called Mission Shakti.
■ The interceptor was able to strike a test satellite at a 300-kilometre (186 mi) altitude in low earth orbit (LEO), thus successfully testing its ASAT missile.
● The fragmented junk poses a bigger challenge as tracking debris smaller than 10 centimetres is tough.
Countries responsible for the Space debris:
● Close to 35% originated from the Soviet Union/Russia, 31% from the U.S., and 29% from China.
● Over 2,700 pieces of debris from a Chinese anti-satellite test in 2007, marked as the single worst. contamination of space in history, are still in orbit.
India's contribution in Space debris:
● India’s contribution is 0.5%. India added to the problem in 2019 by testing an ASAT missile which targeted a live satellite in LEO.
● It resulted in 400 pieces of orbital debris and invited criticism. The then NASA head Jim Bridenstine termed it as a “terrible thing” as it posed threats for astronauts aboard the International Space Station (ISS).
● While all the “trackable” debris from India’s test have re-entered Earth in subsequent years, over 50 pieces from a break-up event of the 4th stage of PSLV-C3 in 2001 are still in orbit.
Collision avoidance manoeuvre:
● While debris has the potential to cause serious accidents, the cost of manoeuvres to avoid collisions is high.
● In 2022, ISS had to conduct two such collision avoidance manoeuvres due to threats posted by debris from Russia’s ASAT test in 2021.
● Such manoeuvres are costly as they require hours of monitoring, fuel for movement, and also result in loss of data as instruments are turned off during such operations.
● India conducted 21 such corrections for its satellites in 2022, the highest ever for the country.
● Also, in 2021, ISRO monitored 4,382 events in LEO and 3,148 events in geostationary orbit (GEO) in which debris or other space objects came close to India’s space assets.
Threats of Space debris:
1. Threat to active satellites:
● The floating space debris is a potential hazard for operational satellites and colliding with them can leave the satellites dysfunctional.
2. Increase the risk of further collisions:
● Future space exploration is greatly endangered by an increase in the likelihood of collisions (Kessler syndrome). For example, the collision between Cosmos 2251 and Iridium 33
3. Affect the navigational and communication systems:
● Its performance is impacted by collisions with navigation and communication satellites.
● Damage to satellites can seriously hinder the communication and other satellite services like weather forecasting.
4. Impact on earth’s natural environment:
● On rare occasions, larger debris may strike Earth and harm the environment. For instance, the Altai region of eastern Siberia is covered in Proton rocket debris from Russia.
5. Affects human spaceflight program:
● Larger space debris will create an unsafe environment for human spaceflight, increasing the risk of collision and damage to spacecraft.
Why should we remove the Space debris?
1. Protecting active satellites:
● Removing space debris will reduce the risk of collisions with operational satellites, protecting them from damage and ensuring their continued functionality.
2. Protecting the space environment:
● Removing space debris will help to prevent the long-term impacts on the space environment, reducing the potential for a "debris belt" that could limit future missions.
3. Cost-effective:
● Removing space debris is more cost-effective than constantly avoiding collisions and repairing or replacing damaged satellites.
4. Sustainable use:
● By removing space debris, we can maintain the use of outer space for scientific, commercial, and military purposes, ensuring its continued sustainability.
5. Ensuring safe human spaceflight:
● Space debris removal will create a safer environment for human spaceflight, reducing the risk of collision and damage to spacecraft.
India's Initiatives to tackle the menace of Space debris:
1. NETRA:
● To safeguard its space assets from space debris, ISRO had set up a dedicated Space Situational Awareness (SSA) Control Centre named “Netra” in Bengaluru last December.
● Netra’s key objective is to monitor, track and protect the national space assets and function as a hub of all SSA activities.
● Only the US, Russia and Europe have similar facilities in place to track space objects and share collision warnings.
2. Mission Shakthi:
● Mission Shakti is a joint programme of the Defence Research and Development Organisation (DRDO) and the Indian Space Research Organisation (ISRO).
● As part of the mission, an anti-satellite (A-SAT) weapon was launched and targeted an Indian satellite which had been decommissioned. Mission Shakti was carried out from DRDO’s testing range in Odisha’s Balasore.
Global level initiatives:
1. Inter-Agency Space Debris Coordination Committee:
● IADC is an inter-governmental forum whose aim is to coordinate efforts to deal with debris in orbit around the Earth founded in 1993.
2. Clear Space-1 Mission:
● In this a "chaser" with its four robotic arms will grab the leftover of 2013 craft known as VESPA (Vega Secondary Payload Adapter) and drag it down to Earth's atmosphere where both will burn up.
● To be launched in 2025.
3. e-Deorbit:
● It is an European Commission led mission that aims to demonstrate the feasibility of capturing and deorbiting a non-functional satellite using a net and a harpoon.
4. 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.
WAY FORWARD:
1. Reusable Launch Vehicles:
● Using reusable launch vehicles instead of single-use rockets can help reduce the number of new debris generated from launches.
2. Global level treaty:
● The treaty should ensure that producers and users take responsibility for their satellites and debris and enforce collective international legislation with fines and other incentives to make countries and companies accountable for their actions.
3. Improved Tracking and Monitoring:
● Improving the ability to track and monitor space debris can help mitigate the risks it poses to operational satellites and human space missions.
4. Active debris removal (ADR):
● It refers to the use of specialised spacecraft to capture, retrieve, and dispose of space debris. The ADR technique can help remove large and dangerous debris from the Earth’s orbit.
5. Multiple satellites in single launch:
● Cooperation between the countries in launching their satellites from a single rocket will reduce the space debris at a high level. Example India had launched 97 satellites in a single launch.
6. Graveyard orbit:
● Once a spacecraft's mission is over, moving it to a safer orbit. That is a "graveyard orbit" high above the low-Earth space.