- Because of the increasing number of rocket launches and payloads, as well as anti-satellite missile tests and collisions, space debris, particularly in Low Earth Orbit (LEO), is becoming an increasingly urgent problem. ISRO successfully completed a controlled re-entry for the decommissioned Megha-Tropiques-1 on March 7, 2023. (MT1).
ISRO’s controlled re-entry of the decommissioned
- Megha-Tropiques-1 (MT1) satellite ISRO successfully completed a controlled re-entry of the decommissioned Megha-Tropiques-1 (MT1) satellite.
- MT1 was launched over a decade ago with the goal of studying clouds in the world’s tropical regions.
- Because the satellite had reached the end of its operational life, ISRO brought it down in a controlled manner in order to reduce space debris in the Low Earth Orbit (LEO) and the risks associated with it.
Space junk
- Any man-made object in orbit around the Earth that no longer serves any useful purpose is referred to as space debris. This can include pieces of spacecraft, rocket stages, and other materials that have been left in space after their missions have been completed or discarded.
- The size of space debris can range from small paint flecks and bolts to larger objects such as satellites and old rocket bodies.
- There are currently over 26,000 objects larger than 10 cm in orbit around the Earth, as well as many smaller objects that cannot be tracked.
Increase in Space Debris
- Expanding the number of payloads: The increasing number of rocket launches and payloads carried in recent years has exacerbated the space junk problem, particularly since private companies such as SpaceX launched thousands of satellites to provide Internet access.
- For example, over 2,160 objects were launched into space in 2022, approximately 300 more than in 2021 and 900 more than in 2020.
- Information on fragmented debris: The number of satellites in space has surpassed 10,000, including active and defunct ones still orbiting Earth, and fragmentation debris is approaching the 14,000 mark.
- Smaller debris presents a greater challenge: While satellite launches are to blame for the increase in rocket bodies in orbit, fragmented debris is mostly the result of collisions and Anti-Satellite (ASAT) missile tests. The fragmented junk presents a greater challenge because it is difficult to track debris smaller than 10 centimetres.
Countries responsible
- Russia: Close to 35% originated from the Soviet Union/Russia,
- US: 31% from the U.S.,
- China: 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: India’s contribution is 0.5%.
- In 2019, India exacerbated the problem by testing an ASAT missile that targeted a live satellite in low-Earth orbit, resulting in 400 pieces of orbital debris.
- While all trackable debris from India’s test has returned to Earth in subsequent years, over 50 pieces from a break-up event of the PSLV-fourth C3’s stage in 2001 remain in orbit.
The cost of avoiding a collision
- High cost: While debris has the potential to cause serious accidents, the cost of manoeuvring to avoid collisions is high.
- For example, due to threats posed by debris from Russia’s ASAT test in 2021, the ISS had to perform two such collision avoidance manoeuvres in 2022.
- Challenges: Such manoeuvres are expensive because they necessitate hours of monitoring, fuel for movement, and data loss because instruments are turned off during such operations.
- India’s sincere efforts:
- In 2022, India performed 21 such corrections for its satellites, the most ever for the country.
- In addition, in 2021, ISRO monitored 4,382 events in low-Earth orbit (LEO) and 3,148 events in geostationary orbit (GEO) in which debris or other space objects were in close proximity to India’s space assets.
@the end
Small debris orbiting Earth poses a threat to space assets; the immediate need is for countries to accept responsibility. India’s ongoing efforts towards controlled decommissioning have raised the bar.
Source: https://m.economictimes.com/news/science/india-has-217-space-objects-orbiting-earth-working-towards-reducing-space-debris-report/articleshow/90762001.cms