The debris created by India’s anti-satellite test in March 2019 seems to have all decayed or disintegrated, and India’s contribution to space debris has fallen to the lowest levels in the last four years, latest data shows.
There are thousands of big and small unwanted objects floating in the space — out-of-operation satellites and its fragments, the remains of rocket and its parts, and other kinds of junk – that are collectively referred to as space debris. The pieces, moving at very high speeds just like every other object in space, are considered threat to functional satellites and other space assets. A collision with even a milimeter-sized space debris can destroy satellites or render them useless.
According to the latest issue of Orbital Debris Quarterly News, published by NASA’s Orbital Debris Program Office, there are 25,182 pieces of space debris, of sizes larger than 10 cm, in the lower earth orbits which are within 2,000 km of earth’s surface.
Of these, the debris from Indian space assets is only 114, the lowest among major space-faring nations, and around the same level as in 2018. In addition, India has 103 active and defunct spacecraft that are also in orbit. The United States, China and countries of the former Soviet Union have the largest number of active or defunct satellites, as well as space debris, each contributing several thousands.
India’s contribution to space debris had increased sharply in 2019 after the country’s first-ever anti-satellite test, during which India had demonstrated its capability to strike at an enemy country’s space assets.
On March 27, 2019, India had shot down its own 740-kg Microsat-R satellite to demonstrate this capability. That anti-satellite test had made India only the fourth country in the world to have the ability to destroy space-based infrastructure an enemy country.
The destruction of Microsat-R satellite had resulted in the creation of large amount of space debris. NASA had estimated that about 400 big and small pieces were created, though only about 100 were large enough to be tracked. Almost 90 per cent of the total pieces had disintegrated within a few weeks of the test. NASA had flagged about 50 large pieces that had remained in the space for several weeks.
India had maintained that since the test was carried out in the lower atmosphere, the space debris would disintegrate quickly. The lower atmosphere has small amounts of friction as well as gravity, due to which the pieces were expected to burn out while falling towards the earth.
Before the anti-satellite test, there were about 115 pieces of debris attributed to India. In the few months after the test, this number had risen to 160. But over a period of time, many of these pieces either decayed or got destroyed. It is possible that some of the pieces from the anti-satellite test are still in space, while a few pieces of junk from earlier years have decayed. However, the total number of space junk attributable to India is now lower than what it was before the anti-satellite test.