Indian PM announced that India had carried out a successful anti-satellite missile test (ASAT), Mission Shakti. Click here to know more.
Here are the reasons why ASATs are not widely used by countries, and their implications in terms of space debris.
Why is ASAT not widely used?
ASAT requires very advanced capabilities in both space and missile technologies that not many countries possess.
But more than that, destroying space infrastructure like satellites is also taboo in the international community, at least till now.
Almost every country agrees that space must not be used for wars and has spoken against weaponisation of space.
There are also international treaties governing the use of space, mandating that, it must only be exploited for peaceful purposes.
What are the international agreements in place?
The Outer Space Treaty of 1967 prohibits countries from placing into orbit around the Earth any objects carrying nuclear weapons or other weapons of mass destruction.
India is a signatory to the Outer Space Treaty.
The treaty also prohibits the stationing of such weapons on celestial bodies, like the moon, or in outer space.
It mandates that outer space, and celestial bodies like the Moon, must only be used for peaceful purposes.
There are at least four more multilateral treaties that deal with specific concepts agreed to in the Outer Space Treaty.
But besides these, the problem of space debris is a key reason why countries resist from destroying each other’s satellites.
What is space debris?
Anything launched into the space remains in space, almost forever, unless it is specifically brought down or it slowly disintegrates over decades or centuries.
Satellites that are past their life and are no longer required also remain in space, orbiting aimlessly in some orbit.
As per the recent Orbital Debris Quarterly News, published by NASA, there were 19,137 man-made objects in space that were large enough to be tracked.
These included active and inactive satellites, rockets and their parts, and other small fragments.
Besides these, there are millions of other smaller objects that have disintegrated from these and keep floating around in space.
According to the European Space Agency, there were an estimated 7,50,000 objects of size one cm or above in space.
In this context, a satellite that is destroyed by a missile disintegrates into small pieces, and adds to the space debris.
How is space debris a threat?
Space debris is one of the principal threats to satellites as they could collide with the operational satellites and render them dysfunctional.
E.g. China carried out its first anti-satellite missile test in 2007, destroying its Fengyun-1C weather satellite.
This created more than 2,300 large pieces of space debris, and an estimated 1.5 lakh pieces of objects that were larger than 1 cm in size.
Each of them could render a satellite useless on collision, and the debris damaged a functional Russian satellite.
Debris also came close to hitting the International Space Station.
Countries are launching more and more satellites, with each of them being a strategic or commercial asset.
So avoiding collisions could become a challenge in the future for all.
Why is Mission Shakti safe?
None of the international treaty or agreements technically prohibits the kind of test that India presently carried.
By government statement, the Indian test was done in the lower atmosphere to ensure that there was no space debris.
So whatever debris that is generated will decay and fall back on to the earth within weeks.
[Nevertheless, India has the technology to go deeper in the space i.e. higher orbits.]
