SPACE DEBRIS

Subject : Science & tech

Context : China silent on falling debris of its space rocket amid rising concerns

Concept :

Space debris

Space debris, also called space junk, artificial material that is orbiting Earth but is no longer functional.
This material can be as large as a discarded rocket stage or as small as a microscopic chip of paint.
Much of the debris is in low Earth orbit, within 2,000 km (1,200 miles) of Earth’s surface; however, some debris can be found in geostationary orbit 35,786 km (22,236 miles) above the Equator.
Kessler syndrome postulates that crashes would first be seen between fragments and larger objects like satellites and would eventually be between two fragments. Crashes will continue till the debris becomes very small.
There is almost 7,000 tons of active space debris—from old satellites and spacecraft to lost components and spent rocket parts—orbiting Earth at any given moment. While some of the space junk in orbit decays with time, debris that is located at a higher orbit can take years to disintegrate.

Kessler Syndrome

The probability of a collision of a space craft with a particle more than 10 cm is very rare. But a large density of the orbital junk is capable of causing a chain collisions.
This has been named the “Kessler Syndrome” by NASA consultant Donald J. Kessler. One collision will create more debris and increase the likelihood of further collisions. Such collisions will destroy satellites worth millions of dollars and could render space exploration unfeasible for centuries.

International laws

There is no binding international legal rule (yet) which prohibits the wanton creation of space debris.
1967 Outer Space Treaty bars states party to the treaty from placing weapons of mass destruction in Earth orbit.
Since 2002, the world’s space powers have complied with an informal code of conduct to avoid the creation of space junk and the United Nations has endorsed a resolution along those lines.

Removal of debris

There have been several initiatives to remove debris like global mitigation measures by Committee on the Peaceful Uses of Outer Space, and Inter-Agency Space Debris Coordination Committee (IADC) ; e-Deorbit mission of European space agency etc.

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 warning