General Studies- III (Awareness in the fields of Space)

Gist Of Editorials

12 May 2021

Recently, a core segment of China’s Long March 5B rocket re-entered Earth’s atmosphere above the Maldives in the Indian Ocean and most of it burned up.

The Long March 5B rocket carried the main module of China’s first permanent space station — Tianhe, or Heavenly Harmony — into orbit on April 29.

• Usually, discarded rocket stages re-enter the atmosphere soon after liftoff, normally over water, and don’t go into orbit.
• However, the roughly 100-foot long rocket stage did not fall soon after discharging its payload.
• China’s space program hasn’t said why it put the main component of the rocket into space rather than allowing it to fall back to earth, as is usual in such operations.

Uncontrolled de-orbits:

Uncontrolled de-orbits are not unheard of.

• One of the largest ever was NASA’s 77-ton Skylab de-orbit which occurred in 1979.
• NASA was not able to prevent it from sinking out of orbit, and it eventually came down over the Indian Ocean but also over populated areas of Western Australia.

What is the solution?

The solution involves steps to clean up the mess, mitigate damage, and avoid future debris.

• There are systems in place to track the debris and avert disasters.
• Various space organisations have been working on reducing the amount of trash by adopting better designs of rockets and other objects. For example, making reusable rockets could vastly cut down waste.
• The UK’s TechDemoSat-1 (TDS-1), launched in 2014, was designed in such a way that once its mission is over, a system, like a parachute, would drag the satellite to re-enter the atmosphere and burn up.
• Some satellites at the end of their lifecyle are made to fall out of orbit and burn up in the atmosphere, provided they still have fuel left in them for the descent. Some satellites are sent even farther away from Earth.

Way forward:

Technologies to remove space junk are also being developed.

Cleaning the debris that already exists comes at a high cost, because it will take multiple trips to remove objects from space. Other proposals include the use of a laser to remove debris by changing their course and making them fall towards the atmosphere of Earth and later burn up.

Source: The Hindu