Chinese Rocket Debris Falls Into Sea Again — Why Does This Happen?

What’s in Today’s Article:

• Chinese Space Station Tiangong
• News Summary

 

Why in news?

• Recently, large fragments of China’s Long March 5B rocket plunged uncontrolled into the south-central Pacific Ocean. This was reported by the US Space Command.
• The fragments were stages of the rocket used to deliver the third and final module of the Tiangong space station.

 

Chinese space station

• Tiangong is China's new space station.
  • In May 2021, China launched Tianhe, the first of the orbiting space station's three modules.
    • The country aims to finish building the station by the end of 2022.
  • In June 2021, China had launched three astronauts into orbit to begin occupation of the country's new space station.
• Tiangong will be much smaller than the International Space Station (ISS), with only three modules compared with 16 modules on the ISS.

 

News Summary

• Recently, large fragments of China’s Long March 5B rocket plunged uncontrolled into the south-central Pacific Ocean.
• As per the reports, it was one of the largest pieces of debris re-entering in the near past.

 

Background:

• Few days back, China had launched its Long March 5B rocket to deliver the third and final module of the Tiangong space station.
  • China currently relies on the Long March 5B to carry its heaviest payloads to space.
  • For the latest mission, the rocket carried Mengtian, a science laboratory module, to Tiangong.
• The rocket broke up during re-entry and plunged uncontrolled into the south central Pacific Ocean.
• One of the pieces was left over from the core stage of the rocket that was about 30 metres long and weighed between 17-23 tonnes.

 

Associated Danger

• Such was the danger that the air navigation authority of Spain shut down parts of its airspace for about 40 minutes in view of the uncontrolled entry of remains from the Chinese space object.
• However, security analysts claim that the chances of humans being hit were minuscule.
• What was worrying though, is the fact that the rocket stage did not by design have a system to ensure it fell in a designated place on Earth.

 

Criticism

• The uncontrolled return of rocket's core stage has raised questions about responsibility for space junk.
• Chinese space agency has also been criticised for not following the international norms while designing the rocket.
  • The international norm is to design rockets so that it disintegrates into smaller pieces upon re-entry.
  • Designing objects to disintegrate upon atmospheric re-entry is challenging as it is done partly by using materials which have low-melting point temperatures, such as aluminium.
  • In the case of rockets, this can be expensive, as historically the materials used for housing fuel, such as titanium, require very high temperatures to burn up.
  • The sheer size of such objects is also an issue which makes disintegration difficult.
• The current incident also raised questions regarding the safety and security of human population on the earth.

 

Previous instances of uncontrolled returns

• The recent incident was the fourth time something like this had happened with a Chinese rocket.
  • In May 2020, during the rocket’s first deployment, fragments had landed in Ivory Coast, causing some damage to buildings;
  • Debris from the second and third flights had plunged into the Indian Ocean and near the Philippines respectively.
• China also faced criticism after using a missile to destroy one of its defunct weather satellites in 2007.
  • This had created a field of debris that other governments said might jeopardise other satellites.