Breaking its silence on its tumbling space rocket, whose debris is expected to fall on Earth this weekend, China said most of it would be burnt during re-entry and it is “highly unlikely” to cause any damage on the ground.
Replying to questions about the Long March 5B rocket, which last week launched the core module of the country's space station and started hurtling down to Earth, Chinese foreign ministry spokesman Wang Wenbin told a media briefing in Beijing on Friday that China will provide timely updates on it.
The Pentagon said on Tuesday that it was tracking a large Chinese rocket that is out of control and set to re-enter Earth's atmosphere this weekend.
Wang said part of the rocket will be burnt and contracted when it enters the atmosphere.
“It is an international practice. On April 29 Long March 5B has successfully entered the expected orbit and we are also paying high attention to the re-entry of the rocket.
“As we understand, the rocket has adopted some special technical designing. Most of the part of the rocket will be burnt during its re-entry into the atmosphere. It is highly unlikely to cause any danger and harm to the aero activities or the Earth. The relevant competent authority will give an update in due course,” he said.
Asked whether China knows where the debris is likely to fall and if the concerned countries have been alerted to take preventive measures, Wang reiterated that the competent authority on the Chinese side will give updates in due course and in a timely manner.
Official media in Beijing quoted Chinese experts as saying that the parts of the disintegrated rocket will fall in international waters.
The rocket was used by China to launch part of its space station. While most space debris objects may burn up in the atmosphere, the rocket's size -- 22 tonnes -- has prompted concern that large parts could re-enter and cause damage if they hit inhabited areas.
State-run Global Times on Thursday quoted Wang Ya'nan, chief editor of Aerospace Knowledge magazine, as saying that the development of rocket debris falling was carefully considered by China's space authorities from the initial rocket design phase and the choice of a launch site, to the rocket's lift-off attitude and its trajectory.
"Most of the debris will burn up during re-entry into Earth's atmosphere, leaving only a very small portion that may fall to the ground, which will potentially land on areas away from human activities or in the ocean," Wang told the daily.
On May 4, the US defence department said it was tracking a large Chinese rocket that is out of control and set to re-enter Earth's atmosphere this weekend, CNN reported.
The Chinese Long March 5B rocket is expected to enter Earth's atmosphere around May 8, the report quoted a statement from defence department spokesperson Mike Howard, who said the US Space Command was tracking the rocket's trajectory.
The rocket's "exact entry point into the earth's atmosphere" can't be pinpointed until within hours of re-entry, Howard said, but the 18th Space Control Squadron will provide daily updates on the rocket's location through the Space Track website.
"I don't think people should take precautions. The risk that there will be some damage or that it would hit someone is pretty small -- not negligible, it could happen -- but the risk that it will hit you is incredibly tiny. And so I would not lose one second of sleep over this on a personal threat basis," Jonathan McDowell, an astrophysicist at the Astrophysics Centre at Harvard University said.
Last year, re-entry of debris from the first Long March 5B flight fell on Ivory Coast, damaging several homes in villages. It was the largest craft to crash to Earth since the US space laboratory Skylab scattered debris over the southern Australian town of Esperance in 1979.
China is expected to carry out more launches in its space station programme in the coming weeks as it aims to complete the space station project next year.
Once finished, the structure will have a mass of about 100 tonnes, about a quarter of the size of the International Space Station, (ISS), which is 15 years old and expected to be decommissioned in the coming years.
After that, the Tiangong is expected to be the only space station operating in near-Earth orbit by the end of the decade.