Part of a huge rocket that launches China’s first module for its Tianhe space station falls back to Earth and could make an uncontrolled re-entry into an unknown landing point.
The 30-meter core of the Long March 5B rocket launched the unmanned module of the Heavenly Harmony nucleus into low Earth orbit on April 29 from Wenchang in the Chinese province of Hainan.
On Tuesday, the core orbited the Earth every 90 minutes at about 27,600 km / h and an altitude of over 300 km. The U.S. military has named it 2021-035B and its path can be seen on websites including orbit.ing-now.com.
Since the weekend, it has dropped by nearly 80 km above sea level, and SpaceNews reports that amateur ground observations show that it is collapsing and out of control. This and its speed make it impossible to predict where it will land when the Earth’s atmosphere eventually pulls it down.
“Since 1990, nothing over 10 tons has been intentionally left into orbit to re-enter uncontrollably,” space flight observer Jonathan McDowell told SpaceNews.
It is estimated that the main stage of the long March 5B is about 21 tons.
McDowell said he hoped China would organize a controlled deorbit after seceding from Tianhe. “I think it’s unacceptable by current standards to be allowed to re-enter uncontrolled,” he told SpaceNews.
Based on its current orbit, the rocket travels over Earth as far north as New York, Madrid and Beijing and as far south as southern Chile and Wellington, New Zealand, and can re-enter anywhere in the area.
Given its speed, a small change in its path can make a big difference to where it ends up, although experts believe the most likely event will see debris surviving the heat of re-entry into one of the the oceans, which cover about 70% of the surface.
The rocket launch is part of 11 planned missions as part of the construction of the Chinese space station, which is expected to be completed by the end of 2022. The T-shaped space station is expected to weigh about 66 tons, significantly smaller than the International space station, which launched its first module in 1998 and weighs about 450 tons.
The Chinese space station will have a docking port and will be able to connect to a Chinese satellite. Theoretically, it can be expanded to six modules.