Part of the first rocket to launch China’s Tianhe space station is returning to Earth, and could make an unrestricted re-entry to an unknown landing site.
The Long March 5B rocket was launched at a 30-meter high core “Heavenly Harmony” Unmanned Core Module In low Earth orbit on April 29 from Wenshang in China’s Hainan province.
Long entered a temporary orbit after March 5b, the largest ever unrestricted re-entry. Some experts fear it could land in a populated area.
Jonathan McDowell, an astronomer at Harvard University’s Center for Astronomy, said: “This is not good.
“Finally they launched the Long March 5B rocket, which flew into the sky with large elongated metal rods and damaged several buildings in Ivory Coast,” he said.
“Most of it burned, but these massive pieces of metal hit the ground. We were very lucky, no one was hurt.”
On Tuesday, the center orbited the Earth at a speed of about 27,600 km / h every 90 minutes and was at an altitude of more than 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 to an altitude of almost 80km and Spacenews amateur ground observations have shown that it is falling and out of control. This, and its velocity, makes it impossible to predict where it will land when the Earth’s atmosphere eventually drags it out, although McDowell says the effect is largely that it falls into the ocean, because the ocean covers 71% of the planet.
But McDowell said parts of the rocket would escape re-entry, “equivalent to a small plane crash scattered over 100 miles”.
Nothing more than 10 tons since 1990 has been intentionally left in orbit without re-entry. The Long March 5B core level is assumed to be around 21 tons.
“The worst thing is that this is really indifferent on the part of China. We will not allow things over ten tons to fall from the sky on purpose,” McDowell said.
Based on its current orbit, the rocket passes through New York, Madrid and Beijing to the north of the earth and Chile and Wellington, New Zealand to the south, and can re-enter its territory at any time.
Considering its speed, a small change in its trajectory can make a big difference to where it ends. It is expected to return to Earth on May 10, plus or minus two days.
McDowell said once the day of his return to Earth is clear, experts can predict its landing time within a six-hour window.
The rocket was launched as part of 11 planned missions as part of the construction of China’s space station, which is expected to be completed in late 2022. The T-shaped space station is expected to weigh about 60 tons, significantly smaller than the International Space Station, which launched its first module in 1998 and weighed approximately 408 tons.
China’s space station will have a docking port and can connect to a Chinese satellite. Theoretically it could be expanded to six blocks.