Changzheng-5B: Missile phase will crash uncontrollably on Earth

A 20-ton rocket stage from the Chinese Space Agency will uncontrollably fall to Earth in the next few days. It has been reported by the US Astromagazine among others »Spacenews.com«. When and where the land will collide cannot be said at the moment. However, looking at the trajectory of the object, it is certain that Germany will not be a hit.

The stage is the remnant of the Changcheng-5B (“Long March”) transport rocket, which launched the main module of the new Chinese space station Tiangong-3 in late April 2021. It reached orbital speed and is now hitting speeds of 170 to 372 kilometers around the Earth at a speed of seven kilometers per second, where it is slowly slowed down by friction with the atmosphere. The central steps are 30 meters long and five meters wide. It is unclear how much material will survive the flight through the atmosphere. According to experts, 20 to 40 percent of the Earth’s mass will hit the ground.

The inclination of the rocket stage’s orbit is 41.5 degrees, meaning it can crash anywhere in the corridor between latitude 41.5 degrees north and south. In Europe, the important border runs roughly along the line of Barcelona – Rome – Istanbul. To know the exact location of the crash, one must accurately predict the time of the accident, the speed at which the rocket phase orbits the Earth. A mere five-minute error would mean that the platform has overflowed over 2,000 kilometers in the meantime.

The most likely outcome is that the rocket stage will fall into the sea. Nevertheless, according to space expert Jonathan McDowell, the uncontrolled accident represents an extraordinary and “unacceptable” process on behalf of the Chinese space agency, he said “Spacenews.com”. Since 1990, nothing more than ten tons has been dropped in such an uncontrolled way.

With braking maneuvers, rocket stages can be forced into a quick and predictable crash. It is not known whether such a system failed or was not planned in Changzheng-5B.