The 21-ton rocket stage was left as a part of the Wentian space station module, which was launched on Sunday and docked with the Tiangong space station safely.
The rocket has been tracked by Jonathan McDowell, of the Harvard-Smithsonian Center for Astrophysics. He also said that, “on average”, American launches “do a rather better job of upper stage disposal and China on average a worse one.”
Two objects cataloged from the CZ-5B launch: 53239 / 2022-085A in a 166 x 318 km x 41.4 deg orbit, 53240 / 2022-085B in a 182 x 299 km x 41.4 deg orbit. Orbital epoch of ~1200 UTC confirms that the inert 21t rocket core stage remains in orbit and was not actively deorbited.
— Jonathan McDowell (@planet4589) July 24, 2022
“Unfortunately we can’t predict when or where,” Dr McDowell told Gizmodo via email. “Such a large rocket stage should not be left in orbit to make an uncontrolled reentry; the risk to the public is not huge, but it is larger than I am comfortable with.”
Neither the US military, Space Command, nor the 18th Space Defense Squadron has issued alerts on Twitter about the event yet.
The odds of rocket debris landing on people or property is low, but this is not due to preventative or defensive measures as much as how much ocean covers the surface of the Earth. However, researchers say there is roughly 10 per cent chance that one or more casualties will be caused in the next 10 years.
This is the third time that China has left a rocket to descent uncontrolled to Earth. In May last year, a rocket that carried a central part of the Tianhe space station module shot around the Earth so quickly that it was impossible to say where it would land. The debris circled the Earth once every 90 minutes.
If the rocket had re-entered the atmosphere above a populated area, the result would have been akin to a small plane crash scattered over 100 miles,
The year before, a similar prototype craft came within 13 minutes of hitting New York City.