Tianhe module is one of three key parts of permanent space station China is building to rival the ISS.
Remnants of China’s largest rocket launched last month plunged back through the atmosphere on Sunday, landing west of the Maldives in the Indian Ocean and ending days of speculation over where the debris would hit.
“After monitoring and analysis, at 10:24 [02:24 GMT] on May 9, 2021, the last-stage wreckage of the Long March 5B Yao-2 launch vehicle has reentered the atmosphere,” the China Manned Space Engineering Office said in a statement.
It added most of the components burned up in the re-entry.
US Space command confirmed the re-entry of the rocket over the Arabian Peninsula, but said it was unknown if the debris impacted land or water.
“The exact location of the impact and the span of debris – both of which are unknown at this time – will not be released by US Space Command,” it said on its website.
Monitoring service Space-Track, which uses US military data, also confirmed the re-entry.
“Everyone else following the #LongMarch5B re-entry can relax. The rocket is down,” it tweeted.
“We believe the rocket went down in the Indian Ocean, but are waiting on official data from @18SPCS,” it added in a separate tweet, referring to a squadron of the US Space Force.
China now reporting https://t.co/dHSJVoItCY that the rocket reentered at 0224 UTC at 72.47E 2.65N which is right over the Maldives. If correct will be interesting to see if we get reports from there pic.twitter.com/NQovz33pqg
— Jonathan McDowell (@planet4589) May 9, 2021
US and European authorities had been monitoring the rocket, which was travelling at a speed of 13.7km/second (4.8 miles/second).
A difference of just one minute in the time of re-entry translates to hundreds of kilometres difference on the ground and earlier predictions had the rocket landing in several possible locations from the Mediterranean Sea to the Pacific Ocean.
According to experts, with most of the Earth’s surface covered by water, the odds that it would land in a populated area were low, and the likelihood of injuries even lower.
But uncertainty over the rocket’s orbital decay and China’s failure to issue stronger reassurances in the run-up to the re-entry fuelled anxiety over its descent.
China’s foreign ministry said on Friday the re-entry was highly unlikely to cause any harm.
The Long March 5B – comprising one core stage and four boosters – lifted off on April 29 from China’s Hainan Island with the unmanned Tianhe module, which contains what will become living quarters on a permanent Chinese space station.
The rocket is set to be followed by 10 more missions to complete the station.
Most experts said the risk to people from the re-entry was low.
“Given the size of the object, there will necessarily be big pieces left over,” said Florent Delefie, an astronomer at the Paris-PSL Observatory.
“The chances of debris landing on an inhabited zone are tiny, probably one in a million.”
In May 2020, pieces from the first Long March 5B fell on Ivory Coast, damaging several buildings. No injuries were reported.
“Spacefaring nations must minimize the risks to people and property on Earth of re-entries of space objects and maximize transparency regarding those operations,” NASA Administrator Bill Nelson, a former senator and astronaut who was picked for the role in March, said in a statement after the re-entry.
“It is clear that China is failing to meet responsible standards regarding their space debris.”
Debris from Chinese rocket launches is not uncommon within China. In late April, authorities in the city of Shiyan, Hubei Province, issued a notice to people in the surrounding county to prepare for evacuation as parts were expected to land in the area.
The latest remnants of Long March 5B make up one of the largest pieces of space debris to return to Earth.
The core stage of the first Long March 5B that returned to Earth last year weighed nearly 20 tonnes, surpassed only by debris from the Columbia space shuttle in 2003, the Soviet Union’s Salyut 7 space station in 1991, and NASA’s Skylab in 1979.