In a statement released on Sunday, NASA Administrator Bill Nelson, a former senator and astronaut, said that it was “clear that China is failing to meet responsible standards regarding their space debris”.

The rocket launched just over a week ago and soared into orbit at nearly 30,000 km an hour, slowly losing altitude. Most of the debris reportedly broke up over the Indian Ocean, near the Maldives.

The odds were in China’s favour when the rocket landed at longitude 72.47 degrees east and latitude 2.65 degrees north on Sunday afternoon (AEST).

Considering the Earth is 70 per cent water, the space junk landing in the sea was always a high probability. But it was never certain.

NASA said despite the odds, China had failed to meet “responsible standards”.

“Spacefaring nations must minimize the risks to people and property on Earth of re-entries of space objects and maximize transparency regarding those operations,” Mr Nelson said.

“It is clear that China is failing to meet responsible standards regarding their space debris.

“It is critical that China and all spacefaring nations and commercial entities act responsibly and transparently in space to ensure the safety, stability, security, and long-term sustainability of outer space activities.”

Rocket ‘could have done damage’

Meanwhile another expert has said China should have “learned its lesson” instead of allowing its rocket to crash back to Earth.

Space debris expert Ted Muelhaupt has called into question China’s decision to allow such an event to occur.

Mr Muelhaupt, principal director of Aerospace’ Corporations Centre for Orbital and Re-entry Debris Studies, told the BBC the rocket hurtled through “some of the most populated parts” of the world and that “on this particular track, it went straight over the heart of Spain and between the toe and boot of Italy and Sicily. It came straight over the Middle East.

“It could have done some damage.”

He explained to Reuters: “Think of an unloaded semi truck – it’s about 30m long, it weighs about 22 metric tons. And that’s going to have a lot of material survive – about 9 tonnes we estimate will survive.”

“That’s kind of the equivalent of dropping three pick-up trucks on somebody’s head or crashing a small aeroplane.

“It’s really hard to say what will happen, but most people, you will be fine,” he said.

“I usually use this as like winning the lottery. The odds that you will win the lottery tonight are really low – I’ll bet my pay cheque you will not win the lottery. I won’t make the bet that no one will win the lottery. That’s a different bet.”

In China’s case, he pointed out that the last uncontrolled re-entry which occurred was also of a Chinese rocket, questioning whether they should have “learnt their lesson” after that.

“This is the second largest uncontrolled re-entry in the last couple of decades. The previous one was the previous version of this launch last May and that one rained pieces down in Eastern Africa and did some damage, I believe.

“It didn’t injure anyone that I know of though,” he said.

“Most people thought they would have learnt their lesson and not done it again. But apparently they have.

“So they’re two for two with this particular design,” Mr Muelhaupt said.

“The question that people have asked is, did they not plan for this, and if not, why not. But the Chinese haven’t said.”

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The Pentagon also hit out at China last week, with US Secretary of Defence Lloyd Austin saying the country should have done a better job of controlling the rocket which was launched last week to deliver the first module for China’s new space station.

“I think this speaks to the fact that for those of us who operate in the space domain … there should be a requirement to operate in a safe and thoughtful mode,” he said.

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China certain space junk posed no risk

In the lead-up to the re-entry of the debris, China was adamant it would pose no risk to human population.

Chinese state mouthpiece The Global Times, reported the Long March 5B rocket would land in international waters. It added that reports that the rocket was “out of control” and could land in an inhabited area were “hype”.

The publication said the situation was “not worth panicking about”.

The article claimed the debris was likely to “burn up during re-entry … leaving only a very small portion that may fall to the ground, which will potentially land on areas away from human activities or in the ocean”.

No way to know where it would land

But experts said there was no way China – or anyone else – could know where the rocket would land as it crashed back to Earth.

Aussie scientist, Dr Fabian Zander from University of Southern Queensland’s Institute for Advanced Engineering and Space Sciences, said in the lead-up to the return of the rocket it was impossible to know its final destination.

“The short answer is we don’t really know where it’s going to come down,” he told Seven’s Weekend Sunrise.

“Our current best estimates have it coming into the Indian Ocean, so that’s somewhere between Africa and Australia.”