Chinese rocket tracker - live: Falling spacecraft falls to Earth over Indian Ocean, reports say

There are a number of ideas to prevent rockets falling to Earth again in the future, according to McDowell.

Usually, rocket stages will be built with a booster to steer them into safe landing points in water, or built with some kind of stabilisation system where they can turn 180 degrees and slow their descent.

Since China’s Long March 5B was not built with either of those options “it’s just left in orbit the old fashioned way to reenter uncontrolled and that is very unusual nowadays”.

Most countries take these considerations into account when building rockets, however, and it is only China’s decision not to that has resulted in concerns about Long March 5B.

“The likelihood is that people will remain safe and there will be little damage to buildings or the environment. This is not due to preventative or defensive measures, however, but rather a question of statistics.”

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This may not be the first time that an out-of-control rocket has plunged to Earth, but it could be the most deadly.

Since 1990, nothing weighing more 10 tonnes have fallen back to Earth uncontrolled – and the Chinese rocket is thought to weigh about 10 tonnes.

You can read the full round-up here, courtesy of Andrew Griffin:

Another Chinese rocket fell to Earth in May 2020.

Most of the pieces landed in the Atlantic Ocean, but pieces of debris were reported in Ivory Coast, and experts calculated that it had missed New York by minutes.

In 2017, the Tiangong-1 space station also fell back to the planet in an uncontrolled descent after the Chinese’s CNSA space agency said that they had lost control of the lab.

Much like this rocket, engineers could not accurate predict where the craft would land. Wind and weather could have sent it from one continent to another; it eventually burnt up over the middle of the South Pacific.

“Worst case [scenario] is one of the structural rods hits someone, potentially a fatality but unlikely to see multiple casualties”, Jonathan McDowell, Astrophysicist at the Astrophysics Center at Harvard University, told The Independent.

He added that the debris will be travelling at approximately 100 miles-per-hour, so there could be expensive property damage, but because it will be spread over 100 miles of along-track only one or two pieces are likely to hit a populated area.

As space agencies cannot predict where the rocket will fall, a detailed risk assessment for those concerned about falling debris is not available.

However, the ESA says that people should not be worried about being struck from falling debris.

“In general, most objects burn up entirely in the atmosphere during the re-entry. Parts of larger objects, or components that are made of material with a high melting point, may survive to reach the ground or ocean surface”, it says.

“As these are rare events, and as about 75 per cent of the Earth’s surface is covered by water while large portions of land area are uninhibited, the risk for any single individual is several orders of magnitude smaller than commonly accepted risks, such as those encountered when driving a car, taken in day-to-day life.”

While we might not know where it’s going to land, but scientists know where Long March 5B is going to avoid.

Since CZ-5B’s orbit (the classification for the debris) is inclined at 41 degrees to the Earth’s axis, any debris will not fall further than that either north or south of the latitude.

“Therefore, the risk zone includes any portion of Earth’s surface between 41N and 41S latitude. This, briefly, and for what concerns ESA Member States, includes portions of Spain, Italy and Greece”, the ESA says.

While it is likely that the rocket will fall into the ocean - simply due to the large percentage of the Earth being covered in water - astronomers believe that some pieces of the rocket will survive re-entry.

This would be the “equivalent of a small plane crash scattered over 100 miles”, according to Jonathan McDowell, Astrophysicist at the Astrophysics Center at Harvard University.

Right now, predicting the rocket’s fall is very difficult, but it is expected that it will return to Earth on 10 May. Once the specific day has been confirmed, experts can apparently narrow its landing time down to a six-hour window.

“The Long March 5B core stage is seven times more massive than the Falcon 9 second stage that caused a lot of press attention a few weeks ago when it re-entered above Seattle and dumped a couple of pressure tanks on Washington state,” McDowell also said. “I think by current standards it’s unacceptable to let it re-enter uncontrolled. Since 1990, nothing over 10 tons has been deliberately left in orbit to re-enter uncontrolled.”

The Long March 5B rocket is currently fluctuating at an altitude of between 170 and 372 kilometres.

Currently, the rocket is keeping within those parameters, but has dropped further today. At 10:00am GMT, when the rocket was over Africa, it dropped to nearer 160 kilometres.

Amateur observations from the ground show regular flashes from the rocket in the night sky, suggesting that it is not under any control.

It is likely much of the rocket will break down as it crashes, but some debris will remain.

“It is always difficult to assess the amount of surviving mass and number of fragments without knowing the design of the object, but a reasonable “rule-of-thumb” is about 20-40 per cent of the original dry mass,” Holger Krag, head of the Space Safety Programme Office for the European Space Agency said.

“Fortunately, the likelihood is that people will remain safe and there will be little damage to buildings or the environment. This is not due to preventative or defensive measures, however, but rather a question of statistics.”

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