[sparky@home]

On April 28th, a Chinese Long March 5B rocket went up, successfully delivering its payload, a new section of the Tianhe space station, into orbit, but then the 21-ton rocket is coming down, uncontrolled. No one was sure where it would come down, though it was feared it would be in Canada or the US. However, it is now confirmed that it landed in an area which is right next to the Maldives, thankfully not on the island, thus avoiding any major catastrophe.


Mods : Did not see any thread on this matter, if not required, kindly delete.

[Jeroen]

Apparently, they had not idea where this thing was coming down. Which I thought was a bit unusual. As long as they can track it accurately why cant they calculate where it is going to come down? Usually, on much smaller object they tend to be able to give a rough prediction that gets adjusted and becomes more precise over the days leading to the actual crash.

About 71% of the earth surface is covered in water, so a good chance it will hit water. I guess the orbit does make a difference too on the percentage.

Jeroen

[V.Narayan]

Originally Posted by sparky@home

On April 28th, a Chinese Long March 5B rocket went up, successfully delivering its payload, a new section of the Tianhe space station, into orbit, but then the 21-ton rocket is coming down, uncontrolled. No one was sure where it would come down, though it was feared it would be in Canada or the US. However, it is now confirmed that it landed in an area which is right next to the Maldives, thankfully not on the island, thus avoiding any major catastrophe.


Mods : Did not see any thread on this matter, if not required, kindly delete.

I wonder if these lat-long co-ordinates in the tweet are correct? 50 degrees East and 22 degrees North is in the Arabian peninsula.

[Sanidhya mukund]

I am just glad that this uncontrolled rocket did not crash on top of any densely populated human settlements. Would have led to a huge loss of life and limb.

This reminds me of a similar incident from a couple of years ago, but thankfully, even then no casualties were reported. Apparently, it is a routine occurrence with Chinese rockets and their military even evacuates vulnerable areas:

https://youtu.be/ERTQFDPC558

[Jeroen]

Some members might not remember as it happened in 1979. The American Skylab fell back to earth and bits hit a town in Australia.

The US town Gladewater in east Texas got hit by debris from the shuttle Columbia as it disintegrated upon re-entering earth atmosphere. My brother in law and his family were living in Gladewater at the time. Got us worried initially.

Jeroen

[Indian2003]

Whatever comes out from the Western media I take with a pinch of salt. The Vietnam war was just around the corner from where I grew up. The US was winning on all fronts according to the Western media.

During the 1971 war, Pakistan was the darlig of the West and India was the aggressor. In the begining, the West closed their eyes to the killings taking place in East Pakistan. Then too Pakistan was supposed to be winning on all fronts.

During the Gulf of Tonkin incident, Tass wrote that it was a false flag operation but a combined Western media screamed fake news and killed it. When the US fled Vietnam the same press was not surprised that the US was fleeing from a war they were winning.

Had this been an American rocket, they would have called it a spectacular show of fireworks.

[sparky@home]

Originally Posted by V.Narayan

I wonder if these lat-long co-ordinates in the tweet are correct? 50 degrees East and 22 degrees North is in the Arabian peninsula.

I did not check the Lat Long, just took it for granted. Other sources also say that it dropped off Maldives Island only.

[francisvellara]

Originally Posted by Jeroen

As long as they can track it accurately why cant they calculate where it is going to come down?

As I understand it, the difficulty in predicting where it falls arises from fluctuations in air pressure in the upper atmosphere. When the rocket starts to enter the atmosphere, the kind of air pressure it encounters has a large bearing on how its velocity changes. As these pressure fluctuations are hard to predict accurately, there is a resulting uncertainty in determining when the rocket will go into re-entry. I read that even a 30-minute error in predicting the re-entry time can lead to a 10000km difference in the predicted landing spot.

[lemedico]

Aren't we glad it didn't crash into a family home! The map area of a possible crash site was very broad indeed.

And, aren't they optimistic by naming their rocket- "LONG"

[anjan_c2007]

The third such incident of sinking out of orbit, if we consider the 77 ton US Skylab debris of July 1979, followed by two such incidents involving Chinese rockets in 2020 and 2021.

The Skylab made an uncontrolled entry and crashlanded with its debris on the Indian Ocean, off the coast of Western Australia. No loss of human lives was reported, though the publicity the unpredictable Skylab fall got through the media ( there was no social media then), sent shivers down the spine of all humans on earth, aware of the eventuality.

During May 2020, a rocket similar as the one of April-May 2021 (Long March 5B), with an experimental crew capsule with the hope to launch future manned missions, reached a height of about 7,500 kms before making an uncontrolled entry to the earth. It passed over New York City on 11.05.2020, hovered over the Atlantic Ocean and finally its debris was found in Cote d'Ivoire, in Africa.

The latest was the Long March 5B, a 20 ton rocket, launched as recently as on 29.04.2021, which was also not designed to de-orbit in a controlled way.

The wasted space debris of such failed or end of life space missions has always been a matter of concern and such uncontrolled de-orbits puts the life and property of innocents at risk. Moreover, if its of a Chinese origin, the news-blackout creates lots of uncertainities and leads to speculations in the media and in the minds of the people.

[veyron_head]

May be I am stupid, but I wonder how much of marine life a crash like that would have killed!

[Jeroen]

Originally Posted by veyron_head

May be I am stupid, but I wonder how much of marine life a crash like that would have killed!

Most likely very few if any. Especially on the oceans there is not that much marine life at the surface. Most of it lives a bit deeper. Unless it happened to hit a shoal of fish hovering around the surface I don’t think it would be an issue at all.

There has been another very large piece of machinery that came down to earth, although it did come down in a more controlled manner. The Russian

https://en.wikipedia.org/wiki/Deorbit_of_Mir

At the time the Mir was the largest piece of man made machinery that fell back to earth. The Russian decided to de-orbit the Mir as they ran out of funding. It was a big piece of kit

Jeroen

[dragracer567]

Originally Posted by veyron_head

May be I am stupid, but I wonder how much of marine life a crash like that would have killed!

This may come as a surprise for many people but most of the marine life are actually present near the shore on the continental shelf (which is only about 7% of the area covered by oceans) with the open oceans being comparatively devoid of life. This is because phytoplanktons (which if I overly simply are small plants on which the entire oceanic food chain is build) require nutrients as much as they need sunlight and these nutrients reach the sea through surface runoff from land, so phytoplanktons can only grow in places where there are sufficient nutrients which are found only near the coast and hence most marine life which are dependent on that are found near the coast. Exceptions are larger migratory fish like tuna for example.

So yea, since most marine life live within 7% of the total oceanic area, they are probably safe from a falling rocket!

[Malyaj]

Any news on what happened to this? Could not find anything on the internet