Tiangong-1 space station to crash within weeks

[+and-then]

4 hours ago, Sir Smoke aLot said:

So, all in all this wasn't total fail but very valuable 'experiment' for future uses of technology. That sounds reasonable.

It also seems to show their confidence that it won't damage anything on the descent.

[Merc14]

5 hours ago, Jon the frog said:

They extended by two years is lifetime to do more experiment and after that equipment started to fail... lost opportunity to make it fall gracefully but they used it longer.

Ok and thanks Jon.  I disagree with their decision as I believe everyone sending craft into LEO needs to ensure controlled de-orbit but not a big deal, IMHO, as it IS coming down and very likely will be nothing more than a thrilling light show, if it comes in over a populated area.

Edited March 10, 2018 by Merc14

[+and-then]

1 hour ago, Merc14 said:

Ok and thanks Jon.  I disagree with their decision as I believe everyone sending craft into LEO needs to ensure controlled de-orbit but not a big deal, IMHO, as it IS coming down and very likely will be nothing more than a thrilling light show, if it comes in over a populated area.

2

This is the highest probability but it raises an interesting legal question.  What kind of legal jeopardy would be incurred if pieces of a deorbiting craft were to destroy property or kill or maim a person?  I'll have to do a bit of research  

http://www.thespacereview.com/article/1948/1

http://www.thespacereview.com/article/1930/1

Just as I suspected  The legal Beagles have it sewn up, tight...

Edited March 10, 2018 by and then

[Chaldon]

On 08/03/2018 at 10:28 PM, Astra. said:

I wouldn't be fretting too much. Even natural space debris such as meteorites rarely impact on towns or where a large population of people live. So as the article said, there is a very minute chance that anybody will be affected by any fallout of this space station. There's probably more chance of being struck by lightening than being clobbered by space junk. 

Also, according to the below article no injuries or casualties had been reported with that launch. But back in 1996 a Long March 3B veered off course causing some casualties and injuring people.

Unlike US launch centres where they are closer to coastal waters. This Chinese launch centre is located further inland, where there are more chances that rockets / or parts of them can fall on land. They actually have to calculate drop zones, and sometimes evacuate a town or area, which I certainly wasn't aware of until now. 

https://www.popularmechanics.com/space/rockets/a15072094/rocket-booster-falls-from-the-sky-and-explodes-near-chinese-town/

Yeah, sure, but until the traffic back and forth to space greatly increases. In the future, when the real space era comes. I guess that's not the last reason why Elon Musk been working on his reusable rockets. Throwing off the boosters hoping they will miss certain ground points is just technically wrong. And deorbiting a space station without disassembling or simply exploding it first is just as wrong.

Edited March 10, 2018 by Chaldon

[Nzo]

If you know its relative distance, and the speed its going at not to mention its general trajectory cant you just calculate where its going to drop? I mean its just a math equation that needs to be solved. Its not like its going to stop all of a sudden and change directions. Its at a constant speed until it starts to drop which any physicist can calculate with the right data set. Even if its more complicated then that, a super computer should be able to give a general idea of where it will drop. I find it extremely odd that we cannot calculate where it will drop. Seems to be a failed mission going up and down.

[+and-then]

2 hours ago, Nzo said:

If you know its relative distance, and the speed its going at not to mention its general trajectory cant you just calculate where its going to drop? I mean its just a math equation that needs to be solved. Its not like its going to stop all of a sudden and change directions. Its at a constant speed until it starts to drop which any physicist can calculate with the right data set. Even if its more complicated then that, a super computer should be able to give a general idea of where it will drop. I find it extremely odd that we cannot calculate where it will drop. Seems to be a failed mission going up and down.

As Waspie pointed out, the unit is tumbling and until it actually drags into the atmosphere to a certain extent, it can't be even narrowed down too much.  It's just about probabilities until then.  By the time they can say for certain, I doubt there'll be much time to warn anyone that might be in the way.  Still, a very low likelihood of anyone being injured or killed.

[Waspie_Dwarf]

3 hours ago, Nzo said:

If you know its relative distance, and the speed its going at not to mention its general trajectory cant you just calculate where its going to drop? I mean its just a math equation that needs to be solved.

To expand on what and then said:

You seem to be making two assumptions here, the first is that the satellite is simply falling to Earth. The second is that everything mathematical problem can be reduced to a simple equation and solved. Both these assumptions are massively wrong,

Tiangong-1 is not following a ballistic trajectory that will cause it to fall to Earth. It is in orbit. It would remain in orbit indefinitely if there were no outside forces acting on it. The outside force acting on it is drag with the tenuous upper atmosphere. As I said previously:

On 3/7/2018 at 6:41 PM, Waspie_Dwarf said:

However the density of that upper atmosphere varies as a result of all sorts of things, such as temperature and solar activity. Further more the orientation of the spacecraft will have an effect on the drag it experiences. Since Tiangong-1 is no longer being controlled it's orientation at any given moment is effectively random.

Your second incorrect assumption is that this can be reduced to a simple equation and solved.

4 hours ago, Nzo said:

 Its at a constant speed until it starts to drop which any physicist can calculate with the right data set.

You are ignoring (or are unaware of) an entire branch of mathematics known as chaos theory:

Quote

Chaos theory is a branch of mathematics focusing on the behavior of dynamical systems that are highly sensitive to initial conditions. 'Chaos' is an interdisciplinary theory stating that within the apparent randomness of chaotic complex systems, there are underlying patterns, constant feedback loops, repetition, self-similarity, fractals, self-organization, and reliance on programming at the initial point known as sensitive dependence on initial conditions. The butterfly effect describes how a small change in one state of a deterministic nonlinear system can result in large differences in a later state, e.g. a butterfly flapping its wings in China can cause a hurricane in Texas.

Small differences in initial conditions such as those due to rounding errors in numerical computation yield widely diverging outcomes for such dynamical systems, rendering long-term prediction of their behavior impossible in general.

Source: wikipedia

Consider that in two weeks the Tiangong-1 will travel nearly 5.9 million miles, tiny differences in the density of the upper atmosphere, or orientation of the spacecraft will have a massive effect on where on it's ground track the space station re-enters. It is a problem that can not be solved by a simple equation since it is impossible to know what terms to put into such an equation. It is a chaotic system.

4 hours ago, Nzo said:

 Even if its more complicated then that, a super computer should be able to give a general idea of where it will drop.

It doesn't matter how good the computer is if you don't know what figures to put in, it can't give you a result.

4 hours ago, Nzo said:

I find it extremely odd that we cannot calculate where it will drop.

I hope that is no longer the case now that the problem has been explained.

4 hours ago, Nzo said:

Seems to be a failed mission going up and down.

Failed in what way? Once again you are ignoring the facts. Jon the Frog has already explained that this was a HIGHLY successful mission.

It's objectives were to provide China with experience of longer duration crewed missions and to test their ability to send cargo and fuel to replenish their future space station,. Since it achieved these objectives it can not possibly be described as a failed mission.

[Nzo]

8 hours ago, Waspie_Dwarf said:

To expand on what and then said:

You seem to be making two assumptions here, the first is that the satellite is simply falling to Earth. The second is that everything mathematical problem can be reduced to a simple equation and solved. Both these assumptions are massively wrong,

Tiangong-1 is not following a ballistic trajectory that will cause it to fall to Earth. It is in orbit. It would remain in orbit indefinitely if there were no outside forces acting on it. The outside force acting on it is drag with the tenuous upper atmosphere. As I said previously:

Your second incorrect assumption is that this can be reduced to a simple equation and solved.

You are ignoring (or are unaware of) an entire branch of mathematics known as chaos theory:

Source: wikipedia

Consider that in two weeks the Tiangong-1 will travel nearly 5.9 million miles, tiny differences in the density of the upper atmosphere, or orientation of the spacecraft will have a massive effect on where on it's ground track the space station re-enters. It is a problem that can not be solved by a simple equation since it is impossible to know what terms to put into such an equation. It is a chaotic system.

It doesn't matter how good the computer is if you don't know what figures to put in, it can't give you a result.

I hope that is no longer the case now that the problem has been explained.

Failed in what way? Once again you are ignoring the facts. Jon the Frog has already explained that this was a HIGHLY successful mission.

It's objectives were to provide China with experience of longer duration crewed missions and to test their ability to send cargo and fuel to replenish their future space station,. Since it achieved these objectives it can not possibly be described as a failed mission.

Well from the little I read about this small space station, It was supposed to be dropped back in 2013 but they kept it going or maybe they had no control over it for a few more years and then they lost control of the unit all together. I don't know that's pretty much a fail to me. Maybe you can explain how that's not a fail losing control over a space station orbiting earth?

As for the math, I assumed that the Chinese still had data like velocity, etc. on the space station. I had no idea it was just tumbling in space aimlessly. As for chaos theory, that is why we try to get as much data sets as we can so we can get as accurate as possible with any predictions. For example, we(more like supercomputers) calculate the weather daily and these predictive models have become very accurate over the years. The more data sets we enter the less chaos we expect. In terms of this piece of junk in space we must really have no data sets at all... which just emphasizes the failure of this mission. Lets hope the Chinese learn from this fiasco and no one gets hurt or dies because of their failures. I just hope their are no hidden surprises like them testing out nuclear materials etc. I hope the world agencies that monitor radioactivity in our atmosphere take care to measure any such changes.

[Astra.]

On 11/03/2018 at 5:33 AM, Chaldon said:

Yeah, sure, but until the traffic back and forth to space greatly increases. In the future, when the real space era comes. I guess that's not the last reason why Elon Musk been working on his reusable rockets. Throwing off the boosters hoping they will miss certain ground points is just technically wrong. And deorbiting a space station without disassembling or simply exploding it first is just as wrong.

Well, I'm certainly not a rocket scientist. But sure, hopefully in the future they will begin to fine tune the problem with boosters coming off rockets more effectively as to ensure 'exactly' where they want them to land. Until then, at least the Kennedy Space Centre off the Florida coast drops it's expendable rocket parts into the ocean rather than on or near land..(unlike China where often inland towns have to be evacuated because of greater risk).

As far as this out-of-control space station is concerned, then maybe experts will come up with a way to disassemble or detonate these type of situations if they are alerted earlier enough that something is wrong. If memory serves right tho, this isn't the first time that an uncontrolled reentry of a spacecraft has occurred. Also, as far as I'm aware nobody was hurt. 

   

Edited March 12, 2018 by Astra.

[Truthseeker007]

10 minutes ago, Astra. said:

Well, I'm certainly not a rocket scientist. But sure, hopefully in the future they will begin to fine tune the problem with boosters coming off rockets more effectively as to ensure 'exactly' where they want them to land. Until then, at least the Kennedy Space Centre off the Florida coast drops it's expendable rocket parts into the ocean rather than on or near land..(unlike China where often inland towns have to be evacuated because of greater risk).

As far as this out-of-control space station is concerned, then maybe experts will come up with a way to disassemble or detonate these type of situations if they are alerted earlier enough that something is wrong. If memory serves right tho, this isn't the first time that an uncontrolled reentry of a spacecraft has occurred. Also, as far as I'm aware nobody was hurt. 

   

Or use something more advanced then these stone age rockets.

[Astra.]

2 hours ago, Truthseeker007 said:

Or use something more advanced then these stone age rockets.

Well, I think by the looks of things NASA is forging well ahead with more modern / futuristic rocketry. Things are only going to get more exciting as far as rockets and space exploration goes. 

https://www.nasa.gov/sites/default/files/atoms/files/sls_october_2015_fact_sheet.pdf

Just to add - lets not forget tho, that those 'stone aged' rockets actually helped get man to the moon ..

Edited March 12, 2018 by Astra.

[Truthseeker007]

1 hour ago, Astra. said:

Well, I think by the looks of things NASA is forging well ahead with more modern / futuristic rocketry. Things are only going to get more exciting as far as rockets and space exploration goes. 

https://www.nasa.gov/sites/default/files/atoms/files/sls_october_2015_fact_sheet.pdf

Just to add - lets not forget tho, that those 'stone aged' rockets actually helped get man to the moon ..

Good points but they haven't accomplished much after getting a man to the moon. I also don't think the future is in rockets but another type of technology. To me NASA is just a waste of tax dollars even though it is only half a penny on every federal tax dollar..

[rashore]

16 minutes ago, Truthseeker007 said:

Good points but they haven't accomplished much after getting a man to the moon. I also don't think the future is in rockets but another type of technology. To me NASA is just a waste of tax dollars even though it is only half a penny on every federal tax dollar..

NASA hasn't accomplished much since 1969? NASA has had a lot going on since 1969: https://spinoff.nasa.gov/Spinoff2008/pdf/spinoff2008.pdf

[Truthseeker007]

26 minutes ago, rashore said:

NASA hasn't accomplished much since 1969? NASA has had a lot going on since 1969: https://spinoff.nasa.gov/Spinoff2008/pdf/spinoff2008.pdf

Almost 50 years and still not a man on Mars. They didn't get very far at all with millions if not billions of dollars. I would say NASA is a failure.

[Merc14]

1 minute ago, Truthseeker007 said:

Almost 50 years and still not a man on Mars. They didn't get very far at all with millions if not billions of dollars. I would say NASA is a failure.

So your only measure of success is a man on Mars, anything else is simply failure?   

[RoofGardener]

1 minute ago, Truthseeker007 said:

Almost 50 years and still not a man on Mars. They didn't get very far at all with millions if not billions of dollars. I would say NASA is a failure.

There is no political will to spend money putting a man on mars. That is a political decision, made by politicians, not a technical decision made by NASA. 

NASA has put multiple probes on Mars, and orbited Jupiter, and a whole BUNCH of stuff. 

[Truthseeker007]

1 minute ago, Merc14 said:

So your only measure of success is a man on Mars, anything else is simply failure?   

What exactly is the point of NASA if they can't even get to Mars one of our closest planets?

[Truthseeker007]

2 minutes ago, RoofGardener said:

There is no political will to spend money putting a man on mars. That is a political decision, made by politicians, not a technical decision made by NASA. 

NASA has put multiple probes on Mars, and orbited Jupiter, and a whole BUNCH of stuff. 

So maybe space exploration shouldn't be based on political decisions. It is holding us all back.

[Astra.]

43 minutes ago, Truthseeker007 said:

Good points but they haven't accomplished much after getting a man to the moon. I also don't think the future is in rockets but another type of technology. To me NASA is just a waste of tax dollars even though it is only half a penny on every federal tax dollar..

Wow, you can't be serious ? 

5 minutes ago, Truthseeker007 said:

Almost 50 years and still not a man on Mars. They didn't get very far at all with millions if not billions of dollars. I would say NASA is a failure.

I'm actually gobsmacked...NASA is certainly not a failure ...

[Merc14]

2 minutes ago, Truthseeker007 said:

What exactly is the point of NASA if they can't even get to Mars one of our closest planets?

Answer yes or no to the original question and I will answer this one.

[Truthseeker007]

1 minute ago, Astra. said:

Wow, you can't be serious ? 

I'm actually gobsmacked...NASA is certainly not a failure ...

We will agree to disagree then. I really don't see a future with NASA if we are going to get anywhere close to traveling through space.

[RoofGardener]

14 minutes ago, Truthseeker007 said:

So maybe space exploration shouldn't be based on political decisions. It is holding us all back.

Where does NASA get its money from ?  

[toast]

44 minutes ago, Truthseeker007 said:

What exactly is the point of NASA if they can't even get to Mars one of our closest planets?

Close is relative or do you enjoy walking yr dog on the ground of a nearby river?

[Nzo]

Lets say your an engineer for NASA back when they first landed on the moon. Could you imagine the conversations about how this truly is the first step for man and that a moon base would be just around the corner and their grand children would be flying throughout the solar system. Then for the next 50 years nothing happens except sending a few hobby shop radio controlled toys worth billions to distant planets?

IMHO NASA is a failure... not the engineers or the people working there... just the organization as a whole. They never had any real leader to push for stuff, its always been told what to do. Had they had a leader with some clout, by now I have no doubt we would be on Mars with a base on the moon, maybe a small civilian underground town as well.

It seems that Elon Musk is filling that much needed leadership role that every cause needs. I don't really like the fellow tbh, but he does seems to be able to BS his way to money for funding.

[Truthseeker007]

42 minutes ago, Nzo said:

Lets say your an engineer for NASA back when they first landed on the moon. Could you imagine the conversations about how this truly is the first step for man and that a moon base would be just around the corner and their grand children would be flying throughout the solar system. Then for the next 50 years nothing happens except sending a few hobby shop radio controlled toys worth billions to distant planets?

IMHO NASA is a failure... not the engineers or the people working there... just the organization as a whole. They never had any real leader to push for stuff, its always been told what to do. Had they had a leader with some clout, by now I have no doubt we would be on Mars with a base on the moon, maybe a small civilian underground town as well.

It seems that Elon Musk is filling that much needed leadership role that every cause needs. I don't really like the fellow tbh, but he does seems to be able to BS his way to money for funding.

Well said friend!! I totally agree and I am glad somebody here makes some sense of the matter!