Spacecraft Graveyard

[LordFerret]

Stumbled across this article earlier this evening. Interesting. I've heard comment about such before, but this is the first time I've seen an actual article about it... one that gives a precise location no less. I suppose if you're a developing country with enough money and outside help providing ocean research resources (ships, ROV's, etc), you might find yourself some useful technology remnants there. Maybe?

A spacecraft graveyard exists in the middle of the ocean — here's what's down there

[Nibb31]

 I doub't you would find much there. That is the point that they aim for for reentry. Not necessarily where the stuff splashdowns. The actual debris field is probably bigger than Texas. Locating any debris there would be like finding the wreckage of MH370, and anything that you could recover would hardly have much value.

[DerekL1963]

This gets reprinted every couple of years...  and as Nibb says, the actual debris field is huge and the chunks of debris small.   If you have that kind of money, you're better off spending it directly on space related R&D.

[PB666]

On 10/23/2017 at 1:26 AM, Nibb31 said:

 I doub't you would find much there. That is the point that they aim for for reentry. Not necessarily where the stuff splashdowns. The actual debris field is probably bigger than Texas. Locating any debris there would be like finding the wreckage of MH370, and anything that you could recover would hardly have much value.

Shhhhh, quite, I was keeping 370 in my back yard, at least until I can launch my new web cast 'where in the world is MH 370'.

hmmm, too soon?

 

'

[kerbiloid]

~48S 123W.
Its antipode point (48N 123E) is somewhere in China.
This is wise: they have chosen the place most distant from Japan, so Godzilla wouldn't wake up.

[DerekL1963]

2 minutes ago, kerbiloid said:

~48S 123W.
Its antipode point (48N 123E) is somewhere in China.
This is wise: they have chosen the place most distant from Japan, so Godzilla wouldn't wake up.

Wrong on both counts according to the Antipodes Map website. 

The antipode point for the Graveyard is (roughly) near the Caspian Sea:



Japan's antipode point is off the Atlantic coast of South America:

[YNM]

20 minutes ago, kerbiloid said:

~48S 123W.
Its antipode point (48N 123E) ...

Antipodes don't work that way ! Should be 48N 57E.

 

On original topic : I don't think there would suddenly even be a stretch of seabed strewn with molten metals. I guess there'd be more earthly rubbish than spacely invaders...

[kerbiloid]

Indeed. Now I get worried.

[NSEP]

Would there also be a spent stage graveyard in the Atlantic Ocean near Florida. The junk there is alot bigger and needs to go trough alot less speed back on their way down right?

[DerekL1963]

6 hours ago, NSEP said:

Would there also be a spent stage graveyard in the Atlantic Ocean near Florida. The junk there is alot bigger and needs to go trough alot less speed back on their way down right?

"It's not the fall that kills you, it's the sudden stop at the end."   I.E. they still hit the surface at a considerable speed, and still end up submerged in highly corrosive seawater.

[tater]

We can just wait for the Chinese space station to rain down on us, and hold out buckets.

[LordFerret]

Yes ^, and apparently they're not giving us much advance notice as to when or where.

[YNM]

24 minutes ago, LordFerret said:

Yes ^, and apparently they're not giving us much advance notice as to when or where.

I'm pretty sure if they won't NORAD will.

[kerbiloid]

8 hours ago, YNM said:

I'm pretty sure if they won't NORAD will.

Optimist...

[YNM]

39 minutes ago, kerbiloid said:

Optimist...

ISS needs near-miss data daily, down to paint flakes size. I'm sure it doesn't have any problem tracking and predicting another space station.

Edited October 28, 2017 by YNM

[DerekL1963]

10 hours ago, LordFerret said:

Yes ^, and apparently they're not giving us much advance notice as to when or where.

Not won't, more like can't.  It's simply the nature of the beast.

[LordFerret]

1 hour ago, DerekL1963 said:

Not won't, more like can't.  It's simply the nature of the beast.

I almost find that hard to believe, especially considering all the available science involved today. We're not talking Skylab here, this is 2017, the 21st century. After 60 years of launching rockets, you're telling me we don't have better ability to compute this?

[Nibb31]

Uncontrolled reeentries are typically unpredictable, even for NORAD. We usually only get a vague notice of where it's going to fall a couple of hours beforehand.

It depends on atmospheric density , which varies with a lot of variables, and drag, which will depend on the shape and attitude of the spacecraft. Predicting a date is extremely difficult. They can sometimes get it down to range of several days and refine it once they get into that range. The landing area is pretty much anywhere downrange of the orbital path. Since the spacecraft typically covers 16 orbits per day, it can impact anywhere in the inclination latitude range.

Edited October 29, 2017 by Nibb31

[DerekL1963]

12 hours ago, LordFerret said:

I almost find that hard to believe, especially considering all the available science involved today. We're not talking Skylab here, this is 2017, the 21st century. After 60 years of launching rockets, you're telling me we don't have better ability to compute this?

Computers are not magic.

In this particular instance, you can't calculate a solution to any greater degree of accuracy than allowed by the accuracy of the input data.  We don't know the weight and aerodynamics of the station to any degree of precision - and it's tumbling.   (Which means drag varies over time, independent of speed and altitude.) We can calculate an average drag value and ballistic coefficient, but there will be errors...  Not only due to the imprecise values of weight and aerodynamics, but also the inherent errors in using an average.  Worse yet, drag varies with speed and altitude...  and the tumble will be affected by drag.  In this case, that means a small error in near term calculations propagate forward and become increasingly large errors in longer term calculations.  An error in drag leads to an error in predicting speed and altitude, which causes a further error in predicting drag, which increases the error in speed and altitude...  lather, rinse, repeat. Even very small starting errors can grow into significant errors over time due to this feedback loop.

And that's without dragging in any errors in current knowledge of or predicting future atmospheric conditions...

So calculating when to any degree of accuracy at this point is nothing but a crapshoot.  You might as well use a Ouija board.

And then, on top of all that, an error as small as fifteen minutes (an infinitesimal error given the thousands of hours to even the earliest likely re-entry) moves the debris eclipse by thousands of miles.  That makes predicting where essentially impossible at this point.

[YNM]

On 27/10/2017 at 6:24 AM, tater said:

We can just wait for the Chinese space station to rain down on us, and hold out buckets.

 

On 28/10/2017 at 11:10 AM, LordFerret said:

Yes ^, and apparently they're not giving us much advance notice as to when or where.

I had no idea, until I find some news...

 

So, Skylab to the max ?

[Nibb31]

1 hour ago, YNM said:

 

I had no idea, until I find some news...

 

So, Skylab to the max ?

Only if you live between 42.8° latitude N and S.

It's also much smaller than Skylab, so there is less chance of it reaching the ground.

Edited October 29, 2017 by Nibb31

[YNM]

2 hours ago, Nibb31 said:

Only if you live between 42.8° latitude N and S.

It's also much smaller than Skylab, so there is less chance of it reaching the ground.

Well, I live near the equator (-6°)...

By referring "to the max" is, they have even less control of the thing (or even none) so they really can't do anything...

Given that China already ratified Space Liability Convention, surely they'll care at one point ? (I hope they don't forget).

[tater]

Yeah, it's tumbling, and the drag parameters change minute by minute. What I have seen so far I think said December-February.

[LordFerret]

10 hours ago, DerekL1963 said:

We don't know the weight and aerodynamics of the station to any degree of precision

Oh come now, Wiki has the basics of this information, starting with its mass.

 

 

A single solitary little satellite, such complex math, so many variables, and we're to believe climatologists can model and give concrete answers on climate change. I'll sit back and enjoy my coffee now.

[kerbiloid]

Soyuz's butt + Salyut's narrow half.