Tiangong-1 Re-entry

[Ultimate Steve]

Not going to reveal where I live, but the predicted reentry path comes to within walking distance of my house and could possibly fall on my church and the Wal-Mart next to it.

[tater]

 

I'm very close to some overlapping bands on satflare, in one band.

[MaxwellsDemon]

A bit I read made the interesting point that the chances of actually being struck by a piece of falling Tiangong are virtually zero (not zero, but statistically about the same as zero... I think it said about ten million times *less* probable than being struck by lightning), but that there could potentially be some risk in approaching a piece of fallen Tiangong on the ground, due to a small chance of persistence of hydrazine or other toxins.  Those are realistically expected to be gone by the time anything strikes the ground, but they're toxic enough that it's still a risk.  Local emergency authorities should be alerted in the unlikely event someone finds something; and a reminder, it still belongs to China, fallen or not...  

[PB666]

2 minutes ago, MaxwellsDemon said:

A bit I read made the interesting point that the chances of actually being struck by a piece of falling Tiangong are virtually zero (not zero, but statistically about the same as zero... I think it said about ten million times *less* probable than being struck by lightning), but that there could potentially be some risk in approaching a piece of fallen Tiangong on the ground, due to a small chance of persistence of hydrazine or other toxins.  Those are realistically expected to be gone by the time anything strikes the ground, but they're toxic enough that it's still a risk.  Local emergency authorities should be alerted in the unlikely event someone finds something; and a reminder, it still belongs to China, fallen or not...  

If it falls on my house its mine. 

[MaxwellsDemon]

Just now, PB666 said:

If it falls on my house its mine. 

   I won't argue the point.   Though you might have to give it up to get compensation money.

[monophonic]

On 27.3.2018 at 5:33 PM, lajoswinkler said:

My hopes were the toilet seat strikes my house but I'm out of the danger zone.

Me too, way too high to even see the fireworks. And no waffle house in the entire country either.  

[tater]

I'm near where 4 of those cross, and under 2-3 of them. Woot! I want to see some space junk on fire!

2 hours ago, PB666 said:

If it falls on my house its mine. 

Me, too. I'll hose it off (looks like remediation of hypergolics is loads of water), and put the chunk on my coffee table (or make a new coffee table out of it).

Heck, if I saw it land in the mountains behind the house I'd walk up and find it for the same purpose, lol.

[kerbiloid]

Now, as time is more or less clear, we can mark meridians and make bets.

Spoiler

 

[YNM]

8 minutes ago, kerbiloid said:

Now, as time is more or less clear, we can mark meridians and make bets.

TBH, this is more like the ultimate Russian Roulette.

[kerbiloid]

Spoiler

14 minutes ago, YNM said:

TBH, this is more like the ultimate Russian Roulette.

Historical Russian roulette is not a random suicide, but a pure physics.

Standard revolvers in Russian army had drums rotating freely without clicks, so the rotating drum was stopping in loaded-cell-down position if not stop it manually.
A veteran player just knew were the bullet is, while a newbie was thinking it's random.

So, it's a casino roulette.

 

[MaxwellsDemon]

"The more you know..."

[PB666]

2 hours ago, kerbiloid said:

  Hide contents

Historical Russian roulette is not a random suicide, but a pure physics.

Standard revolvers in Russian army had drums rotating freely without clicks, so the rotating drum was stopping in loaded-cell-down position if not stop it manually.
A veteran player just knew were the bullet is, while a newbie was thinking it's random.

So, it's a casino roulette.

 

Noone plays Russian roulette with antique Russian revelovers. 

[Scotius]

If it falls down somewhere in China, a lot of jaws will hit the floor

[kerbiloid]

Spoiler

7 hours ago, PB666 said:

Noone plays Russian roulette with antique Russian revelovers. 

But you call it so.
Also, the revolvers were not Russian: American and French.

 

[Nibb31]

On 3/27/2018 at 9:08 PM, MaxwellsDemon said:

Definitely non-trivial.

(To be clear, I wasn't saying that they should be reboosting or trying to control it now.  I was wondering why not several months ago... but if they don't have the capability, then it's a moot point.)

They lost contact with the station. It is extremely difficult to dock with an uncontrolled, tumbling object.

The Russians managed to do it with Salyut-7, but it was an extremely risky mission with low chances of success (and considerable chances of losing the crew). It was the height of the Cold War, and Russia could not afford to lose soft-power points by losing their station while NASA was having a lot of success with the early Space Shuttle flights. Additionally, the Russians were scared to death that this new-fangled Space Shuttle thing could be used to capture and bring back Salyut-7, revealing the secrets of glorious Soviet engineering to the West. That would have been a stupid (politically reckless, highly dangerous, and probably impossible) mission for the Shuttle, but somehow the Russians were convinced that it was a credible threat.

For the Russians, it was a matter of national pride and the political motivation for the mission outweighed the difficulty and risk of cosmonaut lives.

For Tiangong-1, the situation was different:

• The station had already completed its mission so there was nothing to save.
• China didn''t have any spare Shenzhou spacecraft sitting around.
• Nobody was going to steal Tiangong-1 and there wasn't much technology worth stealing anyway.
• The political gain of saving Tiangong-1 was inexistant
• The cost of developing RV and docking procedures and training a crew were high.
• The risk of failure was high.

So really, it never made sense to send a rescue mission to save Tiangong-1.

Edited March 29, 2018 by Nibb31

[YNM]

18 hours ago, kerbiloid said:

Historical Russian roulette is not a random suicide, but a pure physics.

Well, to a Total Perspective Vortex, the trajectory of anything is pure physics as well...

7 hours ago, Nibb31 said:

... So really, it never made sense to send a rescue mission to save Tiangong-1.

Tiangong-1 is basically a stretched Shenzou orbital module anyway. It's nowhere close to TKS or FGB.

Couldn't be arsed, not worth it.

Edited March 29, 2018 by YNM

[kerbiloid]

So, 25.7°S 209.8°W Atlantics, 1000 km to the East from Rio. 
Casino wins.

https://translate.google.ru/translate?sl=ru&tl=en&js=y&prev=_t&hl=ru&ie=UTF-8&u=www.interfax.ru/world/605946&edit-text=

 

Edited March 29, 2018 by kerbiloid

[DAL59]

On 3/28/2018 at 1:43 PM, YNM said:

TBH, this is more like the ultimate Russian Roulette.

Chinese roulette

[YNM]

2 hours ago, DAL59 said:

Chinese roulette

Who's in Macau ? XD

[K^2]

2 hours ago, DAL59 said:

Chinese roulette

US did it first with Skylab, so it's American Roulette, if anything.

[Nibb31]

It is nowhere near Skylab, Mir, or even Salyut.

Folks have to remember that Tiangong-1 isn't much bigger than most upper stages. It's basically a Chinese version of Progress. There are upper stage reentry events after every single orbital launch, pretty much once or twice every week, so all the hype here is really unjustified.

 

Edited March 30, 2018 by Nibb31

[tater]

5 hours ago, Nibb31 said:

It is nowhere near Skylab, Mir, or even Salyut.

Folks have to remember that Tiangong-1 isn't much bigger than most upper stages. It's basically a Chinese version of Progress. There are upper stage reentry events after every single orbital launch, pretty much once or twice every week, so all the hype here is really unjustified.

 

It's just a fun thing to look out for. I'd honestly like to get alerts for upper stage engine firings that might be visible to me, or even booster entries (since they are usually over water, and I'm not near water).

[MaxwellsDemon]

6 hours ago, Nibb31 said:

It is nowhere near Skylab, Mir, or even Salyut.

Folks have to remember that Tiangong-1 isn't much bigger than most upper stages. It's basically a Chinese version of Progress. There are upper stage reentry events after every single orbital launch, pretty much once or twice every week, so all the hype here is really unjustified.

 

The comparison with Progress is incorrect.  Tiangong-1 is larger than Progress, and Russia is quite scrupulous about maintaining control of Progress and deorbiting it in a planned manner.

I agree that it's been over-reported, though.  As I pointed out to the kids, the chances of even spotting it going by in the sky are pretty remote (assuming they look up from their phones), and the most likely scenario is a bit more dust in the mid-Pacific.

[YNM]

1 hour ago, MaxwellsDemon said:

... Tiangong-1 is larger than Progress...

... In internal pressurized space volume. The overall dimension aren't too far away - Tiangong-1 is, again, basically just a (obscenely) stretched Shenzou orbital module.

 

 

Still, the possibility of someone finally fining China govt for littering is worth it.

Edited March 30, 2018 by YNM

[MaxwellsDemon]

17 minutes ago, YNM said:

... In internal pressurized space volume.

And weight, by not quite half again.

But again, agree with the above that there's being much hay made of comparatively little.  I just didn't want to see "Progress" unnecessarily smeared.