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#840
by
savuporo
on 02 Dec, 2011 17:26
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ESA Operations
esaoperations ESA Operations
In consultation and agreement with #PhobosGrunt mission controllers, ESA engineers will end #ESTRACK ground station support today
1 hour ago
IMHO, that last one was as close to a confirmation to "it's dead, Jim" as we're likely to get.
No, no.....No, 'e's stunned!. They stunned him, just as he was wakin' up! Norwegian Blues stun easily, major...
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#841
by
Ben the Space Brit
on 02 Dec, 2011 17:33
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A point- wouldn't it be futile to distroy the vehicle as the big pieces would still re-enter, just with more uncertainty as to where?
That's a good question. The optimistic answer is that, if you break up the spacecraft, there is less structure (effectively insulation) around the densest components, increasing the rate at which these items are heated by their interaction with the atmosphere.
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#842
by
olasek
on 02 Dec, 2011 17:54
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If the fuel is frozen, that will be a large piece or several, how many tanks?
The idea is that the tanks are made from aluminium which burns quite lovely during reentry so if there is any frozen fuel it will unfreeze and explode.
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#843
by
hop
on 02 Dec, 2011 17:56
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OK, so I'm going on the idea that it's done.
So what happens now:
1. Blow it out of orbit now?
2. Wait to see where it may re-enter and then decide?
3. Who will be tasked with destroying it, if that is the outcome?
Option (2) is most likely to be chosen. As for 'who', only the Chinese and the US have proven ASAT capability at this time.
By far the mostly likely option is it will be left to re-enter own it's own, just like thousands of other larger objects.
Option 2 is basically impossible, the uncertainty spans several orbits right up until it re-enters.
A point- wouldn't it be futile to distroy the vehicle as the big pieces would still re-enter, just with more uncertainty as to where?
No. The main risk would be ~
710 tons of (edit: potentially) frozen propellant. If you disperse that, there's very little to worry about, and equivalent and larger masses re-enter uncontrolled on a regular basis (like the Zenit 2nd stage that launched PG in the first place.)
edit:
One other thing to watch: Around Dec 13, PG will enter ~2 days of continuous daylight.
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#844
by
Targeteer
on 02 Dec, 2011 18:10
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With the Russians already paranoid about the extremely limited US Missile Defense capability, the US shooting down a Russian satellite, dead or not, probably would not be warmly received.
As for the effort the shoot down USA-193, it's been done once so in theory doing it again could go quicker because most or all of the problems have been worked out.
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#845
by
ChileVerde
on 02 Dec, 2011 18:23
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2. Wait to see where it may re-enter and then decide?
Decide what? We won't have a good idea where it's going to reenter until perhaps an hour before it does. In fact, it might not be until a few days after reentry.
That is the question isn't it. So if we are unable to do so in meaningful timeframe, then one would think your answer would be option 1? Take it out now?
I'm not sure anyone has that capability. If someone does and it isn't the Russians, who would pay for such a large effort? And they'd likely have to get started right away. Remember, the USA 193 thing took many weeks/months of planning and work.
I fear this discussion may be drifting from topicality, but if the GMD ABM system with its interceptors in Alaska and California doesn't currently have the capability to take out PG, the Missile Defense Agency has some 'splainin to do.
That said, I agree that the probability that anyone will take action against PG is at most minuscule.
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#846
by
Michael J
on 02 Dec, 2011 18:39
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With the Russians already paranoid about the extremely limited US Missile Defense capability, the US shooting down a Russian satellite, dead or not, probably would not be warmly received.
As for the effort the shoot down USA-193, it's been done once so in theory doing it again could go quicker because most or all of the problems have been worked out.
The point is that unless it looked like it was determined to come down in a densely populated area in the US, there would be no intercept without the approval of the Russian Federation. Given the current impasse over missile defense, the chances of that happening are slim to none. There is also the issue of the Chinese orbiter (which I forgot to mention in my article in the Space Review). Any intercept attempt would require the approval of both the Russian Federation and China. The probability of both Russia and China giving their approval is closer to zilch then slim to none. So unless the Russian Federation has an undeclared ASAT capability or China chooses to intervene, my guess is that the Russian Federation will allow it fall and hope that it does not turn into a Cosmos 954 redux or worse.
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#847
by
olasek
on 02 Dec, 2011 18:49
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if the GMD ABM system with its interceptors in Alaska and California doesn't currently have the capability to take out PG, the Missile Defense Agency has some 'splainin to do.
I don't think so. These are still fairly limited assets positioned to counter threats of ballistic missiles (and not objects coming from orbits) from specific directions (Northern Russia, North Korea, etc.) and there is no way you could cover all possible entry profiles of the PG heading for the US.
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#848
by
Chris Bergin
on 02 Dec, 2011 18:51
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I'm guessing this isn't the sort of thing where the Russian side will hold a presser or put out a statement if they have given up all hope and this is now a question of when it'll re-enter?
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#849
by
Prober
on 02 Dec, 2011 19:01
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I'm guessing this isn't the sort of thing where the Russian side will hold a presser or put out a statement if they have given up all hope and this is now a question of when it'll re-enter?
Russia did before Perth picked up access.
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#850
by
JimO
on 02 Dec, 2011 19:06
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I suspect one-off or not, operational or not, if it's tracked to populated areas, any nation that has the potential capability has the obligation to try.
I'm not so sure. Remember the common law dictum: "You break it, you buy it." More generally the last person who touches it, is responsible for it.
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#851
by
JimO
on 02 Dec, 2011 19:09
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If the fuel is frozen, that will be a large piece or several, how many tanks?
The idea is that the tanks are made from aluminium which burns quite lovely during reentry so if there is any frozen fuel it will unfreeze and explode.
That's one idea, but frozen propellants are immense reservoirs for sucking up heat as they thaw and then transport heat away from the hot forward skin.
Besides, haven't you ever boiled water in a paper 'Dixie Cup'? The paper survives the fire very very nicely, while there's water left.
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#852
by
olasek
on 02 Dec, 2011 19:10
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I'm guessing this isn't the sort of thing
You guessed correctly.
Many things changed since Soviet times but many are too depply engraved in their psychic to be changed anytime soon.
We should be greatful to have had all the info about this mission, photos, drawings, info abut the actual launch time but don't expect NASA style press briefings.
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#853
by
Prober
on 02 Dec, 2011 19:10
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I suspect one-off or not, operational or not, if it's tracked to populated areas, any nation that has the potential capability has the obligation to try.
I'm not so sure. Remember the common law dictum: "You break it, you buy it." More generally the last person who touches it, is responsible for it.
I agree, this is Russia's problem to fix. Along those lines, couldn't the command to drop the tanks while in a long orbit over water be a good thing?
Sure it would fix the drop tank covering communications problem.
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#854
by
olasek
on 02 Dec, 2011 19:14
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but frozen propellants are immense reservoirs for sucking up heat as they thaw and then transport heat away from the hot forward skin.
Provided they preserve the shape and integrity of a 'reservoir.' But if outer layers explode everything could get broken into hundreds/thousands of tiny pieces and you no longer have this 'reservoir' to speak of.
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#855
by
Michael J
on 02 Dec, 2011 19:16
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I suspect one-off or not, operational or not, if it's tracked to populated areas, any nation that has the potential capability has the obligation to try.
I'm not so sure. Remember the common law dictum: "You break it, you buy it." More generally the last person who touches it, is responsible for it.
I agree, this is Russia's problem to fix. Along those lines, couldn't the command to drop the tanks while in a long orbit over water be a good thing?
Sure it would fix the drop tank covering communications problem.
And along those lines it is their legal responsibility if it impacts land and causes damage.
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#856
by
hop
on 02 Dec, 2011 19:17
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Russia did before Perth picked up access.
This claim contradicts available evidence. Perth wouldn't have been trying if the Russians had given up completely, and there's no evidence that Russian ground stations had stopped trying.
I agree, this is Russia's problem to fix. Along those lines, couldn't the command to drop the tanks while in a long orbit over water be a good thing?
Huh ? The immediate problem is that they have no ability to command the spacecraft. If they did, there's a whole lot of things they could do.
Sure it would fix the drop tank covering communications problem.
This "problem" was rumor, never confirmed by any reliable sources. The actual configuration of the spacecraft suggests it's not a major problem.
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#857
by
wolfpack
on 02 Dec, 2011 19:17
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With the Russians already paranoid about the extremely limited US Missile Defense capability, the US shooting down a Russian satellite, dead or not, probably would not be warmly received.
No. It would make for a very awkward situation in the next Soyuz capsule as well!
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#858
by
rdale
on 02 Dec, 2011 19:30
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No. It would make for a very awkward situation in the next Soyuz capsule as well!
In what way? Have you heard of Apollo-Soyuz?
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#859
by
olasek
on 02 Dec, 2011 19:56
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In what way? Have you heard of Apollo-Soyuz?
I don't have any problem understanding what he was referring to.
Any such shoot-down could be received by Russian as 'aggression' or violation of their property or showing off US might in space (you can do it, we can't), etc, etc. Nothing of the sort adds to warm fuzzy feeling in combined manned space missions. And lets face it, Apollo-Soyuz was a highly choreographed political endeavour during times when Cold War was still very much raging on.