#167018 - 02/13/09 02:14 AM
Re: Satellites destroyed,no sat phone,GPS,spot,PLB's
[Re: ironraven]
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Veteran
Registered: 09/01/05
Posts: 1474
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I expect a small but very loud portion of the population will wake up, and they aren't people we want unsedated, bored, and roaming the streets waiting to find out that they can't get money, and their plastic is no good. I'd give it that first two or three days before we started to see riots due to a full comm outage.
Funny but true.
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#167020 - 02/13/09 02:50 AM
Re: Satellites destroyed,no sat phone,GPS,spot,PLB's
[Re: LED]
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Pooh-Bah
Registered: 09/01/07
Posts: 2432
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Somewhat fortunate that the satellites were roughly 500 miles up. Shuttles and the space station are at about half that. So they are at somewhat higher risk as the pieces spiral down and deorbit. Fortunately space is really big so odds remain low of any interaction.
The GPS, main communications and military surveillance satellites are, for the most part, much higher and gravity says the pieces will pretty much all go lower, not higher. So they are at far less risk. So while there are likely to be repercussions this unfortunate event isn't reason for hair-on-fire alarmism.
Even the loss of all middle orbit satellites, something that simply doesn't seem likely, would be far less an issue than it was a decade ago. Communications have shifted quite a bit in the last decade away from satellites to optical fiber cables where the bandwidth is wider, the disruptions are fewer (in part because we over invested in fiber in the 90s and there are now many redundant lines), and the maintenance and upkeep are cheaper.
On the other hand technology, and the fact that it sometimes fails, is easy to take for granted. It is easy for people to get used to GPS for wilderness, marine, even automotive, navigation and assume it will always be there.
The GPS system is great but it is not a replacement for knowing how to navigate with compass, maps, sextant, time-rate calculations and dead reckoning. IMHO learning to navigate without GPS gives a person a better, far more useful and practical, intuitive feel for the intricacies of real-world navigation. Far better than just reading a GPS screen and plotting it on a map.
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#167033 - 02/13/09 10:30 AM
Re: Satellites destroyed,no sat phone,GPS,spot,PLB's
[Re: scafool]
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Veteran
Registered: 12/12/04
Posts: 1204
Loc: Nottingham, UK
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Yes, the higher the level of the technology the more fragile it is.
Also the more tightly controlled a system is the more brittle it becomes. The key is efficiency. The more efficient a system is, the less redundancy it has to cope with problems. The satellite systems mentioned have quite high redundancy - I regularly get 12 GPS satellites visible on my unit, for example, and I really only need 4. Even this Iridium system has some redundancy. From The Register: "This satellite loss may result in very limited service disruption in the form of brief, occasional outages," the firm said, adding that the company expects to have a network solution in place by Friday, and will move one of its in-orbit spares to permanently replace the destroyed satellite within 30 days.Efficiency is the enemy of reliability.
_________________________
Quality is addictive.
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#167085 - 02/14/09 02:58 AM
Re: Satellites destroyed,no sat phone,GPS,spot,PLB
[Re: Grouch]
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Carpal Tunnel
Registered: 11/09/06
Posts: 2851
Loc: La-USA
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This satellite incident seems to me to have been arranged to prove a point, There are plenty of "old, broken down satellites that still have fuel and are still able to be manuevered so as to become an inplace ASAT system,,,,,,
especially against the geosynchronous orbits that have been considered (in the past) as "untouchable"!
Reminds me of the USS SCORPION.
_________________________
QMC, USCG (Ret) The best luck is what you make yourself!
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#167086 - 02/14/09 04:29 AM
Re: Satellites destroyed,no sat phone,GPS,spot,PLB's
[Re: frediver]
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Stranger
Registered: 08/16/07
Posts: 8
Loc: Colorado
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Most likely no one at "SPACECOM" is going to lose a job. AFSPC, through the Space Surviellance Network tracks 10,000+ objects. That is not everything up there, just the stuff they can track on a regular basis due to size, reflectivity, orbit, etc.
So they are tracking it, how to do predict potential collisions? You "fly" the orbits out days in advance on computer systems to look for close passes, then you keep an eye on those. The problem is you cannot run these predictions for everything. The permutations with 10,000+ object, even with altitude and orbital screens takes huge amounts of time and computing power. Screens can be done, but often only for high priority satellites.
So why not Iridium. Don't know if they screened or not. Something to think about though is the legal and financial liabilities the government could get into if they were screening privat civilian satellites. What if the gov't said there would be a collision, so a private company moves a satellite. Then come to find out the orbital predictions were off, there never would have been a collision. Is the gov't now fiscally liable for the loss of satellite life due to fuel expenditure on an active satellite? I bet the civilian lawyers would say yes. What if the gov't, providing screens, missed a collision? Is the gov't now liable for that? These are real questions that come up when gov't agencies provide support to private companies. They can be overcome, but processes, data clearinhouses, etc have to be established. Those cost money. Who is going to pay?
Get the idea?
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#167099 - 02/14/09 07:10 PM
Re: Satellites destroyed,no sat phone,GPS,spot,PLB's
[Re: ironraven]
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Addict
Registered: 09/13/07
Posts: 449
Loc: Texas
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I expect a small but very loud portion of the population will wake up, and they aren't people we want unsedated, bored, and roaming the streets waiting to find out that they can't get money, and their plastic is no good.
This happens every hurricane. Newbies don't visit an ATM until after the phone lines go down. Some stores will re-open before power and phones come back, but on a cash basis...
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#167102 - 02/14/09 07:26 PM
Re: Satellites destroyed,no sat phone,GPS,spot,PLB's
[Re: Brangdon]
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Cranky Geek
Carpal Tunnel
Registered: 09/08/05
Posts: 4642
Loc: Vermont
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Efficiency is the enemy of reliability. May I borrow this for work?
_________________________
-IronRaven
When a man dare not speak without malice for fear of giving insult, that is when truth starts to die. Truth is the truest freedom.
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#167105 - 02/14/09 08:29 PM
Re: Satellites destroyed,no sat phone,GPS,spot,PLB's
[Re: RogerC]
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Pooh-Bah
Registered: 09/01/07
Posts: 2432
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As In understand it the advice give civilian satellite owners/operators is offered as a 'best estimate' basis. Where the space authority will allow you to see most of the data they use and draw your own conclusions. That if a company does use advice offered by the agency they are doing so at their own risk.
Far all practical purposes the US government has the only integrated space traffic center and tracking system of any significant size.
It is my understanding this is similar to their legal status of the GPS system. The US government doesn't really guarantee accuracy or availability. It offers statistical estimates of accuracy and availability but does not guarantee either accuracy or availability at any specific time or place.
So if they suggest you move your satellite and it gets run over by an obsolete soviet satellite nobody saw coming your pretty much on your own.
Similarly if your following your GPS signal hiking or driving and you go off a cliff that is supposed to be twenty miles to the left your not going to have much legal recourse. You take the information on an as-is basis, warts and all.
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#167115 - 02/15/09 09:42 AM
Re: Satellites destroyed,no sat phone,GPS,spot,PLB's
[Re: Art_in_FL]
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Addict
Registered: 09/13/07
Posts: 449
Loc: Texas
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The Russian satellite "died" long ago.
It's widely assumed that many satellites that "die" are not in fact dead but instead secretly operational. This is part of the reason so much effort is put into accurately tracking "dead" satellites: we want to know which are ones are not as "dead" as claimed.
It's also desirable not to let the bad guys know just how carefully we track "dead" satellites, especially ones that have been "dead" a decade or more - we don't want to give away just how much activity an undead satellite can get away with before being caught.
I don't believe it's particularly hard to find "close calls" in tracking data even for as many objects as the US tracks. The problem is collecting high-quality tracking data in the first place.
There are a lot of things that affect the orbit very slightly but enough to matter (gravity from Earth, Moon, Sun and even Jupiter, atmospheric drag depending on day/night heating and solar activity/CMEs acting on Earth, etc). I have read that the tracking data is no good in less than a week for many objects before the position must be measured again.
There have been enough "no comments" from SPACECOM that I'm assuming they're not going to say whether they suspected a collision was possible or not - they don't want to give away whether we do or don't put that much effort into watching long-"dead" satellites. Even if the data had said a collision was possible they might not have told Iridium in order to preserve the secret, since the odds of actually colliding are so low.
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