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Doubts About Future GPS Reliability
loped_index writes "IT Week reports that the U.S. GPS system is in a delicate state, and that full coverage could be lost if older satellites fail faster than the current rate. From the article: 'The system relies on a network of satellites, which cannot be repaired once launched and have a limited lifespan. Sixteen of the present 28 satellites were built to last seven and a half years, but are now between eight and 14 years old. Twenty-four satellites are required for full coverage.'"
We'll never find them when they fall then..?
Meow meow meow meow, meow meow meow meow...
Is it just me, or does everyone else also realize we're still capable of launching new satellites into orbit?
Is there a concern about current GPS-enabled devices reading signals from new satellites?
I'd be shocked if there is not money available in the Pentagon Budget, or elswhere, for replacement of needed satellites. Then again, cutting funding of absolutely necessary programs is a great way to dodge real budget cuts... since there will need to be a "special appropriation" to cover the shortfall.
"Trolls they were, but filled with the evil will of their master: a fell race..." -- J.R.R. Tolkien on Olog-hai
Toto, I don't think we're in Kansas anymore.
I read
I use one of these as my GPS.
No folly is more costly than the folly of intolerant idealism. - Winston Churchill
we're close to the point where we don't need satellites
That idea falls apart when you're in, say, the alps. Or the sahara. Or most of the planet.
If you put up satellites at a quicker rate then you have too much redunancy in the skies and too much junk in space. It's all a balance, as it should be. Another timely "This is why Europe should run everything" spin story. Be good if Europe invented something really new and useful, for American's to play with (for free)....
Given the military's dependence on GPS, do you think they would allow one second of interuption? And they use it on almost every corner of the globe. They would notice holes in service much sooner then you ever would.
Call this article what it is, FUD to prop up EU's Galileo.
It's not that the satellites were just left up there longer because they couldn't be replaced, it's because they've lasted longer than they were intended to. Kind of a "if it's not broke, don't fix it" philosophy.
With redundant satellites and constant monitoring from the ground, it's possible to let one go until it fails, mark it as "bad" and replace it a little later.
The article is wrong about 24 satellites being required for full coverage. A full set is 21 with 3 as spares.
The article also implies that the satellites are failing at greater than planned rate, when the opposite is true.
It's probably just a coincidence that the guy quoted in the article, Norman Bonnor, is a backer of the European counterpart to GPS: Galileo. It's not like he'd have an interest in bashing the GPS system to help further justify Galileo's funding?
From: ftp://tycho.usno.navy.mil/pub/gps/gpstd.txt
A. BLOCK II/IIA/IIR/IIR-M INDIVIDUAL SATELLITE STATUS
SVN PRN
15 15 Launched 01 OCT 1990; usable 15 OCT 1990; operating on Cs std
24 24 Launched 04 JUL 1991; usable 30 AUG 1991; operating on Cs std
25 25 Launched 23 FEB 1992; usable 24 MAR 1992; operating on Cs std
Scheduled unusable 20 Oct 0130 to 1330 UT for repositioning
maintenance (NANU 2005131/14 OCT)
26 26 Launched 07 JUL 1992; usable 23 JUL 1992; operating on Rb std
27 27 Launched 09 SEP 1992; usable 30 SEP 1992; operating on Rb std
29 29 Launched 18 DEC 1992; usable 05 JAN 1993; operating on Rb std
30 30 Launched 12 SEP 1996; usable 01 OCT 1996; operating on Rb std
31 31 Launched 30 MAR 1993; usable 13 APR 1993; operating on Rb std
Unusable 14 Apr 1634 UT and will remain unusable until
further notice (NANU 2005055)
32 01 Launched 22 NOV 1992; usable 11 DEC 1992; operating on Cs std
33 03 Launched 28 MAR 1996; usable 09 APR 1996; operating on Cs std
34 04 Launched 26 OCT 1993; usable 22 NOV 1993; operating on Rb std
35 05 Launched 30 AUG 1993; usable 28 SEP 1993; operating on Cs std
36 06 Launched 10 MAR 1994; usable 28 MAR 1994; operating on Rb std
37 07 Launched 13 MAY 1993; usable 12 JUN 1993; operating on Rb std
38 08 Launched 06 NOV 1997; usable 18 DEC 1997; operating on Cs std
39 09 Launched 26 JUN 1993; usable 20 JUL 1993; operating on Cs std
40 10 Launched 16 JUL 1996; usable 15 AUG 1996; operating on Cs std
41 14 Launched 10 NOV 2000; usable 10 DEC 2000; operating on Rb std
43 13 Launched 23 JUL 1997; usable 31 JAN 1998; operating on Rb std
44 28 Launched 16 JUL 2000; usable 17 AUG 2000; operating on Rb std
45 21 Launched 31 MAR 2003; usable 12 APR 2003; operating on Rb std
Unusable 13 Oct 0217 to 0905 UT due to repositioning
maintenance (NANUs 2005129, 2005130/13 OCT)
46 11 Launched 07 OCT 1999; usable 03 JAN 2000; operating on Rb std
47 22 Launched 21 DEC 2003; usable 12 JAN 2004; operating on Rb std
51 20 Launched 11 MAY 2000; usable 01 JUN 2000; operating on Rb std
53 17 Launched 26 SEP 2005
For more information about PRN17/SVN53, see:
http://www.spaceflightnow.com/delta/d313a/
54 18 Launched 30 JAN 2001; usable 15 FEB 2001; operating on Rb std
56 16 Launched 29 JAN 2003; usable 18 FEB 2003; operating on Rb std
59 19 Launched 20 MAR 2004; usable 05 APR 2004; operating on Rb std
60 23 Launched 23 JUN 2004; usable 09 JUL 2004; operating on Rb std
61 02 Launched 06 NOV 2004; usable 22 NOV 2004; operating on Rb std
Exactly! Sure, the US invented the system, launched all the satellites, and bears the maintenance cost, but everybody else in the world depends on it, so it's obviously right that the UN control it!
If you don't know where you are going, you will wind up somewhere else.
In fact, a newer GPS satellite was just launched weeks ago. As stated before, the DOD has a special spot in their hearts for GPS. The GPS operators get treated extra special because of the US military's reliance on them. There are already plans in place for each satellite to be super-orbited when the time comes and for a new launch to follow.
In other words, if the military isn't worried about it, neither should we be.
So maybe the US will stop its attemps to prevent the European Galileo...
Actually, it looks like this whole thing may be just misinformation to drum up support for Galileo.
The satellites are lasting LONGER than expected, and we have plenty of spares. It appears the article may also have the number of necessary satellites wrong.
As someone else has pointed out:
Bonnor said launches of new satellites are "only just keeping up" with current losses of around two satellites per year.
So we HAVE SPARES and we're REPLACING THE SPARES AS WE USE THEM. Sounds like it's working just dandy.
Life is too short to proofread.
Let me get this straight. You nearly praise the European nations and call the US incompetent, despite the EU-related solution is over 4 years off, not to mention have questionable delivery systems themselves.
You take the word of a UK individual who, like folks anywhere in the world, gives talks to promote their opinion that are largely unsubstantiated unless they are privy to manufacturing data and known defects which allow him to, within reason, truly call into question satellite failure en masse. I doubt a UK RAF person will know the intimate details of the satellites. What we do know is their failure rate to date.
It's not like nothing is being done with this problem and the problem is not unknown or being ignored; the US has known about this for some time now. Our delivery systems have had problems and huge delays (space shuttle, rockets blowing up), yet we still have been managing to replace the birds that do croak. And are replacing them next with longer lasting birds.
You overlook the fact that many satellite systems are overbuilt and typically do last well beyond their expected lifetimes. Not all do, but a good number have (classic would be the Voyager; one still is running rather well). Until these systems start dropping rapidly faster than we can replace them, I don't see the issue. 4 of them could croak now, and you'd still get accurate info. If a 5th dies, we have one waiting to be launched already and would likely ramp up replacement schedules. If a 6th dies before all that, it depends on WHICH it dies and WHERE you are to determine if it may affect you directly.
You trust this same Old World Europe at the expense of the US, yet look at the recent examples of them deliberately trying and "warning" regarding the domain system (which is something that could have occurred at any time prior anyways).
You use this as an opportunity attack ad hominum US diplomacy, when that has little to do with satellite failure and more to do with their tactics of trying to get their own system (Galileo) up.
I'm not a bible thumper. And yet even I know the problems with the proverb you quote and at the very least, it points to lack of real world experience on your part. Anytime I've spoken softly, the other person being receptive listened, but they weren't, I've watched people get pushed around and one person punched. Anytime I've yelled at someone, they overwhelmingly back down or at the very least snap from the focus, if temporarily, from the object of their violence. I just choose to yell when the situation merits it and that's not often, only when I've or another has been physically threatened and do so then to try to avoid or head off fights.
You attack the right, making no distinction between it and the religious right, just to be critical of the US, meanwhile the EU (multiple nations too) kisses the ass of some of the most suppressive fascist and religious states in the world. Freakin hypocrite. Anytime the Old World gets involved in diplomacy, nothing of substance positive comes about to improve the world order. It's not like the EU is doing this out of the goodness of their hearts either; they want the markets, a price cut, the membership, the money just as well if not more so than the US counterparts.
There will always be those who read a story about "US companies do [questionable or suspected evil activity]" and say, damn, it's all the US's fault, never asking or researching the EU or any other nation's track record on that same matter. But if the EU ballerinas in and bends over before doing a twirl and says "all will be okay, we're here", you're more inclined to take their word for it.
You want to doubt and disagree with the US government? Good. I'm with you. But don't think that because you do and can that the US government is worse than some other half-baked government out there; that's a totally different set of standards and questions which you certainly have not addressed yourself.
People seem to forget that GPS is a military system, developed for military purposes. They opened it up for civilian use and that's wonderful, it's been a massive boon, but it was developed for the US Military alone. It is also the prime location system for just about all military units, from individual soliders up to large ships these days. While I'm sure the military COULD function without it, it would seriously screw things up.
It's a strategic asset, and they aren't going to let it fail. If it was all private run, ok maybe then there'd be a worry that someone would decide to cut costs on it and let it slide, but it's the military's toy and there's no way in hell they are letting it fail.
All the military implications aside, US commercial intrests rely very heavily on GPS these days and letting it fail would also not be in the economic intrest of the US government.
Thus, being able to "just keep up" with the current failure rate will not be sufficient to prevent the system from collapsing.
But the implication that we're only able to just keep up is false.
We're only launching that number of satellites per year because that's how many we need to provide adequate redundancy, not because it's the best we can do. We could send up more, but it would be a waste of money.
What several posts fail to understand (e.g., grand parent or a few posts in parallel threads) is that the failure rate of a system is not constant over time
I understand this concept, but what you're failing to properly acknowedge is that:
A) The system is redundant
B) The failure rate to needs to increase by orders of magnitude in order to outpace our ability to replace satellites.
I highly doubt that the stastical data supports such claims.
Go ahead fit the standard function to the availible data form the GPS satellites the have already failed. I bet it's going to agree with the course of action the the US is taking. Why? Because they can do the same math you can. As a matter of fact, I be they have even better data they don't publish.
I am not trying to enter into the politcal side of this discussion, and I agree that the author of the article may have is own motives, but this is simply not relevant to the logic of his argumentation.
There are gaping holes in his logic. Is it more likely that he's:
A) incompetent
or
B) pushing an adgenda?
Life is too short to proofread.
But don't think that because you do and can that the US government is worse than some other half-baked government out there.
Sorry, but I think this speaks of lack of real world experience in international settings on your part. The US winner take all election system can produce some really nasty outliers when it comes to the quality of your government. BTW I mean the whole selection process - just imagine McCaine winning the 2000 primaries.
In the EU all member nations need to compromise to get anything done. This process certainly squashes all brilliance but it also quite reliably squashes complete and utter idiocy. And guess what, because the EU only moves by compromise the government that yells the loudest hardly ever wins. It is the ones that can moderate compromises the best that end up with the most influence.
Leaving off the Swiss turbocharger thing (Americans made them practical).
Jets just flat out don't come from turbochargers.
Jets use fan blades, turbochargers do not. Turbochargers use impellers and are only compressors. Jets have different compression sections, burners (flame fronts) and actually make thrust.
It's like saying cars came from trains because both have round wheels. It just doesn't work.
I don't see how England invented TV. Nipkow (German) invented mechanical TV, and Farnsworth (American) invented electronic TV (far more important to getting us to where we are now).
The grandparent did miss that England invented RADAR. A great invention.
Note to other posters, Alexander Graham Bell was not Canadian. He resided there fora while, but never changed nationality, he was a Scot up intil he became American. He was a Scot (living in Boston?) when he invented the telephone.
http://lkml.org/lkml/2005/8/20/95