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Geostationary GPS Satellite Galaxy 15 Out of Control
Bruce Perens writes "The Galaxy 15 commercial satellite has not responded to commands since solar flares fried its CPU in April, and it won't turn off. Intelsat controllers moved all commercial payloads to other birds except for WAAS, a system that adds accuracy to GPS for landing aircraft and finding wayward geocaches. Since the satellite runs in 'bent pipe' mode, amplifying wide bands of RF that are beamed up to it, it is likely to interfere with other satellites as it crosses their orbital slots on its way to an earth-sun Lagrange point, the natural final destination of a geostationary satellite without maneuvering power." (More below.)
Bruce continues: "The only payload that is still deliberately active on the satellite is its WAAS repeater. An attempt to overload the satellite and shut it down on May 3 caused a Notice to Airmen regarding the unavailability of WAAS for an hour. Unsaid is what will happen to WAAS, and for how long, when the satellite eventually loses its sun-pointing capability, expected later this year, and stops repeating the GPS correction signal. Other satellites can be moved into Galaxy 15's orbital slot, but it is yet unannounced whether the candidates bear the WAAS payload."
Nuke the rogue satellite in the orbit.
Fuck systemd. Fuck Redhat. Fuck Soylent, too. Wait, scratch the last one.
Haven't the military got some super satellite-busting weapon they've been dying to test?
No sig today...
And create all that space debris that will jeopardize countless other satellites?
Here's a list of what AMC-11 is used for on Lyngsat.
Basically, if this wayward sat gets in the way, the average cable/DBS subscriber in the USA is going to wonder where half their digital channels went.
but it's the only way to be sure!
It should be mentioned that the stable libration points for geostationary satellites are earth-relative (105 deg west, 75 deg east) and are not the same as the Sun-Earth lagrange points (such as those occupied by SOHO and other observation satellites). If we could get spacecraft without maneuvering capability to perform that orbital transfer, we'd be much closer to living in a Star Trek-esque world.
"Open the pod by doors, Hal" > "I'm afraid I can't do that, Dave" sudo "Open the pod bay doors, Hal" > alright
After sending between 150,000 and 200,000 commands to the satellite to coax it back into service, Intelsat was forced to scrap its satellite-recovery efforts and to resort, on Monday, to a limited-duration effort to force the satellite to shut down its transponders. This was to be accomplished by sending a stronger series of signals designed to cause Galaxy 15's power system to malfunction and force a shutdown of the satellite's payload. That attempt, which Luxembourg-based, Washington-headquartered Intelsat had viewed as its last, best-understood option for Galaxy 15, was unsuccessful.
The last message from the satellite was "I'm sorry, Intelsat. I'm afraid I can't do that."
"Kill 'em all and let Root sort 'em out"
In 1998, Galaxy IV blew out, which controlled commercial communications for a metric assload of services (including my former employer's dealership communications network, FordStar). I (and every other remote admin) got a $50 bounty per dish that we hurriedly re-pointed to a different satellite. Cleaned the whole thing up across the global network (four continents) in less than three weeks.
I'm fairly sure that cable TV, which has more sats on tap and relatively less dishes to re-position (and nobody has to crawl on top of a zillion roofs with a wrench and a compass in hand), could likely recover in very short order - probably hours.
That said, there's always the danger of a chain reaction (after all, there's a LOT of satellites in geosync orbit) - if not at this time, then certainly in the coming future, as the numbers continue to increase.
Quo usque tandem abutere, Nimbus, patientia nostra?
It isn't GPS, it's WAAS. http://en.wikipedia.org/wiki/Wide_Area_Augmentation_System which is an "air navigation aid developed by the Federal Aviation Administration to augment the Global Positioning System (GPS), with the goal of improving its accuracy, integrity, and availability. Essentially, WAAS is intended to enable aircraft to rely on GPS for all phases of flight, including precision approaches to any airport within its coverage area."
This is a commercial communications satellite that hasnothing to do with the Global Positioning System
It is not a GPS satellite, in that it is not part of the constellation of satellites that provide position reference. However, as TFA and the other links say, this satellite is one of only two that operate the Wide Area Augmentation System. WAAS uses ground-based GPS receiving stations with known positions to generate a correction signal which increases the accuracy of GPS position fixes to less than 25ft within North America and surrounding areas. Without WAAS, plain GPS can have error in the hundreds of feet. Without the accuracy provided by WAAS, GPS navigation cannot be used for instrument flight approaches - one of the most critical, important, and common uses of GPS today. If this satellite fails, the WAAS system will remain operational throughout most of its original coverage area - but will almost certainly fall outside the reliability limits required for instrument flight certification. It will be a very serious problem for many commercial users of GPS, and possibly for some military applications as well.
I am a geek attorney, but not your geek attorney unless you've already retained me. This is not legal advice.
There are No GPS satellites in GEO. They have their own special orbits. The title is really, really wrong... http://en.wikipedia.org/wiki/Gps#Space_segment
Reminded me of this gem from NotAlwaysRight:
Apparently, it is possible for someone to be standing next to your satellite and cause interference, as long as the someone is another satellite. (But it isn't easy to tell them to stop... :P )
Perhaps they can launch and rendezvous a 100 ton steel 'funnel' and fit it over the satellite thus preventing it from spewing tons of satellite pollution toward earth. In fact, such a device has already been built and is currently not being used. Bonus, it's currently located not all that far from Cape Canaveral and transport ships are located nearby.
Light doesn't just illuminate something. It has pressure. If you illuminate a satellite from the proper angle with less than the energy required to blow it apart, for long enough, you can change its orbit.
Bruce Perens.
Atmoshperic entry from GEO 15 minutes after reentry burn? No way.
One that hath name thou can not otter
There is, as far as I am aware, a special L-band payload for WAAS. It was contracted to be installed on several communications satellites that are otherwise used for C-band and other civilian bands.
Bruce Perens.
You underestimate the power of sudo.
LAGRANGE POINTS? Good God almighty? What in the holy heck are you talking about? That's just ridiculous. It's not going to go to the Lagrange points (any of them). If nothing else there's no maneuvering and so the semi-major axis is FIXED at essentially geosynchronous period. What will happen is that that it will drift at varying speeds on the order of fractions of degrees a day, speeding up as it goes towards the gravity wells, passing through at pretty high speeds, then climbing back out, slowing all the time. I haven't checked the TLEs but it will either oscillate back and forth in one of wells or pass from one to the other. Just like dozens of other "died in place" spacecraft that had exactly the same problem. Eventually as the inclination changes it might go over the side of the hill (since the wells are 3-dimensional) like Skynet II/9354. Look that one up, or DSCS II/Flight II/9432 TLEs and history, that's what it's going to do.
Brett
WASS is used to provide corrections to upper atmospheric disturbances in the GPS signal. It works like this: you have a lot of beacons on ground, mostly close to the shore but pretty much everywhere in the country. These stations know *exactly* where they are, but they anyway measure their position via GPS. By looking at the difference between what GPS says and what they know, they calculate the effect of these atmospheric disturbances. These are uploaded to a central system and get in turn broadcasted via WASS. WASS signals get used mostly by air and maritime vehicles in the North America. Europe has something similar called EGNOS, that depending on the country it could be used with limited advantage on terrestrial measurements. In Germany for instance, the angle to EGNOS is about 20 degrees which makes it almost impossible to capture free-line-of-sight by anyone that is not airborne or in open waters. Now back to the issue. One WASS satellite is failing. There are two WASS satellites and we are fortunate that the one about to fail is not the most important one. This link has some nice images showing the coverage. Sorry for copy-pasting, it's my first post and don't know how to add tags yet. http://www.gpsworld.com/gnss-system/augmentation-assistance/news/failure-imminent-waas-geo-satellite-9841 The problem is that airspace people don't like single point of failure so having one satellite only is a yellow lamp. How this will affect air traffic is still to be seen. GPS accuracy is about 16m with a good view, and when traveling 200 mph during approach, this is not crucial if you ask me. Maritime is something different. You don't wanna sail in Sweden and hit an underground island because you are 10m too far left. For final approach to runway and landing WASS has never been an enabling technology, so business as usual. The US will either replace the satellite or bring the functionality to another one. Until then, people must know that WASS could be out for a few seconds every once in a while. Nothing new really. None of us here will probably feel anything particular happening in the sky.