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R.I.P. Iridium
Archeopteryx writes, "Motorola has posted a notice that they expect, barring a financial 'White Knight,' Iridium service to end at 11:59 p.m. EST on March 17.
A few questions come to mind: 1) What becomes of the abandoned satellites? They are a real nuisance to astronomers due to the 'Iridium Flash' effect, and they complicate launch windows for satellites destined for any inclination. 2) Have these any Ham Radio use? 3) Assuming there is a use for them, who owns them after they are abandoned? Any Space Law experts out there? An abandoned ship is subject to salvage laws; how about an abandoned spacecraft?"
Last time I heard anything about this, they were considering selling the sattelite network to NATO or the U.S. military. I don't know too much about the Iridium network, and I know it's probably not quite up to military specifications, but with a little creative engineering, they could have a nice sattelite network dirt cheap.
WARNING: there is a trojan on your
When the iridium satellite passes the field of view of the telescope, you see suddenly a very bright flash because the sattelite is rather reflective ... hence the name Iridium Flash :-)
I have to wonder whether Iridium would have sold better if the US Gov't wasn't so antsy about being able to wiretap it.
How did Qualcomm get around this for their tri-band GlobalStar phones?
-P
Rogue communication satellites abandoned by their creators and no longer supported by their users? Satellites /designed/ for cellphone-like communication?
Hmmmmm... hack targets. *drool* Think of the freenet-style net we could bring on if someone hacked these babies and set up satelite networking. Do they have inband commands?
My bets are on the Cult of the Dead Cow to be the first to OwN these guys. Heh. I predict a satellite-hack version of king of the hill coming up.
Returned Peace Corps IT Volunteer
It took me a moment to realize what it was that I was seeing, but for a few tense seconds.... :-)
Let it be forever known that on this day, March 10, 2000, I lay claim to the staellites. They are mine, now and forever.
If anyone wishes to purchase one, the bidding starts at a mere $250.
Any takers?
I'm still working on a clever footer.
Well it may just work, if email is worth 3,000$ to someone. That's the MSRP for the Iridium phone with a data rate of 2400 bps.
Also, I just found this article on the amount of money Motorola recieves from Iridium to operate and maintain everything. Between 128 and 179 million per quarter!!
The Iridium satellites will be bought for pennies on the dollar, and the service will resurface at much lower cost (IMHO). Will it be competitive with cell phones across town, no - but for ships at sea, scientists in the brush, etc. it will be useful.
Now, what kind of deal will there be on these phones on eBay in a few months? ;^)
Ken
1. What becomes of the satellites?
...
Well, my bet is the NSA will "borrow" them. Or else the military wing will use them as "hot rocks" for space defense. Sadly, due to Bill G's and Paul A's holdings, they won't be used to bombard Redmond
2. Ham Radio use.
Nah
3. Who owns them?
The country that the company resides in. AKA The United States of America. But if truly abandoned and noted as such, you could get salvage rights. My bet is the govt agency that takes them will file under the Black Budget restrictions, so you won't know they own them.
4. Can we pirate them? (bonus question)
Yes. Satellites keep working even after the ground crews stop them. Just give them the power up signal and reprogram them. This will show up in the next Bond movie "The Spy Who Spied On Me", when the evil Bill Sateg tries to rule the world, forgetting that he already owns it.
Will in Seattle
Iridium is a satellite telephone network. Worldwide service, very expensive.
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gotta love those faq's at the bottom of the page...
q: can motorola help me out at all in finding an alternative satellite service provider?
a: motorola cares deeply about its customers. However, motorola feels it cannot provide you any more help than listing a couple of phone numbers at this time.
While I'm not a lawyer and I don't play one on TV, if I remember rightly (My minor was Space Studies from UND) spacecraft are under the same salvage rules as abandoned ships at sea.
Now just cause Iridium is out of business doesn't classify these as abandoned craft. However if Iridium's offices etc is entirely shutting down and no more signals are sent to these craft then indeed it would seem that someone with "broadcast" capabilities could take over themselves a satellite provided they have the knowledge, software to do so.
I'm sure no matter what this will be a first in the realms of space law. If I were Iridium I'm most certainly want to give these satellites over to someone, otherwise it could be bumper cars in outspace. Certainly don't want somebody unqualified hacking on a spacecraft's navigations. (Scenes from MST 3K the Movie start rolling through my head)
Regards,
One of Iridium's press releases stated that if a "White Knight" was found that they had drawn up a plan for restructuring in the coming year. They also stated that the same plan had steps for de-orbiting the satellites, a process that they expect to take 6 or 7 months. http://dailynews.yahoo.com/h/nm/20000306/tc/teleco ms_iridium_4.html
Either that, or they will become the new Skynet.
bun-fhuinneog agam!
A link from an old Slashdot story is a story in Wired. Basically, Iridium use(s|d) a frequency that "bled" into one frequently used by radio-astronomers to observe the cosmos.
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The Future: Some assembly required; batteries not included.
In addition to desperately looking for new financing, the Iridium folks will be preparing a "de-orbiting" plan for safe destruction of the Iridium constellation. (If they were just left derelict, they might cause significant problems down the road.)
If there is no last-minute financial rescue by the deadline, the de-orbiting plan will start, although it may take up to six months to complete.
http://www.satellite.eu.org/sat/vs ohp/iridium.html
Iridium satellites have three large, flat, reflective antennas arrainged at an angle to the main spacecraft. These antennas, when at the right angle, can produce a very bright glint of reflected runlight. If you know where to look, the flares can be seen in broad daylight.
Look here: http://www2.satellite.eu.org/sa t/vsohp/iridium.html
They explain the effect, and even link to flare prediction software.
Specifically, the antennae on the Iridium are flat and highly polished surfaces. The flashes can get as bright as -8 magnitude for a few seconds.
The web page to check out is www.heavens-above.com. Give them your latitude and longitude, and they can provide you with predictions of where to look and when.
Some of the work I do is in the space debris area, specificaly in collision avoidance. I'm not an expert, but I believe that all recent satelites are supposed to file a plan for what to do at their end of life. For LEOs (Low Earth Orbit satelites) that usually involves deorbiting them so they either burn up entierly or what doesn't burn up lands in the ocean where it isn't likely to hit something. The Iridium birds will only last a few more years before they fall out of the sky on their own. Since nobody seems to want them, I suspect they will get dumped in the Pacific.
-- Any statement of the form "X is the one, true Y" is FALSE.
To Whome it may concern:
It has my come to your attention that failing to find a buyer you will soon abandon your network of communications satellites, known as Iridium.
I am prepared to offer $100.00 US for your satellite network.
Thank you for your attention to this matter. I'm sure you will agree that such a remarkable sum underscores the seriousness of my offer.
Regards,
........
____________________________________
-- I beleve you'll like this -->
What if, instead, they were not made of reflective material?
The handful of iridium satellites is nothing compared to all the other debris and satellites that we have put in orbit - if iridium satellites are such nuisances to astronomers, then what about all the other ones?
Is there a set of rules for satellite construction? I'm sure there some rules that everyone follows loosely.
Is there an international organization that regulates satellite launch schedules? I'm sure there is, it's too important for there not to be any.
If satellites were problems to astronomers, should we be concerned about all the satellite launches that seem to happen all the time?
Certainly, the iridium satellites can be put to use doing something, otherwise we'd just billions of dollars of floating space junk?
The frequencies were protected by international treaty. Additionally, MOT agreed to respect the critical frequencies when they received nearby frequencies. Later, they went back on their word and ignored the international treaty.
In fairnes to MOT, they have worked with the major radio astronomy facilities to avoid making the frequency completely useless by scheduling windows when they would significanly limit their interference in certain locations. However, they still interfere and it makes scheduling time an even for obnoxious task for astronomers who try to maximize the utility of their observatories.
Even worse, it sets a very bad precedent for a big company to threaten to ruin an important scientific resource, and then "be nice" by being better than originally planned. What if every big company decides to put up a big network of satelites interfering with one frequency range, but agrees to be nice in certain locations at certain times? Not good for science!
IANAL of course, but I know that anything over 200 miles off the coast in the ocean is complete legal limbo, I would imagine the same thing applies in space, although there may very well be UN agreements of something because we couldn't have people making attack satellites to kill ours and getting away with it just because its in space (like you can go 200 miles out from the coast into the ocean, slay a bunch of people, then come back with no repercussions (at least from what I've read about hospice cruises where they euthenize dozens of elderly sick people once they get 200 miles out))
Esperandi
As it goes, last Tuesday they talked about Irridium because some guy was bailing on them, it's the guy who owns vodafon. Anyhow, if nobody buys irridium then they will stop driving the satallites and after a while they will all enter the Earth's atmosphere and burn up. A few of them might make it a while but they will all suffer the same fate eventually. CNBC made it sound like on March 17 they will turn the satallites off and just let them drift.
It's really kind of a bummer, I love the idea of a universal mobile phone. There are tons of applications for it. Irridium has been mismanaged since the get-go though. Nobody is going to be a $3000 portable phone and pay $8 a minute for service except for in the most extreme circumstances or they are the most reckless rich guys around. From what I've heard the line quality wasn't so hot either. My PCS phone works just about everywhere I've been in this country and I could easily buy a few more and use call forwarding in other jurisdictions if I needed it for much less than Irridium. There are also alternative satallite world phone ventures that are going on. I also think there are some laws in the US about satallite communication. I think NORAD or some other government agency will track your satallite and possibly even guide it for you if you for some small fee, that fee being something like they have access to your uplinks. I'm not 100% sure on it, but I suspect that once Irridium shuts down they will make sure the satallites cannot be used by anybody. I think there are a number of fears about people sniffing intelligence data to our spy satallites or determining where our spy satallites are. Perhaps someone else in the know knows the details on this.
Whatever the reasons, I'm pretty sure they will just turn the satallites off and let them crash.
This is my signature. There are many signatures like it but this one is mine..
I must say that for what Iridium did, it did well. Technically. (Since I worked on the software I'm not going to say it sucked ;-) It's just too bad that by the time Iridium came to market, the market didn't care!
As far as the satellites are conserned, they will either (1) go in to safe mode then auto-deboost after some period of silence, or (2) Motorola will continue to spend money to command the satellites in order to control their descent so no one gets banged by space junk.
I seriously doubt the constellation will be of much use for anything other than what it was designed for, since the satellites were built for cheap and Iridium would have liked to capitalize on any alternative use.
Hmmn. A friend of mine _JUST_ bought an Iridium pager and service so that she could stay in touch for her 6+ month trip to the Near and Middle East. Now, less than a month after this purchase, the service is completely going away.
Will she have some kind of recourse?
Will she still have this recourse available several months from now, when she actually gets back to someplace with enough connectivity to file a claim?
Enquiring minds want to know.
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According to space law one can not be held responsible for the damage an abandoned spacecraft causes. This means that an abandoned spacecraft can be subject to salvage by anyone who feels like it and has the means to do so.
I am not a space law expert, but I did take up a course on space law in college as part my aerospace enigineering degree. During this course the professor gave us an exammple of such a situation in which a sovjet satellite with a nuclear reactor on board caused some damage to other spacecrafts. The sovjets could not be held responsible because they had officially abandoned the spacecraft. It ended up that others had to clean up the mess.
So if these iridium satellites would be officially abandoned anyone who feels like it could try to "safe" them.
"Basic research is what I am doing, when I don't know what I'm doing."
Werner von Braun (The big boss at NASA a while back)
Here is a Reuters article with information about the Iridium destruction plans.
On Sunday ICO Global Communications is going to lanuch its first sat as part of a global moblie network
d _673000/673221.stm
http://news.bbc.co.uk/hi/english/sci/tech/newsi
It's like slashdotting a telescope. Iridium satellites are so reflective that they cause numerous false hits, flooding a telescope with light and making genuine observation impossible.
And the brethren went away edified.
They're a network of communications satellites in very low orbits. Users have handsets that contact the satellites directly. You can travel anywhere in the world with an Iridium telephone and are able to call anywhere else in the world, on or off the Iridium net, without depending on the local infrastructure. Theoretically a good idea, but it was badly executed.
And the brethren went away edified.
Here we have 80+ satellites in orbit that nobody wants, and I still have to access the net at 56k.
The world is full of irony.
By the way, Heavens Above is a great place to look if you want to know when and where iridium flashes will take place. I'm sure those will be missed...
-CausticPuppy "Of all the people I know, you're certainly one of them." -Somebody I don't know
The Iridium Flash effect occurs when a great idea for a worldwide product flashes onto the scene, allowing people who want to have the best of everything spend more money. In a flash of bright light, the idea burns out leaving behind an armada of outrageously expensive technology orbiting the earth.
... [read page to get context] ...
Seriously, though, check out Observing Iridium Flashes and Heavens Above (as someone already mentioned).
According to this article in Sailing Source, the last link: tells you where and when to look for IRIDIUM satellite "flashes" as the sun reflects light off the satellites passing overhead. You plug in your lat/long position and it will tell you where and when in the night or predawn sky to look to see an Iridium "flash."
Some people call them flares apparently to differentiate from meteor flashes.
The reason satellites are made of highly reflective materials is so they reflect the sunlight and not gather heat, sort of like a car baking in the hot sun. I imagine there *are* some coating materials which would reduce the glare and imagine that so far, there has been little reason to use them.
But remember that the Iridium "flare" is the reflection from the solar panels, which cannot be covered so easily as with some kind of paint.
That's an attractive but malicious thought, Lew! While we can think and talk of that amongst ourselves, I shudder to think of the child wanting to take his telescope into the back yard some night and Mom objects, saying that watching the sky is "evil" because she has no idea of the difference between a meteor flash and an Iridium flare!
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He lives in a world where those who do not run the client software of the omnipresent meme are unacceptable.
Actually I think Hemos get's a check everytime a piece of space junk wipes out a useful piece of space junk.
Specifically, depending on how you "take it out", you are likely to introduce a lot of orbital debris. An energetic disassembly (i.e., you blow it up) will result in many small particles being spread out with a broad range of directions and velocities. Many of these will be directed into the atmosphere, where they'll burn up. Many will be directed out into space: if they have sufficient velocity, they'll leave the earth system, however, most will assume a very "tall" elliptical orbit and will burn up in the atmosphere when trying to approach perigee.
But there is a class of the particles that will remain in orbit. These will often have an interesting orbital dynamic in that they'll all have orbital foci at the point of the detonation and at the opposite point on the orbital sphere.
For more information, and some diagrams, look up references to the disastrous Haystack project.
Also, remember that objects in orbit are (not surprisingly) moving at orbital velocity, which is quite fast. Even a small particle or fleck of paint is an amazing kinetic energy weapon at that speed -- especially if you're in a different orbit, and the net vector adds. There are some scary pictures of aluminum portions of the Long Duration Exposure Facility (LDEF) that were badly pitted or blasted through by debris that was 1mm or smaller.
That's why the shuttle always tries to keep the narrow profile (keep tangent to the orbital sphere). It's also why you couldn't get me out on a space walk!
Eloi, Eloi, lema sabachtani?
www.fogbound.net
Someone was interested in Ham Radio use of the sats (like the Phase 3D or Oscars). There's a lot of them up there (66 Iridium sats), but they're out of frequency. Also, they're right in the LEOsat hotspots for spectrum use, so I don't doubt that they'll re-farm them out or resell them.
Satellites: 66
Orbital Planes: 6
Orbit Height: 780 km (these are LEOsats)
Inclination of Orbital Planes: 86.4
Orbital Period: 100 min. 28 sec.
Lifetime: 5 to 8 years
Frequencies and Rates
Telephone and Messaging Service Links are 1616 - 1626.5 MHz (L-Band)
Intersatellite Links are 23.18 - 23.38 GHz (Ka-Band)
Ground Segment Links:
Downlinks: 19.4 - 19.6 GHz (Ka-Band)
Uplinks: 29.1-29.3 GHz (Ka-Band)
Digital Voice, Fax, and Data are transmitted at 2.4 Kbps
"First things first, but not necessarily in that order."
- Doctor Who
The company cannot leave the satellites there. They will be brought back down and burnup by judicial order. It is unclear how this will be paid for.
The judge has mandated that Iridium or its creditors "deorbit" the satellites, although it was not clear who was going to pay for this.
Crash them into Earth and search for intelligent life. (Good luck finding any). Or, better yet, watch the president of Iridium start taking potshots at his mother-in-law's house starting around 11:55PM ;)
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I think there is a world market for maybe five personal web logs.
At least one of the Globalstar retailers is offering a $495 trade-in on a Globalstar phone. This is a pretty good deal, since the G* phones are much cheaper anyway, and by all accounts work much better. Plus, they're the only game in town at the moment, unless you enjoy GEO-style voice latency (eg:Inmarsat)
The link is worth it just for the animated GIF of the Iridium logo (the constellation Ursa Major) falling out of the sky.
For an excellent on-line collection of relevant international documents and statutes relating to space law, check out the Archimedes web site. A survey of applicable treaties can be found at the Space web site.
An article on the point raised in the note is: "Emerging law of outer space - the analogy of maritime salvage" / Almond, Harry H., Jr. / 19 J. OF SPACELAW #1, 1991, P67. You should be able to find this in most law school libraries.
The problem with the salvage analogy is that there is at present no legal mechanism for a nation to absolve its responsibility for objects placed into outer space. There doesn't really seem to be legal recognition of abandoned property in space. I understand that the prohibitions against military operations in the Outer Space Treaty have been argued to preclude private salvage as well. This is not to say that salvage is prohibited, only that interest in any property rights to the salvage estate are unclear.
Though I practice intellectual property law, these remarks should be considered coming from a lay person -- I have absolutely no real clue what is going on in these space law/admiralty issues beyond a rudimentary understanding of the Space Patent Act.
Besides the price, Iridium had performance issues. It was based on GSM, but its link power budget limited the net bit rate to 2400, which meant that the voice quality wasn't so hot. And its data applications are somewhat limited, though by no means nonexistent (not everything is fast web browsing!).
But it didn't work in a car. It didn't work indoors. It didn't even work well through leafy trees, or if buildings were in the way. It was for people who were "out standing in their field."
They designed it before cell phones were widely available around the world, and continued to build it for business travelers even after that market no longer needed them. They designed it with complex sat-to-sat relaying, bypassing cheap terrestrial fiber optics. Again, a 1985 design decision gone bad. These errors add up.
It was called Iridium because that precious metal is element number 77, and there were to be 77 satellites in the original constellation. They later lowered it to 66, a decision which might have strained its performance budget even more than it saved on cost... but they didn't change which element it was named for. How fitting, though, that element 66 is named Dysprosium. (Other slashdotters are invited to check out its etymology.)
Look in the upper right-hand corner of this page:
http://www.iridium.com/docs/copyright.ht ml
I don't think they implied the meaning to be what we are thinking! Haha!
EC
EverCode
The reflective material is most likely used for thermal control. Without it the spacecraft would most likely become too hot and burn out. Yes, there are other cooling mechanisms, but making a surface reflective is pretty darn cheap and easy.
The handful of iridium satellites is nothing compared to all the other debris and satellites that we have put in orbit - if iridium satellites are such nuisances to astronomers, then what about all the other ones?
Who says they aren't? ;-) Seriously, though, most satellites are in orbits that aren't such a problem:
GeoSynchronous Earth Orbits (GEO) are way the hell away from the earth, and orbiting at the equator, and really easy for astronomers to avoid. The satellites are also in predictable places in the sky (by design). There are many hundreds of satellites in the GEO ring. These are the satellites you have the most immediate contact with - pagers, cable TV, satellite TV, etc.
Polar or Sun Synchronous satellites (weather satellites and land imaging, for instance) are in orbits that run north-to-south and generally pass overhead only very infrequently, and very quickly. Usually there's only a few satellites in these sorts of orbits.
LEO satellites, like Iridium, are pretty common. They're used for a whole host of different applications. I suppose theoretically any of these would pose the same problems as Iridium to astronomers, however they are usually at altitudes where they move too fast or too slow for them to be much of a problem. Iridium is a bit different in that it is a "Constellation". By *design* you're supposed to always have one in view; their velocity is set such that it "maximizes" the problem to astronomers. ;-) I don't know if there are currently other constellation systems like Iridium in orbit, but I know there's been a bunch designed on paper (I should know, I helped design a few).
You may find this an interesting irony... Hubble is in one of these LEO orbits (so that the shuttle can get to it). So one of the things fouling up the Earth-based telescopes is a better telescope. ;-) (Actually, Hubble is at a low enough orbit that it probably moves too quickly to be much of a problem, but there's other telescopes up there.)
Is there a set of rules for satellite construction? I'm sure there some rules that everyone follows loosely. Is there an international organization that regulates satellite launch schedules? I'm sure there is, it's too important for there not to be any.
Lots of red tape. Remember, your government has had its hand in this industry since its inception. ;-)
If satellites were problems to astronomers, should we be concerned about all the satellite launches that seem to happen all the time?
From an astronomy standpoint, no, I wouldn't worry. Let me explain.
First, consider that the vast majority of satellites are going into orbits that for one reason or another won't be a problem. Period.
Second, step back and give thought to how astronomy has developed and evolved. Long ago, we knew so little about the heavens that a simple telescope out the window of a city apartment could generate a vast wealth of scientific data. As they gathered more data and started looking for higher quality images they were forced to move out of the cities, eventually to remote islands and mountaintops, in order to find clear, light-polution-free skies. Would it have made any sense to restrict electric lights in cities simply for astronomer's benefits?
Today, to achieve the major scientific advancements scientists are having to go into space orbit. Nothing we can trace to ourselves as the fault - it's the atmosphere itself that's at issue, this time. Does it make any more sense to hinder commercial spacecraft than it would have to place controls on electric lighting?
I've had the opportunity to work on some conceptual designing for the next generation telescopes. Very cool things are being designed for the new "mountaintops". In fact, NGST (Next Generation Space Telescope) is being designed to orbit a gravitational anomaly! Check it out: http://www.trw.com/ngst/ (My job is to come up with a propulsion system that'll keep it orbiting this point, without fouling the optics, and is as efficient as possible.)
Certainly, the iridium satellites can be put to use doing something, otherwise we'd just billions of dollars of floating space junk?
Perhaps... However it's not like we can retrofit them with radar sensors or something. I'm sure within a few months we'll hear some novel new use for them, but these spacecraft were pretty optimized for the task and business model they were set for.
I must say that for what Iridium did, it did well. Technically. (Since I worked on the software I'm not going to say it sucked ;-) It's just too bad that by the time Iridium came to market, the market didn't care!
Iridium had a few more launch failures than planned, but yes, the system as a whole worked pretty much as planned (as far as I know). It overlooked the massive drop in cell phone costs, as well as the rise of the Internet.
As far as the satellites are conserned, they will either (1) go in to safe mode then auto-deboost after some period of silence, or (2) Motorola will continue to spend money to command the satellites in order to control their descent so no one gets banged by space junk.
The satellites will (eventually) decay and burn up in the orbit no matter what anyone does. The orbit is high enough that this won't happen any time soon (unlike the space station, which is at such a low altitude that it'll fall back to Earth if you so much as look at it crosseyed. I don't think the satellites have sufficient fuel to conduct a controlled reentry, but it doesn't matter - these things are small enough that they'll burn up completely before coming anywhere near the ground.
Then in 1991, following on my legislative successes in space commercialization I went to work with E'Prime Aerospace as Vice President of Public Affairs. I took on that job because they had a potential customer (Norris Satellite Communications -- run by a Dutch Amish expatriate from my ancestral county of Lancaster Pennsylvania) who wanted to launch a geostationary Ka Band satellite called "Norstar", but he couldn't get the license thorugh the FCC. There had never been a Ka Band satellite licensed and there was a lot of conflict over letting this Amish character have the first crack at commercializing the Milstar technology (NASA likes people to think ACTS was the pioneer in Ka band, but even thought ACTS was launched first, the Harris ECL satellite switching guys Norris used did their pioneering work with Milstar, not ACTS). Anyway, to make a long story short, we managed to get the FCC licensing dislodged and the first Ka band satellite license was awarded to Norris, the Amish dude. The satellite specifications called for multiple geostationary Ka band satellites with onboard switching of time division multiplexed spot beams that would allow you to adaptively switch the power (both informational and energetic) to various geographic hotspots as needed. This was getting close to what I had predicted as a geostationary computer network, because the ECL switches were systems that Seymour Cray himself would have respected, and the spot beams made it feasible to load-level much more effectively to stationary ground dishes only inches in diameter. If Cray's gallium arsenide switches, developed for the Cray-4, had made it into production, I think the systems could have been a lot high capacity at lower power while retaining their radiation hard characteristics.
Unfortunately, Norris's satellite system was to go the way of another Norris's (William) Plato system -- to the "before its time" scrap heap of history. The Calling Communications Corporation guys who were cursing me at the 1993 Small Satellite Conference in Logan, UT for grabbing their coveted Ka band first eventually, along with Iridium, got it reallocated. Calling Communications Corporation eventually went away from voice communications to computer networking and changed their name to Teledesic. Everyone seemed to forget about geostationary Ka band computer networking.
Even so, I still think there is enormous opportunity for a geostationary orbital computation satellite network based on phased-array spot beam switching and intersatellite optical links.
Seastead this.
The Iridium satellites are orbiting at 780km. This means they will stay up for thousands of years (at least) if they are not deorbited.
For an interesting discussion of the problem and a novel solution see the Terminator Tether.
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Stop worrying about the risks of nuclear power and start worrying about the risks of not using nuclear power.
Globalstar satellites are much smaller (480kg) and cheaper. They are not switchboards in the sky with satellite cross-links like Iridium. They are just dumb frequency translators ("bent pipe" transceivers).
All the smarts are on the ground. You can think of them as antennas connected to the cellular base station with a really long cable. As a result, they will not work in places like the middle of the pacific ocean. You must be within about 1000km from a ground station. They will also not work in the polar regions. They orbits are inclined and do not cover the poles since there aren't that many customers there... Compare this with Iridum where the poles get the best coverage since all Iridium orbits intersect over the poles.
Globalstar uses CDMA. Your handset can communicate with two or more satellites simultaneously and actually sum their signals coherently before decoding (soft handoff). This should result in better coverage.
Globalstar uses a variation of IS-95 CDMA and probably has the same vocoder - variable rate QCELP at up to 9600 bps. Iridium is not GSM, it uses a low rate vocoder (2400bps).
Both Iridium and Globalstar have negligible propagation delay because of their low orbits. The vocoders cause most of the delay.
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Stop worrying about the risks of nuclear power and start worrying about the risks of not using nuclear power.
At last check, JAWSAT wasn't working too well or at all. It's a shame because JAWSAT had a camera that was taking pictures of the deployment of the other nanosatellites. That would have let us see what we looked like after launch so we could check for external damage. Not likely, I know, but it would be one less question.
Hope that clears things up.
for the guys working on TeleDisc? TeleDisc is a constellation of LEO satillites that will provide high speed internet acess wherever you are in the world (supposedly). It's supposed to work with low power nodes (mobile stuff) and higher power nodes (homes, businesses). I think it would be rad to have a single high speed internet connection that I could take on the road with me when I was out with my laptop. Now I'm wondering if Iridium's failure is going to scare off other satillite based communication ventures.
I'm a loner Dottie, a Rebel.
If you go to the Iridium home page, everything is just fine. You can still order an Iridium phone. No indication that the service may go down within a week, except a vague note about the McCaw deal falling through. Are they in denial over there, or what?