This is Radio Free Brazil

April 22, 2009 5:43 PM

On March 18, 39 licensed amateur radio operators were apprehended throughout Brazil for clandestine activities of telecommunication. This followed six months of investigations from local officials who received information from the US Department of Defense in regards to unauthorized use of Fleet Satellite Communications System. These geosynchronous satellites, also known as FLTSAT, were used by the U.S. Navy for UHF radio communications between ships, submarines, airplanes and ground stations. These satellites are simple repeaters with no authentication or control over what they retransmit. But the illicit satellite use was not limited to those experimenting with radio systems. Truck drivers love the birds because they provide better range and sound than ham radios. Rogue loggers in the Amazon use the satellites to transmit coded warnings when authorities threaten to close in. Drug dealers and organized criminal factions use them to coordinate operations.

People have noticed the Brazilians using the old satellites for a while, and the recent bust hasn't quieted the transmissions: "I logged another 3 channels over the weekend full of pirate activity although 255.550 MHz seems to be the centre of activity. I can monitor all of the channels using the UBC-3500XLT with just a standard antenna so it's suprising how strong the FM signal is from these old satellites." Another user of that forum found this video of the bust, and users have commented on the equipment used. There are plenty of videos recording live transmissions, and some of the YouTube user comments note what equipment you can use to listen. The Wired article links to a PDF, auto-translated here, which discusses some more history and technical details. The rest of the author's site has more PDFs, for your perusal. (via)

posted by filthy light thief (27 comments total)

filthy light UHF-radiowaves thief
posted by qvantamon at 5:47 PM on April 22, 2009

Like something from an early William Gibson novel. Before he started writing about omnipotent Belgian advertising executives.
posted by thatwhichfalls at 5:52 PM on April 22, 2009

This is cool.
posted by absalom at 7:04 PM on April 22, 2009

For those lacking the relevant technical background, to what extent is the use of the satellite a limited resource?
posted by aeschenkarnos at 7:49 PM on April 22, 2009

I want to try this now, but I don't speak Portuguese and I don't have $20,000 in case I get caught.

I hope that the next generation of birds are locked down a little tighter.
posted by double block and bleed at 7:56 PM on April 22, 2009

It's unfortunate that an unnecessary reliance on non-packetized, unauthenticated radio for government use necessitates these expensive raids and criminal prosecutions.
posted by doteatop at 8:02 PM on April 22, 2009

Wait, I'm confused. The US government launches some mirrors into space. International, unregulated space. And they're mad when Brazilians look at themselves in those mirrors? If you wanted to control the bandwidth, you need to secure the protocol.

What I think is awesome is that casual users found a way to take advantage of this free resource. Also astonished there's no way to reprogram the satellites from the ground to shut this down.
posted by Nelson at 8:19 PM on April 22, 2009 [1 favorite]

Ha! Take THAT, good intentions!
posted by Balisong at 8:31 PM on April 22, 2009 [1 favorite]

It surprised me, at least initially, how unsophisticated these satellites are. They basically just receive on one range of frequencies and retransmit the signal on a different set. Apparently there's not much more to it. I'm not even sure that the satellites fully demodulate the signal; I suspect it's some sort of block converter.

Although this is easy to criticize, the more I think about it the more it strikes me as a legitimate design choice. Let's say you're designing a communications satellite. You want it to be absolutely reliable, which means it needs to be simple. You also want it to have a long useful lifespan, which means it needs to be future-proof: a system that's tied to a particular modulation scheme (like FM or SSB) — which is how most ground-based repeaters are built — would quickly become obsolete. Plus, you want it to be efficient: every milliwatt you spend on control circuitry is overhead; it's power you don't get to spend broadcasting the signal back to Earth.

So a very simple system, where you just change the frequency and do as little else as possible, starts to make sense. Plus, when the satellites were designed, the sort of authentication system that would be relatively trivial today (some sort of public-key cryptography) would have dramatically increased the cost and complexity of user equipment, perhaps even creating the risk that a legitimate user might get locked out due to an expired key or other issue.

All that said, I don't believe the Navy would have implemented such a system without realizing it was very open to jamming: anyone with a powerful enough radio can basically hijack the satellite by transmitting over top of you on the input frequency. So I doubt a few Brazilians here and there are really going to compromise the fleet. However, just letting them go until the whole system becomes unusable might start to present a more serious problem.

The sad part is that the really optimal solution is unlikely to happen. That would be the radio amateurs and other users in Brazil getting together and launching a satellite of their own, rather than pirating the Navy's: there are quite a few similar projects in orbit right now. Although I don't think any of those are up in geosync; I think they're mostly in LEO because that's a lot cheaper and easier to launch. But if the demand and interest is there — and clearly it is — I don't think an amateur geosynchronous satellite is at all impossible.
posted by Kadin2048 at 8:31 PM on April 22, 2009 [6 favorites]

Great points, Kadin2048.

It seems a mistake to round up anyone for their unauthorized use of these satellites -- particularly if they're not a resource which can be overused. If nothing else, they're a convenient communications aggregation point on which to eavesdrop.
posted by Kikkoman at 8:53 PM on April 22, 2009

But if the demand and interest is there — and clearly it is — I don't think an amateur geosynchronous satellite is at all impossible.

But the geosynchronous satellite space is very tightly regulated and very expensive.

I'm surprised they don't just decommission this old satellite.
posted by eye of newt at 9:23 PM on April 22, 2009

In short: old satellites have been up since the 1970s, and were using security through obscurity. Time passes, technology improves, yet the satellites are still up. Here's the long version. The Brazilians are using a limited resource, which the US is currently utilizing for some level of communications (all encrypted, of course).

As noted in the wiki page for FLTSAT: "Altogether eight satellites were launched in the years from 1978 to 1989 by Atlas Centaur rockets into geostationary orbit. The system became operational in 1981. ... In the late 1990s FLTSATCOM satellites were gradually replaced by the UFO satellites."

From the Wired article: in the mid 1990s, "Brazilian radio technicians discovered they could jump on the UHF frequencies dedicated to satellites in the Navy's Fleet Satellite Communication system. ... Navy contractors are working on a next-generation system called Mobile User Objective System beginning in September 2009. Until then, the military is still using aging FLTSAT and UFO satellites — and so are a lot of Brazilians. While the technology on the transponders still dates from the 1970s, radio sets back on Earth have only improved and plummeted in cost — opening a cheap, efficient and illegal backdoor.

To use the satellite, pirates typically take an ordinary ham radio transmitter, which operates in the 144- to 148-MHZ range, and add a frequency doubler cobbled from coils and a varactor diode. That lets the radio stretch into the lower end of FLTSATCOM's 292- to 317-MHz uplink range. All the gear can be bought near any truck stop for less than $500. Ads on specialized websites offer to perform the conversion for less than $100. Taught the ropes, even rough electricians can make Bolinha-ware.

"I saw it more than once in truck repair shops," says amateur radio operator Adinei Brochi (PY2ADN) "Nearly illiterate men rigged a radio in less than one minute, rolling wire on a coil." "
posted by filthy light thief at 9:34 PM on April 22, 2009 [2 favorites]

Slight phrasing error, but you get the idea.
posted by filthy light thief at 9:36 PM on April 22, 2009

> International, unregulated space.

Use of the radio spectrum is heavily regulated by international treaties, and frequency allocations are coordinated (at the highest level) by the International Telecommunications Union. Very few countries do not participate.* As part of being a member, Brazil has almost certainly signed treaties and implemented domestic laws aimed at respecting agreed-upon frequency allocations.

The fact that the receiving station is in space really has nothing to do with it; the transmitters are in Brazil (and in one case the US) and that's where the enforcement action is taking place.

Plus, putting the onus completely on the receiver to reject interfering transmissions, as you would seem to do, isn't practical in many real-world scenarios. Even if you had a method for authenticating the channel, that wouldn't stop a malicious person from simply using a powerful transmitter to swamp the input, preventing use of the relay (ground or satellite-based). This would be perfectly legal if you put the blame on the receiver for not discriminating between the owner's signal and someone else's. I'm not generally a pro-regulation sort of guy, but RF spectrum is very clearly one of those "commons" areas where the shared resource quickly becomes useless if there aren't rather strictly enforced rules about who gets to use what when.

> I'm surprised they don't just decommission this old satellite.

Well, assuming the author of the Wired article wasn't just talking out of his ass, it's not uncommon to hear encrypted digital traffic on the satellites, so they are probably still up because they're still in use.

I assume the Navy has other, presumably more modern, communication systems for use if FLTSAT failed or was jammed (which seems like it'd be easy to do), but it might be convenient for day-to-day peacetime use, re-ordering toilet paper and the like. If the alternative is something narrowband like VLF/ULF — which pushes a whole 50 baud or so IIRC — I can see why they'd stick with FLTSAT.

* An impressive 191 — out of 193 recognized by the UN — are members. Here's a list for the curious.
posted by Kadin2048 at 9:36 PM on April 22, 2009 [2 favorites]

An impressive 191 — out of 193 recognized by the UN — are members. Here's a list for the curious.

OK, North Korea is one of the 191. So who are the two?
posted by dirigibleman at 10:16 PM on April 22, 2009

OK, North Korea is one of the 191. So who are the two?

"Only Palau and East Timor are not participating at this time."
posted by zippy at 10:29 PM on April 22, 2009 [1 favorite]

Kadin2048 wrote: It surprised me, at least initially, how unsophisticated these satellites are. They basically just receive on one range of frequencies and retransmit the signal on a different set. Apparently there's not much more to it. I'm not even sure that the satellites fully demodulate the signal; I suspect it's some sort of block converter.

Hey! You just described how almost every commercial communications satellite works!
posted by wierdo at 11:34 PM on April 22, 2009

The phrase "attractive nuisance" may apply to these satellites.
posted by Kirth Gerson at 3:25 AM on April 23, 2009

It seems a mistake to round up anyone for their unauthorized use of these satellites -- particularly if they're not a resource which can be overused. If nothing else, they're a convenient communications aggregation point on which to eavesdrop.

That was my thought exactly. If their primary use is not by truck drivers chatting to pass the time, but by rogue loggers, drug dealers, et. al., why not eavesdrop and use the conversations as the basis for warrants, traffic stops, etc.? I'm not sure of the legality of this, particularly given that it's Brazil and not the U.S., but it seems likely that they could at least secure warrants to listen to repeat users and then use those warrants to execute stops and searches. Arresting them for using the satellite seems like looking a gift horse in the mouth.
posted by notashroom at 6:57 AM on April 23, 2009

Like something from an early William Gibson novel. Before he started writing about omnipotent Belgian advertising executives.


Actually, it reminds of something out of Bruce Stirling's Distraction; China launches satellites into space and commits economy warfare by broadcasting copyrighted material. Stirling's conclusion is that this would destroy most of American enterprise, and that some displaced IT workers turn to cybercrime to make ends meet rather than leave the field.

I think the truth makes for a better story. America ruins itself, and short sighted military power undermines enterprise based on copyright.
posted by pwnguin at 12:13 PM on April 23, 2009

Sigh. I keep wanting to use blockquote, forgetting that Live Preview is a liar and they aren't allowed.
posted by pwnguin at 12:15 PM on April 23, 2009

Isn't the internet already allowing that? No satellites needed (unless you want to get somewhere remote w/o landlines).

And blockquote still works, at least as of 8:40 AM today.
posted by filthy light thief at 12:34 PM on April 23, 2009

Yeah, I imagine that the moment some guy realized that with the equipment he had sitting around, he could tap into someone else's space based communications gear and repurpose it for his own uses, I have to hope that he had a big goofy "I'm a cyberpunk motherfucker" grin on his face. I know I would have.

Nelson : Also astonished there's no way to reprogram the satellites from the ground to shut this down.

I believe the term of the art that could be applied here is "hyper-velocity, thermally induced de-orbital commission reclassification"

Also known as crashing it into the atmosphere.
posted by quin at 1:04 PM on April 23, 2009 [1 favorite]

particularly if they're not a resource which can be overused.

Whenever non-US-military users are transmitting on a particular channel of the satellite, that's one fewer channel for the legitimate users. The satellites are not magic; they have a fixed capacity.
posted by kiltedtaco at 3:44 PM on April 23, 2009

Quin... you can't deorbit geosynchronous satellites. They're decommissioned by boosting them slightly above GEO, where without guidance tidal forces will tend to drag them ever further out. I suspect most of them will in the fullness of geological time crash into the Moon.
posted by localroger at 4:54 PM on April 23, 2009

well you theoretically could deorbit a geosynchronous satellite, but the fuel budget required to do it would be ridiculous. satellites which are successfully put into graveyard orbits are usually boosted when the satellite has less than 5% of its total lifetime stationkeeping fuel remaining. Also worth mentioning that the ESA has done a study on everything geostationary launched since 1965, less than half of satellites are succesfully put into graveyard, a lot of them which fail in place (such as NIGCOMSAT-1) or other that have spontaneous total power system failures just die in place, and remain drifting where they are....
posted by thewalrus at 6:44 AM on April 24, 2009

...you can't deorbit geosynchronous satellites....

could... but the fuel budget required to do it would be ridiculous....

I had no idea. It's pretty nifty when I learn something that contradicts my expectations.
posted by quin at 7:32 AM on April 24, 2009