US spy satellites built by SpaceX send signals in the “wrong direction”

It seems US didn't coordinate Starshield's unusual spectrum use with other countries.

See full article...

 

[Fatesrider]

“But then the question is, can somebody prove that that’s caused a problem?” Reaser said. Other systems using the same spectrum in the correct direction probably aren’t pointed directly at the Starshield satellites, he said.

The signals are there, which is apparent.

But are they just like a navigation beacon - broadcasting a signal at a specific frequency? Or are they coherent signals containing data?

These are SPY SATELLITES. Transmitting a signal means waving a big-assed flag saying, "I'm here!" They announce when they're up there and WHERE THEY ARE if someone wants to passively home in on them and do mean things to them.

So, to ME at least, that's a BIG fucking problem for spy satellites.

Other kinds, probably not so much.

 

[JFTestudo]

The author did a good job giving us the background and in exploring the implications of this. The two primary thoughts that struck me are that if an amateur home brewer observed this obvious activity, it is highly probable national states who explicitly seek out and monitor what clandestine spy satellites do are well aware of it.

To be fair though, Tilley strikes me as somebody with a lot more expertise and investment than just an 'amateur home brewer'. Like, widespread deployment of Starshield began in 2023? 2024? So far, the only "public" response to this has originated with him.

Discussions of ethics of disclosure aside, if this really was causing issues, you would figure somebody actively using the spectrum outside the U.S. would have screamed by now.

 

[Wickwick]

The signals are there, which is apparent.

But are they just like a navigation beacon - broadcasting a signal at a specific frequency? Or are they coherent signals containing data?

These are SPY SATELLITES. Transmitting a signal means waving a big-assed flag saying, "I'm here!" They announce when they're up there and WHERE THEY ARE if someone wants to passively home in on them and do mean things to them.

So, to ME at least, that's a BIG fucking problem for spy satellites.

Other kinds, probably not so much.

Any satellite that's sending information to the ground is waving a massive beacon as you describe. The entire point of Starshield is that there are too many to bother to home in on individually. It's more expensive to shoot one down than to have launched it in the first place.

 

[Wickwick]

To be fair though, Tilley strikes me as somebody with a lot more expertise and investment than just an 'amateur home brewer'. Like, widespread deployment of Starshield began in 2023? 2024? So far, the only "public" response to this has originated with him.

Discussions of ethics of disclosure aside, if this really was causing issues, you would figure somebody actively using the spectrum outside the U.S. would have screamed by now.

I think the point is that Tilley's disclosure didn't come as a surprise to any nation state interested in US capabilities in space.

 

[Sukasa]

...since no where was it mentioned that these satellites are transmitting in these bands over other countries...

The first sentence of the fourth paragraph makes it clear that these signals are being received in another country.

 

[graylshaped]

To be fair though, Tilley strikes me as somebody with a lot more expertise and investment than just an 'amateur home brewer'. Like, widespread deployment of Starshield began in 2023? 2024? So far, the only "public" response to this has originated with him.

Discussions of ethics of disclosure aside, if this really was causing issues, you would figure somebody actively using the spectrum outside the U.S. would have screamed by now.

Oh, no question, and amateur astronomers--as a quasi-related expertise--have made extraordinary contributions. That being said, space is infinite; satellite launches not so much and governments do tend to pay attention to them, and people both within and without the US would have absolutely squawked had opportunity presented itself.

 

[butcherg]

Doppler radar gives you the velocity along the transceiver direction. So a down-looking radar would see a velocity of zero for an aircraft at level flight. Sure, you can use image processing to give you velocities, but that takes processing.

Doppler radar gives you the velocity on the return signal directly. There's no more work than the heterodyning you have to do on a radar signal. If you're looking at the horizon, you're getting the component of velocity to/from the satellite. You can then filter for velocity ranges such that hypersonic vehicles would stick out like a sore thumb.

If the target is flying at a vector perpendicular to the beam, with doppler you're going to get a very different velocity than if it were flying head-on to the beam. Might be okay for detection, but to develop an intercept I'd think you 'd need a much better velocity vector. Now, if you have multiple radars painting the same bogey, fusion might make doppler sources work, but that's processing.

 

[Komarov]

Doppler radar gives you the velocity along the transceiver direction. So a down-looking radar would see a velocity of zero for an aircraft at level flight. Sure, you can use image processing to give you velocities, but that takes processing.

Doppler radar gives you the velocity on the return signal directly. There's no more work than the heterodyning you have to do on a radar signal. If you're looking at the horizon, you're getting the component of velocity to/from the satellite. You can then filter for velocity ranges such that hypersonic vehicles would stick out like a sore thumb.

[my emphasis] To be pedantic, in special relativity, you do get a Doppler effect on EM bounced off objects moving perpendicular to the direction of view. I have no idea whether modern SAR can take advantage of that. At LEO speeds, the effect would be quite small.

 

[butcherg]

What you're describing is the mentality of "it's not wrong if we get away with it". If radio frequency spectrum was reserved for specific purposes, it should only be used for those purposes.

Do you have a frequency management background? Not picking at you, if you do I'd like to know how what you assert fits with the command media.

 

[forkspoon]

“…These earth stations control ninety domestic and international space missions including the Space Shuttle, the Hubble Space Telescope, and the International Space Station.”

Is the space shuttle also a secretly operating orbital object today?

 

[Wickwick]

[my emphasis] To be pedantic, in special relativity, you do get a Doppler effect on EM bounced off objects moving perpendicular to the direction of view. I have no idea whether modern SAR can take advantage of that. At LEO speeds, the effect would be quite small.

I think the frequency offset from the relativistic Doppler shift would be within the emission bandwidth of the emitter for objects traveling below a few km/s.

 

[Erbium68]

I don't believe anyone thinks these are Starlink satellites doing Starlink business.

You know MIC stands for military-industrial complex, don't you? It is extremely difficult in the USA - and some other developed countries - to know where commercial industry and the military begin and end?

 

[Wickwick]

If the target is flying at a vector perpendicular to the beam, with doppler you're going to get a very different velocity than if it were flying head-on to the beam. Might be okay for detection, but to develop an intercept I'd think you 'd need a much better velocity vector. Now, if you have multiple radars painting the same bogey, fusion might make doppler sources work, but that's processing.

Right. You get the component of velocity along the beam. So a craft flying perpendicular to the satellites view would not yield an interesting result. You can tell it's there, but you can tell that without using Doppler.

But if I have an overlapping constellation of satellites looking at overlapping regions of space from multiple directions, it's impossible for a craft to be moving perpendicular to all viewers. I don't need to correlate between satellites. I need only check that nothing is exceeding my speed limits for each satellite. Not to mention that the view angle of an object is always changing for a given satellite.

Edit: And I'm not suggesting that these systems would be accurate enough to resolve an intercept. More powerful assets can be brought to bear for that. But those more powerful assets tend to be tightly-focused devices. They aren't good at large-area coverage.

 

[vonduck]

is it pointing in the right direction that you know nothing about or pointing in the wrong direction as in sending shit to russia?

 

[EllPeaTea]

If Elon Musk were a Russian (Chinese, North Korean, Iranian) agent, what would he do differently than he has?

I don’t think he would have given the US a massive advantage in ability to put stuff in space.
Or make electric cars desirable.
Or build the best electric car charging network in the world.

 

[pmhparis]

The second paragraph states: "The signals are sent from space to Earth in a frequency band that’s allocated internationally for Earth-to-space and space-to-space transmissions." (emphasis mine)

Then goes on to exhaustively explain how using these frequencies Space-to-earth is not according to the norms.

So how did Scott Tilley and the author conclude that the emissions are NOT being used space-to-space and are not being received as an unintended sideband of the satellites using them as space-to-space communications? I mean other than seeing that it's SpaceX so Musk adjacent and jumping to the conclusion that it HAS to be judged the worst way possible.

Is there a technical reason for excluding these frequencies being used in space-to-space communications?

 

[Komarov]

The second paragraph states: "The signals are sent from space to Earth in a frequency band that’s allocated internationally for Earth-to-space and space-to-space transmissions." (emphasis mine)

Then goes on to exhaustively explain how using these frequencies Space-to-earth is not according to the norms.

So how did Scott Tilley and the author conclude that the emissions are NOT being used space-to-space and are not being received as an unintended sideband of the satellites using them as space-to-space communications? I mean other than seeing that it's SpaceX so Musk adjacent and jumping to the conclusion that it HAS to be judged the worst way possible.

Is there a technical reason for excluding these frequencies being used in space-to-space communications?

The high signal-to-noise ratio is a dead giveaway. You wouldn't get that from an accidentally scattered transmission, it requires a high-gain antenna pointed in the right direction, i.e., towards the ground.

 

[miken32]

Experts told Ars that the NRO likely coordinated with the US National Telecommunications and Information Administration (NTIA) to ensure that signals wouldn’t interfere with other spectrum users.

Whatever they’re for, Reaser said the emissions were likely approved by the NTIA and that the agency would likely have consulted with the Federal Communications Commission.

Randall Berry, a Northwestern University professor of electrical and computer engineering, agreed with Reaser that it’s likely the NTIA approved the downlink use of the band

Umm, maybe these guys haven't been reading the news? The way things are going, I'd say it's 50/50 as to whether or not anyone in an executive branch department would coordinate and authorize their actions with anyone! I admire their faith in "norms" and whatnot, but...

 

[saltyfrog]

... like TV news broadcasters that have vehicles equipped with satellites to...

I think there is a word missing here. Perhaps Dr. Gitlin could set me straight, but I don't know of too many vehicles that have their own satellite.

 

[Wickwick]

The high signal-to-noise ratio is a dead giveaway. You wouldn't get that from an accidentally scattered transmission, it requires a high-gain antenna pointed in the right direction, i.e., towards the ground.

Unless we're seeing the side lobes of a massively high-powered transmission. And sending that much power between satellites would almost certainly be interfering with ground-to-space operations for any strays caught in the transmission.

 

[Avalon]

SAR would be obvious from the signal behavior so presumably it wasn't executing SAR. Other forms of radar are certainly possible and could also be assessed based on signal behavior and characteristics. PNT manipulation/jamming is bizarre since that has nothing to do with the band that these are operating in (and would not benefit from current use as described). Most likely these are passive sensors and this is their downlink. If that's the case, I doubt they would transmit over un-allied nations so I'd be very interested to hear what countries outside of NA see this activity.

 

[Edzila]

The headline feels a little misleading. These aren’t SpaceX satellites going rogue. They’re NRO intelligence satellites that SpaceX built under contract, and the article itself makes that clear. Any unusual spectrum use is a government decision, not something SpaceX configured on its own.

If there’s a transparency or coordination issue, that falls on the agencies that operate the constellation — not the contractor that manufactured the hardware. SpaceX is the clickable name, so it ends up carrying the headline even when it’s not the actor making these choices.

 

[Aw189]

Author may want to look into why the FCC, late in the afternoon of the day before the government shutdown, granted to Starlink the right to use (I think exclusively) an unprecedented number of frequency bands.

 

[Stugray]

My Guess:
Star shield employs a Software defined radio and variable frequency transmit and receive bands.
I bet they (Govt/Military) can use Star shield as an orbital "Ground Station" (yes an oxymoron).
If an orbital platform has all the same capabilities as one of your ground stations, then you can communicate with all of your satellites even when they are not in contact with a real ground station.
The S-band "command" (uplink) signals you are seeing are likely commands to other spacecraft via the starlink/starshield network.

 

[Nalyd]

Nerd discovers spy sats sending signals to earth. Potential interference with another countries spectrum. No complaints from other countries. SpaceX provided the sats. OH! Nazi bastards! "Post article ASAP!"

RTFA. It's a lot more nuanced than that and does not implicate SpaceX in doing anything wrong.

is it pointing in the right direction that you know nothing about or pointing in the wrong direction as in sending shit to russia?

RTFA. That's not what it means by "wrong direction".

FFS.

 

[Deleted member 221201]

The article headline makes it seem like it’s Spacex’s fault

Journalistic standards are also going in the wrong direction

 

[danan]

how can an explanation be more left-handed?

It uses sign language

 

[Astro99]

An alternate form of GPS, among other things. Probably tied to lessons learned from the loss of that RQ-170 in Iran a few years back. Cool stuff!

 

[InvariantCapitalist]

If Elon Musk were a Russian (Chinese, North Korean, Iranian) agent, what would he do differently than he has?

Not send jet chartered at his expense to Ukraine, full of free Starlinks, within 24 hours of their urgent request, that first week of “Special Operation”?

 

[InvariantCapitalist]

Anyone expecing international cooperation with the 2025 US is a dreamer.

Weren’t these satellites put up during Biden administration, implying that his team also signed off on the NRO using these frequencies?

 

[thesquirrelsaremarried]

This seems concerning, but i wish Ars could refrain from clickbate headines

As the article does a great job of explaining, this isn't spacex sending stuff the wrong way, its (most likely) spacex performing the service requested by our government.

Which seems really problematic as it apparently disregards international norms, or possibly even law.

But in this age of hyper polarization, which includes stuff misk is associated with, the distinction is critical.


(Quick edit for typo)

 

[Vidi Vici Veni]

Thoughts as to whether these satellites would have enough receive gain to be using these bands for Doppler radar?

They may not, but it could easily be an SAR constellation with a separate receiver(s). I imagine you could probably identify just about anything flying.

 

[graylshaped]

You know MIC stands for military-industrial complex, don't you? It is extremely difficult in the USA - and some other developed countries - to know where commercial industry and the military begin and end?

Oh, puhleeze leave off with that crap. There has never in all of human history ever been an economy or society of any type not touched by military considerations.

 

[SiberX]

As an amateur radio operator and amateur astrophotographer, I thoroughly enjoyed this article.

Interestingly, the signal powers that Tilley describes are likely underestimates. You would assume the satellites are using directional antennas, and Tilley's antennas are almost certainly not directly in the target receiving location. 15-20dB above the noise from a random location likely means a quite powerful transmission at the actual intended receiver location.

 

[windbourne]

I don't believe anyone thinks these are Starlink satellites doing Starlink business.

Oh, I am sure that there are PLENTY of ppl that think that.
Just few, if any, that have an education in logic or work in these fields ( sat building, intelligence ).

 

[drankin]

The article headline makes it seem like it’s Spacex’s fault

Journalistic standards are also going in the wrong direction

Exactly, it's not RTFP, it is RBTL. lolz

 

[Wickwick]

As an amateur radio operator and amateur astrophotographer, I thoroughly enjoyed this article.

Interestingly, the signal powers that Tilley describes are likely underestimates. You would assume the satellites are using directional antennas, and Tilley's antennas are almost certainly not directly in the target receiving location. 15-20dB above the noise from a random location likely means a quite powerful transmission at the actual intended receiver location.

Unless it's an omnidirectional (or wide-angle at least) emission.

 

[adespoton]

Anyone expecing international cooperation with the 2025 US is a dreamer.

And we know what the current administration does with Dreamers.

To be fair though, Tilley strikes me as somebody with a lot more expertise and investment than just an 'amateur home brewer'. Like, widespread deployment of Starshield began in 2023? 2024? So far, the only "public" response to this has originated with him.

Discussions of ethics of disclosure aside, if this really was causing issues, you would figure somebody actively using the spectrum outside the U.S. would have screamed by now.

That's covered in the article. Anyone experiencing issues would be unlikely to discover the cause unless they were directly looking for it. Thanks to Tilley, they now can. But before he made this public, they likely wouldn't have known what they were looking for, especially terrestrial groups like ENG that operate in short bursts from constantly changing locations.

I see this quite a bit in electronics troubleshooting. Until someone discovers the potential issue, everyone just makes do with their own problems hoping that someone will figure out what's going on. Once an underlying cause is discovered, everyone has a look at it, and we quickly find out which of the issues it was causing.