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Comment by cryptoegorophy | Hacker News Reader

Spacex satellites blockage was the surprise. How did they do it? I thought it would be the best dooms day kind of insurance. Turns out not.

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AFAIK they used GPS spoofing which confuses the Starlink terminals - they need to know where they are to properly connect to the satellites above.

This can be overriden to use "Starlink positioning" where the terminal ignores GPS signals and dtermines its position based on Starlink satellite signals. I think this is what is used in Ukraine where GPS is mostly jammed/spoofed to hell even far from the front.

The GPS positioning is the default as it is likely more user friendly/has quicker lock in normal circumstances.

Another venue of attack could be the Starlink WiFi AP included in the terminals- you could track that down.

So in general:

* switch the terminal to Starlink positioning

* disable the Starkink terminal WiFi AP and conect by ethernet or connect an AP via ethernet with a new SSID and different MAC address

And it should be good to go.

Spoofing - ok, but how did they detect all the starlinks? Assuming that users were smart to not turn on WiFi on starlink. Do these antennas emit certain waves that a “scanner” can detect and with 99% certainty figure out that that point on a map is a starlink antenna ?

My wild guess is that jamming is local. Major cities may be fully jammed. To get an idea about GNSS jamming range (different signal of course, probably much easier to jam), there are maps online where you can see which parts of Europe are currently GNSS-jammed. But I have the same question as you.

> probably much easier to jam

Definitely much easier to jam. Much higher orbits for gnss satellites, much lower signal intensity.

Also, starlink uses phased arrays with beamforming, effectively creating an electronically steerable directional antenna. It is harder to jam two directional antennas talking to each other, as your jammers are on the sides, where the lobes of the antenna radiation pattern are smaller.

Still, we're talking about signals coming from space, so maybe it is just enough to sprinkle more jammers in an urban setting.. I'm curious as well.

https://gpsjam.org/

The GPS jamming maps are based on commercial air traffic flying in the area.

While that gives some ideas of how widespread the jamming is, it won't give accurate information about the range (air traffic avoids areas with jamming) of the interference or any information from places where there is no commercial air traffic (war zones, etc).

Supposedly it's high packet loss but still available to at least some extent. Or at least it was initially? Really highlights the importance of low bandwidth P2P capable messaging systems that support caching messages for later delivery as well as multiple underlying transports.

You can jam the satellites, you can jam the receivers and you can jam GPS.

RF and GPS jamming has been a solved problem for decades. As a SWE, we are all expected to take Physics E&M, Circuits, and CompArch in our CS undergrad - think back to those classes.

Genuine question, is it that easy to deploy these tools over a country that big?

Yes in most population centers. Any country that has the ability to stand up a cellular network has the ability to deploy jamming at scale.

The components needed to build jammers and EW systems have been heavily commodified for a decade now (hell, your phone's power brick, car, and TV all have dual use components for these kinds of applications), and most regional powers have been working on compound semiconductors and offensive electronic warfare for almost a generation now.

I don't think it's as easy as you're suggesting. GPS L1 jamming has been done routinely enough but the satellite bands (X/Ku/Ka) appear to be much more difficult to pull off.

Iran was reported to have mobile units with a fairly short range that constantly roamed around, only hitting 2 of the 3 bands (Ku/Ka). They're also reported to have received mobile Russian military units capable of jamming all 3 (X/Ku/Ka) over a much wider area. (I'm not actually clear the extent to which X band is associated with either Starlink or Starshield. Starshield also reportedly operates to at least some extent in parts of the S band. [0])

So the technology clearly exists but it doesn't seem to be something you can trivially throw together in your basement. That's quite unlike (for example) a cell phone jammer which a hobbyist can cheaply and easily assemble at home. I assume the extreme directional specificity of the antennas plays a large part in that.

[0] https://www.npr.org/2025/10/17/nx-s1-5575254/spacex-starshie...

Couldn't they target each starlink satellite for jamming as it flies overhead? The sat would still send fine, but you could effectively kill the antenna?

I guess (non-expert understanding) that it depends on how tight the beamforming is (relative to the distance of the jammer from a given ground station) or alternatively if the jammer can prevent the satellite from successfully locating the ground station to begin with.

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