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Umjammable is not guaranteed. It’s a new tech (which is/was also geofenced from parts of the front line), so we there wasn’t that much time yet for adversaries

Umjammable is not guaranteed. It’s a new tech (which is/was also geofenced from parts of the front line), so we there wasn’t that much time yet for adversaries to develop jamming tech. It’s very likely harder to jam, but unjammable is a very bold statement.

baq 3y ago
I agree. A more precise statement would be - as of now, Russia does not have the tech to jam it. They must be working on it and same for the Chinese, but for now, we haven't had any evidence that jamming is operationally deployed.
xoa 3y ago
Jamming ultimately works by known physics though, and Starlink seems like inherently an incredibly tough thing to jam (even ignoring anything in the future like optical). It's very high frequency, in LEO, using phase arrays and electronic steering. That makes for something that's highly directional, fairly tight beams, fairly strong signal, that are heading up into the sky (in a military context meaning anything trying to get between you and the sats is right above your SAMs/AA/fighter screens), moving very fast, with the built-in (needed anyway) ability to near instantly jump between satellites in different directions of the sky. That's a big list of fundamental physical challenges that omnidirectional low frequency radio or single HEO sats or the like just don't have. It will likely not even be reasonable for a long while to shoot down the constellation (retaliation aside). SpaceX's launch and mass manufacture costs are already cheaper than anyone and Starship will take that down another order of magnitude or more. Starlink sats will be cheaper than ASAT missiles, and orbiting low enough that atmospheric drag means Kessler Syndrome is not a concern either. Attacking the launch site(s) means attacking the continental USA. It seems to add up to a pretty dang hardened looking system? Cyberattacks, sabotage and so on could be real concerns, but to jam a tight beam phased array looking at very specific spots for signal from 10-100 miles away looks hard from a physics point of view. And of course any powerful jammer will by definition be an absolute magnet for HARMs. The US takes SEAD/DEAD very seriously and is thus pretty heavily equipped for that.
- lr1970 3y ago
  > Jamming ultimately works by known physics though, and Starlink seems like inherently an incredibly tough thing to jam (even ignoring anything in the future like optical). Jamming DownLink is certainly difficult especially if ground terminal uses receiver beam steering and pointing upwards. Jamming UpLink is easier by beaming directly at the satellites' receiver antennas. Jammers can use beam steering too.
  - xoa 3y ago
    Even ignoring a number of other tricks it could be using: >Jammers can use beam steering too. Beam steering doesn't make the beams curve though. The satellites know where the terminals are, and last I checked they do 8 or 16 beams and current beam spot size is 22km in diameter (and set to shrink with full size v2 and future, that's key to improving density of service). Which means your jammer would need to be tracking the right satellites without help from the satellites themselves (unlike real terminals), and within 22km (or far, far less, and on the correct side of the cell) of the terminal. I invite you to compare that to the range of basic 155mm artillery, GMLRS missiles, JDAMs, HARMs, or other such weapon systems, and remember we're talking about this in a military context. Is a jammer that has to be so close it gets destroyed right away militarily significant?

baq 3y ago

I agree. A more precise statement would be - as of now, Russia does not have the tech to jam it. They must be working on it and same for the Chinese, but for now, we haven't had any evidence that jamming is operationally deployed.

xoa 3y ago

Jamming ultimately works by known physics though, and Starlink seems like inherently an incredibly tough thing to jam (even ignoring anything in the future like optical). It's very high frequency, in LEO, using phase arrays and electronic steering. That makes for something that's highly directional, fairly tight beams, fairly strong signal, that are heading up into the sky (in a military context meaning anything trying to get between you and the sats is right above your SAMs/AA/fighter screens), moving very fast, with the built-in (needed anyway) ability to near instantly jump between satellites in different directions of the sky. That's a big list of fundamental physical challenges that omnidirectional low frequency radio or single HEO sats or the like just don't have. It will likely not even be reasonable for a long while to shoot down the constellation (retaliation aside). SpaceX's launch and mass manufacture costs are already cheaper than anyone and Starship will take that down another order of magnitude or more. Starlink sats will be cheaper than ASAT missiles, and orbiting low enough that atmospheric drag means Kessler Syndrome is not a concern either. Attacking the launch site(s) means attacking the continental USA. It seems to add up to a pretty dang hardened looking system? Cyberattacks, sabotage and so on could be real concerns, but to jam a tight beam phased array looking at very specific spots for signal from 10-100 miles away looks hard from a physics point of view. And of course any powerful jammer will by definition be an absolute magnet for HARMs. The US takes SEAD/DEAD very seriously and is thus pretty heavily equipped for that.

lr1970 3y ago
> Jamming ultimately works by known physics though, and Starlink seems like inherently an incredibly tough thing to jam (even ignoring anything in the future like optical). Jamming DownLink is certainly difficult especially if ground terminal uses receiver beam steering and pointing upwards. Jamming UpLink is easier by beaming directly at the satellites' receiver antennas. Jammers can use beam steering too.
- xoa 3y ago
  Even ignoring a number of other tricks it could be using: >Jammers can use beam steering too. Beam steering doesn't make the beams curve though. The satellites know where the terminals are, and last I checked they do 8 or 16 beams and current beam spot size is 22km in diameter (and set to shrink with full size v2 and future, that's key to improving density of service). Which means your jammer would need to be tracking the right satellites without help from the satellites themselves (unlike real terminals), and within 22km (or far, far less, and on the correct side of the cell) of the terminal. I invite you to compare that to the range of basic 155mm artillery, GMLRS missiles, JDAMs, HARMs, or other such weapon systems, and remember we're talking about this in a military context. Is a jammer that has to be so close it gets destroyed right away militarily significant?