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>>There aren't enough anti satellite missiles in the world to make a dent, it would cost trillions to manufacture enough Few big nukes are enough to take out a

>>There aren't enough anti satellite missiles in the world to make a dent, it would cost trillions to manufacture enough Few big nukes are enough to take out all satellites.

modeless 1y ago
I don't believe this is true. And of course detonating nukes in space would be an act of war against the whole world.
- baq 1y ago
  nukes optimized for EMP may be able to do this just fine. https://en.wikipedia.org/wiki/Nuclear_electromagnetic_pulse https://en.wikipedia.org/wiki/Nuclear_electromagnetic_pulse
  - modeless 1y ago
    I'm aware of the existence of the EMP weapon concept. I doubt its effectiveness against modern satellites in LEO at long range. That very article says "The damaging effects on orbiting satellites are usually due to factors other than EMP". Also "for equipment to be affected, the weapon needs to be above the visual horizon". Given how low Starlink orbits and the fact that they are dispersed evenly over the whole Earth, the number of weapons you would need to detonate just to ensure line of sight to every satellite at a range short enough to be effective is absolutely enormous.
    - baq 1y ago
      digging a bit deeper, apparently most damage is coming from irradiated material interacting with solar panels of satellites passing through the cloud. sounds like it'll work, just not immediately and not necessarily via an actual EMP.
    - ianburrell 1y ago
      Nukes produce lots of gamma and x-rays. On Earth, those are absorbed to produce the fireball. In LEO, some are absorbed by upper atmosphere to make EMP. In space, they are radiation. Except for military satellites like GPS, most satellites aren't hardened to deal with that much radiation. My guess is that the range would be thousands of miles.
      - oskarkk 1y ago
        I wondered how much energy could pass through some area 1000 miles away from the explosion, so I made some rough calculations. Assumption: all energy of the nuclear explosion is radiation uniform in every direction. The energy E would be spreading in a sphere with area 4*pi*R^2. Area A being a part of that sphere would capture E*A/(4*pi*R^2) of energy. So with: energy E = 209 PJ (Tsar bomba for an extreme example) area A = 1 m^2 radius of the sphere R = 1000 miles (1609 km) That would give: 2.09 * 10^17 J * 1 m^2 / (4 * pi * (1.609 * 10^6 m) ^ 2) = 6.4 kJ So at the distance of 1000 miles an 1 m^2 object would be exposed to 6.4 kJ of radiation. I don't know how destructive would that be. That energy would be equivalent to 6 seconds of sun irradiating a 1 m^2 area above the Earth's atmosphere, but of course sun's radiation is less dangerous (very little gamma/x-ray), and all of that radiation would be almost instant. From what I'm reading about high-altitude nuclear testing, it can cause artificial radiation belts around the Earth (composed of high-energy electrons). I think that may be more dangerous to satellites at distances like 1000 miles (or at any distance) than the immediate gamma/x-ray radiation.
        ianburrell 1y ago
        Radiation is measured in gray, which is 1 J absorbed by 1 kg. I can't find the conversion between flux to absorbed dose. 5 gray is fatal. If even a fraction of that energy is absorbed, it would be fatal. I found that satellites get 100-1000 rad per year. Getting that much in a moment would cause problems.
        oskarkk 1y ago
        So, given that human body area viewed from the front is around 0.5 m^2, then a 70 kg human in space 1000 miles from the explosion would get 6.4 kJ * 0.5 / 70 kg = 45 gray. That would mean that even being a couple thousand miles away could be fatal. But that's assuming 100% of Tsar Bomba energy would be ionizing radiation, I don't know what % would that be in reality.
xoa 1y ago
>Few big nukes are enough to take out all satellites. Um, no. Not even vaguely remotely. "Thousands of satellites" is a lot by historical human space standards, but compare that to the number of cars you see every day and then remember these are spread out over an area bigger then the surface of the entire planet. Don't be fooled by the simulation maps you can find online, where the satellites and tracks are shown thousands of times bigger then they would be to scale because otherwise they couldn't be seen. They are very, very far apart. Even on the ground, "a few big nukes" wouldn't do diddly. And nukes do less, not more, damage in space. A lot of the damage enhancement effects of nukes comes from their interaction with atmosphere. In a vacuum, it's only direct radiation which falls by the square of the distance, and satellites are of course designed to handle plenty of thermal and ionizing radiation all the time already by virtue of being designed for space. But Starlink sats aren't so high that Kessler syndrome is a concern either, there's plenty of atmospheric drag to bring debris down without active boosting. GP is correct and I don't understand the downvotes: as far as physical resilience goes the Starlink constellation is a pretty damn hard target on an absolute basis, even before we get into the geopolitics of some country trying to shoot down US property that is also a US strategic asset.
- baq 1y ago
  > Starfish Prime caused an electromagnetic pulse (EMP) that was far larger than expected, so much larger that it drove much of the instrumentation off scale, causing great difficulty in getting accurate measurements. The Starfish Prime electromagnetic pulse also made those effects known to the public by causing electrical damage in Hawaii, about 900 miles (1,450 km) away from the detonation point, knocking out about 300 streetlights, setting off numerous burglar alarms, and damaging a telephone company microwave link. The EMP damage to the microwave link shut down telephone calls from Kauai to the other Hawaiian Islands. https://en.wikipedia.org/wiki/Starfish_Prime https://en.wikipedia.org/wiki/Starfish_Prime
  - xoa 1y ago
    Yes, very good you're capable of a simplistic wikipedia search. Now I'd like you to try thinking about the paragraph you just linked for a moment: is "Hawaii", the "300 streetlights", "numerous burglar alarms", and a "microwave link" in the atmosphere (and on the ground, or indeed literally the ground) or in Earth orbit? If you read further, you'll find that the mechanism of generation involves the interaction of the gamma ray emissions with the atmosphere and Earth's magnetic field, that at 500km+ the effect are is reduced, and then find that in your example of Starfish Prime the primary damage to the satellites it affected was not due to EMP at all but rather because the test created radiation belts that damaged solar panels as satellites passed through. This would reduce design lifetime but isn't an immediate killer of everything. You'd need far more then a couple of nukes. Of course, purposefully detonating nuclear weapons to create large scale NEMP effects might well still disrupt Starlink to the degree that it'd effect any piece of ground electronics, because the ground effects would be far, far worse. The satellite constellation could be ok enough to still be functional at reduced capacity, but if terminals and ground stations get toasted that's not immediately helpful. But that directly leads, again, to the fact that you're talking about LAUNCHING A NUCLEAR WAR ON THE ENTIRE WORLD here. No internet is going to be doing very well! So yes: Starlink is pretty darn robust.

>>There aren't enough anti satellite missiles in the world to make a dent, it would cost trillions to manufacture enough Few big nukes are enough to take out all satellites.

modeless 1y ago

I don't believe this is true. And of course detonating nukes in space would be an act of war against the whole world.

baq 1y ago
nukes optimized for EMP may be able to do this just fine. https://en.wikipedia.org/wiki/Nuclear_electromagnetic_pulse https://en.wikipedia.org/wiki/Nuclear_electromagnetic_pulse
- modeless 1y ago
  I'm aware of the existence of the EMP weapon concept. I doubt its effectiveness against modern satellites in LEO at long range. That very article says "The damaging effects on orbiting satellites are usually due to factors other than EMP". Also "for equipment to be affected, the weapon needs to be above the visual horizon". Given how low Starlink orbits and the fact that they are dispersed evenly over the whole Earth, the number of weapons you would need to detonate just to ensure line of sight to every satellite at a range short enough to be effective is absolutely enormous.
  - baq 1y ago
    digging a bit deeper, apparently most damage is coming from irradiated material interacting with solar panels of satellites passing through the cloud. sounds like it'll work, just not immediately and not necessarily via an actual EMP.
  - ianburrell 1y ago
    Nukes produce lots of gamma and x-rays. On Earth, those are absorbed to produce the fireball. In LEO, some are absorbed by upper atmosphere to make EMP. In space, they are radiation. Except for military satellites like GPS, most satellites aren't hardened to deal with that much radiation. My guess is that the range would be thousands of miles.
    - oskarkk 1y ago
      I wondered how much energy could pass through some area 1000 miles away from the explosion, so I made some rough calculations. Assumption: all energy of the nuclear explosion is radiation uniform in every direction. The energy E would be spreading in a sphere with area 4*pi*R^2. Area A being a part of that sphere would capture E*A/(4*pi*R^2) of energy. So with: energy E = 209 PJ (Tsar bomba for an extreme example) area A = 1 m^2 radius of the sphere R = 1000 miles (1609 km) That would give: 2.09 * 10^17 J * 1 m^2 / (4 * pi * (1.609 * 10^6 m) ^ 2) = 6.4 kJ So at the distance of 1000 miles an 1 m^2 object would be exposed to 6.4 kJ of radiation. I don't know how destructive would that be. That energy would be equivalent to 6 seconds of sun irradiating a 1 m^2 area above the Earth's atmosphere, but of course sun's radiation is less dangerous (very little gamma/x-ray), and all of that radiation would be almost instant. From what I'm reading about high-altitude nuclear testing, it can cause artificial radiation belts around the Earth (composed of high-energy electrons). I think that may be more dangerous to satellites at distances like 1000 miles (or at any distance) than the immediate gamma/x-ray radiation.
      - ianburrell 1y ago
        Radiation is measured in gray, which is 1 J absorbed by 1 kg. I can't find the conversion between flux to absorbed dose. 5 gray is fatal. If even a fraction of that energy is absorbed, it would be fatal. I found that satellites get 100-1000 rad per year. Getting that much in a moment would cause problems.
        oskarkk 1y ago
        So, given that human body area viewed from the front is around 0.5 m^2, then a 70 kg human in space 1000 miles from the explosion would get 6.4 kJ * 0.5 / 70 kg = 45 gray. That would mean that even being a couple thousand miles away could be fatal. But that's assuming 100% of Tsar Bomba energy would be ionizing radiation, I don't know what % would that be in reality.

xoa 1y ago

>Few big nukes are enough to take out all satellites. Um, no. Not even vaguely remotely. "Thousands of satellites" is a lot by historical human space standards, but compare that to the number of cars you see every day and then remember these are spread out over an area bigger then the surface of the entire planet. Don't be fooled by the simulation maps you can find online, where the satellites and tracks are shown thousands of times bigger then they would be to scale because otherwise they couldn't be seen. They are very, very far apart. Even on the ground, "a few big nukes" wouldn't do diddly. And nukes do less, not more, damage in space. A lot of the damage enhancement effects of nukes comes from their interaction with atmosphere. In a vacuum, it's only direct radiation which falls by the square of the distance, and satellites are of course designed to handle plenty of thermal and ionizing radiation all the time already by virtue of being designed for space. But Starlink sats aren't so high that Kessler syndrome is a concern either, there's plenty of atmospheric drag to bring debris down without active boosting. GP is correct and I don't understand the downvotes: as far as physical resilience goes the Starlink constellation is a pretty damn hard target on an absolute basis, even before we get into the geopolitics of some country trying to shoot down US property that is also a US strategic asset.

baq 1y ago
> Starfish Prime caused an electromagnetic pulse (EMP) that was far larger than expected, so much larger that it drove much of the instrumentation off scale, causing great difficulty in getting accurate measurements. The Starfish Prime electromagnetic pulse also made those effects known to the public by causing electrical damage in Hawaii, about 900 miles (1,450 km) away from the detonation point, knocking out about 300 streetlights, setting off numerous burglar alarms, and damaging a telephone company microwave link. The EMP damage to the microwave link shut down telephone calls from Kauai to the other Hawaiian Islands. https://en.wikipedia.org/wiki/Starfish_Prime https://en.wikipedia.org/wiki/Starfish_Prime
- xoa 1y ago
  Yes, very good you're capable of a simplistic wikipedia search. Now I'd like you to try thinking about the paragraph you just linked for a moment: is "Hawaii", the "300 streetlights", "numerous burglar alarms", and a "microwave link" in the atmosphere (and on the ground, or indeed literally the ground) or in Earth orbit? If you read further, you'll find that the mechanism of generation involves the interaction of the gamma ray emissions with the atmosphere and Earth's magnetic field, that at 500km+ the effect are is reduced, and then find that in your example of Starfish Prime the primary damage to the satellites it affected was not due to EMP at all but rather because the test created radiation belts that damaged solar panels as satellites passed through. This would reduce design lifetime but isn't an immediate killer of everything. You'd need far more then a couple of nukes. Of course, purposefully detonating nuclear weapons to create large scale NEMP effects might well still disrupt Starlink to the degree that it'd effect any piece of ground electronics, because the ground effects would be far, far worse. The satellite constellation could be ok enough to still be functional at reduced capacity, but if terminals and ground stations get toasted that's not immediately helpful. But that directly leads, again, to the fact that you're talking about LAUNCHING A NUCLEAR WAR ON THE ENTIRE WORLD here. No internet is going to be doing very well! So yes: Starlink is pretty darn robust.