3 ms·

> you need to care what happens if all the different ones in your sky (above your horizon) target your location at the same time No, you don't need to, because

by T-A 5y ago

> you need to care what happens if all the different ones in your sky (above your horizon) target your location at the same time No, you don't need to, because they don't need to. >>> put them in a low orbit [...] worry about multiple orbit-to-ground beams being directed at the same spot >> >> That ellipsis is combining different scenarios. Only if you insist that "about half a dozen giant ground-station for half a dozen giant beams" is the limit for what can be put in geostationary orbit, which you now seem to acknowledge is not true.

ben_w 5y ago
I don’t understand how you can assert what you’re asserting, especially as you appear to be claiming to read my mind despite the paragraph break you cut with the ellipsis. Hypothetical scenario: 1000 satellites evenly arranged around geostationary orbit, each beaming 1 GW to a ground station. Now hackers point all the ones visible to NYC at NYC. How do you guarantee this does not happen? I can only think of two options: (1) small number of big satellites (down side being centralisation); (2) low orbit (downside being no nighttime power because they’re now in shade at local night). I say you must not allow this hypothetical to happen. This is a safely limit, and it never has anything to do with the volume of the orbit. It is still a limit.
- T-A 5y ago
  > Now hackers point all the ones visible to NYC at NYC. What you just did there is called moving the goalposts. The discussion up to that sentence was about constraints imposed by orbital geometry. You claimed incorrectly that the "limited" space available in geostationary orbit would allow "up to about half a dozen giant ground-station for half a dozen giant beams", concluded that it would therefore be necessary to use LEO instead (it's not), and (again incorrectly) jumped to the conclusion that this would necessarily imply multiple beams on the same target. Neither you nor anybody else said anything about sabotage. > This is a safely limit, and it never has anything to do with the volume of the orbit. Actually you just threw away your original argument and made up a whole new one. > How do you guarantee this does not happen? I don't. I also don't guarantee that terrorists won't fly airliners into skyscrapers or put a nuclear device in a container and ship it to New York's harbor. Yet we keep building skyscrapers, flying airliners and shipping containers across the world, despite the obvious risks, because the advantages of doing so outweigh those risks. The specific risk in question is not even all that hard to mitigate, especially when you're dealing with large stations in geostationary orbit, each targeting a limited set of fixed locations (which would be dedicated receiver arrays, not cities). You put fail-safes on station which are hardwired to track antenna orientation and shut down the beam if it strays from its target. Now all your hypothetical hackers can do is interrupt the beam until you regain control, which is irritating but nothing new: https://en.wikipedia.org/wiki/Ukraine_power_grid_hack https://en.wikipedia.org/wiki/Ukraine_power_grid_hack
  - ben_w 5y ago
    I am not going to make a further attempt to show you that my position is consistent or rephrase anything. If you are unable or unwilling to understand that all of my comments in this sub-thread are consistent, that there is no goalpost moving, and that I am demonstrating the flaws with each possible configuration and thereby excluding the whole, this conversion is over. You falsely claim I said this is about limited space. I didn’t use the word “limited” until now, and wrote of half a dozen orbital components right next to saying why it’s bad to have more, without claiming it was impossible. You falsely claim I’m moving the goalposts, when I said it was about safety of overlapping beams in first thing you replied to. In point of fact, the half-dozen number wouldn’t even be geostationary in the scenario I was envisioning, which ought to have been obvious from even a cursory moment’s thought. If you feel like working out what this scenario actually was instead of arguing against things I did not write, feel free, but I won’t bother looking much less replying. One misunderstanding is on me, but this many isn’t worth the effort.
    - T-A 5y ago
      >> You falsely claim I said this is about limited space. I didn’t use the word “limited” until now This is what you wrote: > put them in high orbit so they do useful things in local night, limiting you to a small total count planet-wide Do you seriously wish to claim this is not a statement about limited space? > You falsely claim I’m moving the goalposts, when I said it was about safety of overlapping beams Nobody is disputing that your original argument was about the safety of overlapping beams. You moved the goalposts when you replaced that argument, which was based on your incorrect understanding of orbital geometry, with one about intentional sabotage ("hackers point all the ones visible to NYC at NYC"). > In point of fact, the half-dozen number wouldn’t even be geostationary in the scenario I was envisioning, which ought to have been obvious from even a cursory moment’s thought. The article linked at the top of this page (you know, the thing we are supposed to be discussing) is about a development program which starts with a LEO demonstrator, followed by a larger MEO demonstrator, followed by GW-class stations in geosynchronous orbit. The latter are the standard commercial scenario which has been envisioned since the 70s. If you had another scenario in mind, you "forgot" to say so. Again. Even while confirming that the "limit is not how many physically fit in geostationary orbit — I agree that’s fine". > One misunderstanding is on me, but this many isn’t worth the effort. No problem, it was obvious from your first reply that you're not interested in a factual discussion.

by T-A 5y ago

ben_w 5y ago

I don’t understand how you can assert what you’re asserting, especially as you appear to be claiming to read my mind despite the paragraph break you cut with the ellipsis. Hypothetical scenario: 1000 satellites evenly arranged around geostationary orbit, each beaming 1 GW to a ground station. Now hackers point all the ones visible to NYC at NYC. How do you guarantee this does not happen? I can only think of two options: (1) small number of big satellites (down side being centralisation); (2) low orbit (downside being no nighttime power because they’re now in shade at local night). I say you must not allow this hypothetical to happen. This is a safely limit, and it never has anything to do with the volume of the orbit. It is still a limit.

T-A 5y ago
> Now hackers point all the ones visible to NYC at NYC. What you just did there is called moving the goalposts. The discussion up to that sentence was about constraints imposed by orbital geometry. You claimed incorrectly that the "limited" space available in geostationary orbit would allow "up to about half a dozen giant ground-station for half a dozen giant beams", concluded that it would therefore be necessary to use LEO instead (it's not), and (again incorrectly) jumped to the conclusion that this would necessarily imply multiple beams on the same target. Neither you nor anybody else said anything about sabotage. > This is a safely limit, and it never has anything to do with the volume of the orbit. Actually you just threw away your original argument and made up a whole new one. > How do you guarantee this does not happen? I don't. I also don't guarantee that terrorists won't fly airliners into skyscrapers or put a nuclear device in a container and ship it to New York's harbor. Yet we keep building skyscrapers, flying airliners and shipping containers across the world, despite the obvious risks, because the advantages of doing so outweigh those risks. The specific risk in question is not even all that hard to mitigate, especially when you're dealing with large stations in geostationary orbit, each targeting a limited set of fixed locations (which would be dedicated receiver arrays, not cities). You put fail-safes on station which are hardwired to track antenna orientation and shut down the beam if it strays from its target. Now all your hypothetical hackers can do is interrupt the beam until you regain control, which is irritating but nothing new: https://en.wikipedia.org/wiki/Ukraine_power_grid_hack https://en.wikipedia.org/wiki/Ukraine_power_grid_hack
- ben_w 5y ago
  I am not going to make a further attempt to show you that my position is consistent or rephrase anything. If you are unable or unwilling to understand that all of my comments in this sub-thread are consistent, that there is no goalpost moving, and that I am demonstrating the flaws with each possible configuration and thereby excluding the whole, this conversion is over. You falsely claim I said this is about limited space. I didn’t use the word “limited” until now, and wrote of half a dozen orbital components right next to saying why it’s bad to have more, without claiming it was impossible. You falsely claim I’m moving the goalposts, when I said it was about safety of overlapping beams in first thing you replied to. In point of fact, the half-dozen number wouldn’t even be geostationary in the scenario I was envisioning, which ought to have been obvious from even a cursory moment’s thought. If you feel like working out what this scenario actually was instead of arguing against things I did not write, feel free, but I won’t bother looking much less replying. One misunderstanding is on me, but this many isn’t worth the effort.
  - T-A 5y ago
    >> You falsely claim I said this is about limited space. I didn’t use the word “limited” until now This is what you wrote: > put them in high orbit so they do useful things in local night, limiting you to a small total count planet-wide Do you seriously wish to claim this is not a statement about limited space? > You falsely claim I’m moving the goalposts, when I said it was about safety of overlapping beams Nobody is disputing that your original argument was about the safety of overlapping beams. You moved the goalposts when you replaced that argument, which was based on your incorrect understanding of orbital geometry, with one about intentional sabotage ("hackers point all the ones visible to NYC at NYC"). > In point of fact, the half-dozen number wouldn’t even be geostationary in the scenario I was envisioning, which ought to have been obvious from even a cursory moment’s thought. The article linked at the top of this page (you know, the thing we are supposed to be discussing) is about a development program which starts with a LEO demonstrator, followed by a larger MEO demonstrator, followed by GW-class stations in geosynchronous orbit. The latter are the standard commercial scenario which has been envisioned since the 70s. If you had another scenario in mind, you "forgot" to say so. Again. Even while confirming that the "limit is not how many physically fit in geostationary orbit — I agree that’s fine". > One misunderstanding is on me, but this many isn’t worth the effort. No problem, it was obvious from your first reply that you're not interested in a factual discussion.