2 ms·

I'm not sure how exactly they are making these calculations but I just don't see it. Both Reflect and SpaceX are targeting SSO orbits where they are only reflec

I'm not sure how exactly they are making these calculations but I just don't see it. Both Reflect and SpaceX are targeting SSO orbits where they are only reflecting for an hour or two at sunset. That isn't true of Starlink, but that constellation is already up there and if its fine right now, I don't see it getting much worse as the materials on it get refined to be less problematic. More regulations would just have the result of cementing a monopoly for Spacex.

ben_w 3mo ago
All satellites in LEO only show up at close to sunset (and sunrise): When they're away from the terminator, they're either on the sun-side, and hence you can't see them for all the blue sky around them, or the night-side, in which case you can't see them because they're not lit by the sun because the Earth is in the way. I'm still checking the maths on how bright a million satellites in a terminator-following SSO would be. I'm getting very big numbers. But then, the (vague and aspirational) suggestions I'm seeing right now for SpaceX are in the 120 kW range, which is huge, and lining up a million of those is enough for a contiguous ring just under 10 meters wide (how much under is "just under" depends both on how efficient the PV is and how high in LEO you go). Regardless of if they're all in one orbit or spread over in multiple orbits at different shells that are all terminator-following SSO, from the ground you're getting a train of things with somewhat higher brightness than the ISS, with a fairly small apparent separation that (I tentatively think) becomes less than your eyes can resolve at at least one point in the sky (if there's say 50 shells, where those 50 get close to crossing).
mirashii 3mo ago
> that constellation is already up there and if its fine right now A lot of astronomers disagree.
- criddell 3mo ago
  And a lot of starlink customers agree. How can this be resolved?
  - estearum 3mo ago
    Easy: Starlink should internalize its negative externalities. As a first pass, we can estimate how much astronomy infrastructure ($$$) is negatively impacted ($$$) by Starlink and pass those costs to them.
    - brookst 3mo ago
      And new astronomy infra should obviously pay Starlink for the mitigations they put in place, right? Maybe water rights really are the best model for this, but it’s a terrible model as demonstrated everywhere there are water rights. I’d like to think there’s a more sensible approach.
      - estearum 3mo ago
        Why would new astronomy infra pay for the Starlink's negative externalities? Yeah it turns out that "divvy up finite resource" is actually just an intrinsically nightmarish problem when it's something no one intrinsically owns, didn't create, but needs nonetheless, like water and land.
        brookst 3mo ago
        Well if you build a new telescope where there are already satellites doing their business with no objections, shouldn’t you be required to pay for changes in their business, if the principle is first claimant?
deleted 3mo ago
[deleted]

ben_w 3mo ago

All satellites in LEO only show up at close to sunset (and sunrise): When they're away from the terminator, they're either on the sun-side, and hence you can't see them for all the blue sky around them, or the night-side, in which case you can't see them because they're not lit by the sun because the Earth is in the way. I'm still checking the maths on how bright a million satellites in a terminator-following SSO would be. I'm getting very big numbers. But then, the (vague and aspirational) suggestions I'm seeing right now for SpaceX are in the 120 kW range, which is huge, and lining up a million of those is enough for a contiguous ring just under 10 meters wide (how much under is "just under" depends both on how efficient the PV is and how high in LEO you go). Regardless of if they're all in one orbit or spread over in multiple orbits at different shells that are all terminator-following SSO, from the ground you're getting a train of things with somewhat higher brightness than the ISS, with a fairly small apparent separation that (I tentatively think) becomes less than your eyes can resolve at at least one point in the sky (if there's say 50 shells, where those 50 get close to crossing).

mirashii 3mo ago

> that constellation is already up there and if its fine right now A lot of astronomers disagree.

criddell 3mo ago
And a lot of starlink customers agree. How can this be resolved?
- estearum 3mo ago
  Easy: Starlink should internalize its negative externalities. As a first pass, we can estimate how much astronomy infrastructure ($$$) is negatively impacted ($$$) by Starlink and pass those costs to them.
  - brookst 3mo ago
    And new astronomy infra should obviously pay Starlink for the mitigations they put in place, right? Maybe water rights really are the best model for this, but it’s a terrible model as demonstrated everywhere there are water rights. I’d like to think there’s a more sensible approach.
    - estearum 3mo ago
      Why would new astronomy infra pay for the Starlink's negative externalities? Yeah it turns out that "divvy up finite resource" is actually just an intrinsically nightmarish problem when it's something no one intrinsically owns, didn't create, but needs nonetheless, like water and land.
      - brookst 3mo ago
        Well if you build a new telescope where there are already satellites doing their business with no objections, shouldn’t you be required to pay for changes in their business, if the principle is first claimant?

deleted 3mo ago

[deleted]