91–100 of 105 posts
Earlier quoted context omitted.
Stop trying to make Kessler syndrome a thing. Kessler syndrome isn’t a thing, and it will never be a thing. PS The original paper expects the cascade to take decades to centuries. No one can afford to shoot down Starlink except SpaceX.
Stop trying to boss people around, and just make your point with some citations.
Earlier quoted context omitted.
If it's WWIII, and you're using ballistic missiles against satellite constellations, then either: - You are not targeting individual satellites; you're setting off nuclear warheads in space, and relying on the EMP to disable all satellites within a large radius of the blast - https://en.wikipedia.org/wiki/Nuclear_electromagnetic_pulse or - You're nuking the ground-based command & control centers for those satellites.…
> - You're nuking the ground-based command & control centers for those satellites. Again, nothing like 10,000 missiles needed. With Starlink's peer-to-peer capabilities, hitting every single ground station and keeping the satellites from working through new ground stations may actually be quite difficult. Starlink orbits close enough that they're looking into offering LTE coverage from "space". You don't need a giant…
Yes-ish? I was thinking the command & control facilities - far scarcer than the (probably unmanned) StarLink-to-Internet Backbone connection ground stations.
> The moment you launch a nuke...
Yes-ish. The (great-)^n grandparent comment posited WWIII starting, and the nukes flying at scale. Between the widespread obliteration of ground-side infrastructure, ground-side EMP damage, and very likely EMP in space - I'd assume that Starlink would quickly go down. Plus, the ionosphere could become opaque to Starlink's radio frequencies. Finally, the ionosphere's upper layers might expand enough (due to nuclear detonations in or near space) that the orbits of the Starlink satellites started degrading very quickly.
With how easily any major space power could set off "small n" nukes in space during a major crisis, to knock out satellites - I would not rule someone doing so. The responsible parties need not claim responsibility. And sane leaders might hesitate to go full nuclear in response.
I think it's important to note that not all collisions are equally dangerous. Consider a sat on a polar orbit colliding with one on a equatorial orbit. Or two satellites on different directions. That is going to be spectacular. Otoh, these kind of collisions are unlikely and should be manageable by just assigning certain shells (say 5km) for every possible direction and orientation. If two Starlink satellites collide…
Not quite how it works, unfortunately. Once you've got even hundreds of satellites in non-equatorial orbits, trying to provide global coverage - their ground tracks very frequently cross each other. Even if they're all at the same orbital inclination. While those mostly won't be 90 degree crossings - the great majority will involve several km/s relative velocity. And you'd run out of (say) 5km LEO shells very quickly…
I get that 'probably safe' or '0.001% chance of destruction per day' is not very satisfying for an investment that cost millions, but everything always comes down to odds. None of these satellites are eternal, even if they're the only thing in their orbit.
Earlier quoted context omitted.
Not quite how it works, unfortunately. Once you've got even hundreds of satellites in non-equatorial orbits, trying to provide global coverage - their ground tracks very frequently cross each other. Even if they're all at the same orbital inclination. While those mostly won't be 90 degree crossings - the great majority will involve several km/s relative velocity. And you'd run out of (say) 5km LEO shells very quickly…
But the orbit is a minimum of about 50,000 kilometers, and the satellite is maybe a meter across. That's a very low probability of a collision per crossing. I get that 'probably safe' or '0.001% chance of destruction per day' is not very satisfying for an investment that cost millions, but everything always comes down to odds. None of these satellites are eternal, even if they're the only thing in their orbit.
Lower orbits > Increased atmospheric drag > More fuel expended to maintain orbit > Heavier sats due to more fuel > Increased launch cost per unit
Or even: Lower orbits > Increased atmospheric drag > Quicker orbit decay > Shorter lifespan of sats > More frequent launches
Forgive my Kerbal-based space knowledge here.
Earlier quoted context omitted.
So, for this they have a bit of expendable extra mass on board? What material is it, would it not cause even more debris then?
Satellites need thrusters for station keeping. Otherwise they drift out of their desired orbits over time.
Won't this make running Starlink more expensive? Lower orbits > Increased atmospheric drag > More fuel expended to maintain orbit > Heavier sats due to more fuel > Increased launch cost per unit Or even: Lower orbits > Increased atmospheric drag > Quicker orbit decay > Shorter lifespan of sats > More frequent launches Forgive my Kerbal-based space knowledge here.
> "As solar mininum approaches, atmospheric density decreases, which means the ballistic decay time at any given altitude increases — lowering will mean a >80% reduction in ballistic decay time in solar minimum, or 4+ years reduced to a few months," Nicolls wrote in his X post. "Correspondingly, the number of debris objects and planned satellite constellations is significantly lower below 500 km, reducing the aggregate likelihood of collision."
Earlier quoted context omitted.
If that's the only risk, sure. But there's modelling and observation that suggest the required number of ASAT weapons to cause a Kessler cascade is currently zero, i.e. we're already in the early stages of one. Because physics of orbital dynamics is less dramatic than shown in film, lowering orbits of satelites is an effective way to mitigate this.
> there is a pretty good chance Source?
https://conference.sdo.esoc.esa.int/proceedings/sdc9/paper/3...
Earlier quoted context omitted.
Stop trying to boss people around, and just make your point with some citations.
It's a reference to the "stop trying to make fetch happen" meme from the movie Mean Girls.
Earlier quoted context omitted.
But the orbit is a minimum of about 50,000 kilometers, and the satellite is maybe a meter across. That's a very low probability of a collision per crossing. I get that 'probably safe' or '0.001% chance of destruction per day' is not very satisfying for an investment that cost millions, but everything always comes down to odds. None of these satellites are eternal, even if they're the only thing in their orbit.
Is it still a small number when multiplied by the square of the number of satellites and the number of times they orbit each day?