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SpaceX lowering orbits of 4,400 Starlink satellites for safety's sake

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Re: SpaceX lowering orbits of 4,400 Starlink satellites for safety's sake

#71

Post by NetMageSCW »

GuB-42 wrote: post #29
xxs wrote: post #3

Earlier quoted context omitted.

[flagged]

What kind of pictures can starlink would take? When I look at pictures of starlink satellites, I don't see a camera. Maybe they have one, but if we can't see it, it is most likely useless for observation, except for taking pretty pictures of the Earth, or maybe other passing satellites. Spy satellites are more like space telescopes, but pointed at the Earth. As an example, Hubble is designed after a spy satellite, th…

Perhaps Starlink can not (or wasn’t designed for it) but Starshield includes cameras and other sensors on some of its satellites.

Re: SpaceX lowering orbits of 4,400 Starlink satellites for safety's sake

#72

Post by NetMageSCW »

bell-cot wrote: post #8
Jean-Papoulos wrote: post #2

From a comment : >The first move in the coming WWIII, where the emperors try to expand their empires militaril,y will be to wipe out any orbit with Starlink satellites. I find this highly unlikely, given Starlink is soon to reached 10k satellites and will continue to grow. Why expand 10 000 ballistic missiles to bring down one of many communications networks ?

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.…

The BB idea doesn’t really work either- if they are in orbit they circle with the satellites and don’t hit anything, if they are at different speeds they are in different orbits and fly above and below the satellites and miss, if they cross the orbit SpaceX just moves the satellites to miss.

Re: SpaceX lowering orbits of 4,400 Starlink satellites for safety's sake

#73

Post by NetMageSCW »

aucisson_masque wrote: post #7

There are so many satellites in orbit that there is a pretty good chance that if even one was to be hit by something and explode in many pieces, it would crash another one and then another one until there is nothing left. The nasa is pretty scared of it, so is SpaceX.

There is no chance at all of that happening, and especially not at the orbital height of Starlink.

Re: SpaceX lowering orbits of 4,400 Starlink satellites for safety's sake

#74

Post by pixelpoet »

NetMageSCW wrote: post #68
TOMDM wrote: post #4

Earlier quoted context omitted.

Because Kessler syndrome means you don't need to hit all 10k yourself. Lowering the orbits just means that we get back to normal faster, not that the it's impossible.

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.

Re: SpaceX lowering orbits of 4,400 Starlink satellites for safety's sake

#75

Post by childintime »

notahacker wrote: post #63
ben_w wrote: post #38

Earlier quoted context omitted.

> Hard to see how the repositioning appreciably alters this risk, since there are still thousands of satellites in the same plane to get hit by shrapnel from intentionally caused collisions, and the satellites in the lower orbit aren't invulnerable to it either Yes, but the lower the orbit, the faster atmospheric drag (which isn't zero, just low) cleans up a cascade.

Feel like I'm repeating myself here, but they're moving less than half of them , which is going to have a negligible impact on a state with sufficient ASAT weapons' ability to create a massive mess with the many thousands of Starlink satellites operating in their original plane. Not even like the satellites in the lowest orbit are insulated from the effects of debris cascades set off in higher reaches of LEO either P…

It is the difference between optimization and unacceptable risks. Unacceptable risks make you act, they create a leitmotiv, and you don't seem to get that. So you talk about other motives, while ignoring the potentially main one.

Space no longer is a friendly place, it is the battle field of the future. SpaceX is a major military power in ascent, Musk is richer than many nations already, and he'll be in the supervillain category soon, and alone in actual physical power. He sits between the nations as a different entity in nature. It's happening in front of your eyes but you don't see it. That's why you are repeating yourself, as if we didn't see what you see. You speak about a technical motive we all see, as if only you see it. We all see that, it's trivial given the subject, and I mentioned it. Maybe we're not as stupid as you think we are, "teacher".

Re: SpaceX lowering orbits of 4,400 Starlink satellites for safety's sake

#76

Post by gehwartzen »

goku12 wrote: post #53
jdiez17 wrote: post #12

Earlier quoted context omitted.

You would likely need at least one per orbital plane, of which there are about 24.

Blowing up something in the same orbit as the targets isn't an effective strategy. The explosion disperses the fragments into different orbits that intersect the original orbit only at one or two points. And even if some of those fragments find their targets, the collision velocity will be low (relatively slow). It will be like getting hit with with shrapnels from a grenade. Depending on how they collide, the target…

I imagine you could just send a rocket to the specific orbit and just start metering out 100s of thousands of small steel (or whatever) BBs like seeding a yard; seeding a Kessler event.

Something just a bit bigger than:

https://en.wikipedia.org/wiki/Project_West_Ford

Re: SpaceX lowering orbits of 4,400 Starlink satellites for safety's sake

#77

Post by laughing_man »

ben_w wrote: post #43
Jean-Papoulos wrote: post #2

From a comment : >The first move in the coming WWIII, where the emperors try to expand their empires militaril,y will be to wipe out any orbit with Starlink satellites. I find this highly unlikely, given Starlink is soon to reached 10k satellites and will continue to grow. Why expand 10 000 ballistic missiles to bring down one of many communications networks ?

Looking at the price of industrial lasers, right now the only thing stoping a random 3rd world terrorist cell from being able to afford to destroy all of them is the adaptive optics to compensate for atmospheric turbulence. Well, that and the fact that so much of the stuff on Amazon etc. that's listed as "welding laser" is actually a soldering iron.

When people attack satellites with lasers, what they're trying to do is blind surveillance sats. To actually physically damage a satellite would take enormous amounts of power and accurate tracking tied into powerful radars. That's something a state might do, but too many resources are involved for terrorists.

Re: SpaceX lowering orbits of 4,400 Starlink satellites for safety's sake

#78

Post by laughing_man »

pandemic_region wrote: post #44
frumiousirc wrote: post #42

Earlier quoted context omitted.

Eject mass in the forward direction of its current tangent of motion. Slow down to go down.

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.

Re: SpaceX lowering orbits of 4,400 Starlink satellites for safety's sake

#79

Post by laughing_man »

aucisson_masque wrote: post #7

There are so many satellites in orbit that there is a pretty good chance that if even one was to be hit by something and explode in many pieces, it would crash another one and then another one until there is nothing left. The nasa is pretty scared of it, so is SpaceX.

At that altitude the pieces will deorbit in less than a few months.

Re: SpaceX lowering orbits of 4,400 Starlink satellites for safety's sake

#80

Post by impossiblefork »

laughing_man wrote: post #77
ben_w wrote: post #43

Earlier quoted context omitted.

Looking at the price of industrial lasers, right now the only thing stoping a random 3rd world terrorist cell from being able to afford to destroy all of them is the adaptive optics to compensate for atmospheric turbulence. Well, that and the fact that so much of the stuff on Amazon etc. that's listed as "welding laser" is actually a soldering iron.

When people attack satellites with lasers, what they're trying to do is blind surveillance sats. To actually physically damage a satellite would take enormous amounts of power and accurate tracking tied into powerful radars. That's something a state might do, but too many resources are involved for terrorists.

I don't think that's necessarily true. I think with modern lasers the power to get permanent damage is there.

I don't think powerful radars are required either. The satellites will probably reflect the laser. At 4000 km this is 26 ms, so you would probably be able to use the laser itself for the adjustments.

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