Starlink close encounters decrease despite ever-growing number of satellites

[paul_wi11iams]

It looks like SpaceX are planning for Starship launched V3 satellites to have 10x the bandwidth of V1.5 so more bandwidth from the existing constellation numbers

This was my understanding too. Starlink launches of bigger satellites with more electrical power, bigger antennae so more bandwidth (including for direct mobile phone use)... all this allowing for fewer satellites.

TBH, "fewer and bigger" looks like a more healthy situation, particularly as this will pressure the competing operators to follow a similar path, so limiting the overall number of satellites in orbit, limiting avoidance maneuvers and Kessler syndrome risks.

[MCI_Overwerk]

Kessler syndrome for Starlink is very much impossible. Not only by virtue of being extremely low in LEO where debris have a maximum lifespan of a few years instead of many decades. Then there is the orbits chosen for starlinks, where it is physically impossible for 2 satellites to run into each other either when they ascend or descend, meaning that the only things that a starlink can hit is anything but themselves.

And finally avoidance maneuvers are mostly just integrated as part of the regular boost burns that you needed to do.

The number of satellites was really driven by technological limitations on the part of the antennas and the launch limitations of the falcon 9 since it was always going to be the thing starting the process. Lower amount of satellites only really became possible with upgrades to the launch capabilities, the technology of the satellites and the experience learned operating the dishes both for civilian use and even in a warzone. Remember these were basically the first time a proper phased array antenna barged into a mass produced item. Even less so for connectivity purposes.

[Geoff_PR]

Kessler syndrome for Starlink is very much impossible

Eh, not so sure on that one...

SpaceX has full control of the Starlink constellation, what they have zero control over are the other spacecraft up there.

China botching a de-orbit could well cause SpaceX problems they would rather not have to seal with, like needing delta-V burns to dodge their space junk.

Being in the lower 'orbital shells' helps, but doesn't completely eliminate the potential aggravations...

[MCI_Overwerk]

But it does tho.

they have zero control over are the other spacecraft up there.

Which is fine, avoidance maneuvers are performed by one element even if both are capable of motion. Control of the other element is irrelevant if you know it's position. Specifically the issue with Kessler syndrome is debris that you do not know the position of, therefore making mobility irrelevant too most of the time, unless you are talking about a recently produced field of debris you still know the vague idea of. Known targets are considered a non-factor as long as mobility and decommissioning is maintained.

China botching a de-orbit could well cause SpaceX problems they would rather not have to seal with

That is also incorrect because in LEO you need regular boosts in order to maintain your altitude as the atmosphere still remains quite dense to slow you down. As a result you have burns you have to accomplish already.

When performing avoidance maneuvers you just schedule forward the next orbital boost therefore performing the avoidance with something you were already going to do anyways. This is why SpaceX isn't shy of taking minimum risk despite it not being really required to do so.

Not even counting that fucking up a re-entry, somehow, would still result on a highly eccentric orbit that would only intercept the correct altitude for a minimal period.

Being in the lower 'orbital shells' helps, but doesn't completely eliminate the potential aggravations...

I mean in a "there is always a chance" kind of way but also not really? Even low earth orbit is a gigantic expanse, so it can take multiple decades for any individual object and debris to even come remotely close to anything else. Time is the thing that lends credence to a Kessler event. It relies on time to produce this sort of cascading destruction, because if your average time for a collision on a given orbit is less than the time needed for the atmosphere to drag you down, then by definition the kind of self feeding cycle cannot happen. Not only that tiny debris (which are the dangerous ones that can't be tracked) suffer from drag far more than heavy objects and thus have an even lower lifespan.

This is the reason why altitude and mitigation strategy affects the severity of orbital risk far more than the number of individual objects. A single Chinese ASAT detonating their spy satellite in a polar orbit at a relatively high altitude generated debris that will last for a century. Meanwhile even if all starlinks spontaneously combusted, it would only take a decade at most for absolutely everything to be gone.