Mastodawn

Kessler Syndrome update:
They report 144,000 collision avoidance maneuvers across the whole constellation in Dec-May. That's about one maneuver every 2 minutes.

Every 2 minutes there's a chance for a mistake that would lead to a very bad day in orbit. And as this paper shows (with Dr. Kessler himself as a co-author!), a very bad day at that altitude would lead to a runaway collisional cascade. No more satellites at that altitude! https://conference.sdo.esoc.esa.int/proceedings/sdc9/paper/305/SDC9-paper305.pdf

SpaceX spends a lot of time saying how safe they are with their threshhold for collision avoidance maneuvers, which is great. But they HAVE to be! With those densities, high collision probability conjunctions happen many times per day. It is impressive that they have been operating perfectly, but how long do they think they can keep this up with zero mistakes?

And what if all the Starlinks are not all fully burning up as they claim? That's a lot of stuff hitting the ground...

Coincidentally, this great article just came out (that I got interviewed for) that really nicely summarizes the issues in orbit: https://www.smithsonianmag.com/science-nature/with-space-junk-on-the-rise-is-a-catastrophic-event-inevitable-180986907/

Weather_Rock_Wx Jul 3

@sundogplanets
That's a well-written article highlighting yet another concern in addition to dark and quiet skies. Thanks for sharing.

JevidL Jul 4

@sundogplanets “And they absolutely had this mentality of, ‘You just burn it up in the atmosphere and it’s gone. It’s fine, right?’ That’s really how they think about it.”

I know this is true. I know that *a lot* of people just think it disappears. It does nothing to make it easier for me to understand. Like, conservation of mass, people! 😫

xinit ☕Jul 3

@sundogplanets
I'm not sure which is worse - completely burning up in the atmosphere or not doing so. Both options are killing us.

Methylzero Jul 3

@xinit @sundogplanets balance it out with a mandatory extra payload of 10 kg of elemental sulfur on every LEO sat

Elliot Schlegelmilch Jul 3

@sundogplanets if KSP has taught me anything it's that it's impossible to achieve an exact orbit.

ROTOPE~1

Jul 3

@elliot @sundogplanets you just gotta git gud at eyeballing it

ScottMGS Jul 3

@sundogplanets Unfortunately, I think *they* think that since they've done it so far they can keep doing it forever. How they think they'll do when they have to dodge not only their huge constellation but Amazon's and China's (etc.), is anyone's guess. Especially if everyone starts locking down their orbital information like your post yesterday kind of implied!

Todd Heberlein (social)Jul 3

@ScottMGS @sundogplanets Is there a legal framework in place to address what happens if satellite collisions from one companies (i.e., Starlink) cause debris that damages satellites from another company (i.e., Kuiper/Amazon)?

ScottMGS Jul 4

@toddheberlein @sundogplanets This is *way* outside my area of expertise but the Outer Space Treaty (https://en.wikipedia.org/wiki/Outer_Space_Treaty) is the only thing I've heard of. Not sure it covers what you're asking but my understanding (based on what I read in A City on Mars by Kelly and @ZachWeinersmith) is that the country the space objects are launched from is legally? financially? responsible for damages caused but that might only apply to damages on Earth, not beyond it. But don't quote me on that!

Outer Space Treaty - Wikipedia

Prof. Sam Lawler Jul 4

@ScottMGS @toddheberlein Further reading: https://www.cambridge.org/core/books/who-owns-outer-space/960CCB0464744F845B09434D932699EC

Who Owns Outer Space?

Cambridge Core - Astronomy: General Interest - Who Owns Outer Space?

Cambridge Core

Weekend Editor Jul 3

Even if they *do* burn up, how much heavy metals are they delivering to the atmosphere each year?

Schroedinger Jul 3

@sundogplanets And I wonder what happens when they have 2 objects to avoid collision with? Do they cope?

It is just a disaster.

MidgePhoto Jul 4

Tangentially, Neal Stephenson included in his world building for SevenEves a program called Perambulator for swarming and avoiding collision.

In the second part of the book "5000 years later..." Perambulator is still doing that job - presumably having had some refactoring.

Vernor Vinge in A Deepness in the Sky has programmer archaeologist as one of the career paths, along with programmer at arms.

Done once right: should carry on.
Most things working have unfound flaws.
#SF

Dahie Jul 3

@sundogplanets did you write the thread on what Kessler-Syndrome would look like with a timeline description of the fireworks? I saw it a year ago here on mastodon, but didn't bookmark and don't remember the author :/

Daniel Pache⚓Jul 3

@dahie @sundogplanets there were some great posts by @mastodonmigration too: https://mastodon.online/@mastodonmigration/111033681573345249

Mastodon Migration (@mastodonmigration@mastodon.online)

@7leaguebootdisk@mindly.social @arstechnica@mastodon.social This is not true. They orbit at 550 km which is low earth orbit, but relatively high. The ISS for instance is at 420 km. The 5 year deorbit claim comes from a powered deorbit of the space craft. Unpowered spacecraft take 8 to 10 years if intact. However, once the Kessler collision cascade begins the spacecraft will be smashed apart and the bits will take between 5 and 25 years for their orbits to naturally decay. 1/3 #Musk #ISS #KesslerSyndrome #Starlink

Mastodon

Come On Giant Asteroid!Jul 3

https://youtu.be/wUdPHBiJCJI?feature=shared&t=26

Is there a pool on the date this will happen? Being a realist (some say "pessimist" but I reject that) this is about 98% inevitable in my completely made-up reality.

If someone hasn't built a system to automagically make these Mid Course Corrections, I don't see how humans can keep up.

Pigs in Space: Epic Mid-Course Correction | The Muppet Show

YouTube

GhostOnTheHalfShell Jul 3

So here's a question for you. If a cascade occurs, won't it tend to dramatically increase satellite junk, falling to earth along with all the environmental problems that causes?

And what kind of consequence will it bring to the night sky? We're talking about a dramatic increase in the amount of particulates floating around and lower earth orbit, or some such.

Duncan Jul 4

@GhostOnTheHalfShell @sundogplanets in the same vein, post Kessler syndrome would the large number of small particles at that height have any measurable effect on the amount of solar radiation reaching the earth’s surface?

Rue Mohr Jul 3

@sundogplanets @xkcd interstellar collision avoidance maneuvers.

RootWyrm 🇺🇦

Jul 4

@sundogplanets having done a lot of research on it myself, it's not just 'at that altitude.' It's "you will never go past that point ever again in your lifetime." And of course, to save money (and pretend that the speed of light is not a thing,) the Nazi company puts their junk in the lowest possible orbit.
So no more ISS. I hope you don't like anything geosynchronous either. And no moon for you, forget Mars.

vampirdaddy Jul 4

@sundogplanets
It also is not only
"no more satellites at that altitude"
but as most non-low-LEO satellites would have to pass that kesslered deathbelt: no more satellites. Period.
(ok, simplified)

Prof. Sam Lawler Jul 4

@vampirdaddy luckily a lot of the satellites at GEO are designed to last longer, so there would be some time with GEO satellites still?

vampirdaddy Jul 4

@sundogplanets
at least no more NEW satellites (or only with considerable risk).

Plus as shrapnell from collisions can reach higher orbits (mainly by adding collision impulse to the hit target, sobtracted from the imactor), there is a risk of expanding to lower and higher (Low) orbits.

Geosync should be mostly safe, though - until something there gets out of control.

Lauma Pret 🕸️Jul 4

@sundogplanets
If Kessler Syndrome happens, what do we lose in everyday sense of things? GPS and better weather prediction? Of course, it is going to be huuuge problem for science and space travel, I don't want to minimize that, but I wonder how it will look for layperson.

Prof. Sam Lawler Jul 4

@laumapret This is also something I need to understand better myself!

tlohde Jul 3

@sundogplanets natural infall rate! What a cool term. Silly question, but i presume there isn't a natural flux going the other way?

Feel silly for having written that down. Gravity is a one-way street. Right? And post.

Michael Busch Jul 3

@tlohde @sundogplanets

The Earth is massive enough that any ejecta from impactors stays on the planet (Mars is small enough that some rocks escape, so we have martian meteorites).

Earth does lose some gases from the atmosphere to space.

Michael Weiss Jul 3

@michael_w_busch @tlohde @sundogplanets and would lose much more to space if we didn't have the powerful magnetic field keeping most of the solar wind away.

One pretty compelling theory about Martian history is that Mars was much more earth-like until its magnetic field died. That allowed the solar wind to strip the atmosphere, and indirectly then the surface water, away.

Michael Busch Jul 3

@mweiss @tlohde

Mars' atmosphere loss was primarily because of its lower escape velocity and not its lack of magnetic field.

@michael_w_busch @tlohde @sundogplanets

Wm.son Jul 3

And I would hope so! Holding in gasses too long can give the planet cramps/earthquakes, right? 😎

<I'm leaving now to keep reading the thread and maybe learn a little something.>

Rí Rua, The.Jul 3

@sundogplanets evident a human filled out those de-orbit tables! So few of the cells are aligned @_@

Petra van Cronenburg Jul 3

@sundogplanets Do you have a reading tip for laypersons about the effects aluminum has in the atmosphere?
I'm often asked by people who have no idea about satellites and believe that "everything vanishes in the air".

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2024GL109280

simonbp Jul 3

@NatureMC @sundogplanets So, we don't actually know, it's a large scale experiment on what happens when you throw off the balance in the least-understood part of the atmosphere (it's common to hear people call the ionosphere "the ignorosphere").

But there are initial indications that aluminum damages the ozone layer. Meaning that all work around the world for decades to restore the ozone layer could be undermined by satellite trash in a few years.

@simonbp @NatureMC This article is maybe a bit more non-scientist-friendly: https://theconversation.com/thousands-of-satellites-are-due-to-burn-up-in-the-atmosphere-every-year-damaging-the-ozone-layer-and-changing-the-climate-251845

Thousands of satellites are due to burn up in the atmosphere every year – damaging the ozone layer and changing the climate

The number of satellites is exploding, and we still don’t have a fully safe way to dispose of them.

The Conversation

Petra van Cronenburg Jul 3

@sundogplanets This is great, exactly what I searched for (I can give the link to laypersons). Thank you very much! @simonbp

@sundogplanets @simonbp @NatureMC

Paul Sutton Jul 3

Thanks added to an expanding blog post to collate related content

Petra van Cronenburg Jul 3

@simonbp Thank you very much! @sundogplanets

Sylvhem Jul 3

@sundogplanets This is so incredibly irresponsible. How were Starlink ever authorised to operate?

Orb 2069 Jul 3

@Sylvhem @sundogplanets

... Authorized? IIRC, they're operating under the Uber model - bribe politicians, hire lawyers and only concede if you're bankrupted by the fight.

crazyeddie Jul 3

@Sylvhem @sundogplanets Bribes and a coup.

crazyeddie Jul 3

@sundogplanets No use worrying about my anti-antiperspirant then.

Pusher of Pixels Jul 3

@sundogplanets Thank you for covering this!

people have no idea the scale that's coming either. 8000 per year = 20 per day!

And that's *just* starlink, let alone Bezos, China and the EU's fleets.

leberschnitzel Jul 3

@sundogplanets I thought that starlinks are much lighter, I'm shocked that the Gen2 weight increased that much 😳

@leberschnitzel They are very sketchy about releasing numbers. The Gen2 numbers I've seen are 1250 kg each.

0x0 Jul 3

@sundogplanets
Laymaning here but it seems to me that a satellite designed as part of a LEO swarm should be a few kilograms, not cubesat but... small.
That's over a tonne. Could there be imperial confusion?
@leberschnitzel

Zimmie Jul 3

@sundogplanets Sounds an awful lot like “geoengineering”, a common right-wing conspiracy-nonsense boogeyman related to “chemtrails”.

CheapPontoon Jul 3

@sundogplanets
If we ever get a Kessler syndrome fireworks show, I hope #Elon happens to be in orbit at the time.

�Jul 3

@sundogplanets btw, did something happen there? i couldn't find any information https://mastodon.social/@sundogplanets/114603237298467208

Jack C.Jul 3

@sundogplanets dang, I really thought these things were smaller and lighter. 800kg really? Who would've thought that burning up space debris in the atmosphere wouldn't always be a low-impact solution 🙄 yikes

petur 😶🇺🇦🇵🇸🇹🇼Jul 3

@GandalfDG @sundogplanets Most re-entered sats were gen1 which are 'only' up to 306kg, with several gen2 (mini, 740kg) also coming down, and HELP us if full v2's will be launched (req starship) start coming down at 1250kg each 😳

wikipedia has a list of generations and weight
https://en.wikipedia.org/wiki/Starlink

Starlink - Wikipedia

Brandon Jul 3

@sundogplanets why on earth (uh, off earth) are they so bad at keeping satellites in orbit 🤔

foo ✅Jul 3

@brandonscript @sundogplanets Probably Elon thinks explosions are cool

Tim Nicholas Jul 3

@brandonscript @sundogplanets They're deliberately placed in very low orbits so that the latency to earth is minimised. But that means they experience a small amount of atmospheric drag which shows the down and drops them from orbit once they run out of fuel for their thrusters.

In other words, it is a deliberate design outcome. To them the only cost is getting them to space. The cost of them coming down is a burden for the commons.

Tim Nicholas Jul 3

@brandonscript @sundogplanets Hmm. Actually they aren't as low as I thought. Still a deliberate design outcome.