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   Prof. Sam Lawler (sundogplanets@mastodon.social)'s status on Sunday, 15-Oct-2023 06:28:17 JST Prof. Sam Lawler

   Not worried enough about corporate over-development of orbit yet? New article: companies have now filed asking for a total of ONE MILLION satellites: https://www.science.org/doi/10.1126/science.adi4639

   Non-paywalled version here: https://www.outerspaceinstitute.ca/docs/One%20million%20(paper)%20satellites%20-%20Accepted%20Version%20.pdf

   There is no way we can have anywhere near one million satellites in orbit without going into full Kessler Syndrome and destroying everything in orbit - making satellite science, communication, and interplanetary exploration impossible for decades.

   • Embed this notice
     feld (feld@bikeshed.party)'s status on Sunday, 15-Oct-2023 21:51:23 JST feld

     in reply to
     If we do we end up with 1 million in orbit and we don't go 'full Kessler Syndrome' would you admit to being wrong?
   • Embed this notice
     Dr. Alexandre Santerne 🌍 (alexsanterne@astrodon.social)'s status on Tuesday, 17-Oct-2023 22:05:42 JST Dr. Alexandre Santerne 🌍

     in reply to

     • Dr. Jürgen Knödlseder

     @jknodlseder @sundogplanets I thought it was few years for LEO, few decades for MEO and few centuries for GEO (likely the same source).

     Bottom line: exact time doesn’t matter, it’s way too long anyway.

     clacke likes this.
   • Embed this notice
     Dr. Jürgen Knödlseder (jknodlseder@astrodon.social)'s status on Tuesday, 17-Oct-2023 22:05:43 JST Dr. Jürgen Knödlseder

     in reply to

     @sundogplanets Unfortunately not. I got the 1000 km - 1000 years rule from an expert on orbital debris from the French Space Agency who gave a talk at our lab.

   • Embed this notice
     Prof. Sam Lawler (sundogplanets@mastodon.social)'s status on Tuesday, 17-Oct-2023 22:05:44 JST Prof. Sam Lawler

     in reply to

     • Dr. Jürgen Knödlseder

     @jknodlseder I'm thinking Starlink altitudes, but yeah, you are right, and some debris will end up on higher orbits light that if we do indeed enter this worst-case scenario ugh.

     Do you have a good scientific reference for drag/deorbit time vs. altitude?

   • Embed this notice
     Dr. Jürgen Knödlseder (jknodlseder@astrodon.social)'s status on Tuesday, 17-Oct-2023 22:05:45 JST Dr. Jürgen Knödlseder

     in reply to

     @sundogplanets It’s rather centuries, not decades. At 1000 km a satellite stays up there for 1000 years.

   • Embed this notice
     Dr. Jürgen Knödlseder (jknodlseder@astrodon.social)'s status on Tuesday, 17-Oct-2023 22:05:46 JST Dr. Jürgen Knödlseder

     in reply to

     • Dr. Alexandre Santerne 🌍

     @AlexSanterne @sundogplanets I guess once you are in GEO you basically stay up there

     clacke likes this.
   • Embed this notice
     Michael Busch (michael_w_busch@mastodon.online)'s status on Tuesday, 17-Oct-2023 22:05:47 JST Michael Busch

     in reply to

     • Dr. Jürgen Knödlseder

     @jknodlseder @sundogplanets Orbital lifetime up that high depends a lot on eccentricity (higher e meaning more drag at perigee) and inclination, right?

     e.g. I recall discussions about deliberately disposing of MEO satellites by inducing eccentricity oscillations.

     But that supposes that the operator of the satellite acts responsibly. Which neither Starlink nor the various other aspiring LEO megaconstellations are.

     clacke likes this.
   • Embed this notice
     Michael Busch (michael_w_busch@mastodon.online)'s status on Tuesday, 17-Oct-2023 22:05:48 JST Michael Busch

     in reply to

     • Steffen Christensen
     • Dr. Jürgen Knödlseder

     @Wikisteff @jknodlseder My assumption has been that the money backing LEO megaconstellation plans will eventually be cut off - Starlink has run through a few billion dollars and is losing hundreds of millions per year; OneWeb as it now exists has bankrupted multiple companies; etc. ( The article @sundogplanets linked does emphasize overfiling.)

     But that's in no way an excuse for the failure of regulation.

     Especially since when a company goes bankrupt, who becomes liable for the satellites?

     clacke likes this.
   • Embed this notice
     Steffen Christensen (wikisteff@mastodon.social)'s status on Tuesday, 17-Oct-2023 22:05:49 JST Steffen Christensen

     in reply to

     • Michael Busch
     • Dr. Jürgen Knödlseder

     @michael_w_busch @jknodlseder @sundogplanets If only there were a sufficiently well-resourced space agency that had regulatory oversight capabilities and could look ahead 30 years or so for the welfare of all humanity.

     Oh well. Kessler it is, then.

   • Embed this notice
     Steffen Christensen (wikisteff@mastodon.social)'s status on Tuesday, 17-Oct-2023 22:05:50 JST Steffen Christensen

     in reply to

     • Michael Busch
     • Dr. Jürgen Knödlseder

     @michael_w_busch @jknodlseder @sundogplanets I wonder who you can sue when your firm's LEO satellite gets Kesslered?

   • Embed this notice
     Michael Busch (michael_w_busch@mastodon.online)'s status on Tuesday, 17-Oct-2023 22:05:50 JST Michael Busch

     in reply to

     • Steffen Christensen
     • Dr. Jürgen Knödlseder

     @Wikisteff @jknodlseder @sundogplanets If there is no company to sue; you can sue the country that the spacecraft was launched from - but only if your own country lets you do that: https://en.wikipedia.org/wiki/Space_Liability_Convention

     So, for example, when AST SpaceMobile goes bankrupt; if its satellite hits something belonging to someone from the United States, it is not obvious that they would be able to sue anyone.

     clacke likes this.
   • Embed this notice
     Prof. Sam Lawler (sundogplanets@mastodon.social)'s status on Tuesday, 17-Oct-2023 22:05:52 JST Prof. Sam Lawler

     in reply to

     Wowee there is a lot of mansplaining going on in the replies to this thread now. Muting!

     Just a reminder that I have a PhD in astrophysics, and my specialty is orbital dynamics. You really don't need to explain to me how orbits work.

     clacke likes this.
   • Embed this notice
     Burrito Justice (burritojustice@mastodon.social)'s status on Tuesday, 17-Oct-2023 22:05:53 JST Burrito Justice

     in reply to

     @sundogplanets ok how about they can launch a million satellites but only if they require that a mansplainer has to go up with each one

     clacke likes this.
   • Embed this notice
     Matthew Loxton (mloxton@med-mastodon.com)'s status on Tuesday, 17-Oct-2023 22:05:55 JST Matthew Loxton

     in reply to

     @sundogplanets
     Right
     I'm kinda going to side with the PhD Astrophysics lady on this one rather than My Dude who decides that after some scribbling that spacing satellites 2km apart would be fine

     clacke likes this.
   • Embed this notice
     Glitzersachen.de (glitzersachen@hachyderm.io)'s status on Tuesday, 17-Oct-2023 22:05:57 JST Glitzersachen.de

     in reply to

     • Matthew Loxton

     @mloxton

     And I find it sad, that after thus going on, I, also physicist by education, but not well enough versed in orbits, cannot ask a question any more. Which I have.

     :-(

     @sundogplanets

     clacke likes this.
   • Embed this notice
     Chris White (stoneymonster@stoney.monster)'s status on Tuesday, 17-Oct-2023 22:05:58 JST Chris White

     in reply to

     @sundogplanets I swear some people think playing kerbal space program turns them into physicists

     clacke likes this.
   • Embed this notice
     Steve Easterbrook (steve@fediscience.org)'s status on Tuesday, 17-Oct-2023 22:06:00 JST Steve Easterbrook

     in reply to

     • hanscees

     @hanscees @sundogplanets
     Now go watch the movie “Gravity”. It will sear the Kessler effect into your brain.

     clacke likes this.
   • Embed this notice
     hanscees (hanscees@social.sargasso.nl)'s status on Tuesday, 17-Oct-2023 22:06:01 JST hanscees

     in reply to

     @sundogplanets learned something today

     The Kessler syndrome (also called the Kessler effect,[1][2] collisional cascading, or ablation cascade), proposed by NASA scientist Donald J. Kessler in 1978, is a scenario in which the density of objects in low Earth orbit (LEO) due to space pollution is numerous enough that collisions between objects could cause a cascade

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

   • Embed this notice
     CelloMom On Cars (cellomomoncars@mastodon.social)'s status on Tuesday, 17-Oct-2023 22:06:02 JST CelloMom On Cars

     in reply to

     • Steve Easterbrook
     • hanscees

     @steve @hanscees @sundogplanets

     Also Neal Stephenson's SF novel, "Seveneves". A compelling tale.

     clacke likes this.
   • Embed this notice
     Full Metal Accountant (ordrad@lor.sh)'s status on Tuesday, 17-Oct-2023 22:06:04 JST Full Metal Accountant

     in reply to

     @sundogplanets
     We're just making a loose Dyson sphere of the earth.

   • Embed this notice
     Tofu Golem (tofugolem@mastodon.social)'s status on Tuesday, 17-Oct-2023 22:06:06 JST Tofu Golem

     in reply to

     @sundogplanets
     Kessler syndrome is inevitable, I fear.

     Making the problem worse and making it happen faster is really, really dumb.

     clacke likes this.
   • Embed this notice
     Catherine Berry (isomeme@mastodon.sdf.org)'s status on Tuesday, 17-Oct-2023 22:06:07 JST Catherine Berry

     in reply to

     @sundogplanets

     After how many cycles of disaster do we rebrand "The Tragedy of the Commons" to "The Utterly Predictable Consequences of Wrecking the Commons, You Morons"?

     clacke likes this.
   • Embed this notice
     clacke (clacke@libranet.de)'s status on Tuesday, 17-Oct-2023 22:06:08 JST clacke

     in reply to

     • Discovering BTS⁷ - 마리온
     @MondayMarionJ @sundogplanets The aliens didn't need to send a planet killer, they only had to lead us to creating our own prison. =)
   • Embed this notice
     Discovering BTS⁷ - 마리온 (mondaymarionj@apobangpo.space)'s status on Tuesday, 17-Oct-2023 22:06:09 JST Discovering BTS⁷ - 마리온

     in reply to

     @sundogplanets this is insanity. Are they trying to assure that we stay forever earth bound when orbital debris makes it impossible?

   • Embed this notice
     clacke (clacke@libranet.de)'s status on Wednesday, 18-Oct-2023 00:33:08 JST clacke

     in reply to

     • Discovering BTS⁷ - 마리온
     @MondayMarionJ @sundogplanets Just makes the premise of the song even more fantastical than when originally written!
   • Embed this notice
     Discovering BTS⁷ - 마리온 (mondaymarionj@apobangpo.space)'s status on Wednesday, 18-Oct-2023 00:33:09 JST Discovering BTS⁷ - 마리온

     in reply to

     • clacke

     @clacke @sundogplanets "Fly me to the moon and let me play among the stars..." Guess we'll have to change the words to the infamous song.