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   Prof. Sam Lawler (sundogplanets@mastodon.social)'s status on Friday, 04-Jul-2025 02:15:42 JST Prof. Sam Lawler

   New SpaceX report on Starlink conjunctions and deorbits (a.k.a. dumping tons of metal/plastic/solar panels/computers into the upper atmosphere) https://www.scribd.com/document/883045105/SpaceX-Gen1-Gen2-Semi-Annual-Report-7-1-25

   Scariest part:
   472 Starlinks were burned up in the atmosphere in Dec-May. Assuming each satellite is 800kg, and 50% aluminum by mass, that's 1 ton of aluminum PER DAY.

   The natural infall rate of aluminum from meteoroids is 0.3 tons per day. Starlink has been ~3x that, for the last 6 months.

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     Prof. Sam Lawler (sundogplanets@mastodon.social)'s status on Friday, 04-Jul-2025 02:15:41 JST Prof. Sam Lawler

     in reply to

     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

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     Prof. Sam Lawler (sundogplanets@mastodon.social)'s status on Saturday, 05-Jul-2025 00:22:09 JST Prof. Sam Lawler

     in reply to

     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...

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     Prof. Sam Lawler (sundogplanets@mastodon.social)'s status on Saturday, 05-Jul-2025 00:22:21 JST Prof. Sam Lawler

     in reply to

     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/

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     minidisco volante (guenterhack@chaos.social)'s status on Saturday, 05-Jul-2025 00:22:25 JST minidisco volante

     in reply to

     @sundogplanets Is this the way how they establish a first-mover low-orbit communications satellite monopoly? They fill the zone with satellites so that no competitor can emerge?

     clacke likes this.