Mastodawn

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.

SpaceX Gen1-Gen2 Semi-Annual Report (7!1!25) | PDF | Satellite | Space X

SpaceX submitted its semi-annual reports for Gen 1 and Gen 2 satellite constellations, detailing their commitment to sustainability and safety in satellite operations. The report highlights SpaceX's conservative approach to collision avoidance and deorbiting, emphasizing the importance of transparency and collaboration among satellite operators for space sustainability. Additionally, it addresses challenges in collision avoidance processes and the need for consistent data sharing among operators to enhance overall safety in space.

Scribd

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Prof. Sam Lawler Jul 3

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 Jul 3

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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MidgePhoto

@sundogplanets

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