Thread by @rdrimmel

Ok, short thread about why this could be an ecological and cultural disaster. I'm on the beach, so this might be a bit slow..

https://twitter.com/rdrimmel/status/1563073845879541760

Expected capacity of Starship is about 150 tonne, so that means about 120 Gen2 Starlinks per launch. That means to deploy 30k sats you need 250 Starship launches. Expected on-orbit lifetime is same as Gen1: 5 to 7yrs.
nasaspaceflight.com/2022/01/starsh…

That means you have to deploy the consellation in less than 5 to years, or you'll never reach 30k sats before they start falling out of the sky. To deploy 30k sats in 5yrs you need 50 Starship launches per year. And this is just one of many proposed constellations..

A recent estimate is that global launch rates will reach 1000 per year. And yes, this is expected to have a significant effect on the atmosphere.
wired.com/story/the-blac…

But it's not just rocket exhaust: What comes up must come down. Let's generously assume that "only" the 20k Gen2 sats below 400 km orbits have a 5-7yr lifetime: Once deployed you need at least 30 Starship launches per yr to maintain the constellation..

and 4000 1.25 tonne satellites falling to Earth per year. That's 5,000 tonnes of aluminum and rare earth minerals deposited in the upper atmosphere per year. And that is, again, just one constellation.

Scaling this up to 100k sats (estimated total number of constellation sats), that's means *at least* 25,000 tonnes per year of aluminum and other metals deposited in the upper atmosphere. Effect? WE HAVE NO IDEA. So let's see what happens..

And that assumes nothing reaches the ground.
space.com/space-junk-roc…

And I have not even touched on the potential impact on the space environment. Managing such a large constellation needs constant avoidance manuevers, but if an unexpected solar storm even temporarily knocks out a fraction of the sats, the situation will degenerate very quickly.

Finally, the Gen2 Starlink sats are larger than Gen1. Just considering the sat bus, they are about 6X larger. But most of them will be on smaller orbits, between 340 and 400km. So their apparent size, which determines brightness, is about 9 to 10 times larger.

That is, to be no brighter than Gen1, the Gen2 sats will need to be at least tens times darker. Fortunately, Starlink has been working on this, but will it be enough?
teslarati.com/spacex-shares-…

Based on past performance, it's hard to be optimistic..

https://twitter.com/krp234/status/1558181978523852800?t=iekK-_xE5h4erJPVueLyJw&s=19

Truth is we are already transforming the night sky for all of humanity.

https://twitter.com/blt_astro/status/1557663875281166338?t=iekK-_xE5h4erJPVueLyJw&s=19

Again, we are recklessly "developing" a common resource, with little or no regulation, for the benefit of a few, but at a cost that will impact everyone.
#DarkSkiesForAll