[ktrl]

There has been a lot of discussion about light pollution from the 1500+ planned Starlink satellites. However much of the discussion is based on the assumption that the world will collectively let Starlink operate as monopoly.

How much will light pollution increase when the next competitor launches 1500+ satellites?

How much will light pollution increase when a Chinese competitor launches yet another 1500+ satellites?

[modeless]

"Light pollution" for naked eye viewing of the sky is not a big concern for Starlink anymore. SpaceX has designed a sunshade which should make the satellites completely invisible to the naked eye in their service orbits. The sunshade has been designed in collaboration with astronomers to ensure that even the most sensitive telescopes will not have problems with it either.

Will the Chinese do the same? We'll see. But it's definitely possible to mitigate these concerns. There's not much to discuss until a credible competitor to Starlink emerges.

[thekyle]

I'm more concerned about the space junk aspect of it. My understanding is that as satellites collide they produce millions of tiny deadly particles. If we have enough of those in orbit then it will effectively trap us on earth.

I'm all for faster internet, but not at the cost of making space travel impossible.

[modeless]

SpaceX moved the satellites to lower orbits, so any broken satellites or debris will fall out of the sky within a few years due to atmospheric drag. And they are specifically designed to burn up completely in reentry. The real concern is in higher orbits where debris would persist for millennia. This is not a concern for Starlink.

[thekyle]

That's good to hear.

[CrLf]

A collision can eject debris into higher orbits.

[modeless]

Not really. The only way a collision could truly raise an orbit is if a resulting piece of debris had far higher velocity than either incoming satellite which, while maybe not theoretically impossible, seems exceedingly unlikely. Furthermore, the way orbital mechanics works, all orbits resulting from a collision go through the point of the collision, so the collision of two objects in circular orbits can never result in an orbit with higher perigee. The orbit of debris may turn from circular to elliptical with a higher apogee, but those orbits will almost certainly have lower perigees and decay faster.

[NikolaeVarius]

I don't think you understand the magnitudes of distance and energy that we're talking about here