[cryptoz]

> Basically, the constellation's effect on the night sky is proportional to the number of launches in the last month, not the total number in orbit.

For the major brightness issues sure, but they are not invisible or undetectable while in operation. Surely the effects are proportional to both the recent launches and the whole size.

I think it's a bit early to dismiss the whole sky effect of multiple Starlink-style constellations in operation.

Also isn't Starlink intending to do launches for the rest of time? There is always a value for the last month of launches- they'll never stop launching right?

Just thinking out loud.

[ortusdux]

The current satellite version (VisorSat) has a magnitude of about 6, which is generally considered to be the limit of what is visible with the naked eye in a light-pollution free area.

Once you start using any optics they will be visible.

https://arxiv.org/ftp/arxiv/papers/2101/2101.00374.pdf#:~:te....

https://earthsky.org/astronomy-essentials/what-is-stellar-ma...

I might sit down and do the math to see how 1500 satellites at mag 6 compares to 60 at mag 2.

> I think it's a bit early to dismiss the whole sky effect of multiple Starlink-style constellations in operation.

I wasn't trying to dismiss their effect, just address the people who say "you think those 60 are bad, imagine when there are 20,000", or "there go the Americans, ruining the night sky for the whole world".

I have no idea how oneweb or blue origin will handle this issue.

> Also isn't Starlink intending to do launches for the rest of time?

Their satellites are designed for a 5 year lifespan. Without constant boosts, they will deorbit and burn up fully in the atmosphere. This is great, because they will not become space junk, and they can't cause the dreaded kessler syndrome. The downside is that they will need to be constantly replenished. Hopefully this will be streamlined when they can launch 600 at a time, reducing the number of launches by a factor of 10.

[smeyer]

>I might sit down and do the math to see how 1500 satellites at mag 6 compares to 60 at mag 2.

Every 5 astronomical magnitudes corresponds to a factor of 100 difference in brightness, so magnitude 2 is (100^0.2)^4 or about 40 times brighter than magnitude 6. So they're pretty similar, 1500 satellites at magnitude 6 are about 2/3 as bright as 60 satellites at magnitude 2.

[sneak]

There is also the (no help at the moment) fact that the more money that Starlink's parent company makes, the more likely we are to get the world's cheapest heavy lift orbital booster soon, and the more likely we are to soon have multiple large orbital telescopes that far exceed ground-based capabilities.

Basically, if SpaceX makes it, we'll probably have a Starship-launched lunar observatory quite soon, in the grand scheme of things.

This doesn't help the situation now, although there is so much screaming from the anti-Musk people as well as the pro-Musk people that it's hard to tell what the actual impact of the now-somewhat-albedo-mitigated starlink v.whatever satellites are. All of the coverage is breathless sky-is-falling stuff.

In any case, the situation is temporary. Either SpaceX makes it and we get a far side of Luna observatory and LEO/MEO telescopes besides, or they don't and in a few years Starlink all falls down and burns.

[bruckie]

Would cheaper/larger launch vehicles significantly change the economics of deploying space based observatories? The James Webb space telescope has cost about $10 billion, and you can afford even today's largest/most expensive launch vehicle (Delta Heavy) for a relatively small fraction of that ($350M).

[coryrc]

It'd be a lot cheaper if they iterated and could service the machine if needed. Waterfall is the most expensive way of doing something.

[mfer]

I'm reminded of Earth orbit from the film Wall-E for some reason.

[mlindner]

That's distinctly completely impossible in this case.