https://www.universetoday.com/164890/millions-of-satellites-... We have not even certainty that highe numbers of satellites and debris won’t alter earth’s outer magnet field

And 60% of them are Starlink.

I was surprised at the number of dead satellites and tracked debris though — roughly twice the number of active satellites.

And if I’m reading the Orbital Tonnage chart right, then 80-90% of every ton now being launched is a Starlink satellites.

Maybe the biggest hurdle for everyone except Starlink (with their standardized design) is spacecraft design and engineering, not cost to orbit?

And SpaceX’s Starship will be able to put a payload of 150 tons into LEO. How could we possibly make use of that capacity, other than Elon’s idea of sending millions of people to Mars?

It's a good question. A lot of people seem to think SpaceX can build it and the demand will appear, but that isn't how things have played out so far.

SpaceX has lowered launch costs and they do launch a lot, but they're mostly putting their own satellites up. The demand from everyone else has increased a bit, but not really enough to support the "build it and they will come" theory.

The failure of the Falcon Heavy to generate demand speaks volumes about how much demand Starship will see, IMO. Sure we might get an occasional space station, big telescope or Moon landing, but that will add up to a handful of launches. The demand for three launches a day like Musk wants just isn't there, and won't be for a very long time.

> The failure of the Falcon Heavy to generate demand

My understanding is that Falcon 9's thrust has increased to such a degree over it's lifetime that it is capable of taking over most of the missions which would have previously required Falcon Heavy. Recovering Falcon Heavy's central core is also significantly more challenging than a typical Falcon 9 launch due to the increased velocities achieved, increasing cost of the heavy further. And it's fairing is no larger than that of Falcon 9, further reducing it's utility.

Starship is another beast entirely, with none of those limitations.

So is StarLink profitable already? I have heard that SpaceX is going public, and the expectation is they are profitable and will be a big IPO. They have been scooping out contracts from UAL with lower pricing for years, and reusable rockets should save money, but if most of tonnage is StarLink, how much that put profitability at risk? Can they keep the cash flow going without starlink?

> Maybe the biggest hurdle for everyone except Starlink (with their standardized design) is spacecraft design and engineering, not cost to orbit?

Maybe the biggest hurdle is that having stuff in orbit has quite limited applications. Starlink is the first semi-reasonable idea that can utilize this much mass in orbit.

Are there any ways to do anything with the space debris, or is it planned? I am a bit concerned about it and its impact on future missions.

What does all this activity in the firmament do to the worldview of premodern populations around the world ?

Nothing? They are not ignorant of the rest of the world existing.

Define "they". Not every human knows about things like satellites.

I recently started playing with some telescopes. Long-term exposures especially of areas with a bigger angle like nebulas had quite often a starlink trail in it...

while aligning the telescope to some stars I could see the satellites quite often

If you can see it clearly with the naked eye, it's probably not a Starlink.

Did you use astronomy software to identify them, or did you assume the satellite trails must be Starlinks? I remember seeing plenty of satellites visible in the night sky even before the first Starlink launch.

I saw them through the telescope. In the 11" I could see them through the eyepiece and on the 6" it was on the cam captures. I checked e.g. with Stellarium