[user32489318]

What I found so fascinating about starling is how easy it was for a single country, even a single company in this case, to pollute near-earth space.

I understand the mechanics of LEO, and the de-orbit mechanics put in place. But the world-wide impact, unknown side-effects on the upper layers of atmosphere on the re-entry of literally thousands of satellites within fairly short period of time?

[wongarsu]

It wasn't easy at all. Nobody except SpaceX could have done it at the time. This is the result of SpaceX being able to launch much cheaper than anyone before them, and being able to use these high-cadence launches to both implement and test incremental improvements in their rockets and streamline their reuse of preflown boosters.

SpaceX was the only conceivable launch provider for this, and if it had been an external customer that cares too much about the risk of these launches the incremental improvements that made this cost-effective wouldn't have been possible. Realistically this was only viable for SpaceX doing it as part of R&D for their own rockets. And even then this puts severe financial strain on them because their original business plan was built around having Starship available years ago for even cheaper deployment of bigger satellites

Of course now that it has been done and technology has advanced by ~7 years it is much easier for new mega constellations. But at the time SpaceX started doing it the idea was rightfully called insane

[gosub100]

And phased-array antennae. The network would be next to useless if each receiver needed to track the satellite physically.

[0_____0]

Beamforming is an old technology though. It's not hard to do, just a pain to do cheaply when you've got a bajillion emitters unless you have custom silicon.

[xoa]

>Beamforming is an old technology though. It's not hard to do

Well, so is satellite launch right? Cost, efficiency, and scaling are hard to do. That's SpaceX's entire raison d'etre. Doing a general public usable all weather maintenance free well designed phased array terminal they can sell for $250 and pump out by the millions is as worthy an achievement as near anything else in the Starlink project. And I'd love if it was more available too even terrestrially, for PtP/PtMP links alignment even motionless is a certain amount of work at long distances. And long range high bandwidth stuff isn't cheap. It'd be pretty cool if you could have units for $250 that you just needed to aim vaguely in the right direction and then it all just worked.

[0_____0]

Hardware gets a bit easier in some respects when you have unit scale and don't need to make COGS+margin back on the sale. If Ubiquiti sell a base station, half of the unit price is gross margin. If SpaceX sell a Starlink terminal, they don't even have to cover COGS for it to be a good business case, because they're selling the service not the device.

The Starlink terminal is a very cool piece of kit, but it's not nearly as interesting as what they're hucking into LEO, and how they're doing it.

[simondotau]

> Well, so is satellite launch right? Cost, efficiency, and scaling are hard to do.

The famous phrase 'Quantity has a quality of its own' comes to mind.

[perilunar]

I disagree. Driving a small dish antenna only requires a couple of small electric motors. The receivers would be more expensive, and require more power, but they would still be affordable enough.

[verzali]

They would break more often. This was a key limitation of LEO systems prior to Starlink.

[gosub100]

but what about the interruption when the satellite crosses over the horizon? you would then need a 2nd antenna that was ready to take over, or tolerate several seconds of lost signal.

[Thlom]

I think OP was talking about the political side, not the technical side. How one company with the blessing of a regulatory body in one country could put thousands of satellites in LEO with minimal international coordination/deliberation.

[simondotau]

Capability creates reality first, and legal consensus usually arrives later. It has always been thus. On land, states must back claims with an ability to project force. In low Earth orbit, words mean little unless you can literally, physically show up and enforce them.

[severino]

True. And what will happen when another company wants their 10k satellites on orbit too? And companies from another countries, as well.

[kardianos]

By pollute, you mean "make awesome and useful", right?

You do value human utility, right?

[xoa]

The answer to a lot of the pollution problems is probably, and perhaps counter intuitively, "even more mass even cheaper, combined with regulations that are enabled by that". The key identified current concern is very specific to aluminum reentry, not just generic "whatever mass". Around 15000 tons of space dust hits the Earth each year no problem, but the chemical composition is quite different from what present typical satellites produce on reentry.

But in turn the composition of present satellites and the nature of their use/lifespan/safety systems has itself been driven heavily by economics. We don't make satellites out of steel or other safer materials not because they don't work, but because of the cost the extra weight imposes. We haven't put satellites in VLEO not because being lower is bad for communications or imaging (it's the opposite, lower is better) because it'd need more satellites, more fuel per sat, and higher cadence, all increasing cost beyond the historic ROI. But Starship or other future fully reusable methalox designs will give us vastly more mass budget and cadence for the same cost. Some of that could result in more trouble with existing designs made for a low cadence/high $/kg environment, because some externalities that were previously acceptable due to lack of scale stop being so at scale. But the same increased budget also means increased budget to ameliorate that. We can trade some of the gains for materials that burn up harmlessly in the atmosphere, designs for lowering apparent magnitude to the ground, for better self-destruct and end of life systems, more fail-safety, more redundancy in general, etc etc. And if that requires more regularly replacement that too is made easier but order of magnitude or more lower cost.

Some of this may happen naturally just due to self-interest, but other parts like pollution may require thoughtful regulation. But such regulation will be a much easier lift when it's affordable, so it's worth it to try to maintain an appropriately thoughtful mindset on the benefits vs tradeoffs and how to keep the former while reducing the latter.

[mikkupikku]

On a bad year, there might be a few hundred tons of Starlink satellites reentering the atmosphere. In the same year, there will be something like 5000 tons of meteors reentrying, and if you include space dust that radars don't see, you're looking at a few times more than that.

This appeal to scary ignorance to poop on a technology is a cynical reflex. Instead of just saying that a bare number with no context scares you, you should dig deeper and try to actually back up or invalidate your fears.

[kemotep]

A quick search shows that it’s more like 50 tons of meteorites entering the atmosphere per day. Or over 18,000 tons per year.

If Starlink’s are about 2 tons each (the v3’s are going to be much larger) and they each have a roughly 5 year life span and the 10,000 currently are equally spread over that lifespan (so around 2,000 a year need to be replaced) that’s equivalent to around 10 tons per day of Starlink material breaking up in the atmosphere.

With the 1 million SpaceX datacenters Musk talks about and an original projected satellite Starlink swarm size of 40,000, that number balloons to something like 500 tons per day.

So while today it is only a fraction of the total amount of material breaking up in the atmosphere, the idea that multiple companies could have Starlink size satellite swarms with lifespans measured in a few years we start to easily dwarf what meteorites do.

[Retric]

They are 0.8 ton each and last ~5 years. 10,000 / 5 * 0.8 = 1,600 tons per year at 10k satellites, and their goal of 40k satellites would put it well above the amount of asteroid debris impacting each year. Further asteroids contain very different materials and don’t all impact at the very low angles you see from de-orbiting in satellites. Thus, I don’t think you can presume this is meaningless without actually modeling it.

Space dust on the other hand behaves very differently on reentry because of the high surface area to volume ratio.

[mikkupikku]

They last 5 years if they're dead in orbit. These satellites have electric thrusters and boost themselves regularly to maintain orbit, so your estimate is wildly off.

As for presuming them to be safe, there's fuck all evidence to the contrary. Whining with baseless speculations about the effect of satellites burning up is motivated by the base reflex to shit on any technological progress as an environmental disaster in the making, but nobody can come up with a story about how dolphins might choke on satellites so instead we get this "muh aluminum" narrative.

[Retric]

“A Starlink satellite has a lifespan of approximately five years” https://www.space.com/spacex-starlink-satellites.html

A 5 years useful lifespan sets the replacement rate and thus the average number burning up each year. In steady state the delta between end of life and reentry is irrelevant, instead the average number of satellites launched each year = average number that burn up each year.

As to harm. Aluminum is mildly toxic, you don’t eat your bike but vaporized aluminum from a satellite is way more likely to cause harm than if the things were made of steel. The plastic bits are likely fine though.

Saying let’s study something ahead of time rather than contaminating all the world’s farmland with and then seeing what happens seems like a perfectly reasonable standard. Technology has generally been wonderful, but that doesn’t mean everything is equivalent. We want to phase out leaded aviation fuel in the US even though it’s ‘only’ 2,000 tons of lead per year, that’s still enough to be problematic. Perhaps ramping up to ~5k tons/y of vaporized aluminum worldwide is a complete non issue, but if it’s not insisting on some other material isn’t the same as a ban.

[jacquesm]

You're low by a factor of three.

You probably could make the same point in a better way as well.