And with 2.3M customers, that's an average 1.7 Mbit/s per customer, or 550 GB per customer per month, which is kinda high. The average American internet user probably consumes less than 100 GB/month. (HN readers are probably outliers; I consume about 1 TB/month).

The way Starlink satellites are in orbit, the same satellites will remain "ahead" and "behind" you in the orbital plane. Those laser links (specifically!) will remain relatively persistent. This arrangement is similar to Iridium FYI.

FTA: "in some cases, the links can also be maintained for weeks at a time"

I think there is a lot of variance. The article also states about 266,141 “laser acquisitions” per day, which, if every laser link stayed up for the exact same amount of time, with 9000 lasers, means the average link remains established for a little less than an hour: 9000 (lasers) / 266141 (daily acquisitions) * 24 * 60 = 49 minutes

So some links may stay established for weeks, but some only for a few minutes?

I believe Starlink (like Iridium) doesn't even try to establish connections "across the seam," ie the one place the satellites in the adjacent plane are coming head on at orbital speed.

This make side-linking easier because the relative velocity is comparatively low, but in general you unavoidably still need to switch side-link satellites (on one side) twice per orbit. Hence 49 minutes: this average must be calculated per connection not per second, so the front/back links (plus random noise) count less, so it only drags the average from 45 minutes up to 49 minutes.

The slide showing the multiple possible paths traffic can take seems to disagree with this statement?

However looking at other sources, it seems Starlink (having more satellites) actually wraps the orbital planes 360° around the Earth (vs Iridium's minimalist 180° configuration), overlapping both North-moving and South-moving satellites in the same sky simultaneously. This means the Iridium seam disappears entirely. Neat! TIL.

Another problem that vanishes simply by being "hardware rich."

You can't freely blast radio waves into a country without falling subject to its varying regulations, but the regulations for "pre Starlink" satellite broadband/phones/etc are fairly well established.

But that’s me.

Even back to 1950, for per household data, it was above 4 hours.

[1] https://www.nielsen.com/insights/2009/average-tv-viewing-for...

Men spent 3 hours a day watching TV, and women 2.5 hours. But TV time is lower (around 2 hrs/day) from ages 20-44, then increases again after 45 and peaks at 75 years old at nearly 5 hours a day.

Households without kids watch more TV, which surprised me.

I'm not sure that's saying household time. For example, when they survey a household it wasn't clear to me if they survey everyone in the household or just one person. If it's one person then it sounds like they collect how that one person (age 15+) spent their own time and if there were kids in their household.

So then it'd be accurate to say that individuals in households without kids watch more TV as a singular activity (the survey doesn't allow simultaneous activities).

In comparison Nielsen used TV viewing diaries and automated data collection meters. You could have the TV on in the background while doing chores and it would still count.

It's interesting that the 2009 ATUS survey [3] had a 2.82 hour/person average because that's fairly different from the Nielsen data (4 hours 49 minutes/person).

I wonder if this difference is people underreporting in ATUS or Nielsen overreporting or a factor of differences in limitations in ATUS (no simultaneous activities allowed, 15+ age limitation) or Nielsen.

[1] https://www.bls.gov/opub/hom/atus/data.htm

[2] https://www.bls.gov/tus/questionnaires/tuquestionnaire.pdf

[3] https://www.bls.gov/news.release/archives/atus_06222010.pdf

They didn't have per person for the 1950 to 1990 data, only household (pdf in the link).

Maybe I just grew up in a quiet place.

For some it is just the illusion of having more people around them, though.

Personally I need almost complete silence in order to get anything done, his abilities in this regard always fascinated me.

It's useful for some people to have recognisable sounds going on while they work, so they have something to latch their focus if they lose it for a second. Whether that be music, or every seinfeld episode on a shuffled loop on the TV.

I have found it useful in the past to listen through every song I have on shuffle while I read, which was nice when I took a few-seconds break every couple of pages and came across a song I wouldn't have picked out otherwise. Alt-tabbing out of a podcast or something completely wrecks my focus on both for some reason though.

We're outnumbered.

I would kill for some decent high res wide fov AR glasses.

kids these days mostly use youtube or twitch for background noise i think

I don't think that breaks net neutrality either, which the FCC seems to be reimplementing

Edit: see https://openconnect.netflix.com/en/

T-Mobile absolutely counts all data used over the network, my voice lines go QCI 9 (they are normally QCI 6) when over 50GB of any kind of data usage each month, the home internet lines are always QCI 9. I don't have congestion in my area so it does not affect my speeds. This is QoS prioritization that happens at physical sector level on the tower(s).

Imagine they put 10TB of flash memory on the satellites and run virtual machines for the big CDN companies (cloudflare, Google, Netflix etc).

I reckon that 10TB is still big enough to service a good little chunk of internet traffic.

You have to share that 10 TB with everything on that satellite's orbit.

Most ISPs have CND appliances in their racks to save on uplink bandwidth. And from a satellite perspective the uplink (in this scenario: the downlink from the satellite to the gateway) definitely is the expensive bottleneck.

You want to avoid congestion and every bit of caching could be helpful.

Then it comes down to the mass and power budget (and the reliability of flash drives in space) - but that doesn't seem too terrible.

I think a few hundred GB for a typical cord-cut household is about right.

300+ minutes a day for TV + vMOD (streaming services). Since no one actually watches TV anymore, at least not through traditional TV, I summed them.

I'm kinda pissed their is no local ISP competition in my area....and iv tried reaching out to companies with little success...or they say were expanding to your area soon but will not say when.

10GB symmetric fiber isn't hard. Hell I'd use more bandwidth if I could but I'm stuck with no fiber atm

I think I agree that each laser is grossly underused on average, but if you read the article, there's quotes about the uptime of these links. They're definitely not just "used in bursts [of] a few tens of seconds or minutes".

I should probably see if my router can bandwidth limit their mac addresses...

So it's hard to sustain the theoretical 100GPS connection for hours let alone days across 2 end points which are in constant motion.

not for awhile. apple vision / oculus will stream (4k/8k) 3d movies.

https://developer.apple.com/streaming/examples/

Resolution is always determined by angular resolution at viewing distance, even for analog TVs(they were smaller and further away), and also,

Videos on Internet is always heavily compressed - the "resolution" is just the output size passed to the decoder and inverse of minimal pattern size recorded within, technically not related to data size. Raw video is h * v * bpp and have always been like low to dozen Gbps.

Just my bets, the bandiwth may peak or see a plateau, but resolution could continue to grow as needed for e.g. digital signage video walls that wraps around buildings.

It should. At some point you are beyond any difference a human eye can detect on a tv or monitor you’re sitting less than 10ft away from.

It probably won’t though because capitalism means there has to be a reason to sell you a new widget and 3D was an utter failure.

There's of course a limit. The "native" bitrate equivalent of your retina isn't infinite.

Next step though is going to be lightfield displays (each "pixel" is actually a tiny display with a lens that produces "real" 3D images) and I assume that will be a thing, we shall see if it does better than the last generation of 3D TVs/movies/etc. That's a big bump in bitrate.

There's also bitrate for things like game/general computing screen streaming where you need lots of overhead to make the latency work, you can't buffer several seconds of that.

The next gen sci-fi of more integrated sensory experiences is certainly going to be a thing eventually too. Who knows how much information that will need.

When more bandwidth becomes available, new things become possible, sometimes that are hard to imagine before somebody gets bored and tries to figure it out.

When I'm futzing around with ML models, I'm loading tens of gigabytes from disk into memory. Eventually something like that and things orders of magnitude larger will probably be streamed over the network like nothing. PCIe 4.0 x16 is, what 32 GBps? Why not that over a network link for every device in the house in 10 years?

I'd be interested in what the sustained power/thermal budget of the satellites is.

Don't forget that every communication protocol has fixed and variable overhead.

The first is a function of the packet structure. It can be calculated by simply dividing the payload capacity of a packet by the total number of bits transmitted for that same packet.

Variable overhead is more complex. It has to do with transactions, negotiations, retries, etc.

For example, while the theoretical overhead of TCP/IP is in the order of 5%, actual overhead could be as high as 20% under certain circumstances. In other words, 20% of the bits transmitted are not data payload but rather the cost of doing business.

Dead internet theory (alive and well!)

At first this sounded like an utopian dream but now it looks like common infrastructure that has a place in everyones life.

This must have been the same feeling when the first landlines were installed. The very first lines were a sensation and then after only a few years it becomes normal quickly.

My deepest hope currently is that the riches of the universe now on the horizon of being relatively easily accessible, in a systematic and efficient way, will lead to the military industrial complex profit seeking to redirect their efforts to mining the riches of the our solar system and beyond, rather than likely mostly inadvertently driving for hell on Earth.

You can’t deny (I don’t think) that the things he’s done are amazing. He’s in the zone where he’s smelt too many of his farts though, and believes he can do no wrong, which is historically a very bad place to be. I hope, for all of the awesome things he’s said he’d like to do, that they don’t come agutsa due to that

Really?

It's my understanding Elon isn't popular anymore (I could care less), but this point does not help whatever it is you're trying to say. I deal a lot with statistics and making predictions from past performance, and you most definitely can determine future performance with a high amount of accuracy. This shouldn't really need said.

You are probably right about him smelling too many of his farts, but you really hurt your main thesis right off the bat with that first claim.

This is such a baseless and almost comically wrong heuristic I'm curious how it's one you landed on. I'm earnestly curious, do you use the same heuristic in other areas of your life?

If you were in the market for a car, would you let the past performance of other vehicles you've owned influence that decision? It seems to me to be such a simple and fundamental part of decision making, I'm fascinated you've gotten along thus far without it.

If you have enough real-world data, and learned the patterns of history, along with fundamental principles that seem to be precursors or prerequisites to change, then a prophet is more or less someone with a honed and an extended-expanded open mind neural network compared to most.

P.S. It's why it's a really good idea to allow immigrants fleeing from communist countries, as they'll be best and perhaps first to detect and sound the alarm bells if fascism patterns begin to emerge in their new country.

The man has a lot of flaws and since covid drifted into ideologies I don't agree with. I also wouldn't buy a Tesla. But there is no denying that both Tesla and SpaceX revolutionized their respective industries. And it seems safe to say that neither would have managed to do this without Musk. And at least SpaceX manages to sustain a substantial lead over the competition and continues revolutionizing industries.

He is also a founder at Tesla, as when he entered the round A financing Tesla was just three guys, some networking, and nothing more. Even the "Tesla" trademark and logo registration was made by SpaceX people. He didn't found his own car company with just J. B. Straubel (another Tesla founder who was being paid by him to develop electric car batteries at the time) because he thought it would be better to cooperate with that other group that was was inspired by the same idea and he though he would be able to concentrate more on SpaceX that way. He was wrong and had to take the CEO position on Tesla later to avoid bankrupcy, move the Model S design headquarters to SpaceX, etc. And it's now nothing like what it was when he first put money on it.

I would venture a guess that the bulk of Elon animosity started exactly at twitter acquisition time, when the people selling the narratives lost their merchanting channel and so they made sure to poison the well beforehand.

Cross-plane optical links would have a trickier tracking problem.

While there's no explicit mention of same-plane vs cross-plane optical links, I assume that the first time people have a public cross-plane optical link, they will make a big deal out of it. :)

The article also mentions that SpaceX would need to do further study before using laser links between satellites and ground stations-- this kind of optical link would require both more angular tracking and probably atmospheric correction as well.

> For the future, SpaceX plans on expanding its laser system so that it can be ported and installed on third-party satellites. The company has also explored beaming the satellite lasers directly to terminals on the Earth’s surface to deliver data.

The customer terminals will likely never connect through lasers (because a laser can only point in one direction at a time), but moving the ground station uplink to a laser link sounds very beneficial.

Is there rough pointing, followed by some rastering, until the sensor gets a hit? Maybe with some slight beam widening first? My assumption is that you would want exactly one laser, one sensor module, and probably a fixed lens on each? Is the sensor something like a 2x2 array, or pie with three pieces, to allow alignment? Or is it one big sensor that uses perturb and observe type approach to find the middle?

Also, is there anything special about the wavelengths selected? Are the lasers fit to one of the Fraunhofer lines? 760nm seems like a good choice?

On wavelengths, if you're trying to hit 100gbit+, you're probably having to use coherent optics, and there aren't many technology options or wavelengths on the market.

You'd normally achieve this by transmitting a well-known pseudorandom sequence. You also need clock stability into the ppb range.

A path loss of 110 decibels is huge. It can easily account for your lenses being hugely off axis.

https://en.wikipedia.org/wiki/Shannon%E2%80%93Hartley_theore...

Sounds very cool that cross-plane links are doable, even if they have predictable complications compared to in-plane.

I would have thought that someone would make a big deal (have a press release, e.g.) out of successfully establishing cross-plane links, but maybe it just doesn't seem that impressive to people who already have good enough precise predictive ephemerides or satellite states to make those links in the first place.

“ Cross-seam inter-satellite link hand-offs would have to happen very rapidly and cope with large Doppler shifts; therefore, Iridium supports inter-satellite links only between satellites orbiting in the same direction.”

https://en.m.wikipedia.org/wiki/Iridium_satellite_constellat...

There's an animation on linked article that explains this pretty well: https://upload.wikimedia.org/wikipedia/commons/thumb/9/90/Ir...

The wikipedia link above explains it well:

""" Orbital velocity of the satellites is approximately 27,000 km/h (17,000 mph). Satellites communicate with neighboring satellites via Ka band inter-satellite links. Each satellite can have four inter-satellite links: one each to neighbors fore and aft in the same orbital plane, and one each to satellites in neighboring planes to either side. The satellites orbit from pole to same pole with an orbital period of roughly 100 minutes.[8] This design means that there is excellent satellite visibility and service coverage especially at the North and South poles. The over-the-pole orbital design produces "seams" where satellites in counter-rotating planes next to one another are traveling in opposite directions. Cross-seam inter-satellite link hand-offs would have to happen very rapidly and cope with large Doppler shifts; therefore, Iridium supports inter-satellite links only between satellites orbiting in the same direction. """

The 'seams' have interesting implications for latency when I was working on Global Data Broadcast.

I'm assuming two things: That something like Manchester coding is being used so that some clock skew is tolerable, and that the laser carrier is not in fact being frequency or phase modulated. Last I checked FM and PM of optical frequencies was not yet practical outside of laboratories, but I'm happy to be corrected.

If they could only do in-plane links, they would have barely any acquisitions per day, because most links would stay up for long periods of time.

Additionally, their inter satellite links use regular Ka band radio.

And if they have zones where they don’t go to adjacent orbits, but instead go up or down within their orbit for the handover between orbits.

I believe Iridium had way more downlinks than they used to pre-bankruptcy. I guess volume constraints were less of an issue, so ok to hop around more in space.

Apparently it only happens above/below 68 degrees latitude, so the next satellite with a working inter-orbital-plane connection is at most one hop ahead or behind.

https://spaceflight101.com/spacecraft/iridium-next/ has some more photos and diagrams; seems like they're really mechanically steered even on the NEXT constellation.

- About 4,000 customers worth of maxed out Gigabit internet

- ~243,000 simultaneous Netflix 4K streams

- 1.6% the capacity of the latest BlueMed undersea fiber cable

Edit: It's international traffic. YouTube, Facebook video has local cache server by ISP.

https://info.cobaltiron.com/blog/petabyte-how-much-informati...

1GB flash drives are still 1GB today.

>256 GB is now common, which would make that petabyte less than 1 football field. (It's only 4096 such drives.)

If we're completely changing what we're using for scale, you can fit a petabyte on ~10 100TB drives, which is like 3% the length of an olympic swimming pool.

is it supposed to be actual football one or the field for handegg?

As a side-note Canadian Gridiron football uses a longer field than American Gridiron football, though (measuring between the goal lines) still slightly shorter than a typical Association Football pitch.

Australian Rules Football is on a field typically longer even than an Association Football pitch, though I don't believe there is a regulation limiting the size.

ftp.ebi.ac.uk for example.

-- Andrew Tannenbaum

How do I think of 42 petabytes in terms of an ISP? Is that a lot? How does it compare to other satellite providers? How does it compare to 4G capacities? Is this a small country worth of traffic or just any ol' data center? I have no intuition about traffic at this scale.

Per day?

Most people's experience with 4K video is through a streaming service, and 10 minutes of 4K video on a streaming service is more like 1-1.5 GB.

Or a UHD Disc perhaps where 10 minutes is 3.5-7 GB.

Which also makes me wonder how many of the shooting stars I've seen recently are just old starlinks burning up.

Probably close to none. The lifetime of the satellites is about 5 years give or take. According to this page [1], a total of 355 satellites have deorbited over the past roughly 5 years. That's an average of about 71 per year or about one every 5 days.

Since planned disposals are done over uninhabited areas (e.g. the pacific ocean), the likelihood of spotting one is very low.

Hope that helps answer your question, even it wasn't necessarily meant seriously :)

    [1] https://starlinkinsider.com/starlink-launch-statistics/

Wow ... is it economical to replace the entire constellation every 5 years? How does the business side work? Or is it just a great money-burning party?

They also want to make Starlink satellites bigger, which also requires Starship's much larger diameter.

...which I suppose is closely related. The deorbiting satellite burns up because all that potential energy goes into heat because of the ~friction~ [edit: compression, thanks for the correction] that limits it to that low terminal velocity.

https://www.youtube.com/watch?v=sDufpRp57ok

Put another way, every kilogram of Starlink spacecraft has as much energy "stored" in it's motion as around 4-5 tons of TNT.

SpaceX says otherwise, see [1]

   SpaceX spokesman James Gleeson, when asked about the 10 satellites, said SpaceX is “performing a controlled de-orbit of several first iteration Starlink satellites,” using onboard propulsion.  

[1] https://spacenews.com/spacex-launches-fourth-batch-of-starli...

Now, none of this is an actual problem as they're entirely demisable, but the statement that they can achieve controlled de-orbit is false.

So if you control the orbit, you control the zone of re-entry. It's not a point or an oval in this case, but a "strip" a couple of kilometres wide. This is all that's required if the goal is to avoid major population centres.

This also means that the target is not "all over the world" as you put it - it's a very narrow, well defined stripe/trace (remember the scale we're talking about here!) and that's exactly what a controlled de-orbit is about.

I see them 1/3 of the time in outside for 30 minutes or more I’d say. Thought they were much rarer. Only seems a Starlinkn train once.

2. The sky needs to be dark enough to see it (so twilight or night)

3. The satellite needs to be illuminated by the sun.

4. The satellite needs to reflect enough light that you can see it.

Basically this happens just before sunrise, and just after sunset. So the ground and sky are dark (allowing you to see through the atmosphere), and the satellite - being at high altitude - is still illuminated.

As they pass overhead, you can often see them suddenly vanish as they pass into the Earth's shadow.

The International Space Station is a good one to find, as it's quite bright (very large).

There are various websites and apps; some phone apps use the GPS and magnetometer to show you what direction and time to look, and a search tool to look for visible objects at your location. It used to be really good with the old Iridium satellites, which gave a bright flash due to their large flat antennas.

I've seen plenty of satellites in the middle of the night, from very dark areas (wilderness). They look like stars, only they move more quickly. These observations go back a decade, at least.

Higher orbits are visible for longer, due to the angles involved: because they're so high, such satellites can remain illuminated with the Sun further below the horizon. The Moon is the most extreme example: it's almost never in Earth's shadow.

Very good point.

I can tell you that they look like stars - so much that I need a reference point, an actual star or planet, to verify they are moving and not a 'stationary' star (judging movement being otherwise very difficult at that distance). They move very steadily, horizon to horizon, or as far as I can track them. A wild guess, based on memory, is one might take 5 or 10 minutes to cross between my horizons (usually I'm not on a plain - trees, hills, mountains may elevate my 'horizons' and reduce the distance).

Natural celestial object? No way a star is moving that fast relative to other stars and Earth's horizons. Asteroid? That seems hard to believe, due to size and illumination. Comet? Are there lots of tiny ones? I never see tails. Maybe a meteorite entering the atmosphere that doesn't yet have a tail?

Other human-made objects? Airplanes would look bigger and have colored, blinking lights - I've seen plenty of airplanes at night. Maybe there are higher flying airplanes without the colored and blinking lights? Are they illuminated whitish, and so far away they'd look like stars?

I've seen them so many times, I'm confident that I could take anyone to a wilderness area on a clear night and find one within 15-20 minutes, probably less.

Yup 5-10 minutes is right. It depends on the orbit altitude and the height of the pass.

You can use sat tracker apps to identify which one you're seeing. I do this sometimes because I'm a ham radio operator and I track the one I want to use sometimes with a directional antenna.

> No way a star is moving that fast relative to other stars

No star moves relative to other stars when viewed from earth. They are all so far away they appear static. The starscape rotates as a whole (well it doesn't, the earth does, but to the observer it seems that way), but relative to each other they absolutely don't move.

If they do move, it is definitely a sign to stop drinking :) :)

> Asteroid? That seems hard to believe, due to size and illumination.

Also asteroids move way faster across the sky than a satellite. And they're rare except during that time of the year when they're really common.

> Comet? Are there lots of tiny ones? I never see tails.

Comets are incredibly rare in this galactic neighbourhood.

> and Earth's horizons. Asteroid? That seems hard to believe, due to size and illumination. Comet? Are there lots of tiny ones? I never see tails.

And the distance - most asteroids pass by much further out than even the moon, so their motion would be hard to detect.

I would guess, reflected moonlight (moon over the horizon) would be enough to light up the dot well enough to see unaided.

https://www.timeanddate.com/astronomy/different-types-twilig...

It's been awhile, but I'm pretty sure I've seen these much later than that. I'm talking about lying in a sleeping bag, looking up at the amazing starfields of pitch-black wilderness nights (tip: never use a tent except in extremis - look what you're missing!).

Planes are similar, but tend to have flashing or colored lights and obviously aren't as far away.

I'm in a big city, but close to the ocean so I have a bit less light pollution. The city is also heavy military, so that could be part of the frequency.

Update: if you're near any of the spacex launches, you can watch the rocket too. I'm house sitting in Irvine, CA and saw the Monday launch go right near the house. Amazing to watch the plume from the rocket!

I don’t know how you would know that. People are very bad at seeing distances at these scales.

If they were indeed satelites they could be starlink satelites. They are put into orbit as a bunch together and then they spread along their orbital path as they take up their position.

This article has a picture, maybe you can check if it is similar to what you have seen? https://earthsky.org/space/spacex-starlink-satellites-explai...

If you could recall more details then maybe we can figure out more exactly what this might have been. (Such as where you were, which direction you were looking at, when did this happen, how fast did they cross the sky and how far the dots were from each other. Were the line spread in the direction they were moving or sideways?)

And of course, if it is 3am, and there is no sunlight at any altitude because the sun is on the other side of the world, no satellites are visible.

I could be wrong.

I don’t remember the details anymore, but it was one of the coolest practical experiments we did.

You probably just thought it was a star or a plane. They move but relatively slowly (even a fast LEO sat will cover the sky in about 5 minutes). They look just like a star apart from moving slowly. Depending on angles they can look pretty dim, especially the latest SpaceX sats. But the ISS is usually really bright because it's so huge and technically it's also a satellite.

You can tell them apart from a plane because they don't flash.

Edit: But yes there are several conditions that need to be met to see them like the other posters have mentioned. But every clear night near dusk or dawn you will see sats for sure. There are just so damn many in LEO now.

The flashing of satellites will generally be gentler than the short burst strobing of an aircraft.

In general, you can see a satellite when it is overhead and illuminated by the sun. In the evening, it will appear in the west, moving towards the east ( almost all satellites go this way, not just ISS ). As it goes farther east, heading towards darkness, it will fade away. The ISS is bright enough to see a reddish tinge as it passes through sunset light.

Shooting stars go much faster than satellites.

ISS is often visible in the middle of the day even in bright midday Southwest sun, if you know where & when to look.