So that is "432 Mbit/s per laser, and 9000 lasers total". I don't know you guys but I find that statement much more relatable than "42 PB/day". Interestingly, they also say each laser "can sustain a 100Gbps connection per link" (although another part of the article even claims 200 Gbit/s). That means each laser is grossly underused on average, at 0.432% of its maximum capacity. Which makes sense since 100 Gbit/s is probably achievable in ideal situations (eg. 2 satellites very close to each other), so these laser links are used in bursts and the link stays established only for a few tens of seconds or minutes, until the satellites move away and no longer are within line of sight of each other.
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).
>these laser links are used in bursts and the link stays established only for a few tens of seconds or minutes, until the satellites move away
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"
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?
Partially! There are also ascending and descending satellites meeting. Ascending and descending doesn't mean altitude but in a "2D view" sense. See https://www.heavens-above.com/StarLink.aspx
Most customers aren't served by lasers, their data goes up to the satellite and down to the nearest gateway. Lasers serve customers out of range of a downlink gateway, and the traffic probably travels the minimum hops needed to get to one.
But with lasers, it makes sense to route your packets via space. For example traffic to a different continent would be faster (and cheaper) through space. Furthermore, I assume lasers have more capacity than gateways, so they could increase capacity of one satellite by bundling with more gateways.
Yep, but that data originates from the providers network and never leave the providers network, so they probably don't count it towards your usage the same way.
I don't think that breaks net neutrality either, which the FCC seems to be reimplementing
Yeah 1TB seems average for anyone in IT who is really into data.
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’d have guessed they count “delivered bytes” not “transmitted bytes” and then you need to take into account each leg of the transfer. Which for starlink is at least two (for the simple bend pipe situation) and up to potentially something like ?20? (for a “halfway around the globe, totally starlink” connection). The latter is probably statistically negligible, but even the factor two would give ~2% utility. Which, taking into account, that at least 2/3 of the orbit time is spend out of reach of anywhere useful, this would give something like 1 in 10 possible bytes being transmitted. Which is much better than I’d have guessed if asked blindly
Is resolution going to peak? Like speeding on a highway are there diminishing returns? On the other hand, bandwidth availability seems to also drive demand...
There is one key issue of keeping lasers aligned for long durations between satellites and even between a satellite to a ground station. There are vibrations in satellites and even a tiny bit of that vibration translates to beam misalignment. Am not an expert though. That could explain the bursts.
So it's hard to sustain the theoretical 100GPS connection for hours let alone days across 2 end points which are in constant motion.
That means each laser is grossly underused on average, at 0.432% of its maximum capacity. Which makes sense since 100 Gbit/s is probably achievable in ideal situations (eg. 2 satellites very close to each other), so these laser links are used in bursts and the link stays established only for a few tens of seconds or minutes, until the satellites move away and no longer are within line of sight of each other.
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".
> That means each laser is grossly underused on average, at 0.432% of its maximum capacity.
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.
Starlink's big investor and launch customer was US Air Force.DoD had long complained about lack of fast sat comms, it's also why they effectively own Iridium.
So in addition to households add foreign bases and possibly drone command networks to possible sources of traffic going fast enough to warrant sat-to-sat connection.
My parents moved in and, being old, stream TV all day (instead of cable) and end up using about 40 GB per day with 1080p. We keep hitting our max of 1.2 TB set by our cable company (because there are others in the home!).
I should probably see if my router can bandwidth limit their mac addresses...
> 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.
The average household probably watches significantly more tv than HN users. That is almost all streamed - something like 6 hours per day times multiple TVs.
There’s probably redundancy in the links. In other words, A sends a MB to B which sends it to C, that’s 1 MB of information transmitted to customers but 2 MB of laser transmission.
I'm seeing about 6Mbps per customer during peak hour on my own network, so 1.7Mbps over a longer period of time sounds like it's in the right ballpark.
Thermal management is also a tremendous problem in space. All power generated must be radiated away, and satellites effectively sit inside a vacuum insulator.
I'd be interested in what the sustained power/thermal budget of the satellites is.
Where did you get that 100GB/mo number from? 4K streaming eats up data transfer quickly. Comcrap & friends knew what they were doing making arbitrary data caps that sounded like a big number at the time. Wireline data caps should be illegal.
My understanding of the state of the art of inter-satellite optical links is that they have only been used between satellites that are basically in the same orbital plane and in more or less the same orbit. That is, the angle from one satellite to the other changes very very slowly, so that the optics don't have to do much tracking -- and consequently satellites can only form an optical link with other satellites that are ahead or behind themselves in ~ the same orbit.
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.
> “Another really fun fact is that we held a link all the way down to 122 kilometers while we were de-orbiting a satellite,” he said. “And we were able to downstream the video.”
> 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.
Take a look at the slides from the presentation, I think the geometry clearly shows cross-plane links in the mesh. Having worked on these types of systems, I've had more difficulty with the lookahead angles (rx from where the target was, tx to where it will be due to speed of light) than the tracking -- fine tracking performance was required for all modes, and it largely became a GNC and acquisition time issue (since they're ephemeral) for the cross-plane links.
In general, how is the initial alignment performed?
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?
The "routing in the mesh" slide? Definitely given where the satellites are in that picture some of the links would have to be cross-plane, it's just the whole thing looked so messy (even with it being geo-referenced on a globe) that I didn't know whether to consider it a "real routing example" vs a "notional routing example that we overlaid on the globe".
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.
Tracking is an issue, but doppler can also be a thing. At orbital speed (actually up to 2x orbital speeds) the doppler effect between two satellites can change the frequency enough to cause interference. Moving a scope to track a moving target is one problem, allowing the algorithms to adapt at the frequency shifts on the fly another.
Indeed Iridium had to deal with the same thing (or I guess, didn’t):
“ 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.”
Doppler is not a big problem with lasers because the carrier frequency is so much higher than RF that it doesn't matter; it's bang-bang AM modulated.
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.
Nah, I once did a job for a guy and they did LEO-GEO distances alright iirc and LEO-Earth in the mid-end 2000s, which has to deal with some pretty high angular velocities, if not as potentially high as LEO-LEO when they don't happen to be relatively nicely aligned. (In case that sounds strange, the guy was one of the two owners of a small, very specialized company that in turn was subcontracted by a rather bigger company. These laser terminals were quite the beasts and not really cheap.)
Right. The Iridium network had communication between satellites in different orbital planes passing each other but that was a pretty unusual capability.
They do have counter rotating planes though, so there are places where two satellite tracks next to each other moving in opposite directions, and these pairs of satellites cannot use the cross plane communication mode.
Additionally, their inter satellite links use regular Ka band radio.
I'll assume there is a lot of double/triple (or higher) accounting going on here as data is sent through multiple relay hops to get the intended target.
I just noticed that they were launching their first satellites in 2019. It's impressive that they are now able to casually talk about the different routing options for the data streams to remote areas just 5 years after that.
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.
I think it's likely a bad idea at this point to bet against Elon - he seems to make more good decisions than bad decisions, and is able to attract and keep the talent that is enabling his companies to snowball exponentially towards reaching the abundance of the universe.
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.
Past performance is a piss poor indicator of future performance.
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
According to a quick search the average US household is closing in on 600 GB of traffic per month, that makes 42 PB per day the internet traffic of 2.1 million households. Incidentally the second picture in the article says 2.3M+ customers. With an US average of 2.5 people per household that is the traffic of 5 million people or 1.5 % of the US population.
Knowing the size of a video file is exactly not the information, that would help me put this number in a meaningful perspective with any comparable operation.
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.
> 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 :)
>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.
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?
If someone makes a mistake and the satellite deorbits in the wrong place, am I likely to be impaled by a satellite screw or something travelling at terminal velocity?
There are so many that I spot them with my telescope while watching the sky with some frequency. In the last year I've probably caught 6 or so. It's just a spot of light passing through the view, nothing spectacular, but I think it would have been virtually impossible 20 years ago.
1. The satellite needs to be passing overhead at an angle where you can see it, and clear skies etc.
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.
To me, they look like little white dots moving across the sky. Brightness can change as they move too. It'll start off bright and then as it goes away it eventually disappears entirely. Since I usually sit in the same position in the hot tub, I've come to notice that I usually see one of them cross a pretty specific path from north to south, so I've gotten used to looking in that part of the sky as I'm sitting there. It happens so frequently, I get a little disappointed if I don't see one!
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!
My tip is that the very central part of your field of view has worse night vision than the rest (trading off for higher resolution instead), so if you spot something moving in your peripheral vision, don’t try to look straight at it or it’ll disappear; instead, look slightly to the side, and it’ll be easier to see (although maybe blurrier).
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.
It depends where you live certainly - if you live close to a big city you will probably never see them. But there are places - like New Zealand - where you can see them fairly often. There are some online trackers you can use.
The easiest satellite to see is the ISS. NASA provides times when it can be seen from any given place. I subscribe to the SpotTheStation mailing list.
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.
It takes several minutes for your eyesight to adjust enough to spot them with the naked eye. You can use websites to know when one is likely to pass overhead. Choose a suitable time (see: everyone else, basically right after dusk), and then lie down and stare up about 15-minutes ahead. Mushrooms are optional, they increase the chances of seeing something but decrease the chance that what you saw was real.
https://james.darpinian.com/satellites/ Put in your location and it will tell you when and where to look at the sky to see one. Works great for me and hopefully it will work for you.
If the seeing is good it's actually possible to spot up hundred satellites with the unaided eye. Due to light pollution, it's unlikely to spot one in most places, though. The ISS at least should be easily visible due to its size, even in places that aren't particularly dark.
> The lasers, which can sustain a 100Gbps connection per link
> Brashears also said Starlink’s laser system was able to connect two satellites over 5,400 kilometers (3,355 miles) apart. The link was so long “it cut down through the atmosphere, all the way down to 30 kilometers above the surface of the Earth,” he said, before the connection broke.
How do these tiny satellites achieve this kind of accuracy and link quality when they're shooting around Earth with 17.000 miles an hour?
(Meanwhile, me on Earth, has link quality issues due to a speck of dust on a fiber connector)
Relative to the origin satellite I would assume the others are in a fairly fixed position to it. Remember they try to keep them spaced out and even coverage. That means the things are not moving around wildly relative to each other. But to us they are wizzing by. For example I know I am relatively moving fairly quickly to the earths core and pretty fast around the center of the sun. But from my PoV everything around me looks stationary. Also there is not a lot of dirt up there.
This says more about the link budget than anything else, it's much harder to keep tracking when satellites are close to each other moving at high relative velocities. At the distances in your example, movement of the laser link optical head is very slow, on the order of 0.01 - 0.1 deg/s. Optical heads also have a control loop which actively corrects for pointing errors once a positive link is established. Check out: https://www.sda.mil/wp-content/uploads/2022/04/SDA-OCT-Stand...
> (Meanwhile, me on Earth, has link quality issues due to a speck of dust on a fiber connector)
It's incredible really. I remember when I was a kid living with my mom on an island, we got broadband relatively late (compared to the rest of the country), as the island required antennas for getting mainland and the island linked, instead of cables. I think it was set up that way because of costs or something, remember it being expensive...
Regardless, the antennas were setup and we finally got broadband, but every time it got a bit windy and/or rainy, the links started to have huge issues, especially if the lake got lots of waves, then the connection simply disappeared.
And now it seems almost like magic to me how the same setup is literally done but way above our heads, in a really hostile environment like space.
The rate of change of their relative positions is what matters. At 5400km distance this is likely slowish so that tracking is not a big issue as long as position is well known, which it is.
Re. Link quality: laser, line of sight, most of the trip is in vacuum and the rest in very sparse atmosphere. So interferences are likely quite low.
Laser links are not using phased array antennas. It's a physically moving "turret" with a laser and another with a receiver. And they need to be separate units, because the speeds and distances involved are long enough that you are not receiving from the same direction as you are sending.
Real time video and telemetry for military drones that’s nearly immune to electronic warfare counter measures is the real end game. The fpv drone carnage in Ukraine is currently limited to the contact lines plus or minus a few kilometers. Satellite comms change that drastically. Yes it’s available now but highly restricted.
But not immune to missiles. Russia's already threatened to target Starlink satellites. Maybe they're bluffing, or not, but it does offer a reminder that these are just floating computers in the sky.
It doesn't really matter who owns it as long as it can be bent towards national goals when it matters.
American vehicle manufacturing was a strategic advantage during WWII because they swiftly pivoted to selling tanks to the government instead of cars to civilians.
Plenty of US strategic advantages are privately held or otherwise very dependent on the private sector. It's fine because the company can't really leave the US.
Offloading the risk on private players, reduces the amount of government investment required, and shields them from any criticism, should the project fail.
Also, if it is that strategically important, the government can just buy SpaceX.
That any SpaceX user who has a connection established for >2h will have their data sent not via the classic path "ground - satellite - ground" at least once during the connection, but via "ground - satellite 1 - satellite 2 - ground".
I think it means pretty much all Starlink users have at least some data go over laser links every two hours. Which is a bit of surprise to me, if true. I have a year or so of fine-grained latency detail taken with IRTT on a Starlink connection, I should sit down and see if I can see times I'm using a satellite. Latency is highly variable in Starlink though so it's pretty noisy data.
Have you posted that data anywhere? I'm currently on a 10mbps DSL connection and considering StarLink, but have so far been scared away by the cost and concerns about latency, so I'm always on the lookout for real world data.
What are you talking about - weather you think it will work or not, no other company is collecting training data and attempting to solve FSD in the same order of magnitude as Tesla. (last is saw, TSLA collects more video data in 1.5 years then Waymo does in 1 year)
FSD12 is end-to-end neural nets and the videos are pretty impressive. Who else is doing that ?
Optical fiber has an index of refraction of around 1.6, so signals travel at around 0.6c. For a perfectly straight cross-continental link (5,000km) with no delays from amplification/retransmission, that's about 26 milliseconds. Assuming the satellites are directly overhead, Starlink adds another 500km up and down, making the minimum possible latency around 20 milliseconds. The real number might be slightly higher or lower depending on the location of the satellites.
My guess is the real latency depends mostly on the latency of relay nodes (either satellites or routers on earth), not the medium through which signals travel.
Number of hops definitely matters more usually. For example I'm about 150 miles from Azure East US 2 (richmond, va), and at the speed of light that should be sub 2ms round trip, but actual latency to it is ~30ms. But I'm sure I'm going through dozens of switches/routers to get there. What Starlink buys you is that you get to go straight to a satellite, then a laser in a vacuum to other satellite(s) and then a ground station that's likely already at an IXP or very close to one.
That could already be the case. Round trip time to the ~500km orbit is about 4 milliseconds (+ all other network elements before, after and in between). They claim to have a >5000km link running for significant time. Now think of a fibre link of that length and how many repeaters / routers will be needed due to attenuation and physical constraints. I can clearly see a path where Starlink laser links could be a viable option to subsea cables - at least for some priority traffic...
Starlink adds a latency penalty of tens of milliseconds going through the atmosphere. Each round trip is four hops through the clouds. I expect most of this delay is forward error correction, combined with lower bandwidth of the radios.
On top of that, you may have queuing in each satellite.
Finally, the satellite laser links aren’t pointing exactly in the direction you want to your packets to travel. They’re at some diagonal, and the packets need to tack back and forth, which wastes distance. Think the streets of Manhattan.
This is just incorrect. The speed of light through atmosphere is almost identical to speed of light in a vacuum. There's no latency penalty for traveling through the atmosphere. The one-way time delay to a Starlink satellite is about 2 milliseconds.
It's possible for starlink to beat radio, because radio can't always go straight to the target. If I wanted a radio link from NY->Tokyo, what would that path look like?
It would look like the HF radio bouncing off the ionosphere. I have contacted someone in Japan from Oregon. The downside of HF is that the bandwidth is low with 30MHz across the entire band.
There was company recently wanting to do high-frequency trading on HF because of the quickest path.
Random thought I just had: What are the odds of a rocket launch crossing through one of these laser links on its way to a higher orbit and disrupting traffic for a fraction of a second?
I know space is really big and so the odds of a rocket hitting a satellite on its way up are incredibly low, but now we're talking about lots of lines between each satellite rather than just the satellites themselves. Are the odds still tiny?
Not that it would be a big deal if it happened, just curiosity.
It's absolutely incredibly small, think of how large the surface area of a sphere of LEO and the surface area of these lasers linking the vertices of the 5,289 satellites. The gaps between them are probably hundreds of kilometres. I would imagine that each link has multiple routes so if there was a failure traffic can still be routed in the same way the Internet has many routes.
https://satellitemap.space is pretty amazing but a Starlink satellite looks massive on there, really at the scales we are talking they wouldn't even be a pixel. Do we know how many of the satellites are actually interlinked by lasers?
There’s no friction in space. So the question is not how wide the plume of a rocket engine gets, but how spread out does the vapor trail need to be before it stops being an optical impediment?
Interesting question. It used to be zero, before the satellites and before the rockets, but now is probably not zero.
I think you could take the time a rocket would be in the way and compare it to the time it would take any given satellite link pair to make an orbit to form an estimate of the chance of a single interference. Then multiply by rockets and satellite pairs to form an overall estimate.
I've done some research, I don't have a probability but from what I've found. A Falcon 9 shortly before stage 1 separation is around 50km altitude[0] doing ~2000 m/s. Preseperation the F9 is 70m tall, add 130m for plume[1] so 200m total. At 2000 m/s it'll cover it's own length and plume in 100ms. If the laser link is running at 100 Gbps that's 10Gb of data lost.
Which is actually a lot more then I estimated when I started this math, kinda puts into perspective more then 1 of the scales at play here.
Tl;dr Rockets are fast, data is apparently faster.
[0] Apparently on its longest distance link Starlink intersected 30km altitude
It doesn't matter what the odds are; loss of connectivity is going to happen. Packet loss is common across the internet, fortunately we have protocols that can deal with this.
Starlink is rolling out "direct to cell" connections, where the satellites connect directly to GSM cell phones. Is any ground station involved in a cell to cell call?
For Google, I found setting my browser to "Accept-Language: en,sv" when I live in Denmark was sufficient — just English and they seem to assume I can't configure the browser and want the local language.
PCMag serves me English, with "en-GB,en", though I don't know if they would support Danish anyway.
The article mentions that they were able to stream video from a starlink satellite as it was de-orbiting - it would be neat to see the video of that, even if it cuts off as the laser link losing connection (or the satellite burns up)
Just for context, here's SDA's Open Standard on how they expect to do connections over Optical Links. I assume the starlink terminals work in a similar manner:
Has anyone tried Starlink? I super curious as to whether it's a decent drop in replacement for the ISP have been using at home, and have had trouble with since day one. I won't mention any names (but I will say that it sounds a bit like Smodabone). What is the latency like? The variability of the up/down? Does it do what it says on the tin? Is (non-professional) online gaming a go?
Been using it since it was first available. Latency is fine, speeds are good and steady. Occasional outages of several hours every few months or so, but improving as time goes on.
Only complaint is that their DHCP server is buggy so if you don't use their blessed router, you can expect outages when you get transitioned to a new base station and starlink expects your IP to have changed, but it doesn't, or sometimes when your IP lease expires. Took me months to figure out that was the issue. I run almalinux on my router so I just have a script that checks a heartbeat and if it gets interrupted it will nmcli down the wan interface and back up, which usually gets a new IP. Though sometimes it will give the special IP to my router that is supposed to go to the blessed router.
Overall I do recommend, but have a backup ISP if always up is important.
>Has anyone tried Starlink? I super curious as to whether it's a decent drop in replacement for the ISP have been using at home
I use it when I'm venturing around my rural area, which has spotty (or zero) LTE and broadband. It's awesome for that, literal game-changer.
But it does suffer from downtime, sometimes poor reception, bit of lag, etc. It's the difference between 99% uptime and 99.999999%; you'll notice if you're using it all day, every day. It's also more expensive than my home broadband for lower speeds. I don't think you could replace your ISP, unless your ISP is pretty bad.
My experience, a year of use - 300Mbps down pretty consistently, 40Mbps up, 40-60ms latency, fine for gaming for the most part, and the drop outs are unnoticeable short when they do infrequently happen. Never had an outage more than 10 seconds.
They’ve also nearly halved the price since I signed up.
My novice view....Laser connections are point to point, so they can be between satellites....But to the end user equipment,having those many point to point laser connections might be too difficult or impractical to achieve...So that's where they use radiowaves, which means any satellite over the horizon can talk to a dish...
1. Full-circumference world round-trip latency sat to sat (yes it has to go to ground to “count” but I just want to know what the number is)
2. Deployed LEO servers running with laser communication to the Starlink satellites. Preferably gaming or CDN since either is a great way to verifiably test the limits.
4 nines uptime is great, but I would think the SNR matters more in a packet switched network like this. There are conditions that may lead to a very low SNR.
No. The focus of a laser beam is not constant over these large distances. It is the same effect you get if you use a laser pointer over large distances. The spot becomes large quickly.
Is this a serious question? You think SpaceX developed the industry-leading orbital rocket, launched hundreds of times to deliver thousands of in-house developed satellites utilizing homegrown, novel argon gas ion thrusters, to develop a global satellite internet system using inter-satellite laser links, their own in-house developed, incredibly inexpensive phased array antenna system, and everything else, and they forgot to use TLS?
OP was likely referring to this[1] which did in fact have lines like "tesla isn't encrypting their firmware and it's really easy to glean information from the vpn with a packet cap because nothing inside the vpn (was) encrypted".
so you are asking if the traffic is additionally encrypted? i don't think that additional encryption is needed, like your ISP doesn't additionally encrypt your TLS encrypted traffic, that would be waste of resources
Usual selling point in marketing of ground based free space optical links is that it is very hard to intercept. Compared to P2P microwave the beam is significantly narrower and alignment requirements higher and the link loss budget is usually tight enough that when the beam becomes visible off-axis due the weather efects (heavy rain or ridiculously thick fog) the link fails.
On the other hand one can extrapolate from results of reverse engineering of the starlink dish. Everything that goes through the space segment is encrypted and entirerity of the high-level control plane is mTLS authenticated, so one would assume that the inter-satellite links work in similar way. Of note is that software in the dish seems to share large swatches of code with what is not only on the starlink satellites but bunch of other SpaceX embedded linux systems.
the DoD and the NSA surely looked closely in the past couple of years. not least because their Russian and Chinese counterparts for sure are trying to look closely, too, especially in the past couple years.
Global internet traffic is estimated to be 3 yottabytes per day. So Starlink is now carrying one of out every 77 million parts of worldwide traffic. Wow, that's small.
EDIT: there's some confusion information out there. With a more conservative estimate of 150.7 exabytes per month, Starlink gets 1 part of 119, which is more impressive.
So that is "432 Mbit/s per laser, and 9000 lasers total". I don't know you guys but I find that statement much more relatable than "42 PB/day". Interestingly, they also say each laser "can sustain a 100Gbps connection per link" (although another part of the article even claims 200 Gbit/s). That means each laser is grossly underused on average, at 0.432% of its maximum capacity. Which makes sense since 100 Gbit/s is probably achievable in ideal situations (eg. 2 satellites very close to each other), so these laser links are used in bursts and the link stays established only for a few tens of seconds or minutes, until the satellites move away and no longer are within line of sight of each other.
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).
>these laser links are used in bursts and the link stays established only for a few tens of seconds or minutes, until the satellites move away
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"
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?
4 replies →
Partially! There are also ascending and descending satellites meeting. Ascending and descending doesn't mean altitude but in a "2D view" sense. See https://www.heavens-above.com/StarLink.aspx
1 reply →
Most customers aren't served by lasers, their data goes up to the satellite and down to the nearest gateway. Lasers serve customers out of range of a downlink gateway, and the traffic probably travels the minimum hops needed to get to one.
But with lasers, it makes sense to route your packets via space. For example traffic to a different continent would be faster (and cheaper) through space. Furthermore, I assume lasers have more capacity than gateways, so they could increase capacity of one satellite by bundling with more gateways.
9 replies →
Netflix uses 3-7GB an hour. The average person is spending 4-5hrs a day watching TV. I’d say most are above 100GB/month.
But that’s me.
Who has 4-5 hrs a day to watch television? ..or am I completely out of touch?
31 replies →
Yep, but that data originates from the providers network and never leave the providers network, so they probably don't count it towards your usage the same way.
I don't think that breaks net neutrality either, which the FCC seems to be reimplementing
Edit: see https://openconnect.netflix.com/en/
6 replies →
Do you have a source on the 4-5 hrs?
2 replies →
Yeah 1TB seems average for anyone in IT who is really into data.
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
Data might get counted multiple times as it takes many laser hops to reach its destination.
Good point.
I’d have guessed they count “delivered bytes” not “transmitted bytes” and then you need to take into account each leg of the transfer. Which for starlink is at least two (for the simple bend pipe situation) and up to potentially something like ?20? (for a “halfway around the globe, totally starlink” connection). The latter is probably statistically negligible, but even the factor two would give ~2% utility. Which, taking into account, that at least 2/3 of the orbit time is spend out of reach of anywhere useful, this would give something like 1 in 10 possible bytes being transmitted. Which is much better than I’d have guessed if asked blindly
I think the average Instagram or TikTok user must be using more than 100GB/month. And if you count YouTube and Netflix, it's probably more than that.
Is resolution going to peak? Like speeding on a highway are there diminishing returns? On the other hand, bandwidth availability seems to also drive demand...
4 replies →
This is being downvoted but it's probably about right.
My smart TV used 483 GB in the last 30 days
There is one key issue of keeping lasers aligned for long durations between satellites and even between a satellite to a ground station. There are vibrations in satellites and even a tiny bit of that vibration translates to beam misalignment. Am not an expert though. That could explain the bursts.
So it's hard to sustain the theoretical 100GPS connection for hours let alone days across 2 end points which are in constant motion.
That means each laser is grossly underused on average, at 0.432% of its maximum capacity. Which makes sense since 100 Gbit/s is probably achievable in ideal situations (eg. 2 satellites very close to each other), so these laser links are used in bursts and the link stays established only for a few tens of seconds or minutes, until the satellites move away and no longer are within line of sight of each other.
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".
> That means each laser is grossly underused on average, at 0.432% of its maximum capacity.
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.
The first slide says "9000+", suggesting that the number of space lasers is slightly over 9000. I feel like that's an important distinction.
Most likely it's a reference to the "it's over 9000!" meme.
Starlink's big investor and launch customer was US Air Force.DoD had long complained about lack of fast sat comms, it's also why they effectively own Iridium.
So in addition to households add foreign bases and possibly drone command networks to possible sources of traffic going fast enough to warrant sat-to-sat connection.
Launch customer yes. Investor no. That's Google and Fidelity Paying above the regular rate. Definitely
2 replies →
My parents moved in and, being old, stream TV all day (instead of cable) and end up using about 40 GB per day with 1080p. We keep hitting our max of 1.2 TB set by our cable company (because there are others in the home!).
I should probably see if my router can bandwidth limit their mac addresses...
> 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.
Dead internet theory (alive and well!)
The average household probably watches significantly more tv than HN users. That is almost all streamed - something like 6 hours per day times multiple TVs.
1tb feels reasonable to push that much video.
There’s probably redundancy in the links. In other words, A sends a MB to B which sends it to C, that’s 1 MB of information transmitted to customers but 2 MB of laser transmission.
I'm seeing about 6Mbps per customer during peak hour on my own network, so 1.7Mbps over a longer period of time sounds like it's in the right ballpark.
"Customer" may refer to households, not individuals, in which case it could be numerous internet users soaking up data per customer.
Just because they seem grossly underused, there are probably plenty of other non-ideal constraints like power usage for instance.
Thermal management is also a tremendous problem in space. All power generated must be radiated away, and satellites effectively sit inside a vacuum insulator.
I'd be interested in what the sustained power/thermal budget of the satellites is.
Where did you get that 100GB/mo number from? 4K streaming eats up data transfer quickly. Comcrap & friends knew what they were doing making arbitrary data caps that sounded like a big number at the time. Wireline data caps should be illegal.
if you stream you use a lot more than 100gb/month. I use around 1tb with a family of 3.
i think even more relatable is how many customers they can handle at say 200 mbps
My understanding of the state of the art of inter-satellite optical links is that they have only been used between satellites that are basically in the same orbital plane and in more or less the same orbit. That is, the angle from one satellite to the other changes very very slowly, so that the optics don't have to do much tracking -- and consequently satellites can only form an optical link with other satellites that are ahead or behind themselves in ~ the same orbit.
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.
> “Another really fun fact is that we held a link all the way down to 122 kilometers while we were de-orbiting a satellite,” he said. “And we were able to downstream the video.”
> 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.
So what happens to the laser beam when there are clouds?
6 replies →
Take a look at the slides from the presentation, I think the geometry clearly shows cross-plane links in the mesh. Having worked on these types of systems, I've had more difficulty with the lookahead angles (rx from where the target was, tx to where it will be due to speed of light) than the tracking -- fine tracking performance was required for all modes, and it largely became a GNC and acquisition time issue (since they're ephemeral) for the cross-plane links.
In general, how is the initial alignment performed?
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?
7 replies →
The "routing in the mesh" slide? Definitely given where the satellites are in that picture some of the links would have to be cross-plane, it's just the whole thing looked so messy (even with it being geo-referenced on a globe) that I didn't know whether to consider it a "real routing example" vs a "notional routing example that we overlaid on the globe".
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.
GNC?
3 replies →
Tracking is an issue, but doppler can also be a thing. At orbital speed (actually up to 2x orbital speeds) the doppler effect between two satellites can change the frequency enough to cause interference. Moving a scope to track a moving target is one problem, allowing the algorithms to adapt at the frequency shifts on the fly another.
Indeed Iridium had to deal with the same thing (or I guess, didn’t):
“ 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...
6 replies →
Doppler is not a big problem with lasers because the carrier frequency is so much higher than RF that it doesn't matter; it's bang-bang AM modulated.
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.
Links between satellites closing range near 2x orbital speed have two problems: - bigger doppler - the lifetime of the link is much shorter
Nah, I once did a job for a guy and they did LEO-GEO distances alright iirc and LEO-Earth in the mid-end 2000s, which has to deal with some pretty high angular velocities, if not as potentially high as LEO-LEO when they don't happen to be relatively nicely aligned. (In case that sounds strange, the guy was one of the two owners of a small, very specialized company that in turn was subcontracted by a rather bigger company. These laser terminals were quite the beasts and not really cheap.)
[dead]
With 266,000 acquisitions per day, I suggest they are regularly doing links across orbital planes.
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.
Right. The Iridium network had communication between satellites in different orbital planes passing each other but that was a pretty unusual capability.
They do have counter rotating planes though, so there are places where two satellite tracks next to each other moving in opposite directions, and these pairs of satellites cannot use the cross plane communication mode.
Additionally, their inter satellite links use regular Ka band radio.
I wonder how iridium actually handles the tracking (or if it’s just slow enough and lack of attenuation in free space just lets them blast it).
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.
3 replies →
I'll assume there is a lot of double/triple (or higher) accounting going on here as data is sent through multiple relay hops to get the intended target.
I just noticed that they were launching their first satellites in 2019. It's impressive that they are now able to casually talk about the different routing options for the data streams to remote areas just 5 years after that.
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.
I think it's likely a bad idea at this point to bet against Elon - he seems to make more good decisions than bad decisions, and is able to attract and keep the talent that is enabling his companies to snowball exponentially towards reaching the abundance of the universe.
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.
Past performance is a piss poor indicator of future performance.
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
15 replies →
I have absolutely no idea how that number relates to any comparable operation. Can anyone add a banana for scale?
Assuming it's a constant data transfer rate, this is 3,889 Gbps. This is
- 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
Bangladesh, the whole country, usage 2,300Gbps as of 2021. So 1 Petabyte per hour?
Edit: It's international traffic. YouTube, Facebook video has local cache server by ISP.
This is a useful scale of comparison and what I think OP was after
1 reply →
> If you took a petabyte's worth of 1GB flash drives and lined them up end to end, they would stretch over 92 football fields.
https://info.cobaltiron.com/blog/petabyte-how-much-informati...
That's actually a somewhat useful visual.
7 replies →
According to a quick search the average US household is closing in on 600 GB of traffic per month, that makes 42 PB per day the internet traffic of 2.1 million households. Incidentally the second picture in the article says 2.3M+ customers. With an US average of 2.5 people per household that is the traffic of 5 million people or 1.5 % of the US population.
486GB/s
EMBL-EBI’s open transfer systems provide ~5PB of data each month.
ftp.ebi.ac.uk for example.
Better yet, a work in a 35 foot long Twinkie.
If you've got a laptop with a terrabyte drive, it would be 42,000 full laptops worth of data.
Implementing a “comparable operation” to this satellite network using laptops instead is going to be really expensive fuel-wise, I think.
1 reply →
If you have a laptop with a petabyte drive, it would be 42 full laptops worth of data!
1 reply →
[dead]
[dead]
10 minutes of 4k video is ~30GB.
Knowing the size of a video file is exactly not the information, that would help me put this number in a meaningful perspective with any comparable operation.
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.
7 replies →
I feel like this is a bad example.
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.
Based on 2160p movies i've seen around the very largest max out at around 100, and 40 is more common, so this seems wrong.
2 replies →
I sit in my hot tub at night and see 1-2+ satellites go over every single time I'm out there.
Which also makes me wonder how many of the shooting stars I've seen recently are just old starlinks burning up.
> 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 :)
No, I love this data! Thank you.
>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.
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?
1 reply →
If someone makes a mistake and the satellite deorbits in the wrong place, am I likely to be impaled by a satellite screw or something travelling at terminal velocity?
13 replies →
There are so many that I spot them with my telescope while watching the sky with some frequency. In the last year I've probably caught 6 or so. It's just a spot of light passing through the view, nothing spectacular, but I think it would have been virtually impossible 20 years ago.
The first time I saw the long line of starlink satellites in a dark rural area it was unreal. Straight up looked like aliens invading.
As someone who also spends a decent amount of time outside at night, do you also see a ton of shooting stars?
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.
How do you spot a satellite? I've never seen one.
1. The satellite needs to be passing overhead at an angle where you can see it, and clear skies etc.
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.
15 replies →
To me, they look like little white dots moving across the sky. Brightness can change as they move too. It'll start off bright and then as it goes away it eventually disappears entirely. Since I usually sit in the same position in the hot tub, I've come to notice that I usually see one of them cross a pretty specific path from north to south, so I've gotten used to looking in that part of the sky as I'm sitting there. It happens so frequently, I get a little disappointed if I don't see one!
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!
9 replies →
My tip is that the very central part of your field of view has worse night vision than the rest (trading off for higher resolution instead), so if you spot something moving in your peripheral vision, don’t try to look straight at it or it’ll disappear; instead, look slightly to the side, and it’ll be easier to see (although maybe blurrier).
I can guarantee you you have.
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.
1 reply →
It depends where you live certainly - if you live close to a big city you will probably never see them. But there are places - like New Zealand - where you can see them fairly often. There are some online trackers you can use.
1 reply →
The easiest satellite to see is the ISS. NASA provides times when it can be seen from any given place. I subscribe to the SpotTheStation mailing list.
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.
1 reply →
It takes several minutes for your eyesight to adjust enough to spot them with the naked eye. You can use websites to know when one is likely to pass overhead. Choose a suitable time (see: everyone else, basically right after dusk), and then lie down and stare up about 15-minutes ahead. Mushrooms are optional, they increase the chances of seeing something but decrease the chance that what you saw was real.
https://james.darpinian.com/satellites/ Put in your location and it will tell you when and where to look at the sky to see one. Works great for me and hopefully it will work for you.
It's usually a somewhat like a fast moving little but visible star. Fast as in it would usually cross 1/4 of the visible sky within 20 seconds or so.
You should try to find one once, with the help of an app. It's not that difficult.
If the seeing is good it's actually possible to spot up hundred satellites with the unaided eye. Due to light pollution, it's unlikely to spot one in most places, though. The ISS at least should be easily visible due to its size, even in places that aren't particularly dark.
Even in a city you stand a chance if you've got high walls around you. A courtyard garden for example. Just lie back and stare up.
Probably out in a rural area far enough away from a major city its easier to see them.
The Starlink ones look like Santa's sleigh https://i.imgur.com/4S0vbfY.gif
2 replies →
> The lasers, which can sustain a 100Gbps connection per link
> Brashears also said Starlink’s laser system was able to connect two satellites over 5,400 kilometers (3,355 miles) apart. The link was so long “it cut down through the atmosphere, all the way down to 30 kilometers above the surface of the Earth,” he said, before the connection broke.
How do these tiny satellites achieve this kind of accuracy and link quality when they're shooting around Earth with 17.000 miles an hour?
(Meanwhile, me on Earth, has link quality issues due to a speck of dust on a fiber connector)
Relative to the origin satellite I would assume the others are in a fairly fixed position to it. Remember they try to keep them spaced out and even coverage. That means the things are not moving around wildly relative to each other. But to us they are wizzing by. For example I know I am relatively moving fairly quickly to the earths core and pretty fast around the center of the sun. But from my PoV everything around me looks stationary. Also there is not a lot of dirt up there.
3M just invented a new fiber interconnect thing to mitigate the dust issue: https://www.3m.com/3M/en_US/data-center-us/applications/inte...
Maybe the future of usb in 10 years :)
This says more about the link budget than anything else, it's much harder to keep tracking when satellites are close to each other moving at high relative velocities. At the distances in your example, movement of the laser link optical head is very slow, on the order of 0.01 - 0.1 deg/s. Optical heads also have a control loop which actively corrects for pointing errors once a positive link is established. Check out: https://www.sda.mil/wp-content/uploads/2022/04/SDA-OCT-Stand...
> (Meanwhile, me on Earth, has link quality issues due to a speck of dust on a fiber connector)
It's incredible really. I remember when I was a kid living with my mom on an island, we got broadband relatively late (compared to the rest of the country), as the island required antennas for getting mainland and the island linked, instead of cables. I think it was set up that way because of costs or something, remember it being expensive...
Regardless, the antennas were setup and we finally got broadband, but every time it got a bit windy and/or rainy, the links started to have huge issues, especially if the lake got lots of waves, then the connection simply disappeared.
And now it seems almost like magic to me how the same setup is literally done but way above our heads, in a really hostile environment like space.
In some important ways space is actually the least hostile environment. But yeah, it’s still amazing and has its own challenges.
The current Starlinks satellites aren't small. They are almost a ton and 13ft by 9ft.
Even the original ones weren't that small weighing 570lb.
Given this is Gen3 and Gen4 now being launched, it took some figuring out
The rate of change of their relative positions is what matters. At 5400km distance this is likely slowish so that tracking is not a big issue as long as position is well known, which it is.
Re. Link quality: laser, line of sight, most of the trip is in vacuum and the rest in very sparse atmosphere. So interferences are likely quite low.
Phased array antennas probably have a lot to do with this. You can aim the signal more accurately and faster than any mechanical system ever could.
Laser links are not using phased array antennas. It's a physically moving "turret" with a laser and another with a receiver. And they need to be separate units, because the speeds and distances involved are long enough that you are not receiving from the same direction as you are sending.
2 replies →
Surely the lasers aren't phased arrays.
Their exact position in space can be calculated very precisely. The Starlink terminals do this as well.
In the long run that could become a massive strategic advantage for the US. A 2nd layer of resilience over undersea cables
Real time video and telemetry for military drones that’s nearly immune to electronic warfare counter measures is the real end game. The fpv drone carnage in Ukraine is currently limited to the contact lines plus or minus a few kilometers. Satellite comms change that drastically. Yes it’s available now but highly restricted.
But not immune to missiles. Russia's already threatened to target Starlink satellites. Maybe they're bluffing, or not, but it does offer a reminder that these are just floating computers in the sky.
15 replies →
A privately-held strategic advantage?
It doesn't really matter who owns it as long as it can be bent towards national goals when it matters.
American vehicle manufacturing was a strategic advantage during WWII because they swiftly pivoted to selling tanks to the government instead of cars to civilians.
1 reply →
Like all other US defense companies, why not? Do you think US Navy produces their own ships?
5 replies →
Plenty of US strategic advantages are privately held or otherwise very dependent on the private sector. It's fine because the company can't really leave the US.
At that level of strategic usefulness ownership stops mattering if shit hits the fan. It'll simply get commandeered.
Offloading the risk on private players, reduces the amount of government investment required, and shields them from any criticism, should the project fail.
Also, if it is that strategically important, the government can just buy SpaceX.
1 reply →
Assuming imminent domain and pursuant seizure.
A strategic advantage depending on the whims of a single provate company.
Sounds great, what could possibly go wrong?
> "We actually serve over lasers all of our users on Starlink at a given time in like a two-hour window"
I can't figure out what this sentence means.
That any SpaceX user who has a connection established for >2h will have their data sent not via the classic path "ground - satellite - ground" at least once during the connection, but via "ground - satellite 1 - satellite 2 - ground".
I think it means pretty much all Starlink users have at least some data go over laser links every two hours. Which is a bit of surprise to me, if true. I have a year or so of fine-grained latency detail taken with IRTT on a Starlink connection, I should sit down and see if I can see times I'm using a satellite. Latency is highly variable in Starlink though so it's pretty noisy data.
Have you posted that data anywhere? I'm currently on a 10mbps DSL connection and considering StarLink, but have so far been scared away by the cost and concerns about latency, so I'm always on the lookout for real world data.
1 reply →
Hey, I’m very curious if you’ve seen any improvement in latency over the past month.
1 reply →
The amount of bleeding edge innovation that is rapidly developed and deployed into production in Musks companies is incredible.
>The amount of bleeding edge innovation that is rapidly developed and deployed into production in Musks companies is incredible.
SpaceX for sure.
Hard to argue that Tesla is "bleeding edge" anymore; they maintain some advantages, but have fallen behind in other domains.
What are you talking about - weather you think it will work or not, no other company is collecting training data and attempting to solve FSD in the same order of magnitude as Tesla. (last is saw, TSLA collects more video data in 1.5 years then Waymo does in 1 year)
FSD12 is end-to-end neural nets and the videos are pretty impressive. Who else is doing that ?
1 reply →
So which points are getting “faster than fibre” latency because of this? Extra distance up and down, but make up for it on the long-haul.
Won’t beat HF radio though.
Optical fiber has an index of refraction of around 1.6, so signals travel at around 0.6c. For a perfectly straight cross-continental link (5,000km) with no delays from amplification/retransmission, that's about 26 milliseconds. Assuming the satellites are directly overhead, Starlink adds another 500km up and down, making the minimum possible latency around 20 milliseconds. The real number might be slightly higher or lower depending on the location of the satellites.
My guess is the real latency depends mostly on the latency of relay nodes (either satellites or routers on earth), not the medium through which signals travel.
Number of hops definitely matters more usually. For example I'm about 150 miles from Azure East US 2 (richmond, va), and at the speed of light that should be sub 2ms round trip, but actual latency to it is ~30ms. But I'm sure I'm going through dozens of switches/routers to get there. What Starlink buys you is that you get to go straight to a satellite, then a laser in a vacuum to other satellite(s) and then a ground station that's likely already at an IXP or very close to one.
1 reply →
That could already be the case. Round trip time to the ~500km orbit is about 4 milliseconds (+ all other network elements before, after and in between). They claim to have a >5000km link running for significant time. Now think of a fibre link of that length and how many repeaters / routers will be needed due to attenuation and physical constraints. I can clearly see a path where Starlink laser links could be a viable option to subsea cables - at least for some priority traffic...
a few random outages which happened near places some oligarch's yacht has visited recently and it'll become the priority backhaul.
I see folks in the Pentagon doing a collective /phew that this project is online in the next decade, multiple times.
Starlink adds a latency penalty of tens of milliseconds going through the atmosphere. Each round trip is four hops through the clouds. I expect most of this delay is forward error correction, combined with lower bandwidth of the radios.
On top of that, you may have queuing in each satellite.
Finally, the satellite laser links aren’t pointing exactly in the direction you want to your packets to travel. They’re at some diagonal, and the packets need to tack back and forth, which wastes distance. Think the streets of Manhattan.
This is just incorrect. The speed of light through atmosphere is almost identical to speed of light in a vacuum. There's no latency penalty for traveling through the atmosphere. The one-way time delay to a Starlink satellite is about 2 milliseconds.
It's possible for starlink to beat radio, because radio can't always go straight to the target. If I wanted a radio link from NY->Tokyo, what would that path look like?
It would look like the HF radio bouncing off the ionosphere. I have contacted someone in Japan from Oregon. The downside of HF is that the bandwidth is low with 30MHz across the entire band.
There was company recently wanting to do high-frequency trading on HF because of the quickest path.
1 reply →
True, it would be bouncing around between ground and the atmosphere (when it works at all).
Why would we expect faster than fibre?
The speed of light in a vacuum is roughly 50% higher than the speed of light in fiber.
8 replies →
Also, as pointed out elsewhere, the number of hops is the biggest contributor to latency.
1 reply →
Random thought I just had: What are the odds of a rocket launch crossing through one of these laser links on its way to a higher orbit and disrupting traffic for a fraction of a second?
I know space is really big and so the odds of a rocket hitting a satellite on its way up are incredibly low, but now we're talking about lots of lines between each satellite rather than just the satellites themselves. Are the odds still tiny?
Not that it would be a big deal if it happened, just curiosity.
It's absolutely incredibly small, think of how large the surface area of a sphere of LEO and the surface area of these lasers linking the vertices of the 5,289 satellites. The gaps between them are probably hundreds of kilometres. I would imagine that each link has multiple routes so if there was a failure traffic can still be routed in the same way the Internet has many routes.
https://satellitemap.space is pretty amazing but a Starlink satellite looks massive on there, really at the scales we are talking they wouldn't even be a pixel. Do we know how many of the satellites are actually interlinked by lasers?
There’s no friction in space. So the question is not how wide the plume of a rocket engine gets, but how spread out does the vapor trail need to be before it stops being an optical impediment?
3 replies →
I think they are still tiny. Also don't networking systems routinely deal with temporary link disruption?
What does that have to do with the odds of rocket induced dropped packets?
5 replies →
Interesting question. It used to be zero, before the satellites and before the rockets, but now is probably not zero.
I think you could take the time a rocket would be in the way and compare it to the time it would take any given satellite link pair to make an orbit to form an estimate of the chance of a single interference. Then multiply by rockets and satellite pairs to form an overall estimate.
I've done some research, I don't have a probability but from what I've found. A Falcon 9 shortly before stage 1 separation is around 50km altitude[0] doing ~2000 m/s. Preseperation the F9 is 70m tall, add 130m for plume[1] so 200m total. At 2000 m/s it'll cover it's own length and plume in 100ms. If the laser link is running at 100 Gbps that's 10Gb of data lost.
Which is actually a lot more then I estimated when I started this math, kinda puts into perspective more then 1 of the scales at play here.
Tl;dr Rockets are fast, data is apparently faster.
[0] Apparently on its longest distance link Starlink intersected 30km altitude
[1] Ref: my ass
> the odds of a rocket hitting a satellite on its way up are incredibly low
Aside, but it's not left to chance. They only launch when there's a gap in the space traffic.
Fair, but they don't compute and probably can't know the laser paths between Starlink nodes.
It doesn't matter what the odds are; loss of connectivity is going to happen. Packet loss is common across the internet, fortunately we have protocols that can deal with this.
But how do they beam copies of the space to space links down for wiretapping, as Iridium does?
At the ground stations
GS is layer 2. It's done at the POP's like every other company
Starlink is rolling out "direct to cell" connections, where the satellites connect directly to GSM cell phones. Is any ground station involved in a cell to cell call?
2 replies →
I hate that PCMag ignores browser preferred language lists. It switches the language on my geo IP address which is a language I cannot read.
This is a serious annoyance for me all day long, across the internet. Have you found most sites respect your preferred languages list?
For Google, I found setting my browser to "Accept-Language: en,sv" when I live in Denmark was sufficient — just English and they seem to assume I can't configure the browser and want the local language.
PCMag serves me English, with "en-GB,en", though I don't know if they would support Danish anyway.
The article mentions that they were able to stream video from a starlink satellite as it was de-orbiting - it would be neat to see the video of that, even if it cuts off as the laser link losing connection (or the satellite burns up)
42M GB Per day = 3.9tbps
> M GB
I can hear the SI crying.
Just for context, here's SDA's Open Standard on how they expect to do connections over Optical Links. I assume the starlink terminals work in a similar manner:
https://www.sda.mil/wp-content/uploads/2023/06/SDA_OCT_Stand...
Has anyone tried Starlink? I super curious as to whether it's a decent drop in replacement for the ISP have been using at home, and have had trouble with since day one. I won't mention any names (but I will say that it sounds a bit like Smodabone). What is the latency like? The variability of the up/down? Does it do what it says on the tin? Is (non-professional) online gaming a go?
Been using it since it was first available. Latency is fine, speeds are good and steady. Occasional outages of several hours every few months or so, but improving as time goes on.
Only complaint is that their DHCP server is buggy so if you don't use their blessed router, you can expect outages when you get transitioned to a new base station and starlink expects your IP to have changed, but it doesn't, or sometimes when your IP lease expires. Took me months to figure out that was the issue. I run almalinux on my router so I just have a script that checks a heartbeat and if it gets interrupted it will nmcli down the wan interface and back up, which usually gets a new IP. Though sometimes it will give the special IP to my router that is supposed to go to the blessed router.
Overall I do recommend, but have a backup ISP if always up is important.
>Has anyone tried Starlink? I super curious as to whether it's a decent drop in replacement for the ISP have been using at home
I use it when I'm venturing around my rural area, which has spotty (or zero) LTE and broadband. It's awesome for that, literal game-changer.
But it does suffer from downtime, sometimes poor reception, bit of lag, etc. It's the difference between 99% uptime and 99.999999%; you'll notice if you're using it all day, every day. It's also more expensive than my home broadband for lower speeds. I don't think you could replace your ISP, unless your ISP is pretty bad.
My experience, a year of use - 300Mbps down pretty consistently, 40Mbps up, 40-60ms latency, fine for gaming for the most part, and the drop outs are unnoticeable short when they do infrequently happen. Never had an outage more than 10 seconds.
They’ve also nearly halved the price since I signed up.
My novice view....Laser connections are point to point, so they can be between satellites....But to the end user equipment,having those many point to point laser connections might be too difficult or impractical to achieve...So that's where they use radiowaves, which means any satellite over the horizon can talk to a dish...
I’m waiting for two things:
1. Full-circumference world round-trip latency sat to sat (yes it has to go to ground to “count” but I just want to know what the number is)
2. Deployed LEO servers running with laser communication to the Starlink satellites. Preferably gaming or CDN since either is a great way to verifiably test the limits.
When will we see data centers in space?
I think the biggest hurdle would be heat dissipation. Solar power is plentiful, but all that energy then has to be radiated away somehow.
This post currently has 420 points, I bet Musk would like that (wont vote to keep it this way)
Is that a lot?
4 nines uptime is great, but I would think the SNR matters more in a packet switched network like this. There are conditions that may lead to a very low SNR.
Somewhat tangential: I assume that Starlink is not yet profitable. How many customers do they need to become profitable?
I recall reading they were profitable on a quarterly basis at end of 2023.
Is it possible one of these laser satellites miss and hit you in the eye? Would that blind a man?
No. The focus of a laser beam is not constant over these large distances. It is the same effect you get if you use a laser pointer over large distances. The spot becomes large quickly.
If I send one byte and it hops through ten satellites, is SpaceX counting that as ten bytes of data?
Are they using Mynaric technology?
Internet says no: https://www.cnbc.com/2021/11/19/german-space-lasers-company-...
3.65 days of downtime isn't going to be winning any prizes.
If near a ground station, can't the satellites just use their standard radio links to cover that?
Might be an issue for Antarctica and major seas.
That's around 3.9 Tb/s, in case you are wondering.
Don’t you mean 42million Gigabytes?
I was going to put 336,000,000,000,000,000 bits/day, but it seamed a bit overkill.
*seemed
I dont think theres anything having to do with seams or fabric in this conversation
1 reply →
Isn’t that equivalent? What does it help to use GB instead of PB?
https://news.ycombinator.com/item?id=39199368
But how much of that data is insane right-wing conspiracy theories? lol
[dupe] https://news.ycombinator.com/item?id=39199368
OP was posted earliest so I guess we'll merge the other threads hither. Thanks!
[dead]
[flagged]
I'm immensely interested in people commenting how they are disinterested in X thing.
Please go on! I'd love to know the motivation of posting, it makes no sense to me.
Seems to be a self-fulfilled prophecy.
I guess I just wish the HN timeline wasn't so full of his garbage.
17 replies →
Hate the guy all you want, but how do you expect literal space internet to be uninteresting to a forum of self-proclaimed hackers?
It's the intersection of space lasers and the internet, how could we not talk about it.
I hate his politics too but this is talking about planetary space lasers.
I don't think you can separate his ventures from him.
1 reply →
[flagged]
Is this a serious question? You think SpaceX developed the industry-leading orbital rocket, launched hundreds of times to deliver thousands of in-house developed satellites utilizing homegrown, novel argon gas ion thrusters, to develop a global satellite internet system using inter-satellite laser links, their own in-house developed, incredibly inexpensive phased array antenna system, and everything else, and they forgot to use TLS?
OP was likely referring to this[1] which did in fact have lines like "tesla isn't encrypting their firmware and it's really easy to glean information from the vpn with a packet cap because nothing inside the vpn (was) encrypted".
So yeah, it's possible they did.
1. (best version I can find sorry) https://www.reddit.com/r/EnoughMuskSpam/comments/99sbwa/form...
This is HN. Everyone here is more intelligent, capable and aware than people who are industry professionals in their specific field.
5 replies →
"industry-leading" [citation needed]
2 replies →
Given how well Starlink has held up in Ukraine against Russian interference I expect they're doing better than most internet providers.
so you are asking if the traffic is additionally encrypted? i don't think that additional encryption is needed, like your ISP doesn't additionally encrypt your TLS encrypted traffic, that would be waste of resources
Metadata (src/dest ip/port) can be of high value, especially for cross-border traffic.
1 reply →
Except wifi is encrypted
Starlink does encrypt user traffic
> widely visible
Usual selling point in marketing of ground based free space optical links is that it is very hard to intercept. Compared to P2P microwave the beam is significantly narrower and alignment requirements higher and the link loss budget is usually tight enough that when the beam becomes visible off-axis due the weather efects (heavy rain or ridiculously thick fog) the link fails.
On the other hand one can extrapolate from results of reverse engineering of the starlink dish. Everything that goes through the space segment is encrypted and entirerity of the high-level control plane is mTLS authenticated, so one would assume that the inter-satellite links work in similar way. Of note is that software in the dish seems to share large swatches of code with what is not only on the starlink satellites but bunch of other SpaceX embedded linux systems.
Are they widely visible? Aren't these laser links from one satellite to another?
the DoD and the NSA surely looked closely in the past couple of years. not least because their Russian and Chinese counterparts for sure are trying to look closely, too, especially in the past couple years.
And this is what mind control looks like
[flagged]
Wait, I thought only Kuiper has laser.
Kuiper tested 1 laser
Isn’t the user experience with starlink pretty abysmal for the average user? Both the service and the customer service?
It's pretty average ish.
You can try it out for 30 days and form your own opinion.
Global internet traffic is estimated to be 3 yottabytes per day. So Starlink is now carrying one of out every 77 million parts of worldwide traffic. Wow, that's small.
EDIT: there's some confusion information out there. With a more conservative estimate of 150.7 exabytes per month, Starlink gets 1 part of 119, which is more impressive.
Where do you get 3 yottabytes? That is difficult to believe. I see 150 exabytes per month [1], about a thousand times less.
https://gitnux.org/internet-traffic-statistics/ [1]
https://www.statista.com/statistics/216335/data-usage-per-mo...
1 reply →
The quoted number is only for inter-satellite laser links, not for other methods of information transmission.
Most of the traffic is probably just bounced off the satellite down to the nearby ground station still.