[HN Gopher] Starlink's laser system is beaming 42 petabytes of d...
___________________________________________________________________
Starlink's laser system is beaming 42 petabytes of data per day
Author : alden5
Score : 485 points
Date : 2024-01-31 05:31 UTC (2 days ago)
(HTM) web link (www.pcmag.com)
(TXT) w3m dump (www.pcmag.com)
| scohesc wrote:
| 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)
| SushiHippie wrote:
| [dupe] https://news.ycombinator.com/item?id=39199368
| dang wrote:
| OP was posted earliest so I guess we'll merge the other threads
| hither. Thanks!
| advisedwang wrote:
| 42M GB Per day = 3.9tbps
| progbits wrote:
| > M GB
|
| I can hear the SI crying.
| ble wrote:
| 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.
| sandworm101 wrote:
| 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.
| Scoundreller wrote:
| 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.
| ..
| moffkalast wrote:
| Don't all satellites orbit in the same direction? Launching
| retrograde is just throwing away free velocity.
| nightpool wrote:
| In the context of the full article (https://en.wikipedia.
| org/wiki/Iridium_satellite_constellatio...), it's clear
| they're talking about the polar orbits used by the
| Iridium constellation, which have "seams" around the
| Atlantic and the Pacific as the "first" set of satellites
| passing north-to-south overlap with the "last" set of
| satellites coming back south-to-north on the other side
| of their orbits. So of the 6 orbital planes used by the
| Iridium satellites, each plane covers 1/12th of the globe
| for each "half" of its over-the-poles orbit. So there are
| two "seams" where handoff is not supported, one off the
| eastern seaboard and one roughly over Japan.
|
| There's an animation on linked article that explains this
| pretty well: https://upload.wikimedia.org/wikipedia/commo
| ns/thumb/9/90/Ir...
| moffkalast wrote:
| Ah I didn't realize they have all of their stats in polar
| orbits, that's interesting. Starlink is mostly equatorial
| afaik, the higher latitudes aren't very well covered.
| lxgr wrote:
| Most of Starlink's orbits have an inclination of 53
| degrees, which I wouldn't really call equatorial anymore.
| amlozano wrote:
| The Iridium satellites are in what you might call
| "parallel" orbits, if you stretch the meaning of the word
| a little bit.
|
| 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.
| amlozano wrote:
| There were some experiments with communicating over Iridium
| to small cube-like sats back in the day, but we couldn't
| make the system on a chip beefy enough to do the Doppler
| shift calculations on the fly and survive a launch; it was
| close though. I think its possible to do now.
| ble wrote:
| Links between satellites closing range near 2x orbital speed
| have two problems: - bigger doppler - the lifetime of the
| link is much shorter
| dreamcompiler wrote:
| 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.
| ortusdux wrote:
| > "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.
| FpUser wrote:
| So what happens to the laser beam when there are clouds?
| hrkfmud50k wrote:
| maybe it could route around the clouds via some other
| satellites
| odyssey7 wrote:
| Interesting parallel to solar panels.
| caymanjim wrote:
| The lasers aren't used for ground-to-satellite comms. While
| they refer to some of them maintaining a link through the
| atmosphere, the lasers are intended for satellite-to-
| satellite communication way above the atmosphere.
| indolering wrote:
| It would fall back to radio and/or other connections. The
| laser connection would probably be sold at a discount rate
| due to the variable level of service.
| Tuna-Fish wrote:
| There are some wavelengths that maintain decent signal
| quality through cloud cover, and even rainstorms. I cannot
| find the paper right now, but iirc Tightbeam (formerly from
| the Google _sharks with lasers_ team, now spun out as
| Aalyria), demonstrated space to ground comms in adverse
| weather with negligible packet loss and something like 40%
| reduced bandwidth.
|
| 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.
| Symmetry wrote:
| Right. The Iridium network had communication between satellites
| in different orbital planes passing each other but that was a
| pretty unusual capability.
| Scoundreller wrote:
| 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.
| lxgr wrote:
| Supposedly they use steering, since the horizontal azimuth
| to adjacent-plane satellites varies from 0 to 65 degrees
| across an orbit:
| https://apps.dtic.mil/sti/tr/pdf/ADA348174.pdf
| Scoundreller wrote:
| It doesn't get into it too much on pages 14 and 15, but
| it indeed suggests that they probably exclusively use the
| "intra-orbital" links closer to the poles to get data to
| a satellite where the inter-orbital links are more
| practical.
|
| 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.
| lxgr wrote:
| This has more details: https://fcc.report/IBFS/SAT-
| MOD-20131227-00148/1031348.pdf
|
| 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.
| akira2501 wrote:
| 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.
| sephamorr wrote:
| 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.
| stcredzero wrote:
| GNC?
| Rebelgecko wrote:
| Guidance navigation and/or control
| nightpool wrote:
| Guidance, navigation and control
| ble wrote:
| 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.
| nomel wrote:
| _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?
| barbegal wrote:
| There's an interesting paper on the subject of alignment
| here. https://digitalcommons.usu.edu/cgi/viewcontent.cgi?ar
| ticle=4...
| sephamorr wrote:
| Alas there is no 'in general'. Acquisition is often the
| secret sauce due to, among other challenges, the extremely
| tight alignment requirement -- thermal shifts, satellite
| wobbling, etc, are all critical to manage.
|
| 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.
| _0ffh wrote:
| You got it exactly right! I worked on a simulation model
| of the complete optical setup of a laser terminal with
| movable mirrors and all including the fricking servo
| motors and a simple orbital model for the relative
| satellite positions. Plus an interface to drop in the
| actual acquisition and tracking code used on the embedded
| control system. All of that just to be able to do
| reasonably realistic simulations for verification and
| tuning of the secret sauce.
| londons_explore wrote:
| A laser that transmits data at 100Gbps can also transmit at
| 1 bit per second with an additional path loss of 110
| decibels.
|
| 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.
| sneak wrote:
| What books or webpages do I read to learn how to
| understand the why of your first sentence?
| londons_explore wrote:
| This is from the Shannon-Hartley theorem, the 'power
| limited case':
|
| https://en.wikipedia.org/wiki/Shannon%E2%80%93Hartley_the
| ore...
| _0ffh wrote:
| 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.)
| calrain wrote:
| 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.
| londons_explore wrote:
| 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.
| mschuster91 wrote:
| > 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)
| ugjka wrote:
| Given this is Gen3 and Gen4 now being launched, it took some
| figuring out
| sumtechguy wrote:
| 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.
| diggan wrote:
| > (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.
| dkasper wrote:
| In some important ways space is actually the least hostile
| environment. But yeah, it's still amazing and has its own
| challenges.
| polishdude20 wrote:
| 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.
| Tuna-Fish wrote:
| 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.
| topspin wrote:
| > that you are not receiving from the same direction as you
| are sending
|
| It's a thrill to think about that. Starlink is really out
| there.
|
| I bet this is lost on a lot of people. Not to patronize
| anyone, but what Tuna-Fish is pointing out is that due to
| the speed of light, the distance between satellites and
| their relatives velocities, when one satellite is beaming
| data to another satellite it must aim where the receiving
| satellite will be, as opposed to where it is now, when the
| light arrives. Further, the receiver must be looking at
| where the transmitter was back when the signal was sent, as
| opposed to where the transmitter is now. And because this
| is all bidirectional, each satellite must send and receive
| in different, continuously changing directions at the same
| time.
| londons_explore wrote:
| I understand what you're saying... But lets check.
|
| Assuming the lenses are about 2 inches across (from
| photos) and they are 1310nm IR lasers:
|
| https://www.wolframalpha.com/input?i=single+slit+diffract
| ion...
|
| So we have a minimum beam width of 0.0014 degrees.
|
| And the speed of light round trip distance is say 3.3
| milliseconds.
|
| So the question is, does the angle between the satellites
| change faster than 0.0014/0.0033 = 0.42 degrees/second?
|
| Well the worst case is one satellite heading north at 7.4
| Km/s and another heading south at 7.4 km/s. Lets assume
| the satellites are 550 km apart (the distance between
| planes at the equator), and use the small angle
| approximation... Comes out as 1.4 degrees per second.
|
| So yes, these satellites do need the ability to aim
| transmit and receive in different directions! (although
| they might be able to just defocus the beam a little when
| angles are changing fast to trade off throughput for
| design complexity)
| yencabulator wrote:
| Surely the lasers aren't phased arrays.
| ianburrell wrote:
| 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.
| stefan_ wrote:
| Their exact position in space can be calculated very precisely.
| The Starlink terminals do this as well.
| mytailorisrich wrote:
| 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.
| mensetmanusman wrote:
| 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 :)
| lupusreal wrote:
| > _" 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.
| mschuster91 wrote:
| 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".
| NelsonMinar wrote:
| 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.
| gibspaulding wrote:
| 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.
| regpertom wrote:
| My pings roughly 60-80 no matter if I'm going to a friends
| server down the road or across the world. Before starlink,
| my rural internet would be lucky to get below 120. For what
| that's worth.
| quailfarmer wrote:
| Hey, I'm very curious if you've seen any improvement in
| latency over the past month.
| 7e wrote:
| 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.
| uoaei wrote:
| The quoted number is only for inter-satellite laser links, not
| for other methods of information transmission.
| bagels wrote:
| Most of the traffic is probably just bounced off the
| satellite down to the nearby ground station still.
| jlmorton wrote:
| 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]
| 7e wrote:
| https://www.statista.com/statistics/216335/data-usage-per-
| mo...
| sys_64738 wrote:
| Is that a lot?
| heeton wrote:
| Don't you mean 42million Gigabytes?
| Alifatisk wrote:
| Isn't that equivalent? What does it help to use GB instead of
| PB?
| heeton wrote:
| https://news.ycombinator.com/item?id=39199368
| ortusdux wrote:
| I was going to put 336,000,000,000,000,000 bits/day, but it
| seamed a bit overkill.
| MeImCounting wrote:
| *seemed
|
| I dont think theres anything having to do with seams or
| fabric in this conversation
| versteegen wrote:
| Been quite a lot of discussion of both of those things in
| this thread!
| Scoundreller wrote:
| 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.
| edgyquant wrote:
| Why would we expect faster than fibre?
| Cu3PO42 wrote:
| The speed of light in a vacuum is roughly 50% higher than the
| speed of light in fiber.
| andrewpolidori wrote:
| Is attenuation in a vacuum also better?
| mensetmanusman wrote:
| yes, glass has a non zero amount of absorption which is
| why Erbium amplification is required.
| edgyquant wrote:
| The area between a starlink receiver on the ground and a
| satellite isn't a vacuum
| gkfasdfasdf wrote:
| That's a great point, I was curious so I looked it up.
| Google offered the following:
|
| "The speed of light in air is about 299,705 kilometers
| per second, or 2.99705 x 10^8 meters per second. This is
| almost as fast as light travels in a vacuum, slowing down
| by only three ten-thousandths of the speed of light."
|
| So seems like the speed of light in atmosphere is still a
| lot faster than fiber.
| delecti wrote:
| The speed of light in air is 99.97% of that in a vacuum,
| vs about 2/3 of c through fiber.
| ortusdux wrote:
| I will note that this is the case for conventional fiber-
| optic cable. The newer hollow-core fiber cables transmit
| light at nearly c. As far as I know hollow-core has not
| seen wide-spread use, but it will be interesting if trans-
| continental connections switch over.
| ByThyGrace wrote:
| Will adopting the new cables everywhere mean nearly
| halving latency all across the board? Sans routing
| latencies.
|
| This would be huge for realtime gaming across continents.
| Cu3PO42 wrote:
| Any stretch of fibre you replace with hollow core fibre
| will see latency reduced to two thirds of what it was
| before. (It would be half if the speed of light in it
| were double what it is in normal fibre, but it's only 50%
| faster).
|
| You say sans routing latencies, but these are very much
| significant for intercontinental communication:
|
| I get 6ms ping to AWS eu-central, which is less than
| 100km by air from me. I get 114ms to AWS us-east-1, which
| is roughly 6500km. Now 6500km / (2/3 * c) = ~32ms. So if
| there were a fibre running in a straight line, time in
| the fibre would be 32ms. Of course it isn't running in a
| straight line, so let's say 50ms are pure "light
| traveling through fibre". Switching all of that to
| hollow-core would cut that to 33ms, so that's a savings
| of 17ms or roughly 15% of my total latency.
|
| This is still a very nice savings, but very far off from
| cutting latency in half.
|
| (Also, it's a single hop from my company network to DE-
| CIX, one of the largest internet exchanges in the world,
| so I feel confident saying my results aren't skewed by a
| bad uplink.)
| stcredzero wrote:
| Also, as pointed out elsewhere, the number of hops is the
| biggest contributor to latency.
| oger wrote:
| 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...
| baq wrote:
| 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.
| ggreer wrote:
| 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.
| minhazm wrote:
| 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.
| Scoundreller wrote:
| Could also be shit routing.
|
| Some big ISPs here refused to locally peer with some
| cheaper providers, so some packets to a local data centre
| (5 miles away) in Toronto would round trip through Chicago
| and back.
|
| If they wanted a direct connection; they wanted them to pay
| for transit.
| oh_sigh wrote:
| 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?
| Scoundreller wrote:
| True, it would be bouncing around between ground and the
| atmosphere (when it works at all).
| ianburrell wrote:
| 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.
| oh_sigh wrote:
| I'm curious how much the curved route affects the effective
| speed of communication with skywaves. You also have many
| situations where communication becomes impossible due to
| space weather or other atmospheric phenomena.
| 7e wrote:
| 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.
| bilinguliar wrote:
| Are they using Mynaric technology?
| axus wrote:
| Internet says no: https://www.cnbc.com/2021/11/19/german-space-
| lasers-company-...
| jstummbillig wrote:
| I have absolutely no idea how that number relates to any
| comparable operation. Can anyone add a banana for scale?
| adgjlsfhk1 wrote:
| 10 minutes of 4k video is ~30GB.
| jstummbillig wrote:
| 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.
| theropost wrote:
| 42 million gigabytes per day, or if we are working with
| 30GB for 10min of 4k movies - 233,000 hours of ultra HD
| movies per day
| deathanatos wrote:
| It's 42 PB per _day_ , though.
| besnn00 wrote:
| per day*
| e12e wrote:
| > 42 million gigabytes per second
|
| Per day?
| WheatMillington wrote:
| Over estimating by a factor of 86,400.
| MeImCounting wrote:
| I still dont think this is what the OP was asking for.
| This is in the context of an individual-HD video is an
| individual perspective. More helpful would be a
| comparison to say a small town or a major city or state.
| SirMaster wrote:
| 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.
| zetsurin wrote:
| 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.
| Thaxll wrote:
| We're not talking pirated movie here, think Netflix and
| Youtube.
| caymanjim wrote:
| Netflix and Youtube streams are less GB/hour than a
| typical movie rip. Roughly 3GB/hour at 720p and 8GB/hour
| at 4K. A decent-quality pirated 4K movie is more like
| 20GB/hour. A high-quality rip is 40GB/hour.
| colordrops wrote:
| If you've got a laptop with a terrabyte drive, it would be
| 42,000 full laptops worth of data.
| bee_rider wrote:
| Implementing a "comparable operation" to this satellite
| network using laptops instead is going to be really expensive
| fuel-wise, I think.
| jonathankoren wrote:
| "Never underestimate the bandwidth of a station wagon full
| of tapes hurtling down the highway."
|
| -- Andrew Tannenbaum
| madeofpalk wrote:
| If you have a laptop with a petabyte drive, it would be 42
| full laptops worth of data!
| colordrops wrote:
| Might as well get a 42 petabyte drive.
| whycome wrote:
| > 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...
| organsnyder wrote:
| That's actually a somewhat useful visual.
| vikingerik wrote:
| Not really unless you're using 1 GB flash drives from
| fifteen years ago. 256 GB is now common, which would make
| that petabyte less than 1 football field. (It's only 4096
| such drives.)
| dtgriscom wrote:
| You can buy a 1TB microSD card for $150 now.
| danparsonson wrote:
| What a time to be alive! Even those of us without a
| football field can lay out huge amounts of data in a
| straight line.
| tempmac wrote:
| dang I can hear the youtube channel voice
| ziddoap wrote:
| > _Not really unless you 're using 1 GB flash drives from
| fifteen years ago_
|
| 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.
| NooneAtAll3 wrote:
| ...how large is a football field?
|
| is it supposed to be actual football one or the field for
| handegg?
| aidenn0 wrote:
| American Gridiron football, though Rugby League and Rugby
| Union (two other forms of football) use similar length
| fields/pitches. An Association Football pitch is almost
| always longer than a Gridiron field, depending on how you
| measure (it is typical to exclude the end-zones when
| measuring a Gridiron field, and while Rugby and Gridiron
| football have a playable area behind the goal (or try)
| line, Association Football does not.
|
| 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.
| permalac wrote:
| EMBL-EBI's open transfer systems provide ~5PB of data each
| month.
|
| ftp.ebi.ac.uk for example.
| stcredzero wrote:
| Better yet, a work in a 35 foot long Twinkie.
| new_user_final wrote:
| 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.
| MeImCounting wrote:
| This is a useful scale of comparison and what I think OP was
| after
| jstummbillig wrote:
| OP agrees
| theteapot wrote:
| 486GB/s
| nharada wrote:
| 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
| danbruc wrote:
| 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.
| latchkey wrote:
| 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.
| gnrlst wrote:
| How do you spot a satellite? I've never seen one.
| kirubakaran wrote:
| The Starlink ones look like Santa's sleigh
| https://i.imgur.com/4S0vbfY.gif
| qayxc wrote:
| Only directly after deployment, though.
| perilunar wrote:
| Nice image. The Starlink V2 are bigger though, so fewer per
| launch (~15 vs ~60).
| giancarlostoro wrote:
| Probably out in a rural area far enough away from a major
| city its easier to see them.
| TheAlchemist wrote:
| 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.
| dmd wrote:
| I live 10 miles from Boston and I've seen them a whole
| bunch. I've used
| https://james.darpinian.com/satellites/?special=starlink
| latchkey wrote:
| 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!
| aqfamnzc wrote:
| I guess they disappear as they approach the horizon because
| the light is spread/absorbed too much by going through more
| atmosphere?
| latchkey wrote:
| I actually see them disappear long before they get to the
| horizon. My guess is just less reflected light on
| whatever is shiny on the satellite.
| m2fkxy wrote:
| that and/or entering the Earth penumbra.
| krisoft wrote:
| In higschool we did an experiment with one of our science
| teachers based on this fact. We measured the duratuon of
| the iridum flares and could use some basic geometry to
| estimate how high their orbit is based on where the
| shadow of the earth is.
|
| I don't remember the details anymore, but it was one of
| the coolest practical experiments we did.
| PaulDavisThe1st wrote:
| My impression was that you can only see them as they
| reflect sunlight in your direction. As the angle formed
| between you, the satellite and the sun changes, you will
| first not see the satellite, then see, then not see it
| again.
|
| 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.
| streb-lo wrote:
| Just throwing this out there, but has anyone else seen
| 'formations' of satellites? I've only seen them once but
| there were about 5 to 10 (it was a while ago) of what I'm
| assuming are satellites moving in a line formation at high
| speeds across the night sky. They're too distant and too
| fast to be planes so I'm assuming they are some sort of
| military formation of satellites?
| unwiredben wrote:
| That's often a recently launched StarLink formation --
| the bunch up in a line when deployed, and have to be
| maneuvered over several weeks to spread out and take
| different orbits.
| krisoft wrote:
| > They're too distant
|
| 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?)
| m4rtink wrote:
| I saw ISS in formation with visiting spacecraft a couple
| times - once with Space Shuttle back in the day and at
| least once with Dragon. Looks pretty interesting. :)
| qayxc wrote:
| 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.
| flir wrote:
| 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.
| qwertox wrote:
| 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.
| embedded_hiker wrote:
| 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.
| yencabulator wrote:
| Yeah. With Starlink satellites, you need a lot of luck with
| the conditions to see them. I've seen them a handful of
| times and I'm in a relatively dark sky location.
|
| ISS is often visible in the middle of the day even in
| bright midday Southwest sun, if you know where & when to
| look.
| drynewton wrote:
| 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.
| HPsquared wrote:
| 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.
| WanderPanda wrote:
| I remember chasing one of the iridium flares and it was
| very bright, even during the day
| carlosjobim wrote:
| In short: after sunset.
| wolverine876 wrote:
| > Basically this happens just before sunrise, and just
| after sunset.
|
| 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.
| burnished wrote:
| That doesn't seem right, why would they be bright?
| steve_adams_86 wrote:
| They reflect sunlight for some period of the evening and
| morning, before the sun is shining where you are and
| illluminating the sky too much.
| KeplerBoy wrote:
| so not in the middle of the night.
| CrazyStat wrote:
| That depends on the altitude. GPS satellites at 10000km
| can be lit up in the middle of the night. Starlink
| satellites at 500km can't.
| KeplerBoy wrote:
| Ah yes, of course you're right. After all the moon is
| nothing but a satellite either.
| wolverine876 wrote:
| Between when the sun first disappears below the horizon
| and when (nearly) all its light disappears, i.e., the end
| of astronomical twilight when the Sun's center is 18 deg
| below the horizon, seems to be about 90 minutes.
|
| 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!).
| jfoutz wrote:
| I grew up in a rural area, on a moonless night, without a
| fire, as well as giving your vision some time to adjust
| to the darkness, you can see crazy amounts of stars along
| the Milky Way plane.
|
| I would guess, reflected moonlight (moon over the
| horizon) would be enough to light up the dot well enough
| to see unaided.
| wolverine876 wrote:
| That's a very good question. I'm sure of what I've seen,
| many times over years:
|
| 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.
| wkat4242 wrote:
| > 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).
|
| 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.
| mr_toad wrote:
| > Asteroid? That seems hard to believe, due to size and
| illumination.
|
| And the distance - most asteroids pass by much further
| out than even the moon, so their motion would be hard to
| detect.
| HPsquared wrote:
| I was mostly referring to the brightest things like the
| ISS, Starlink and (formerly) Iridium satellites, which
| are in low Earth orbit.
|
| 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.
| wolverine876 wrote:
| > 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.
| pxeger1 wrote:
| 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).
| nativeit wrote:
| 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.
| wkat4242 wrote:
| 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.
| hengistbury wrote:
| Some satellites do appear to flash because they are
| tumbling: https://www.satobs.org/tumble/tumbleintro.html
|
| The flashing of satellites will generally be gentler than
| the short burst strobing of an aircraft.
| qayxc wrote:
| > 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/
| latchkey wrote:
| No, I love this data! Thank you.
| aetherspawn wrote:
| 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?
| latchkey wrote:
| China is still working on those reusable rockets...
|
| https://www.youtube.com/watch?v=sDufpRp57ok
| oconnor663 wrote:
| No, they burn up. You can think of how much work goes into
| the heat shields on spacecraft that are supposed to survive
| reentry. Satellites have none of that.
| scottlamb wrote:
| I also think a screw at terminal velocity might not be
| particularly dangerous, similar to the popular "will a
| penny dropped off the empire skyscraper kill you?"
| question.
|
| ...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.
| iamgopal wrote:
| Heat is Not because of friction but compression of air
| m4rtink wrote:
| Starlinks are actually built so that nothing sizeable
| remains at all after reentry. This even delayed the laser
| coms a bit, as the original laser mirrors were too sturdy
| & so pieces of them could theoretically make it through.
| mlindner wrote:
| Actually the person you replied to somewhat incorrectly.
| They're not targeted re-entries because the on-board
| propulsion of Starlink is too low to precisely control the
| re-entry location. However instead the satellites are
| designed to be intentionally "demisable" meaning that every
| portion of the satellite should vaporize/turn to char/dust
| during re-entry.
|
| Put another way, every kilogram of Starlink spacecraft has
| as much energy "stored" in it's motion as around 4-5 tons
| of TNT.
| weregiraffe wrote:
| You mean 4-5 kg of TNT. Starlink is not relativistic yet.
| qayxc wrote:
| > Actually the person you replied to somewhat
| incorrectly. They're not targeted re-entries because the
| on-board propulsion of Starlink is too low to precisely
| control the re-entry location.
|
| 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.
|
| There's a difference between unscheduled deorbiting (as
| happened to about 40 satellites after a solar storm in
| February 2022) and a scheduled deorbiting manoeuvre
| trigged by ground control. Starlink satellites use
| electric on-board propulsion (Krypton powered Hall
| thrusters) that doesn't run out as quickly as chemical or
| cold gas gas thrusters. There's also not much precision
| needed to avoid major population centres - Earth is
| pretty big after all.
|
| [1] https://spacenews.com/spacex-launches-fourth-batch-
| of-starli...
| macspoofing wrote:
| >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?
| try_the_bass wrote:
| This is a large part of why they're pushing so hard on
| Starship. Falcon 9 is great and wildly economical, but it's
| not enough to make Starlink profitable in the long term.
| They need Starship to make that happen.
|
| They also want to make Starlink satellites bigger, which
| also requires Starship's much larger diameter.
| steve_adams_86 wrote:
| 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.
| whalesalad wrote:
| 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.
| meroes wrote:
| 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.
| Animats wrote:
| But how do they beam copies of the space to space links down for
| wiretapping, as Iridium does?
| supertrope wrote:
| At the ground stations
| inemesitaffia wrote:
| GS is layer 2. It's done at the POP's like every other
| company
| Animats wrote:
| 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?
| panick21_ wrote:
| You could imagine a situation where they can do that.
|
| But practically what happens is the phone connects to a
| sat, the sat connects to a local ground station, then
| across conventional fiber to another ground station, up to
| a sat and then down to the other phones.
|
| The are likely doing that because regulation and so on. But
| the do what you suggest.
| Animats wrote:
| That wastes half the bandwidth of the system. Will Musk
| put up with that?
| 7e wrote:
| If I send one byte and it hops through ten satellites, is SpaceX
| counting that as ten bytes of data?
| why_at wrote:
| 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.
| elevatedastalt wrote:
| I think they are still tiny. Also don't networking systems
| routinely deal with temporary link disruption?
| burnished wrote:
| What does that have to do with the odds of rocket induced
| dropped packets?
| pests wrote:
| Any rocket induced dropped packets will just be resent
| after the rocket has passed or will be routed over other
| links.
|
| Lets not forget about clouds, birds, airplanes, hot hair
| balloons and tons of other things that separate the ground
| from space.
|
| We have protocols and networks already designed today that
| deal with this exact problem.
| wrboyce wrote:
| I don't think there are many birds, aeroplanes, nor hot
| air balloons in LEO? Are there?! (I doubt clouds too, but
| meteorological phenomena perhaps?)
| belthesar wrote:
| I think the GP is saying that we already deal with these
| problems with downlinks, so accounting for similar
| problems on crosslinks is a known, and expected quantity.
| pests wrote:
| Yes thank you, forgot to link everything together. We
| already have point-to-point optical and deal with these
| issues.
| versteegen wrote:
| > 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.
| bdamm wrote:
| Fair, but they don't compute and probably can't know the
| laser paths between Starlink nodes.
| ra wrote:
| 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.
| burnished wrote:
| 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.
| MadnessASAP wrote:
| 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
| andy_ppp wrote:
| 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?
| hinkley wrote:
| 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?
| andy_ppp wrote:
| Volume is even larger than area...
| hinkley wrote:
| You're being condescending. That belongs on Reddit, not
| here.
|
| If you're in low earth orbit you're traveling through
| rocket exhaust. That doesn't mean you're seeing enough to
| affect optical transmission gain. Or orbital decay. But
| the notion that you're going to miss because there's
| 100's of kilometers between fast moving satellites?
| That's the part of this conversation that deserves
| condescension, if anything.
| andy_ppp wrote:
| Until one of us does the actually maths and builds a
| model of the probability of intersection I guess our
| intuition on this being different is fairly irrelevant,
| either of us could be wrong. I didn't really think much
| about my comment, maybe it was patronising I don't know.
| I try not to treat the comments I write here (or receive
| here either) with much seriousness, often you can take
| most things I say here as me thinking out loud rather
| than some planned sarcasm or as you say Reddit type
| posting.
| therealmarv wrote:
| 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.
| shoelessone wrote:
| This is a serious annoyance for me all day long, across the
| internet. Have you found most sites respect your preferred
| languages list?
| Symbiote wrote:
| 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.
| joshspankit wrote:
| 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.
| mrb wrote:
| 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).
| garciasn wrote:
| 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.
| kuchenbecker wrote:
| Do you have a source on the 4-5 hrs?
| garciasn wrote:
| https://www.statista.com/statistics/420791/daily-video-
| conte...
|
| 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.
| carlhjerpe wrote:
| 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/
| ajross wrote:
| They absolutely count it the same way. Comcast just gives
| me a number for bytes used, with a limit of (IIRC) 1.2TB
| above which they start metering. Our family of four comes
| dances around hitting that basically every month. The
| biggest consumer actually isn't video, is my teenage
| gamer's propensity for huge game downloads (also giant mod
| packs that then break his setup and force reinstall of the
| original content).
|
| I think a few hundred GB for a typical cord-cut household
| is about right.
| joecool1029 wrote:
| All my data usage is over LTE and NR. On one line it mostly
| gets used for streaming video (YouTube,plex,twitch) and
| averages around 500GB/mo. I rent a line to a friend and
| he's doing over 10TB/mo on mostly machine learning stuff
| and astronomy data.
|
| 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).
| ancientworldnow wrote:
| This obviously has no relevance for starlink which does not
| have local datacenters for cdn purposes. All that bandwidth
| is going through the satellites right before it reaches the
| user.
| londons_explore wrote:
| I wouldn't be surprised if starlink doesn't at least
| experiment with making the satellites a big bunch of CDN
| nodes.
|
| 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.
| vardump wrote:
| I guess the problem is that most of the useful bits of
| that 10 TB are going to be most of the time somewhere far
| away from the target audience.
|
| You have to share that 10 TB with everything on that
| satellite's orbit.
| oger wrote:
| Definitely sounds like a no-brainer / reasonable next
| step.
|
| 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.
| seemaze wrote:
| Who has 4-5 hrs a day to watch television? ..or am I
| completely out of touch?
| edude03 wrote:
| _actively_ watch? Probably not many. Having it on as
| background noise however? 5 hours is pretty easy
| colordrops wrote:
| Is that still a thing with young people? I associate
| leaving the TV on in the background as an older
| generation thing.
| dguest wrote:
| I'm middle aged. This kind of background noise sounds
| terrible to me.
|
| Maybe I just grew up in a quiet place.
| bbarnett wrote:
| There are people who like to hear other humans blathering
| on all around them. Then there are sane people.
|
| We're outnumbered.
| dr_dshiv wrote:
| John Von Neumann liked to do math with the TV on as
| background noise. Genius.
| jimmy76615 wrote:
| I heard all those stories about Von Neumann working like
| that. According to a biography, his wife once designated
| a room as his office and he became very angry about that
| since it was too quiet for him to work there.
|
| Personally I need almost complete silence in order to get
| anything done, his abilities in this regard always
| fascinated me.
| extraduder_ire wrote:
| It's just a different kind of environmental requirement.
|
| 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.
| lukan wrote:
| It _is_ terrible, yet quite some people rather have that
| distracting noise, than hear their own thoughts.
|
| For some it is just the illusion of having more people
| around them, though.
| msp26 wrote:
| When you have permanent background noise in the form of
| Tinnitus already it's an improvement.
| offices wrote:
| I grew up being accustomed to having the TV as background
| noise but stopped watching it when I moved out. Now, when
| I visit my parents, it's honestly quite difficult for me
| to focus on conversation - there's a machine in the
| corner making deliberately attention-grabbing sights and
| sounds. So I think your experience is normal & I
| empathise with the generation that complained about TV
| ruining family life.
| psd1 wrote:
| Same and same and same, but I know exactly why I won't
| leave the telly on - I'm very susceptible. It grabs me.
| Even though I have no interest in ads or even 95% of
| programming. It's not a pleasant feeling.
| thecatspaw wrote:
| I mean I use youtube lets plays or twitch streams for
| that, but yes its still a thing.
| fennecfoxy wrote:
| If Millennial still = young then yeah, YT or something in
| background on TV, doing something on laptop (dev, or
| photo editing or other) and then occasionally phone over
| laptop as well to reply to chats and stuff.
|
| I would kill for some decent high res wide fov AR
| glasses.
| Izkata wrote:
| Millennials are currently in their late 20s to early 40s.
| GoblinSlayer wrote:
| It's a normie thing coping with unbearable ringing
| emptiness of mind. My sister and niece (7yo) do it.
| hprotagonist wrote:
| watch, or leave running as background noise ...
| Tempest1981 wrote:
| Any recommendations for shows that make good background
| noise? I wish they had more concerts.
| MeImCounting wrote:
| Happy british baking children! I dont know what its
| called but it is on netflix and they are indeed happy,
| british and they bake. Or just put on Asianometry if you
| need to focus a bit more. I must have been through his
| back log a dozen times at this point. There is something
| about that mans voice that helps relax and focus like
| nothing else
| alickz wrote:
| the ones i see most often are: The Office, Futurama,
| Simpsons, Friends, Brooklyn 99, How It's Made (my
| favourite)
|
| kids these days mostly use youtube or twitch for
| background noise i think
| sublinear wrote:
| For me it depends on what I'm doing. During working hours
| I have Soma FM playing at a low volume. Otherwise I'll
| probably have cooking videos or history documentaries
| playing as the background noise.
| GoblinSlayer wrote:
| Shouldn't audio (radio) suffice for that?
| Cheer2171 wrote:
| "What's a radio?" the kids ask.
| Brybry wrote:
| According to historical Nielsen data[1] from 1991 to 2009:
| most Americans.
|
| Even back to 1950, for per household data, it was above 4
| hours.
|
| [1] https://www.nielsen.com/insights/2009/average-tv-
| viewing-for...
| panick21_ wrote:
| Thats per household, not per person. That's different.
| And households also tended to get smaller.
| Brybry wrote:
| The 1991 data and on was 4+ hours per person (older than
| 2). 7-8 hours per household.
|
| They didn't have per person for the 1950 to 1990 data,
| only household (pdf in the link).
| solardev wrote:
| 2022 data from the BLS:
| https://www.bls.gov/news.release/atus.t11A.htm
|
| 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.
| Brybry wrote:
| That's a nice find. I think BLS leisure time data is from
| the American Time Use Survey [1] which I think is asking
| something similar to this questionnaire [2] on page 22.
|
| 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/tuquestionnair
| e.pdf
|
| [3] https://www.bls.gov/news.release/archives/atus_062220
| 10.pdf
| dr_dshiv wrote:
| Children, sadly.
| adl wrote:
| Families sharing an internet connection. Kids watch 1 o 2
| hours each, mom and dad another hour each.
| tonetegeatinst wrote:
| 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
| londons_explore wrote:
| Data might get counted multiple times as it takes many laser
| hops to reach its destination.
| mrb wrote:
| Good point.
| yosito wrote:
| 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.
| calvinmorrison wrote:
| 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...
| tw04 wrote:
| > Is resolution going to peak?
|
| 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.
| spense wrote:
| > Is resolution going to peak?
|
| not for awhile. apple vision / oculus will stream (4k/8k)
| 3d movies.
|
| https://developer.apple.com/streaming/examples/
| colechristensen wrote:
| Sure, but "4k" is still being used as a differentiator for
| streaming companies in how much they charge. Even then they
| serve up some pretty compressed streams where there's room
| to do less of that for a noticeable notch in quality.
|
| 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?
| numpad0 wrote:
| Two things:
|
| 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.
| bluedino wrote:
| This is being downvoted but it's probably about right.
| bhdlr wrote:
| My smart TV used 483 GB in the last 30 days
| jgalt212 wrote:
| > 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!)
| StanislavPetrov wrote:
| "Customer" may refer to households, not individuals, in which
| case it could be numerous internet users soaking up data per
| customer.
| schiffern wrote:
| >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"
| mrb wrote:
| _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?
| jandrese wrote:
| I would guess that the links between satellites on the same
| orbit stay for weeks, but the ones that cross between
| orbits have to constantly re-established.
| schiffern wrote:
| Correct.
|
| 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.
| try_the_bass wrote:
| _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._
|
| The slide showing the multiple possible paths traffic can
| take seems to disagree with this statement?
| gleenn wrote:
| Just because they seem grossly underused, there are probably
| plenty of other non-ideal constraints like power usage for
| instance.
| dredmorbius wrote:
| 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.
| robomartin wrote:
| > 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.
| feedsmgmt wrote:
| 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.
| bottlepalm wrote:
| 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.
| whazor wrote:
| 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.
| beejiu wrote:
| I thought that Starlink always "landed" to a base station
| back in the same jurisdiction? I think relaying through
| space could open a regulatory can of worms.
| psd1 wrote:
| What kind of worms?
| actionfromafar wrote:
| Bypassing spying, geofencing and other regulatory stuff,
| perhaps? Also curious what the can of worms might be.
| beejiu wrote:
| All countries have strict regulations on radio waves,
| whether that's sending or receiving. The UK for example
| requires a license for base stations that stipulates
| things like geographical boundaries, etc.
|
| 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.
| lucioperca wrote:
| Well maybe it makes sense for US costumer to send their
| traffic down from Starlink in Canada and then via fiber
| to the USA? I do not really see the problem if the
| traffic is encrypted and forwarded.
| solardev wrote:
| Does this count for radio waves beamed in from space
| (like GPS)?
| quailfarmer wrote:
| Unfortunately, the routing to make this feasible doesn't
| exist yet. Users need a single IP address from a range
| that's homed at a single PoP. Starlink doesn't support
| user-user connections through the mesh, you need to go all
| the way out to your PoP, then over to the other users PoP,
| then back through Starlink to that user.
| solardev wrote:
| Are you talking about peer-to-peer connections between
| two Starlink users, like if they were both in the same
| satellite's range but separated by a really tall mountain
| between, etc.?
| janalsncm wrote:
| 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.
| cranberryturkey wrote:
| if you stream you use a lot more than 100gb/month. I use around
| 1tb with a family of 3.
| Hadriel wrote:
| i think even more relatable is how many customers they can
| handle at say 200 mbps
| p1mrx wrote:
| The first slide says "9000+", suggesting that the number of
| space lasers is slightly _over_ 9000. I feel like that 's an
| important distinction.
| Tade0 wrote:
| Most likely it's a reference to the "it's over 9000!" meme.
| deepGem wrote:
| 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.
| hnaccount_rng wrote:
| 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
| try_the_bass wrote:
| _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".
| mensetmanusman wrote:
| 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...
| Havoc wrote:
| In the long run that could become a massive strategic advantage
| for the US. A 2nd layer of resilience over undersea cables
| bagful wrote:
| A privately-held strategic advantage?
| supriyo-biswas wrote:
| 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.
| roywiggins wrote:
| They probably wouldn't have to buy them, if there's a war
| on they probably have enough legal tools to just require
| SpaceX to sell them whatever capabilities they have.
|
| https://en.wikipedia.org/wiki/Defense_Production_Act_of_195
| 0
| roywiggins wrote:
| 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.
| forgot-im-old wrote:
| It's already been bent towards missile defense
| https://wikipedia.org/wiki/Starlink#Military_capabilities
| dotnet00 wrote:
| 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.
| Havoc wrote:
| At that level of strategic usefulness ownership stops
| mattering if shit hits the fan. It'll simply get
| commandeered.
| lannisterstark wrote:
| Like all other US defense companies, why not? Do you think US
| Navy produces their own ships?
| dredmorbius wrote:
| The distinction here is that ships are _built_ by
| nongovernmental private enterprises, whilst Starlink is
| _operated_ by a nongovernmental private enterprise. With a
| somewhat volatile executive.
|
| Which isn't unprecedented. But it's also far from the
| equivalence your comment suggests.
| mlindner wrote:
| The US military already uses commercial satellite
| communication systems.
| panick21_ wrote:
| and commercial sensor system like 'Planet'.
|
| and commercial cargo transport.
|
| And lots of other stuff.
| bell-cot wrote:
| Note that, _historically_ , the US Navy had plenty of its
| own shipyards, and _did_ produce many of its own ships.
|
| https://en.wikipedia.org/wiki/Category:United_States_Navy_s
| h...
|
| But that's mostly been "optimized away" in more-recent
| times, in the name of Capitalism and Campaign Donations.
| le-mark wrote:
| 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.
| techopoly wrote:
| 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.
| mindwok wrote:
| How feasible is it though once the network reaches a huge
| size? Starlink satellites are tiny, and they've been
| deploying thousands of them over the last few years. I
| imagine it would take enormous resources to shoot them
| down, especially if the US does treat them like a strategic
| resource and adds more for redundancy.
| supertrope wrote:
| Even if anti-satellite missiles are too expensive to be
| used to shoot down thousands of targets, the ground
| stations could be bombed instead. Hacking the control
| plane and sending de-orbit commands could be even
| cheaper.
| jessriedel wrote:
| The new generation of Starlink satellites have laser
| connections between them (which is what the article is
| discussing). They can send data to the other side of the
| globe to a friendly country for the ground link. (That's
| a less efficient use of the inter-satellite bandwidth, of
| course, but worth doing for war.)
| mlindner wrote:
| Starlink satellites use inter-satellite lasers and can
| send those signals arbitrary distances via multiple
| satellites. Taking out a ground station will just require
| routing changes and the constellation will continue to
| perform.
|
| And you can't just wave around "hacking the control
| plane". Russia's been trying to interfere with Starlink
| for a while and they haven't had any long term success.
| And finally, even if the did somehow get access to the
| control systems at SpaceX, the satellites can't de-orbit
| quickly. It takes weeks to de-orbit, over which time they
| could be commanded to reverse course.
| lucubratory wrote:
| The huge size of the network is itself a risk. Kessler
| syndrome is something everyone is currently trying to
| avoid, but if you wanted to intentionally induce it you
| could just start launching giant payloads of tiny ball
| bearings into their orbits, or take down enough of them
| that the shrapnel becomes equivalent to that anyway.
| Starlink is low enough that the debris from even a full
| Kessler syndrome cascade will deorbit very rapidly, but
| we're still talking a 3-5 year timeframe, not months, and
| trying to rebuild capacity in that period will just
| worsen + extend the problem.
| mlindner wrote:
| This is something commonly misunderstood. Kessler
| syndrome is a statistical process that happens over many
| years. It is not a sudden cascade like is seen in movies
| like Gravity. Statistical processes are not what
| militaries are interested in.
|
| It's actually thought that Kessler syndrome is kind of
| already happening right now, which is why there's a lot
| of push right now to try to de-orbit the very large
| pieces of debris, so they can't act to form further
| debris.
| lucubratory wrote:
| It happens as fast as it happens. Any actual projection
| would depend on the specific orbits, masses, volumes,
| materials, and numbers of satellites - Starlink's orbits
| have a lot of satellites now. There's a very big
| difference between "everyone trying to avoid it" and "one
| of the world's largest space programs trying to cause it"
| in terms of how much we should be worried about it
| happening for any given orbit in the near term.
|
| The reason it's a scary outcome is because it's an
| exponential. It can look like an isolated incident or
| incidents, then the next day be not practically
| stoppable.
| robbiep wrote:
| Why can't every satellite have a small rocket/firework
| like thing on the back pointing out to the expanse and if
| the power goes out or it doesn't receive a signal from
| the dead man's switch for long enough then it ignites?
| Even with a big mass you don't need to give it much of a
| shove downwards in a zero friction environment to speed
| the de-orbit period up.
|
| I'm sure I'm missing something but it just seems like a
| no brainer to make the deorbit process speed up with
| something relatively failsafe, as opposed to
| hopefully/maybe saving a bit of fuel to push it that way
| eventually
| FeepingCreature wrote:
| Satellite failures often involve uncontrolled spinning.
| So you've turned a piece of debris in a known stable path
| that will eventually deorbit into a piece of debris on an
| unknown but potentially energetic orbit.
|
| Satellites do have deorbit thrusters, but they're a lot
| more deliberate. I think Starlink have a whole separate
| remote controllable system just for deorbit control.
| wongarsu wrote:
| Pretty feasible for anyone who has enough ballistic
| missiles to target about 5000 targets, or is willing to
| invest a couple billion into stocking 5000 overpowered
| fighter-launched missiles. Starlink isn't that high up,
| and in military terms 5000 targets isn't _that_ much.
|
| The effort of getting a ballistic trajectory that peaks
| at 500km is a lot smaller than reaching a stable orbit of
| that height. And just like WWII aircraft you don't need
| to hit them, just produce enough shrapnel in their vague
| vicinity.
|
| The biggest hurdle is the universal international
| condemnation you would receive for such an act
| petesergeant wrote:
| There's no way Russia can afford to make a significant dent
| in the number of Starlink satellites, even assuming their
| ASAT missiles aren't mostly filled with water rather than
| rocket fuel as a result of corruption.
| mlindner wrote:
| Yes effectively immune to missiles. SpaceX launches a new
| batch of 22 satellites on average every 4-5 days right now
| and if needed can launch a new batch every 3 days. You'd
| have to shoot down thousands of satellites to create enough
| of a service gap, and keep shooting down the new ones. And
| the problem is only getting harder with time. Unless you're
| building up an armada of thousands of anti-satellite
| missiles that you need to maintain at the ready to do this
| task, you're not really taking the system down.
|
| I should add that anti-satellite missiles are _large_
| missiles. The missiles of this size in the US arsenal are
| SM-3 missiles (or larger). The number even the US has is
| only in the high hundreds to possibly low thousands. That's
| completely out of the ability of Russia. It's maybe
| possible for China but not in their current stockpiles.
| mynameisnoone wrote:
| Missiles are expensive compared to tiny, cheap satellites.
|
| Laser beams are also the replacement for ASAT.
| usrbinbash wrote:
| A strategic advantage depending on the whims of a single
| provate company.
|
| Sounds great, what could possibly go wrong?
| itomato wrote:
| Assuming imminent domain and pursuant seizure.
| throwaway2037 wrote:
| Somewhat tangential: I assume that Starlink is not yet
| profitable. How many customers do they need to become profitable?
| BluSyn wrote:
| I recall reading they were profitable on a quarterly basis at
| end of 2023.
| mmaunder wrote:
| The amount of bleeding edge innovation that is rapidly developed
| and deployed into production in Musks companies is incredible.
| itsoktocry wrote:
| > _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.
| misiti3780 wrote:
| 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 ?
| hk1337 wrote:
| Isn't the user experience with starlink pretty abysmal for the
| average user? Both the service and the customer service?
| inemesitaffia wrote:
| It's pretty average ish.
|
| You can try it out for 30 days and form your own opinion.
| karim79 wrote:
| 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?
| freedomben wrote:
| 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.
| madaxe_again wrote:
| 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.
| itsoktocry wrote:
| > _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.
| mise_en_place wrote:
| 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.
| mrbonner wrote:
| Wait, I thought only Kuiper has laser.
| hasoleju wrote:
| 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.
| loceng wrote:
| 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.
| robbiep wrote:
| 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
| aetimmes wrote:
| > the things he's done are amazing
|
| The things he's _purchased_ are amazing.
| merman wrote:
| This is obviously untrue. what you're really saying is "I
| don't agree with Elons views so it would be uncomfortable
| for me to think that he has some admirable qualities, so
| I don't allow myself to think about it"
| wongarsu wrote:
| The things he purchased were fine. They became
| revolutionary under him.
|
| 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.
| joenot443 wrote:
| It's amazing the mental gymnastics otherwise intelligent
| people reach for just to allow themselves to feel
| superior over someone whose politics they disagree with.
| Manabu-eo wrote:
| SpaceX, the topic of this thread, was wholly started by
| him, with him being very hands own since the beginning
| till at least the first F9. Just watch any fab tour with
| him, be the old ones from 2005 or the new ones at Texas.
|
| 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.
| mensetmanusman wrote:
| Past performance is the only data available to help predict
| the future.
| prossercj wrote:
| Don't forget about prophecy
| loceng wrote:
| Prophecy generally falls in line with "any sufficiently
| advanced technology is indistinguishable from magic."
|
| 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.
| joenot443 wrote:
| > Past performance is a piss poor indicator of future
| performance.
|
| 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.
| robbiep wrote:
| I treat my life as a series of independent variables...
| much like HN comments where sometimes sticking the snappy
| retort in regarding a brilliant but flawed individual
| might jolt someone out of their hero worship, but point
| taken
| merman wrote:
| "past performance is a poor indicator of future
| performance" is quite a weak statement. It's the one of
| the best predictors there is. There are very few
| exceptions. When you were called out you doubled down
| with complete nonsense. If everything were a series of
| independent variables, then every day after work, how do
| you decide whether to return home to your loving spouse
| (of many years) and children, why not go to a bar and
| find some strange? Why bother calling up your longtime
| friends to hang out, why not go to a bar and talk to the
| person next to you - a lifetime of (past) friendship is
| no indication of future kinship! Why bother writing a
| response to a forum post, when one moment from now,
| everything will be independent of everything else, and
| you have no expectations of feeling the same way?
| Finally, you excuse any flaws in your travesty of ideas
| by claiming that sniping at "Elon worshipers" is such a
| just cause that it excuses any sort of flawed thinking.
| This is a fine demonstration of echo chamber thinking.
| Shocka1 wrote:
| > Past performance is a piss poor indicator of future
| performance.
|
| 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.
| eterevsky wrote:
| That's around 3.9 Tb/s, in case you are wondering.
| hypertele-Xii wrote:
| Is it possible one of these laser satellites miss and hit you in
| the eye? Would that blind a man?
| hasoleju wrote:
| 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.
| Denote6737 wrote:
| 3.65 days of downtime isn't going to be winning any prizes.
| vardump wrote:
| 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.
| gotmedium wrote:
| When will we see data centers in space?
| ryankrage77 wrote:
| I think the biggest hurdle would be heat dissipation. Solar
| power is plentiful, but all that energy then has to be radiated
| away somehow.
| ijhuygft776 wrote:
| This post currently has 420 points, I bet Musk would like that
| (wont vote to keep it this way)
| testemailfordg2 wrote:
| 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...
| sheepybloke wrote:
| 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...
| sonicanatidae wrote:
| But how much of that data is insane right-wing conspiracy
| theories? lol
___________________________________________________________________
(page generated 2024-02-02 23:02 UTC)