Those are currently over the ocean but will eventually (after ~1.5h) orbit around to more useful areas.
Satellites in low earth orbit need to move very quickly to stay up. If you want a satellite to stay over the same spot you'd need to put it way way above, in geostationary orbit[1], and get really bad latency.
They're not in geo-stationary orbits. A satellite that's over open ocean now will be over land later in the day. If you zoom in on the visualization, you can see how fast they're moving.
There are a lot of people in the ocean at any given time. This is exactly the type of scenario Starlink is designed for: providing access in very remote and rural areas.
No it's not. Starlink requires satellites have visibility of a ground station and that the users dish be registered to a ground station. Currently neither roaming is supported nor is satellites communicating with other satellites to hop to a ground station that otherwise wouldn't be in range. Thus that makes Starlink inappropriate for use on ships and other platforms in the ocean (stationary or otherwise).
Future iterations of Starlink might support this, the service is still in beta at the moment, but it would be a jump to suggest that is why there are satellites over the oceans.
What's actually happening is they're not on a geo-stationary orbit. ie they're travelling faster than the Earth's rotation. So they'll spend time over land and time over the oceans too.
Starlink Beta users (myself included) already received an updated notice about Sat to Sat laser communications coming online in the near future. It's not a jump to say that's why they are over the ocean, in fact it's already been proven that Starlink is in use on SPACEX recovery platforms. Further, Starlink is working with major airlines already to provide faster network connectivity to commercial and private flight.
Starlink will be available across the globe, facilitate land, air, and sea access. Being designed for this function isn't predicated on current availability. A plane is designed to fly, but because it's on a tarmac doesn't suddenly make that a false statement.
The parent had it right. They are over the ocean because they are in LEO and are constantly in motion relative to earth, it's got nothing to do with Sat-to-Sat laser (though that should enable access to remote areas like the ocean)
Musk has already said the plan is to offer it to ocean going vessels. Yes, they're over the ocean because they're in LEO, but he put them in LEO specifically so they could reach those places. Whether or not it actually materializes can be taken with all the grains of salt you would normally take with anything Musk says.
They don't have to be in LEO to provide service to the oceans the GEO sats provide service for ocean going vessels. They're over the ocean because there's no way for them to provide solid coverage over land without providing solid coverage everywhere between a set N/S latitude band. Any gap to avoid satellites over oceans would be a gap over land periodically it's just how the orbits work.
It also probably has cost benefits on a per satellite and launch basis because it lets them use lower power transmitters and receivers since they're so much closer. Comms sats are generally much larger than the Starlinks with the cost of launches going up because of that.
Another aspect is that the objective is to provide global communications over oceans too, e.g., for container ships, sail boats, planes, global surveillance, etc. The cross-satellite comms are not yet ready to essentially create a global mesh-net, but that's the plan.
Starlink doesn't support roaming between ground stations. Plus if you look at the oceans you can see there aren't any ground stations there anyways. So you wouldn't get internet out in the oceans even with Starlink. At least not in its current phase -- future releases, maybe?
The reason there are satelites over the oceans is simply because they're not at a geo-stationary orbit. ie their orbit is faster than the rotation of the earth.
> Starlink doesn't support roaming between ground stations
That's mostly a beta problem and Starlink is saying they plan to allow roaming eventually. From what I've seen it sounds like right now they only look for your dish in whatever cell it's registered to and don't do any discovery of dishes, it's all preprogrammed.
They also say they will do satellite-to-satellite switching. Let's see if they actually do it.
SpaceX's real innovation is that their base stations are cheap and can go anywhere you can legitimately get a fiber drop. I doubt the inter-satellite switching will _ever_ happen.
Roaming base stations seems simpler than the intra constellation communication at least. It seems like it's largely a problem of doing the discovery on the fly where the multihop communication requires some pretty dynamic routing and complex laser pointing and decoding. I imagine they'll figure both out but the intra constellation communication will be limited to customers like ships where it's required or for people willing to pay for the speed since there's some speculation it could be useful for HFT in places that microwave antenna routes can't be laid easily.
Inter-satellite switching (user laser links) is already happening with the sats in polar orbits. The sats in polar orbits need this, because there is no base stations on the ground within range - They need to route the signal through several satellites to a base station.
Elon Musk has said all satellites will eventually use laser interlinks, but they just don't have this ready yet (and the current generation of satellites probably doesn't have the hardware either)
Starlink is a low altitude constellation, those satellites are moving relative to the surface not stationary like traditional communication satellites. They're setup in a mesh of orbits at give or take the same inclination just offset in phase so there's some moving north east and others moving south east over an area at any given time. So every satellite will spend a lot of time over oceans just because the Earth is mostly ocean.
Is anyone aware of a list of when ground stations went online or a scheduled for future ground stations going online?
I'm curious because a review of starlink that I don't think was all that dated, did some testing from a rural middle American ranch where they were unable to get a connection, supposedly due to the satellite being unable to connect to reach a ground station. The surface level reach of the satellites should have not been an issue though based on my calculations unless some base stations cam online since the testing done as part of the review I watched.
If you like this kind of thing, I recommend Stellarium. It's FOSS, runs locally, and has a gazillion features! You're also not limited to viewing from Earth :-)
Mercator projection does not influence how far north something appears on a map.
It is making the UK appear relatively larger than it is to the US though. This is because it is not an equal-area projection and warps areas further from the equator (UK) more than the ones closer (US).
Yes, Japan for example also receives warm ocean currents though Europe experiences the most extreme impact from this effect. The eastern portion of South American has warm ocean currents but they break off before reaching the southern tip. https://svs.gsfc.nasa.gov/3652
Yes, though I've seen it many times on maps, from the air, and on the ground, I still imagine going directly east from Silicon Valley, across the US, through Virginia, and across the Atlantic ought to end up close to London or Paris. No. That path will take you to northern Tunisia in North Africa.
https://platform.leolabs.space/visualization (add "StarLink" to the search at the top - this one is particularly useful to get an idea of the orbits as you can speed it up to see what's going on)
I think these constallations need to move to some sort of multi-nation joint system.
It's seems likely we'll have 5+ of these constallations up in the near future and all the crowding issues associated with that.
It would be a great humankind project to make 1 or 2 joint systems. Can have relevant base station control to the individual nations for their political and security preferences.
The volume of space is still really large though. If managed well, it will be fine. For some intuition around this, the volume is greater than the part of the atmosphere where airplanes fly, but the traffic is much less and more predictable. It's good to have some competition, additional capacity, and redundancy by having separate networks.
Yeah, the traffic is more predictable, but when something goes wrong, traffic in airspace can easily maneuver to avoid problems. And moreover, in airspace a disaster is local – the debris from a satellite collision is unpredictable and can stay around for years and years!
Yeah this could go bad though there are some mitigations in place. These are relatively low, iirc the full satellites are supposed to burn up in a few years once they go offline without any intervention.
For Starlink, other constellations are being launched in orbits twice as high. Once one collision occurs at those altitudes it takes many lifetimes for the uncontrolled debris to leave ortbit.
There's a national agency actually enforcing this...
Further his point was that if SpaceX disappeared tomorrow, the satellites would all deorbit in under a decade given their low altitude, which is quite fast compared to disposal rules currently mandated by the US government. Physics determines this, not governments or billionaires.
Even when their orbit starts decaying they're not generally a direct threat to other satellites as long as they can maneuver. The US maintains a pretty good tracking network that will pick up any whole satellite at least once every few orbits. On that timescale there's not a significant change to the orbit of an object so they remain pretty predictable out far enough for a maneuverable satellite to make a small change to avoid a collision.
Satellites are very maneuverable too when you consider they normally only need to shift a few yards to avoid a collision, as long as their orbits can be measured precisely enough.
Space is massively big. We can easily have a thousand systems like this without getting the density of an airport airspace. We should be trying to put a trillion people in space.
These orbits aren't that far out, so the volume available to them is actually comparable to that of airspace. However, there are some massive differences. First, in airspace you can easily maneuver and change directions if problems arise. Second, while a collision in airspace is certainly a local disaster, it's limited in scope. A collision between satellites creates a giant scattering of debris with unpredictable orbits. Debris that can stay in orbit for years and years.
Airspace is usually up to flight level 600, or 60k feet. That's around 18km. Starlink flies at an altitude of around 550km, so more than a magnitude higher.
How could the volume between them be in any way comparable?
Uh, because if you wanna talk about the radii of the spherical shells like that, you need to consider the actual radii, namely the distance from the shell to the center of the Earth.
In your example (which is an exaggeration, FL600 isn't really used for commercial flights), airspace goes from 0 to 18 km above the surface of the Earth. The Earth's radius itself is approximately 6400 km. So airspace is the shell between 6400 km and 6418 km. Starlink operates around 6950 km. That's not "an order of magnitude more", it's completely comparable to airspace, so the space available to the satellites scales with the shell's thickness in almost the same way as airspace does.
Think of it this way: the Earth's radius is ~6400km. Starlink orbits less than 10% higher than that.
Depending on the thickness of the orbital shell there might be significantly more vertical space available, but the surface area isn't much bigger at all. (It's actually only ~18% larger[1].)
The vertical space is significantly larger, about 200km (400km-600km height) for usable latencies (35000km if we’re talking any orbit) vs only 3-4km for commercial flights.
>Debris that can stay in orbit for years and years.
Just a note on this, The Starlink constellation is in low earth orbit, ~500km. There is still enough atmospheric drag at this altitude that most things will slow down and re-enter & burn up within months, not years.
Jeez, when visualized like that, that's a lot more than I was expecting.
How many multiples of this do they currently expect they want to get their vision of a general service running?
Maybe a dumb question, what are the ones that seem to be a bunch in an arc/line? They seem to be a somewhat continuous-ish numbered ones, but not very strictly.
Is the latitude limited by physics or just their limited operation? I know the really great case for this is more remote areas, but just wondering like the Nordics, Moscow. Doesn't get much more remote than Siberia. Are they just out of luck?
Probably dumb questions, don't know much about space flight, just kind of astonished by the amount of satellites. I kind of wish it made more sense for me when it becomes available. My internet's okay, but my area is probably populated enough I might not be the target audience, or a place where it works out well.
They have a license for 7x as many (12k vs 1.7k right now) and are applying for up to 30k.
The bunched ones will be freshly launched batches of satellites that have not reached their target altitude, they will spread out in the process.
The latitudes that they overfly are currently limited to up to 53°. The explanation might not be the easiest but here it is: satellites go around in a circle or ellipse that lies on an imagined plane, the so-called orbital plane [0]. This plane can be at an angle with the equatorial plane which is called the "inclination" (this value also gives the maximum latitude that they reach). Starlink uses a lot of these planes, each rotated a bit further around the globe [1]. This is so that all areas on the ground will be in sight of one of the satellites eventually. Starlink should also be able to function a bit further to the north than 53° latitude right now but for any latitude much higher than this, users will need to wait until SpaceX has a working network in polar orbits (i.e. not flying on these tilted plains but more or less directly over the poles instead). They are required to eventually serve Alaska, for example.
> users will need to wait until SpaceX has a working network in polar orbits (i.e. not flying on these tilted plains but more or less directly over the poles instead)
Apparently this has already begun, judging by the train of sats that I'm watching fly over the south pole right now.
They have done a couple polar launches, totaling 13 satellites (they were both “rideshares” with other payload launches). The bigger group (10) was launched ~7 months ago and wouldn’t be in a train anymore.
EDIT: Oh, nevermind, looks like the batch of 10 is still grouped pretty tightly (wonder why they haven’t spread out yet…?)
They've done few test prototype launches of satellites that were grouped together along with a ride share mission that they had other customers paying for. The operational satellites are about to start launching next month at the earliest [0].
Glad to hear about the the plans for polar orbit.
I do volunteer work in Danish version of FEMA and have gotten more involved in our satellite internet solutions.
Our biggest challenge is coverage over Greenland, as geostationary satellites are not visible over the horizon.
Iridium has coverage, but it’s slow and bulky.
We’re awaiting gear to test Starkink, I believe.
They're starting to launch the polar launches next month [0].
SpaceX isn't dependent on RDOF funding to fund their service, it just helps accelerate it and avoid going to the private markets for additional funding and diluting the shares further.
Turns out we are extra lucky today because Scott Manley just released a video which shows an animation of orbit raise and how Starlink satellites from a single launch change orbital planes via precession.
> Jeez, when visualized like that, that's a lot more than I was expecting. How many multiples of this do they currently expect they want to get their vision of a general service running?
They claim that they'll have full operational service (out of beta) in September of this year. Which means you're currently seeing all the ones that will be in the initial operational service, as they can't launch anymore now and have them positioned in time for that date. They're still orbit raising and positioning some of the satellites (which is why you see gaps in a couple of spots).
The initial operational service can't service extremely high latitudes (north of around 55 degrees north, or south of around 55 degrees south) nor can it operate service outside of the range of a ground station near to where the customer is which limits the maximum number of users.
They're about to start launching polar launches (just announced) of the new generation of satellites with laser links so they'll be able to provide service over the ocean and at the poles. https://spaceflightnow.com/2021/07/27/spacex-to-begin-launch...
I was camping in Yosemite earlier this year and happened to look up and see a line of these directly overhead. It was a bit funny being the only person in my group who knew about Starlink and thus the only person not perplexed or even a little freaked out by the sight.
I just asked my wife. She has no idea what it is. I think for people they don’t keep up with tech and have reliable internet options it’s an out of sight out of mind.
I even proposed at one point we divert the cable budget we canceled to get in on the beta and run dual wan/internet.
They could but there aren't many people up there to sell to so they cut down the coverage to save a lot of money on the number of satellites they need to launch.
They can, but I don’t think they want to, that would waste satellites on a very low population circle.
Think of each orbit as a hula hoop around the earth. You’d want to pack as many hoops as you can over the populated areas, with maybe one or two to provide the basic level of service required to the poles.
They technically can, but then you'd have those satellites spend a ton of their time over nearly unpopulated areas doing nothing.
If you instead launch at about a 60 degrees inclination, you spend all of your time between N60 latitude and S60 latitude where it's a lot more populated. This lets you have more coverage in populated areas with fewer satellites.
Additionally, there's no satellite to satellite link capability yet, so for an uplink to work you need a base station in range for the satellite to talk to (you can see these as a "wifi" symbol on the map). It's too expensive to put base stations pretty much anywhere in the artic.
I clicked the "OneWeb" button and was surprised how many satellites they had up, given that they only recently came out of bankruptcy.
I'm worried by OneWeb. Unlike Starlink, their satellites are so high up that if they die, they will just stay there, cluttering up space, unlike Starlink's which are so low that they will fall out of the sky on their own in ~5 years.
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[ 2.9 ms ] story [ 190 ms ] threadwhy did they position them this way?
Satellites in low earth orbit need to move very quickly to stay up. If you want a satellite to stay over the same spot you'd need to put it way way above, in geostationary orbit[1], and get really bad latency.
[1]https://en.wikipedia.org/wiki/Geostationary_orbit
Future iterations of Starlink might support this, the service is still in beta at the moment, but it would be a jump to suggest that is why there are satellites over the oceans.
What's actually happening is they're not on a geo-stationary orbit. ie they're travelling faster than the Earth's rotation. So they'll spend time over land and time over the oceans too.
Starlink will be available across the globe, facilitate land, air, and sea access. Being designed for this function isn't predicated on current availability. A plane is designed to fly, but because it's on a tarmac doesn't suddenly make that a false statement.
The reason there are satelites over the oceans is simply because they're not at a geo-stationary orbit. ie their orbit is faster than the rotation of the earth.
That's mostly a beta problem and Starlink is saying they plan to allow roaming eventually. From what I've seen it sounds like right now they only look for your dish in whatever cell it's registered to and don't do any discovery of dishes, it's all preprogrammed.
SpaceX's real innovation is that their base stations are cheap and can go anywhere you can legitimately get a fiber drop. I doubt the inter-satellite switching will _ever_ happen.
Elon Musk has said all satellites will eventually use laser interlinks, but they just don't have this ready yet (and the current generation of satellites probably doesn't have the hardware either)
More info here: https://arstechnica.com/information-technology/2021/01/space...
EDIT: Deal with the Chile gov to rapidly solve for rural comms [1].
[1] https://developingtelecoms.com/telecom-technology/satellite-...
But that may provide some information you find interesting.
Edit: this previous HN discussion also touches on this: https://news.ycombinator.com/item?id=21325720
Arc length along Earth's surface = R * acos(R/(R+h))
Where R is the Earth's radius, and h is the height above the surface.
https://www.celestialprogramming.com/horizondistance.html
I'm curious because a review of starlink that I don't think was all that dated, did some testing from a rural middle American ranch where they were unable to get a connection, supposedly due to the satellite being unable to connect to reach a ground station. The surface level reach of the satellites should have not been an issue though based on my calculations unless some base stations cam online since the testing done as part of the review I watched.
That's a hard you problem.
It loads in Firefox and is responsive in 1.13s on a system with an nVidia Quadro and 1.59s in a 4c/8gb VM with software rendering.
* changed ms to s (herp derp)
** It took 1.76s to load in Chrome and 2.83s in Edge on the Quadro for me.
Further discussion from a year ago: https://news.ycombinator.com/item?id=23556015
It is making the UK appear relatively larger than it is to the US though. This is because it is not an equal-area projection and warps areas further from the equator (UK) more than the ones closer (US).
https://thetruesize.com/
http://www.stuffin.space/?search=StarLink
https://starlink.sx
https://platform.leolabs.space/visualization (add "StarLink" to the search at the top - this one is particularly useful to get an idea of the orbits as you can speed it up to see what's going on)
It's seems likely we'll have 5+ of these constallations up in the near future and all the crowding issues associated with that.
It would be a great humankind project to make 1 or 2 joint systems. Can have relevant base station control to the individual nations for their political and security preferences.
Further his point was that if SpaceX disappeared tomorrow, the satellites would all deorbit in under a decade given their low altitude, which is quite fast compared to disposal rules currently mandated by the US government. Physics determines this, not governments or billionaires.
Just a few of those, and space is full.
How could the volume between them be in any way comparable?
In your example (which is an exaggeration, FL600 isn't really used for commercial flights), airspace goes from 0 to 18 km above the surface of the Earth. The Earth's radius itself is approximately 6400 km. So airspace is the shell between 6400 km and 6418 km. Starlink operates around 6950 km. That's not "an order of magnitude more", it's completely comparable to airspace, so the space available to the satellites scales with the shell's thickness in almost the same way as airspace does.
Depending on the thickness of the orbital shell there might be significantly more vertical space available, but the surface area isn't much bigger at all. (It's actually only ~18% larger[1].)
[1]: https://www.wolframalpha.com/input/?i=%284%CF%80%28radius+of...
Just a note on this, The Starlink constellation is in low earth orbit, ~500km. There is still enough atmospheric drag at this altitude that most things will slow down and re-enter & burn up within months, not years.
Maybe a dumb question, what are the ones that seem to be a bunch in an arc/line? They seem to be a somewhat continuous-ish numbered ones, but not very strictly.
Is the latitude limited by physics or just their limited operation? I know the really great case for this is more remote areas, but just wondering like the Nordics, Moscow. Doesn't get much more remote than Siberia. Are they just out of luck?
Probably dumb questions, don't know much about space flight, just kind of astonished by the amount of satellites. I kind of wish it made more sense for me when it becomes available. My internet's okay, but my area is probably populated enough I might not be the target audience, or a place where it works out well.
The bunched ones will be freshly launched batches of satellites that have not reached their target altitude, they will spread out in the process.
The latitudes that they overfly are currently limited to up to 53°. The explanation might not be the easiest but here it is: satellites go around in a circle or ellipse that lies on an imagined plane, the so-called orbital plane [0]. This plane can be at an angle with the equatorial plane which is called the "inclination" (this value also gives the maximum latitude that they reach). Starlink uses a lot of these planes, each rotated a bit further around the globe [1]. This is so that all areas on the ground will be in sight of one of the satellites eventually. Starlink should also be able to function a bit further to the north than 53° latitude right now but for any latitude much higher than this, users will need to wait until SpaceX has a working network in polar orbits (i.e. not flying on these tilted plains but more or less directly over the poles instead). They are required to eventually serve Alaska, for example.
[0] https://en.wikipedia.org/wiki/Orbital_plane_(astronomy)
[1] https://en.wikipedia.org/wiki/Longitude_of_the_ascending_nod...
And seeing them fly overhead in the dark of night, all in a line proceeding across the sky is by far the coolest, most sci-fi thing I've ever seen.
Also rather surreal.
Apparently this has already begun, judging by the train of sats that I'm watching fly over the south pole right now.
EDIT: Oh, nevermind, looks like the batch of 10 is still grouped pretty tightly (wonder why they haven’t spread out yet…?)
[0] https://spaceflightnow.com/2021/07/27/spacex-to-begin-launch...
[0] https://spaceflightnow.com/2021/07/27/spacex-to-begin-launch...
https://twitter.com/DJSnM/status/1420416925713133570
They claim that they'll have full operational service (out of beta) in September of this year. Which means you're currently seeing all the ones that will be in the initial operational service, as they can't launch anymore now and have them positioned in time for that date. They're still orbit raising and positioning some of the satellites (which is why you see gaps in a couple of spots).
The initial operational service can't service extremely high latitudes (north of around 55 degrees north, or south of around 55 degrees south) nor can it operate service outside of the range of a ground station near to where the customer is which limits the maximum number of users.
They're about to start launching polar launches (just announced) of the new generation of satellites with laser links so they'll be able to provide service over the ocean and at the poles. https://spaceflightnow.com/2021/07/27/spacex-to-begin-launch...
I even proposed at one point we divert the cable budget we canceled to get in on the beta and run dual wan/internet.
And she says I don’t listen
It has zero relevance to many of the people who regularly follow tech news even it's very relevant to a small subset.
An education also does not amount to knowing trivia.
Think of each orbit as a hula hoop around the earth. You’d want to pack as many hoops as you can over the populated areas, with maybe one or two to provide the basic level of service required to the poles.
If you instead launch at about a 60 degrees inclination, you spend all of your time between N60 latitude and S60 latitude where it's a lot more populated. This lets you have more coverage in populated areas with fewer satellites.
Additionally, there's no satellite to satellite link capability yet, so for an uplink to work you need a base station in range for the satellite to talk to (you can see these as a "wifi" symbol on the map). It's too expensive to put base stations pretty much anywhere in the artic.
https://platform.leolabs.space/visualizations/leo#search=sta...
Realtime Starlink Satellite Map - https://news.ycombinator.com/item?id=23556015 - June 2020 (176 comments)
I'm worried by OneWeb. Unlike Starlink, their satellites are so high up that if they die, they will just stay there, cluttering up space, unlike Starlink's which are so low that they will fall out of the sky on their own in ~5 years.
Nicely organized site containing most of the info: https://celestrak.com/
Actual US government origin site: https://www.space-track.org/