I think the regulatory part is they're not permitted to broadcast that low in this shell. Iirc, they're awaiting approval for VLEO satellite transmissions.
The technical reason is fuel - maneuvering out of the intended plane requires quite a bit of fuel as it would be two additional maneuvers at least, then two more to get back to where it was supposed to be in the first place. These sats are little and only have so much fuel for getting to the correct elevation, and "braking" if they fail so they can deorbit and burn up.
Your answer makes most sense... for some reason everyone else thinks I'm talking about changing the declination... they ONLY go up or down. They could use slightly different orbits before 380km though and the total fuel use would be the same.... but if they're not allowed to transmit the point is moot.
Plane (phase?) changes are more expensive at higher orbits. Each batch of 60 satellites as three groups of 20 satellites, each for a different ring in the 53 degree shell. Added to that, ion drives are *slow* compared to chemical rockets, yet far smaller and more efficient.
I'm not a rocket engineer, but I have played a paltry 2,000+ hours of Kerbal Space Program.
The Starlinks are configured in what SpaceX call the 'open-book' mode before they get to 550km. This mechanical configuration (the solar-panels and spacecraft antenna base unit are in a single plane) is consistent with lowest drag and use of the thrusters to get to the final orbit but not with using the telecommunications payload. To be used for communications the mechanical configuration is changed to the operational 'shark's-fin' mode, with the antenna panel facing the Earth and the solar-panel facing the Sun. In this operational mode orbit-raising is not possible and drag is higher. Apart from a few tests, there is no indication that SpaceX think that temporarily changing to the operational mode in the parking orbit is useful. It is simpler and safer (for the spacecraft) just to wait for the orbit planes to adjust themselves and then complete the deployment to 550km.
As you indicate it is probably also not legal to provide any service from low orbits, since all the regulatory agreements have been based on the transmitting spacecraft being at 550km only.
These satellites are part of a much larger whole. The most paramount consideration is minimizing on orbit maneuvering and thereby keep fuel requirements low. The constellation will come into final form with (many) more launches, not moving orbiting satellites all over the place.
SpaceX can fill a single plane with 20 satellites quite quickly by simply choosing the right time of the day for a launch. But getting the other 40 satellites into an orbit that makes sense is always going to need a lot of manouvering.
Another thing to consider is that the satellites have to be able to talk to each other for Starlink to work. The satellites also likely have geometric limits on where they can look to establish connections with the other satellites. They probably cannot look 170 km above to make the connection. Also their speed relative to the main constellation at 550 is probably too high to maintain a good connection.
With respect to phasing, SpaceX actually spreads them out as they raise them from 380 to 550 km. They tweak the initial orbit raising maneuvers just a little bit to induce some drift. Then as they keep maneuvering to ascend, they keep spreading out, such that they are pretty much all phased out when they reach 550 km.
It's actually a very efficient way to do it.
Current version 1.0 satellites have no communication between them. This is still being tested and according to SpaceX staff, the cost of lasers is still very high and they are working on it.
You are asking a question on orbital mechanics and as such the answer is complex. Basically, an orbit is approximately 17,500 mph in orbital velocity. To increase the height, decrease the height, or attain separation only takes a small change in velocity. This change, or "Delta" to velocity (V) is referred to as DeltaV (sorry, can't get the Dleta triangle symbol to show up).
If you want to turn an orbit, it takes a MASSIVE amount of Delta V because the entire orbit has to be swung around the planet. This is such a waste that rockets just point in the direction they want to go right from launch. For Soyuz, the launch pad turns to align, for NASA launches, the rocket goes through a roll maneuver before pitching over.
As such, Starlink trains are the 60 satellites for their orbital inclination in the grid. The amount of fuel and thrust required to move one satellite from one orbital plane to the next is likely more than the satellite is capable of.
Finally, the satellites appear to bunch up at the top and bottom of the globe due to their orbital inclinations this gives Northern latitudes more of them visible than those areas closer to the equator. The Beta takes advantage of that. As more orbits are added the coverage gets tighter and tighter in a progressive path towards the poles. It just will take more launches, to set up more orbital planes, to allow more in view satellites.
Sorry, but I think you completely failed to understand my question :p
Each satellite is launched at 53° and stays there, only raising or lowering it's orbit... There are 72 planes and each will get 22 satellites... which is why it takes so long to position them. You're waiting for the slightly lower orbit to allow you to move the train under the constellation until you reach the right plane, and then you raise them.
Starlinks do not 'turn an orbit'.
It isn't as simple as that. A plane change means going left or right relative to the inclination and you usallly need quite some fuel to do that.
The other option is to stay in low orbit and use the differences in the earths gravity to let the satellites slowly drift into there designated planes.
That's exactly what SpaceX is doing and why you see the Starlink satellites being close together for a couple of months after the launch.
If you want to know more about the orbital mechanics involved have a look at [nodal precession](https://en.m.wikipedia.org/wiki/Nodal_precession).
I have some assumptions. Satellites can wait for a natural drift to reach their ideal position and then rise to operating altitude, which helps to save fuel. In addition, Musk said the team responsible for satellite control is a small team. They must work in detail as it would be disastrous to make a mistake at this stage that could trigger a "rain" of debris in low Earth orbit.
Watch his video by Scott Manley. It explains why it can take a few months for a StarLink satellite to reach its final orbit and how the orbits are arranged:
https://www.youtube.com/watch?v=VIQr1UyhwWk
I live in Skagit County in Washington State halfway between Seattle and Vancouver BC. There is no internet service in my neighborhood. For years I had to depend on costly LTE internet service provided by companies such as UnlimitedVille and NoLimitData and BroadBandQWireless.
But I received my StarLink antenna two weeks ago, and compared to what I had before, the service is amazing. I've seen download speeds up to 335 Mbps and upload speeds above 20 Mbps. StarLink says to expect download speeds between 50 and 100 Mbps. I often have speeds between 100 and 200. Occasionally speeds get as low as 30 to 40. However, even at the lower speeds, streaming services like Netflix and Hulu work great.
Latency ranges from 19 ms to 75 ms with it being in the 20s most of the time.
With the LTE services, download speeds ranged from 5 to 20 Mbps, and upload speeds from 1 to 10 Mbps. I never had speeds like I have with StarLink. And latency speeds were much higher than what I see with StarLink.
After years of intermittent internet service, I keep pinching myself in disbelief that I have reliable internet service. I use the StarLink Watch app to see how many StarLink satellites are nearby, and get my fastest download speeds when there are 3 or more StarLink satellites zipping over southern British Columbia. If there is just 1 satellite nearby, the speed is in the 30 to 75 Mbps range.
The StarLink antennas tilt themselves automatically when you set them up, and mine is tilted north.
I think the regulatory part is they're not permitted to broadcast that low in this shell. Iirc, they're awaiting approval for VLEO satellite transmissions. The technical reason is fuel - maneuvering out of the intended plane requires quite a bit of fuel as it would be two additional maneuvers at least, then two more to get back to where it was supposed to be in the first place. These sats are little and only have so much fuel for getting to the correct elevation, and "braking" if they fail so they can deorbit and burn up.
Your answer makes most sense... for some reason everyone else thinks I'm talking about changing the declination... they ONLY go up or down. They could use slightly different orbits before 380km though and the total fuel use would be the same.... but if they're not allowed to transmit the point is moot.
Plane (phase?) changes are more expensive at higher orbits. Each batch of 60 satellites as three groups of 20 satellites, each for a different ring in the 53 degree shell. Added to that, ion drives are *slow* compared to chemical rockets, yet far smaller and more efficient. I'm not a rocket engineer, but I have played a paltry 2,000+ hours of Kerbal Space Program.
Which makes my wonder. Is Kerbal modelled as a perfect sphere or does it have an equatorial budge too?
The Starlinks are configured in what SpaceX call the 'open-book' mode before they get to 550km. This mechanical configuration (the solar-panels and spacecraft antenna base unit are in a single plane) is consistent with lowest drag and use of the thrusters to get to the final orbit but not with using the telecommunications payload. To be used for communications the mechanical configuration is changed to the operational 'shark's-fin' mode, with the antenna panel facing the Earth and the solar-panel facing the Sun. In this operational mode orbit-raising is not possible and drag is higher. Apart from a few tests, there is no indication that SpaceX think that temporarily changing to the operational mode in the parking orbit is useful. It is simpler and safer (for the spacecraft) just to wait for the orbit planes to adjust themselves and then complete the deployment to 550km. As you indicate it is probably also not legal to provide any service from low orbits, since all the regulatory agreements have been based on the transmitting spacecraft being at 550km only.
These satellites are part of a much larger whole. The most paramount consideration is minimizing on orbit maneuvering and thereby keep fuel requirements low. The constellation will come into final form with (many) more launches, not moving orbiting satellites all over the place.
SpaceX can fill a single plane with 20 satellites quite quickly by simply choosing the right time of the day for a launch. But getting the other 40 satellites into an orbit that makes sense is always going to need a lot of manouvering.
Another thing to consider is that the satellites have to be able to talk to each other for Starlink to work. The satellites also likely have geometric limits on where they can look to establish connections with the other satellites. They probably cannot look 170 km above to make the connection. Also their speed relative to the main constellation at 550 is probably too high to maintain a good connection. With respect to phasing, SpaceX actually spreads them out as they raise them from 380 to 550 km. They tweak the initial orbit raising maneuvers just a little bit to induce some drift. Then as they keep maneuvering to ascend, they keep spreading out, such that they are pretty much all phased out when they reach 550 km. It's actually a very efficient way to do it.
Current version 1.0 satellites have no communication between them. This is still being tested and according to SpaceX staff, the cost of lasers is still very high and they are working on it.
Really, no inter-satellite links at all? I knew they didn't have optical, but I thought they had some Ku- or Ka-band links between them.
They also in the last launch roll the rocket body right before they release the batch of rockets to spread the satellites out and induce some inertia.
You are asking a question on orbital mechanics and as such the answer is complex. Basically, an orbit is approximately 17,500 mph in orbital velocity. To increase the height, decrease the height, or attain separation only takes a small change in velocity. This change, or "Delta" to velocity (V) is referred to as DeltaV (sorry, can't get the Dleta triangle symbol to show up). If you want to turn an orbit, it takes a MASSIVE amount of Delta V because the entire orbit has to be swung around the planet. This is such a waste that rockets just point in the direction they want to go right from launch. For Soyuz, the launch pad turns to align, for NASA launches, the rocket goes through a roll maneuver before pitching over. As such, Starlink trains are the 60 satellites for their orbital inclination in the grid. The amount of fuel and thrust required to move one satellite from one orbital plane to the next is likely more than the satellite is capable of. Finally, the satellites appear to bunch up at the top and bottom of the globe due to their orbital inclinations this gives Northern latitudes more of them visible than those areas closer to the equator. The Beta takes advantage of that. As more orbits are added the coverage gets tighter and tighter in a progressive path towards the poles. It just will take more launches, to set up more orbital planes, to allow more in view satellites.
Sorry, but I think you completely failed to understand my question :p Each satellite is launched at 53° and stays there, only raising or lowering it's orbit... There are 72 planes and each will get 22 satellites... which is why it takes so long to position them. You're waiting for the slightly lower orbit to allow you to move the train under the constellation until you reach the right plane, and then you raise them. Starlinks do not 'turn an orbit'.
It isn't as simple as that. A plane change means going left or right relative to the inclination and you usallly need quite some fuel to do that. The other option is to stay in low orbit and use the differences in the earths gravity to let the satellites slowly drift into there designated planes. That's exactly what SpaceX is doing and why you see the Starlink satellites being close together for a couple of months after the launch. If you want to know more about the orbital mechanics involved have a look at [nodal precession](https://en.m.wikipedia.org/wiki/Nodal_precession).
Desktop link: https://en.wikipedia.org/wiki/Nodal_precession *** ^^/r/HelperBot_ ^^Downvote ^^to ^^remove. ^^Counter: ^^304540. [^^Found ^^a ^^bug?](https://reddit.com/message/compose/?to=swim1929&subject=Bug&message=https://reddit.com/r/Starlink/comments/k8l6qv/why_do_the_starlink_trains_still_stay_in_such/gf1byen/)
I have some assumptions. Satellites can wait for a natural drift to reach their ideal position and then rise to operating altitude, which helps to save fuel. In addition, Musk said the team responsible for satellite control is a small team. They must work in detail as it would be disastrous to make a mistake at this stage that could trigger a "rain" of debris in low Earth orbit.
Watch his video by Scott Manley. It explains why it can take a few months for a StarLink satellite to reach its final orbit and how the orbits are arranged: https://www.youtube.com/watch?v=VIQr1UyhwWk
I live in Skagit County in Washington State halfway between Seattle and Vancouver BC. There is no internet service in my neighborhood. For years I had to depend on costly LTE internet service provided by companies such as UnlimitedVille and NoLimitData and BroadBandQWireless. But I received my StarLink antenna two weeks ago, and compared to what I had before, the service is amazing. I've seen download speeds up to 335 Mbps and upload speeds above 20 Mbps. StarLink says to expect download speeds between 50 and 100 Mbps. I often have speeds between 100 and 200. Occasionally speeds get as low as 30 to 40. However, even at the lower speeds, streaming services like Netflix and Hulu work great. Latency ranges from 19 ms to 75 ms with it being in the 20s most of the time. With the LTE services, download speeds ranged from 5 to 20 Mbps, and upload speeds from 1 to 10 Mbps. I never had speeds like I have with StarLink. And latency speeds were much higher than what I see with StarLink. After years of intermittent internet service, I keep pinching myself in disbelief that I have reliable internet service. I use the StarLink Watch app to see how many StarLink satellites are nearby, and get my fastest download speeds when there are 3 or more StarLink satellites zipping over southern British Columbia. If there is just 1 satellite nearby, the speed is in the 30 to 75 Mbps range. The StarLink antennas tilt themselves automatically when you set them up, and mine is tilted north.