Starlink updates

Sirfun

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The Starlink antenna(s) will be integrated with the rest of the truck in the same way as the GPS, cellphone and WiFi antennas are today, There will be no need to install anything.
I really hope the Cybertruck is connected with the Starlink system. It would be sooo nice to go wherever you want to go with one and have a reliable signal.
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ldjessee

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If the antenna is the size of a pizza box, I do not think they will 'build it in'.

If the Starlink antenna outputted ethernet or USBC... I assume USBC at this point. Would make it so much easier.
 

ajdelange

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No, and that's why it won't be the size of a pizza box. It will consist of a set of small flat printed circuit boards like the GPS antennas. These will be disposed over the roof of the car or as patches under or even in the roof glass.

Yes, it would be nice to have the functionality of an internet teminal in the car e.g. a couple of ethernet or USB plugin locations here and there throughout the interior and perhaps even the exterior or to put the WiFi modem into service as it usually is in a house. All speculative, of course. They may decide they can't use Starlink because of the building penetration issue I mentioned in No. 10.
 

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Yes, I'm excited IF the latency/jitter are low enough that they are useable with VOIP
The latency can "theoretically" be better than land based internet connections. Here is a cool video a guy did with all available information and a 3d rendering engine.
 


ldjessee

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No, and that's why it won't be the size of a pizza box. It will consist of a set of small flat printed circuit boards like the GPS antennas. These will be disposed over the roof of the car or as patches under or even in the roof glass.
While the Ku and Ka bands are short enough to use such small antennas as you describe, the ability to get the signal from a general spot in the sky and help eliminate other signals, like coming from the tens to hundred of other Starlink satellites that would be in the sky, are probably why it has such a large antenna setup.

I think the pizza box for an antenna is what it means, that they are probably using a concave surface covered by a radio (or microwave) transparent cover to keep elements off of it, as I have seen in some HD TV antennas and antennas for RVs and such. This antenna could be shallow enough to focus on a region in the sky (without narrowing it down so much that it would not cover two or maybe three satellites in its cone), where I am guessing as the satellites pass by, there will be some kind of hand-off from one to the next (much like cell-tower hand-off).

Now, I have seen that some claim this antenna will be a phased array, which would help it mimic some of the properties of a concave reflective surface, but to get the phased array, it will still need a grid of antennas and complex electronics, which I am sure SpaceX can handle, but there are advantages to not have your phased array exist in just two dimensions. Having some slight offset in the third dimension (not sure if it is a full wavelength, or can be useful at 1/2 or 1/4 wavelength). Still not something I am guessing will be built into a ceramic baked armor glass that is already going to be very expensive to replace. Adding this much copper and circuitry that would have to pass a QA test is going to increase the price even more.

But, I could also be wrong. Only when they release their product and people start hacking the antenna to see how small they can get it or other antenna tricks they can do will we know if what you describe is an option or if it really needs all the space I think it will need.
 

ajdelange

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While the Ku and Ka bands are short enough to use such small antennas as you describe,
The wavelength doesn't really have much to do with it but it makes "matching" easier if the patches are half a wavelength or so.. The longest wavelength in the Starlink system will be 2.5 cm at the lower edge of Ku band with a half wavelength of 12.5 mm. Clearly manageable without any fancy matching networks (and their attendant losses).

I think the pizza box for an antenna is what it means, that they are probably using a concave surface covered by a radio (or microwave) transparent cover to keep elements off of it, as I have seen in some HD TV antennas and antennas for RVs and such.

This antenna could be shallow enough to focus on a region in the sky (without narrowing it down so much that it would not cover two or maybe three satellites in its cone),
Probably not. Focal length is immaterial except that the feed (or a subreflector) has to be placed there. And parabolic antennas are expensive to make and they have to be mechanically pointed. A pizza with the pepperoni bits being the patches in much simpler and cheaper to make and has the same aperture (approximately) as a dish of commensurate size and doesn't need a separate feed. Aparabolic antenna would have to track mechanically as would the simplest patch antenna but the patch antenna can be made into a phased array and the tracking done electronically.


where I am guessing as the satellites pass by, there will be some kind of hand-off from one to the next (much like cell-tower hand-off).
Of course. See the video posted in No. 20.


Now, I have seen that some claim this antenna will be a phased array, which would help it mimic some of the properties of a concave reflective surface,
The signals from the individual patches can be phased appropriately and summed to form beams with the width of the beam determined by the maxiumum distance between the pepperoni pieces. This is one of the big potential advantages on the CT as the patches can be placed meters apart and so the beams can be very narrow. The other advantage is that multiple beams can be formed simultaneously so as many sattelites as are visible can be tracked and hand off can be done instantaneously. Tesla has indicated that they are doing the trades on mechanical vs. phased array tracking on the home terminal antenna. We don't even know at this point if they are considering Starlink in their vehicles but if they are clearly mechanical tracking would be out of the question.


but to get the phased array, it will still need a grid of antennas and complex electronics, which I am sure SpaceX can handle,
The antennas in the spacecraft are phased array for sure so yes, Tesla has familiarity with this technology. I started working on it in the 70's and I expect the state of the art has advanced dramatically in the intervening years. Your WiFi router, if it sports multiple antennas, contains adaptive beam forming capability. But this is not to say that there wouldn't be challenges in such a system.


but there are advantages to not have your phased array exist in just two dimensions.
If you want to form beams that are narrow in the vertical plane then you have to have vertical separation between the patches. I hadn't been thinking of that because I assumed that the vehicle would not connect to a SV less than, say, 30 ° above the horizon.


Having some slight offset in the third dimension (not sure if it is a full wavelength, or can be useful at 1/2 or 1/4 wavelength). Still not something I am guessing will be built into a ceramic baked armor glass that is already going to be very expensive to replace.
The narrower the beam, the more vertical separation. If this is an issue the solution would be to combine patches mounted in, for example, the lower windscreen with patches located in the roof glass.

But, I could also be wrong. Only when they release their product and people start hacking the antenna to see how small they can get it or other antenna tricks they can do will we know if what you describe is an option or if it really needs all the space I think it will need.

....the ability to get the signal from a general spot in the sky and help eliminate other signals, like coming from the tens to hundred of other Starlink satellites that would be in the sky, are probably why it has such a large antenna setup.
The fact that the "noise temperature" of the sky is so much grater than Pensius's 2.9 K is really at the heart of this. Aperture for the sake of collecting flux from the desired satellite is no longer the totality of the problem. Collecting it from the direction of the desired emitter and not from undesired emitters is now a major consideration in communications systems design. Using beam forming from widely separated "antennas" clearly has lots of appeal. Whether it is feasible or not for a particular system will depend on many factors about which I have no information. It would be an interesting system to work on for sure.
 

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Starlink satellites are equipped with efficient ion thrusters powered by krypton that enable the satellites to orbit raise, maneuver in space, and deorbit at the end of their useful life. Starlink is the first krypton propelled spacecraft ever flown.”
"All I wanted was a chair that rotates....."
 
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Forrest White

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Almost a century passed since the first artificial satellite launch. For 2020 years there are 74 satellites sent to the orbit for different purposes. Satellites then were used for space exploration thus helping humans on the Earth to observe outer space. And now satellites are used not only in space but also here, on the earth. For example, we can monitor deforestation using satellite technology, satellites are used to observe global environmental change and environmental events that cannot be detected by the human eye https://www.skyrora.com/post/monitoring-deforestation-using-satellite-technology . SpaceX company uses satellites to launch the international Internet all over the world.
 

ajdelange

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Sputnik I was launched on 4 October 1957 so that we won't reach a century until another 37 years have passed.

Starlink is by no means the first to provide internet service. Inmarsat, Iridium and others have been doing that for 25 - 30 years.
 

fritter63

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Starlink is by no means the first to provide internet service. Inmarsat, Iridium and others have been doing that for 25 - 30 years.
Yes, but they haven't been doing it well..... (/me eyes the derelict internet dish on his barn and makes a note to finally remove that damned P.O.C.)
 

ajdelange

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I haven't used either in 20 years but what I remember was kB per second for unimaginable $ from Inmarsat. The Iridium was free but the bit rate was well less than 1k. I could download my e-mails in the hour long drive from the city to the work site.

I believe that internet is available on cruise ships these days. That must come from some satellite service.
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