Author Topic: Starlink : Hardware Design / Manufacturing  (Read 60222 times)

Online gongora

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Starlink : Hardware Design / Manufacturing
« on: 01/21/2020 11:41 pm »
For links to other Starlink discussion threads, launch threads, and FCC filings take a look at the Starlink Index Thread


Discussion of Starlink hardware (satellite, gateway and user terminal)

Offline Tulse

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Re: Starlink : Hardware Design / Manufacturing
« Reply #1 on: 01/22/2020 08:37 pm »
What is the current information on when we might see a version of the hardware with laser interlinks?

Online gongora

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Re: Starlink : Hardware Design / Manufacturing
« Reply #2 on: 01/22/2020 08:39 pm »
What is the current information on when we might see a version of the hardware with laser interlinks?

Late 2020 (if they don't get delayed again.)

Offline Roy_H

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Re: Starlink : Hardware Design / Manufacturing
« Reply #3 on: 01/26/2020 01:13 am »
I am under the impression that laser inter-satellite communication is a relatively mature technology. I.E. already commercially available. The only challenge is to make the mirrors out of something that will burn up on re-entry. Is making that kind of mirror really a major challenge, or is there some other reason for the delay?
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Online gongora

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Re: Starlink : Hardware Design / Manufacturing
« Reply #4 on: 01/26/2020 01:19 am »
I am under the impression that laser inter-satellite communication is a relatively mature technology. I.E. already commercially available. The only challenge is to make the mirrors out of something that will burn up on re-entry. Is making that kind of mirror really a major challenge, or is there some other reason for the delay?

Mature technology?  Please name a few satellites currently using laser inter-satellite relays.

Offline Nomadd

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Re: Starlink : Hardware Design / Manufacturing
« Reply #5 on: 01/26/2020 01:28 am »
I am under the impression that laser inter-satellite communication is a relatively mature technology. I.E. already commercially available. The only challenge is to make the mirrors out of something that will burn up on re-entry. Is making that kind of mirror really a major challenge, or is there some other reason for the delay?

Mature technology?  Please name a few satellites currently using laser inter-satellite relays.
I'd bet the software is 90% of the work. I'd think something mesh based, but knowing these guys, they're liable to be starting from scratch.
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Offline ulm_atms

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Re: Starlink : Hardware Design / Manufacturing
« Reply #6 on: 01/26/2020 01:31 am »
I am under the impression that laser inter-satellite communication is a relatively mature technology. I.E. already commercially available. The only challenge is to make the mirrors out of something that will burn up on re-entry. Is making that kind of mirror really a major challenge, or is there some other reason for the delay?

Can you tell me where they are in use currently?  I was under the impression that RF-Interlinks were mature, but lasers are cutting edge in this application.  I know of no setup where you have hundreds of objects flying at 27.5Km/hr all trying to focus lasers at each other and transmit data.  P2P lasers are available commercially..but they sure ain't the smallest or lightest thing...that's for sure.

Offline Eka

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Re: Starlink : Hardware Design / Manufacturing
« Reply #7 on: 01/26/2020 08:36 pm »
I am under the impression that laser inter-satellite communication is a relatively mature technology. I.E. already commercially available. The only challenge is to make the mirrors out of something that will burn up on re-entry. Is making that kind of mirror really a major challenge, or is there some other reason for the delay?

Can you tell me where they are in use currently?  I was under the impression that RF-Interlinks were mature, but lasers are cutting edge in this application.  I know of no setup where you have hundreds of objects flying at 27.5Km/hr all trying to focus lasers at each other and transmit data.  P2P lasers are available commercially..but they sure ain't the smallest or lightest thing...that's for sure.
It can be done. I can see how to do it. I don't have the time to detail how. It's rather involved when the platform is light weight.

We talk about creating a Star Trek future, but will end up with The Expanse if radical change doesn't happen.

Offline Eka

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Re: Starlink : Hardware Design / Manufacturing
« Reply #8 on: 01/27/2020 01:29 am »
I am under the impression that laser inter-satellite communication is a relatively mature technology. I.E. already commercially available. The only challenge is to make the mirrors out of something that will burn up on re-entry. Is making that kind of mirror really a major challenge, or is there some other reason for the delay?

Can you tell me where they are in use currently?  I was under the impression that RF-Interlinks were mature, but lasers are cutting edge in this application.  I know of no setup where you have hundreds of objects flying at 27.5Km/hr all trying to focus lasers at each other and transmit data.  P2P lasers are available commercially..but they sure ain't the smallest or lightest thing...that's for sure.
It can be done. I can see how to do it. I don't have the time to detail how. It's rather involved when the platform is light weight.
As I was sitting here specifying the requirements for a fast slew pan tilt telescope style system, I figured out a method that is massively better, and has no moving parts that require repeated flexing of flexible couplings for power or signals, and the remaining moving parts are much much lighter. It also incorporates a system that allows slop in assembly, and deployment alignment, yet still provides high accuracy fine tuned aiming to lock onto the other satellite. Also, the only flex electrical coupling only flexes at deployment. It's a bit complex for a text description.
We talk about creating a Star Trek future, but will end up with The Expanse if radical change doesn't happen.

Online gongora

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Re: Starlink : Hardware Design / Manufacturing
« Reply #9 on: 01/27/2020 02:38 am »
I am under the impression that laser inter-satellite communication is a relatively mature technology. I.E. already commercially available. The only challenge is to make the mirrors out of something that will burn up on re-entry. Is making that kind of mirror really a major challenge, or is there some other reason for the delay?

Can you tell me where they are in use currently?  I was under the impression that RF-Interlinks were mature, but lasers are cutting edge in this application.  I know of no setup where you have hundreds of objects flying at 27.5Km/hr all trying to focus lasers at each other and transmit data.  P2P lasers are available commercially..but they sure ain't the smallest or lightest thing...that's for sure.
It can be done. I can see how to do it. I don't have the time to detail how. It's rather involved when the platform is light weight.
As I was sitting here specifying the requirements for a fast slew pan tilt telescope style system, I figured out a method that is massively better, and has no moving parts that require repeated flexing of flexible couplings for power or signals, and the remaining moving parts are much much lighter. It also incorporates a system that allows slop in assembly, and deployment alignment, yet still provides high accuracy fine tuned aiming to lock onto the other satellite. Also, the only flex electrical coupling only flexes at deployment. It's a bit complex for a text description.

Does this actually have anything to do with Starlink?  Maybe we need another thread for ISL designs/speculation.

Offline baldusi

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Re: Starlink : Hardware Design / Manufacturing
« Reply #10 on: 01/30/2020 12:49 pm »
I am under the impression that laser inter-satellite communication is a relatively mature technology. I.E. already commercially available. The only challenge is to make the mirrors out of something that will burn up on re-entry. Is making that kind of mirror really a major challenge, or is there some other reason for the delay?

Mature technology?  Please name a few satellites currently using laser inter-satellite relays.
EDRS and the Sentinel EO use it.

Offline dondar

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Re: Starlink : Hardware Design / Manufacturing
« Reply #11 on: 01/30/2020 01:05 pm »
beside SpaceDataGateway (EDRS +sentinels) lasercom is used by ICEYE sats.

The thing is laser communications are good as relay stations only if you have enough sats close enough to make relay when needed and not when possible. you need something like Starlink constellation....

Online gongora

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Re: Starlink : Hardware Design / Manufacturing
« Reply #12 on: 01/30/2020 03:37 pm »
beside SpaceDataGateway (EDRS +sentinels) lasercom is used by ICEYE sats.

The thing is laser communications are good as relay stations only if you have enough sats close enough to make relay when needed and not when possible. you need something like Starlink constellation....

A test sat that included an ICEYE payload also was testing a laser downlink payload (doesn't seem to be ISL) from Bridgesat.  Do any other ICEYE sats have optical communications?

Offline Kansan52

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Re: Starlink : Hardware Design / Manufacturing
« Reply #13 on: 01/30/2020 03:48 pm »
Mylar mirror. Might not burn up but it may flutter down.

Offline PADave

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Re: Starlink : Hardware Design / Manufacturing
« Reply #14 on: 01/31/2020 07:41 pm »
https://ieeexplore.ieee.org/document/5680175

Quote
Optical inter-satellite communication based on TESAT Laser Communication Terminals (LCT's) is operational by now on LEO satellites for more than two years. The LCT's demonstrate their performance in LEO-LEO inter-satellite links (ISL)

Offline dondar

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Re: Starlink : Hardware Design / Manufacturing
« Reply #15 on: 02/01/2020 11:49 am »
beside SpaceDataGateway (EDRS +sentinels) lasercom is used by ICEYE sats.

The thing is laser communications are good as relay stations only if you have enough sats close enough to make relay when needed and not when possible. you need something like Starlink constellation....

A test sat that included an ICEYE payload also was testing a laser downlink payload (doesn't seem to be ISL) from Bridgesat.  Do any other ICEYE sats have optical communications?
No, in it's current form  laser communication sets don't offer conclusive improvements over existing radio down-link variant. They don't offer it as a feature quite yet.
 (As far as I heard all existing and prospect clients ICEYE clients have  sat communication installations).

 But the test was successful and they plan to use it in the subsequent designs. I believe an article describing some details is in the final processing.

Offline dondar

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Re: Starlink : Hardware Design / Manufacturing
« Reply #16 on: 02/01/2020 11:59 am »
https://ieeexplore.ieee.org/document/5680175

Quote
Optical inter-satellite communication based on TESAT Laser Communication Terminals (LCT's) is operational by now on LEO satellites for more than two years. The LCT's demonstrate their performance in LEO-LEO inter-satellite links (ISL)
You have forgotten to put a date :D.
TerraSAR-X was launched 2007 and was linked with NFIRE (which was launched in april 2007). They were linked a couple of months later after initial shake-off. these two years were full 2008 till 2010.

Offline Tulse

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Re: Starlink : Hardware Design / Manufacturing
« Reply #17 on: 02/03/2020 02:38 pm »
Telesats constellation will also use laser interlinks, but I haven't heard much about the state of their technology.

Online FutureSpaceTourist

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Re: Starlink : Hardware Design / Manufacturing
« Reply #18 on: 02/15/2020 08:05 am »
twitter.com/inzilya777/status/1228589762799378433

Quote
I keep wanting to ask, but I forget. How does the starlink test satellite designed to reduce the albedo feel (did I understand correctly that it has a matte surface?)

https://twitter.com/elonmusk/status/1228598015247536129

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🛰 albedo will drop significantly on almost every successive launch

twitter.com/flcnhvy/status/1228601785364905984

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When are you going to add laser links for comms? Is that even necessary for starting to offer service later this year?

https://twitter.com/elonmusk/status/1228604628750626816

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Direct links aren’t needed to offer service. Starlink will initially bounce signals off ground/ocean relays to get from 🛰 to 🛰.
« Last Edit: 02/15/2020 01:17 pm by FutureSpaceTourist »

Offline FlattestEarth

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Re: Starlink : Hardware Design / Manufacturing
« Reply #19 on: 02/15/2020 12:06 pm »
No comment on lasers suggests it won't be production ready anytime soon, especially if they are going to build ocean relays.

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Re: Starlink : Hardware Design / Manufacturing
« Reply #20 on: 03/09/2020 02:11 pm »
https://twitter.com/chenry_sn/status/1237013319896240134

Quote
Jonathan Hofeller, SpaceX: Our Starlink production facility in Seattle is producing 6 satelites a day. We’ve launched 302 to date, w/ another 60 launching at the end of this week.

Offline thirtyone

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Re: Starlink : Hardware Design / Manufacturing
« Reply #21 on: 03/09/2020 05:58 pm »
https://twitter.com/chenry_sn/status/1237013319896240134

Quote
Jonathan Hofeller, SpaceX: Our Starlink production facility in Seattle is producing 6 satelites a day. We’ve launched 302 to date, w/ another 60 launching at the end of this week.

Anyone know if the discussion that included Jonathan Hofeller is available to stream somewhere? Sounds like a lot of juicy stuff about Starlink and OneWeb.

Offline Rondaz

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Re: Starlink : Hardware Design / Manufacturing
« Reply #22 on: 03/10/2020 02:25 am »
OneWeb, SpaceX optimistic about cheap user terminals..

by Caleb Henry — March 9, 2020

https://spacenews.com/oneweb-spacex-optimistic-about-cheap-user-terminals/

Offline su27k

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Re: Starlink : Hardware Design / Manufacturing
« Reply #23 on: 03/16/2020 12:53 pm »
There's a reddit thread discussing How does each Starlink satellite handle so much bandwidth? What kind of hardware is needed to process this quantity of information?, user Origin_of_Mind made a reply that I think it's interesting:

Quote
SpaceX is very secretive about their hardware.

One reference point that we do have, is the design of the competing OneWeb satellite, which shares the same spectrum with Starlink. The communications package of OneWeb satellites had been described in great detail in this FCC filing (pdf). Although the document is quite old, the guts of the actual satellites look exactly as one would expect from reading the above description. (See also this video.)

Short summary: OneWeb satellite receives Ka-band signal from a gateway using a small steerable dish. This signal is split into 16 bands (labeled as Gateway Uplink 1..16 in the above spectrum diagram). These signals are immediately send down through 16 Ku-band transmitters each feeding one user beam.

These 16 oval-shaped beams tile the rectangular area under the satellite, which is about the size of Texas. To avoid interference, the User Downlink frequencies in the adjacent ovals ("cells") are different, but are reused in the cells that are further apart, to enable the same spectrum to serve more than one set of users. There are 8 frequency bands used overall (labeled User Downlink 1..8 in the above diagram.)

A similar process occurs on the way from the users to the satellite to the gateway, although the bandwidth is much more narrow (User Uplink 1..4 each have 125 MHz bandwidth, which will be shared for all users in one cell -- about 40000 km2)

The satellite serves as a repeater of the analog signals between the gateway and the user -- there is no on-board processing or routing. All the smarts of the system are in the gateway hardware -- it simply has to transmit packets on the right channel for them to arrive to the general area of the intended recipient. User terminals then listen to all the data coming from the satellite, and pick the packets specifically designated for them. The received information also directs user terminal when and on which channel to transmit their Uplink packets, such that the channel can be shared between all users without interference.

-------------

The Gateway Uplink of Starlink is essentially the same as that of OneWeb system -- it uses the same spectrum, and it uses a small motorized dish to talk to the gateway.

Although User Downlink spectrum for Starlink is also the same as for OneWeb, there are differences in how it is used. Where OneWeb uses one fixed antenna for each large cell, Starlink has 4 phased arrays with multiple beams each. What the capabilities of these arrays are, is not known. Potentially, they could afford more efficient area coverage than fixed antennas. Starlink satellites also fly approximately twice lower than OneWeb satellites, and therefore the same bandwidth covers four times smaller area -- providing more bandwidth per user.

Otherwise, available spectrum -- especially the gateway uplink -- constrains operation of Starlink satellites in a similar way as we have seen with OneWeb system.

OneWeb's FCC filing is this document: https://licensing.fcc.gov/myibfs/download.do?attachment_key=1134939, not sure if there's an equivalent filing from SpaceX.

Online gongora

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Re: Starlink : Hardware Design / Manufacturing
« Reply #24 on: 03/16/2020 03:50 pm »
As a reminder: For links to other Starlink discussion threads, launch threads, and FCC filings take a look at the Starlink Index Thread

There are similar documents for the SpaceX filings.  You might need to cross-reference the older and newer filings since SpaceX keeps making changes.  Go to "Attachment Menu" on the filing and then you can look through the relevant documents.

Online gongora

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Re: Starlink : Hardware Design / Manufacturing
« Reply #25 on: 03/16/2020 04:02 pm »
The SpaceX system does use Ku for the user beams and Ka for the gateways.  That's why we're a little fuzzy on how to refer to the v0.9 satellites, and what their future is.  They lack the Ka beams and have to use the Ku beams for both user and gateway (which doesn't match the FCC license).

Offline su27k

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Re: Starlink : Hardware Design / Manufacturing
« Reply #26 on: 03/16/2020 05:12 pm »
My biggest surprise is OneWeb satellite is just acting as analog repeater without routing and processing, I didn't know this before, I always thought at its core it would be a gigabit router, not sure if this is the same for Starlink.

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Re: Starlink : Hardware Design / Manufacturing
« Reply #27 on: 03/16/2020 05:43 pm »
OneWeb made some simplifying architectural decisions when they designed their satellites.  They stuck to a lot of proven design elements.  If their design had been done a couple years later it may have been much different.  The industry is now moving to digital payloads, and if OneWeb makes it to a second generation constellation they probably will too.  SpaceX was much more aggressive with their design.

Offline Eka

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Re: Starlink : Hardware Design / Manufacturing
« Reply #28 on: 03/17/2020 03:30 am »
My biggest surprise is OneWeb satellite is just acting as analog repeater without routing and processing, I didn't know this before, I always thought at its core it would be a gigabit router, not sure if this is the same for Starlink.
As somebody who is familiar with a 10Gb 8ch router that was developed in the late '90s/early 2ks, it can be done. Their programmable logic version was handling 4 ports, and the first test silicon did 8 with ease. There was talk of making a 12 or 16 channel one, but 9/11 hosed them. Now silicon is faster and allows for far more gates.

For low latency, you want to handle that packet now, and send it on as soon as possible. That means a routed system. The plan to use lasers between satellites also means there is a need for routing at the satellite level. Packet routing is simple comparisons and can be done very fast. Often knowable before the whole header is received. Route planning is a different issue than packet routing. When the first packet to a destination site is received, a route plan needs to be generated. I tells which output port to use to get closer to the destination. Subsequent packets can use that route until the geometry of the network changes too much. Then a new route needs to be calculated.
We talk about creating a Star Trek future, but will end up with The Expanse if radical change doesn't happen.

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Re: Starlink : Hardware Design / Manufacturing
« Reply #29 on: 03/18/2020 11:56 am »
Quotes below from today’s SpaceX webcast for the Starlink launch:

twitter.com/thesheetztweetz/status/1240258825078353920

Quote
SpaceX engineer Jessie Anderson says preliminary results from the Starlink satellite "darkening treatment" test "show a notable reduction" in brightness, but the company has "a couple other ideas that we think could reduce the reflectivity even further."

https://twitter.com/thesheetztweetz/status/1240259238141796358

Quote
SpaceX says the most promising alternative is a "sun shade," which "would act as a patio umbrella or sun visor" for the satellite, with a test "slated for a future Starlink launch."

"All these efforts are ongoing."

Offline Roy_H

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Re: Starlink : Hardware Design / Manufacturing
« Reply #30 on: 03/21/2020 04:24 am »
It seems to me that the simplest sunshade would be to use the solar panels. Minimal extra mass and design change. The solar panels shading the rest of the satellite could have heat rejection panels on back side in same orientation as used on ISS which would radiate excess heat away from the satellite.
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Offline RedLineTrain

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Re: Starlink : Hardware Design / Manufacturing
« Reply #31 on: 03/21/2020 08:28 pm »
FYI, the license for the ground terminal shows the antenna diameter as 0.48 meters, or 19 inches.

Offline Bananas_on_Mars

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Re: Starlink : Hardware Design / Manufacturing
« Reply #32 on: 08/14/2020 06:41 pm »
I can’t remember seeing the tension rods on the Starlink stack in such detail before

https://twitter.com/planetlabs/status/1294267537174089729

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Re: Starlink : Hardware Design / Manufacturing
« Reply #33 on: 08/14/2020 07:13 pm »
I can’t remember seeing the tension rods on the Starlink stack in such detail before

The pic of the BlackSky sats from the last launch also showed a lot of detail.  You can see the SpaceX and Planet adapters well here.

Offline Ronsmytheiii

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Re: Starlink : Hardware Design / Manufacturing
« Reply #34 on: 09/05/2020 09:51 pm »
So we know that SpaceX Starlink effort is headquartered out of the 23020 NE Alder Crest Drive Location from filings ect. I noticed a large building was built next door in the last year. Is it the Starlink Manufacturing line building?


Offline RedLineTrain

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Re: Starlink : Hardware Design / Manufacturing
« Reply #35 on: 09/05/2020 10:08 pm »
So we know that SpaceX Starlink effort is headquartered out of the 23020 NE Alder Crest Drive Location from filings ect. I noticed a large building was built next door in the last year. Is it the Starlink Manufacturing line building?

No.  There haven't been any SpaceX building permits for the newly-built adjacent building.  It seems to make sense that they would lease that one to fill out the campus and allow a further ramp of production, but there are no indications of this as yet.

Here's a better picture of the building and a description of it.

https://www.sierraind.com/project-completion-redmond-ridge-113/

We can see the SpaceX building permits supporting the build-out of 22908, 23020, and 23040 NE Adler Crest Drive.
« Last Edit: 09/05/2020 10:30 pm by RedLineTrain »

Offline su27k

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Re: Starlink : Hardware Design / Manufacturing
« Reply #36 on: 09/07/2020 04:33 am »
Tim Farrar is saying on twitter that current Starlink satellite and terminal wouldn't support crosslink, any reason to believe his claims?

https://twitter.com/TMFAssociates/status/1301529567308337152

It seems that he's saying Starlink is the same as OneWeb, basically just acting as a repeater between terminal and gateway, but I thought the general consensus is that that's not the case?

(I know this guy is super shady, just curious if he has any basis to make this claim, since I'm not familiar with the technology details such as TDD)

Offline exilon

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Re: Starlink : Hardware Design / Manufacturing
« Reply #37 on: 09/07/2020 05:59 am »
Why would the consumer terminal care? Signal goes up to a satellite, signal comes down from the satellite.
Currently the signal from a terminal goes from terminal->sat->ground->backbone->ground->sat->terminal

The crosslinks would enable terminal->sat*N->ground->backbone->ground->sat*N->terminal or even a dedicated terminal->sat*N->terminal transmission.
Note that there's no change to the terminal->sat or sat->terminal interface.

The crux of the argument seems to be the satellites cannot host enough compute to handle the routing themselves and Musk is a con-man.

Smells very similar to the end-stage flailing of Twitter Tesla shorts around mid-2019. Dubious/vague technical claim plus character attack, and repeat.

Offline Lar

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Re: Starlink : Hardware Design / Manufacturing
« Reply #38 on: 09/07/2020 06:24 am »
The crux of the argument seems to be the satellites cannot host enough compute to handle the routing themselves...
The satellites cannot, but a ground terminal that masses way less than one bird can?  Seems like FUD to me.
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Offline guckyfan

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Re: Starlink : Hardware Design / Manufacturing
« Reply #39 on: 09/07/2020 06:58 am »
The crux of the argument seems to be the satellites cannot host enough compute to handle the routing themselves...
The satellites cannot, but a ground terminal that masses way less than one bird can?  Seems like FUD to me.

For once I disagree with you. The sat has to handle thousands of connections and the handover to another satellite. I don't see the sats handling routing. They are busy enough handing data through in point to point operations, not handling the higher protocol levels and route every stream separately. A single end user terminal may have hundreds of separate streams. Routing nodes will remain on the ground.

Offline M.E.T.

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Re: Starlink : Hardware Design / Manufacturing
« Reply #40 on: 09/07/2020 07:47 am »
Tim Farrar is saying on twitter that current Starlink satellite and terminal wouldn't support crosslink, any reason to believe his claims?

https://twitter.com/TMFAssociates/status/1301529567308337152

It seems that he's saying Starlink is the same as OneWeb, basically just acting as a repeater between terminal and gateway, but I thought the general consensus is that that's not the case?

(I know this guy is super shady, just curious if he has any basis to make this claim, since I'm not familiar with the technology details such as TDD)

This guy is probably the number one Starlink FUD monger on the web. A lot of his definitive declarations on Starlink’s imminent doom have been proven baseless one by one. He has not acknowledged any of these achievements.

He is (emotionally at least) heavily invested in Starlink’s failure. So take his comments with a pinch of salt.

« Last Edit: 09/07/2020 07:50 am by M.E.T. »

Offline woods170

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Re: Starlink : Hardware Design / Manufacturing
« Reply #41 on: 09/07/2020 09:26 am »
This guy is probably the number one Starlink FUD monger on the web. A lot of his definitive declarations on Starlink’s imminent doom have been proven baseless one by one. He has not acknowledged any of these achievements.

He is (emotionally at least) heavily invested in Starlink’s failure. So take his comments with a pinch of salt.

Emphasis mine.

Not "probably". He IS the number one Starlink FUD monger. Even when people call him out for him being verifiably wrong he will still maintain that he is right, or he will move the goalposts. As happened in the tweets called out earlier in this thread.

There is two reasons IMO why he is specifically targeting Starlink:

1. SpaceX never bothered to consult with him while Tim considers himself to be THE guy to be consulted (you should see his online resume)
2. Teledesic was one of Tim's very first "love-childs". But Teledesic failed miserably after getting only one demo satellite into orbit. And now it looks like Starlink is going to succeed where Teledesic (and by extension Tim) failed. He doesn't like that one d*mn bit IMO.


Hence IMO his negative attitude towards Starlink.
« Last Edit: 09/07/2020 09:38 am by woods170 »

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Re: Starlink : Hardware Design / Manufacturing
« Reply #42 on: 09/07/2020 10:31 am »
First orbital test of optical com between Starlink sats.
https://www.teslarati.com/spacex-starlink-space-lasers-first-orbital-test/

Offline RedLineTrain

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Re: Starlink : Hardware Design / Manufacturing
« Reply #43 on: 09/07/2020 02:00 pm »
Not "probably". He IS the number one Starlink FUD monger. Even when people call him out for him being verifiably wrong he will still maintain that he is right, or he will move the goalposts. As happened in the tweets called out earlier in this thread.

I do find it interesting to watch the falsification progression, so I peek in from time to time.  His negative pronouncements might be a marker showing what the larger players in the industry are thinking at the moment, Amazon and Iridium excepted.

But folks of this type do not give a glimpse of reality.  The world they know is as integrators and operators.  I don't think they understand an entity that does everything from designing its own silicon to launching the constellation reusably to answering support calls from consumers.

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Re: Starlink : Hardware Design / Manufacturing
« Reply #44 on: 09/07/2020 02:35 pm »
Why would the consumer terminal care? Signal goes up to a satellite, signal comes down from the satellite.
Currently the signal from a terminal goes from terminal->sat->ground->backbone->ground->sat->terminal

The crosslinks would enable terminal->sat*N->ground->backbone->ground->sat*N->terminal or even a dedicated terminal->sat*N->terminal transmission.
Note that there's no change to the terminal->sat or sat->terminal interface.

The crux of the argument seems to be the satellites cannot host enough compute to handle the routing themselves and Musk is a con-man.

Smells very similar to the end-stage flailing of Twitter Tesla shorts around mid-2019. Dubious/vague technical claim plus character attack, and repeat.

Quite. Nothing to do with the ground terminals at all. It's a bit like saying your router at home stops working if your internet provider changes their backbone. Which it doesn't.

This guy is talking nonsense.

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Re: Starlink : Hardware Design / Manufacturing
« Reply #45 on: 09/07/2020 03:18 pm »
He also believed (and probably still does) that the motors of the Starlink User Terminal are used for normal operation and not only for setup. I (an electronics engineer) explained to him that an antenna that is both mechanically steered and electronically steered for normal use is stupid and doesn't make any sense and his answer was that it's like that because "That’s what happens with an iterative system level design, you have to constantly adjust other components when another part of the system can’t deliver to spec. So you add motors to the user terminal as the simplest tweak to address the satellite’s shortcomings" which makes no sense what so ever. At that point I knew it didn't make any sense to continue arguing as basically he is advocating that everyone at Starlink is an idiot.

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Re: Starlink : Hardware Design / Manufacturing
« Reply #46 on: 09/07/2020 03:28 pm »
I actually find the idea that routing could be ground terminal based interesting.  It would increase the cost of the ground terminals, but CPU on Earth is much cheaper than on orbit.  That could be attractive.  However, it would be complicated to have ground terminals have an up-to-date picture of current traffic utilization of the constellation to efficiently use and avoid congestion, it's much easier to get that on the satellites themselves.  And aside from that complexity, routing through Starlink ought to be dead simple, as a fully SpaceX built and relatively homogeneous network.  At which point, if it is so simple, it doesn't do much to do it on the ground terminals in the first place...

Yeah, this in no way passes the smell test.
« Last Edit: 09/07/2020 03:29 pm by abaddon »

Offline vsatman

Re: Starlink : Hardware Design / Manufacturing
« Reply #47 on: 09/07/2020 04:53 pm »
This guy is talking nonsense.

I am not familiar with Tim, but I can say that the transmission from the user terminal to the satellite goes normally on the one frequency, if you have a cross link, then you need to somehow divide the information streams one goes  to the ground gateway and the other to another satellite through the cross link , this can be done either by having  data processing on board or by having 2 separate frequences (2 signals)  at  at the user terminal, that is, you must have a terminal of a different design
 one for simple access to internet via gateway and second with two transmitters  and two receivers for  using cross link

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Re: Starlink : Hardware Design / Manufacturing
« Reply #48 on: 09/07/2020 05:03 pm »
I've been wondering how the inter-satellite links would work.  With optical links, don't the send and receive elements both need to be actively pointed at each other?  If so then a satellite sending information can't randomly pick another satellite on some instantaneously calculated optimal path to send the data to, because that other satellite wouldn't know to receive the information.  Wouldn't the data need to go over predefined routes within the constellation?  With a large number of satellites there could be a large number of defined routes, but near the end points there may need to be some sub-optimal routing for a small number of hops.  For really high value routes (New York to London or various other combinations of commercial centers) they could define routes to always keep those as low latency as possible.

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Re: Starlink : Hardware Design / Manufacturing
« Reply #49 on: 09/07/2020 05:12 pm »
First orbital test of optical com between Starlink sats.
https://www.teslarati.com/spacex-starlink-space-lasers-first-orbital-test/
This is significant.

Just need SpaceX direct confirmation.

Also it was expected because of the SpaceX advertisement of job  for Laser comm manufacturing engineer to improve the management of the production of these devices. It just means that instead of large scale deployments (all sats on a launch) is much sooner than thought. Originally it was thought to occur Q1 2021 but now seems possible for Q4 2020.
« Last Edit: 09/07/2020 05:13 pm by oldAtlas_Eguy »

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Re: Starlink : Hardware Design / Manufacturing
« Reply #50 on: 09/07/2020 05:17 pm »
I've been wondering how the inter-satellite links would work.  With optical links, don't the send and receive elements both need to be actively pointed at each other?  If so then a satellite sending information can't randomly pick another satellite on some instantaneously calculated optimal path to send the data to, because that other satellite wouldn't know to receive the information.  Wouldn't the data need to go over predefined routes within the constellation?  With a large number of satellites there could be a large number of defined routes, but near the end points there may need to be some sub-optimal routing for a small number of hops.  For really high value routes (New York to London or various other combinations of commercial centers) they could define routes to always keep those as low latency as possible.
I always thought that configuring that mess would be way harder than building the hardware. Long term links with the two neighbors in your orbit and to others in the next plane over with the same altitude and inclination might be simple, but trying to figure routing and setting up links between sats in different altitudes and inclinations just hurts my brain.
« Last Edit: 09/07/2020 05:18 pm by Nomadd »
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Re: Starlink : Hardware Design / Manufacturing
« Reply #51 on: 09/07/2020 05:23 pm »
First orbital test of optical com between Starlink sats.
https://www.teslarati.com/spacex-starlink-space-lasers-first-orbital-test/
This is significant.

Just need SpaceX direct confirmation.

SpaceX said during the last Starlink launch webcast that they had tested a link between two sats.  That's why Eric wrote the article.

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Re: Starlink : Hardware Design / Manufacturing
« Reply #52 on: 09/07/2020 05:27 pm »
I've been wondering how the inter-satellite links would work.  With optical links, don't the send and receive elements both need to be actively pointed at each other?  If so then a satellite sending information can't randomly pick another satellite on some instantaneously calculated optimal path to send the data to, because that other satellite wouldn't know to receive the information.  Wouldn't the data need to go over predefined routes within the constellation?  With a large number of satellites there could be a large number of defined routes, but near the end points there may need to be some sub-optimal routing for a small number of hops.  For really high value routes (New York to London or various other combinations of commercial centers) they could define routes to always keep those as low latency as possible.
I'm guessing here...
Unperturbed orbits are very reliable, and every satellite could have the database for the current Starlink fleet, and a routine for keeping up to the microsecond positioning of all near neighbours. Reasonable pointing from that is just maths. Maybe there is a homing routine to centre the beam once acquired.
An alternative, or addition is for sats to communicate with neighbours via ground stations, transmitting their current and predicted position, and agreeing to establish "lightspeak".
Further, using laser links forward and behind in one orbit would be much easier. This could be how the initial experiments are being done, and tracking adjacent orbits being harder might be later. Finally communicating from a NE(ish) travelling sat, to one on its "downward" SE(ish) section of orbit, will be most difficult as the angle will change very quickly. Will that be attempted? I assume this can be put off as the first two should give a great improvement, (without wearing out the dish direction motors!)

Edit: Nomad got there first.... less unnecessary words make a quicker posting!
« Last Edit: 09/07/2020 05:48 pm by DistantTemple »
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Offline Mandella

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Re: Starlink : Hardware Design / Manufacturing
« Reply #53 on: 09/07/2020 05:35 pm »
This guy is talking nonsense.

I am not familiar with Tim, but I can say that the transmission from the user terminal to the satellite goes normally on the one frequency, if you have a cross link, then you need to somehow divide the information streams one goes  to the ground gateway and the other to another satellite through the cross link , this can be done either by having  data processing on board or by having 2 separate frequences (2 signals)  at  at the user terminal, that is, you must have a terminal of a different design
 one for simple access to internet via gateway and second with two transmitters  and two receivers for  using cross link

So Tim is guessing that SpaceX would have to use the second choice (two frequency user terminal) since he can't believe that Starlink could have the processing ability on board.

All right. That's not necessarily true, but even if it were why can't the user terminals being shipped initially have that capability already designed in and waiting for the crosslinks?

Offline russianhalo117

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Re: Starlink : Hardware Design / Manufacturing
« Reply #54 on: 09/07/2020 05:38 pm »
I've been wondering how the inter-satellite links would work.  With optical links, don't the send and receive elements both need to be actively pointed at each other?  If so then a satellite sending information can't randomly pick another satellite on some instantaneously calculated optimal path to send the data to, because that other satellite wouldn't know to receive the information.  Wouldn't the data need to go over predefined routes within the constellation?  With a large number of satellites there could be a large number of defined routes, but near the end points there may need to be some sub-optimal routing for a small number of hops.  For really high value routes (New York to London or various other combinations of commercial centers) they could define routes to always keep those as low latency as possible.
In my understanding I'm going to make use of a general comparison to geo survey mapping with modern automated instruments
To install permanent GPS receivers and other instruments in the Pacific Northwest's quadrangles they align mapping instruments laser beams based on a computer generated triangulation map so they get the best points for installation. These are used to study the clockwise rotation of the North American Plate below British Columbia occurring in the region that causes routine silent quakes that tensions the crusts lock zone further every 14 months.

In space this is easier as the spacecraft can have the inter satellite links permanently installed at the intended points around the spacecraft as the center of the spacecraft is the node of the surrounding right triangles. Each optical link would have say 7 DOF to adjust to real time conditions compared to the onboard map. The position info would be continuously updated aboard each sat. The alternative path is the follow on to eLISA which expands the number of sats beyond three sats any they use fixed mounting with micro steering of the optical lenses to get alignment. With radio waves you steer the Digital beams on the patch panel attennae. These are used to relay position and other data to each sat.

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Re: Starlink : Hardware Design / Manufacturing
« Reply #55 on: 09/07/2020 05:40 pm »
First orbital test of optical com between Starlink sats.
https://www.teslarati.com/spacex-starlink-space-lasers-first-orbital-test/
This is significant.

Just need SpaceX direct confirmation.

SpaceX said during the last Starlink launch webcast that they had tested a link between two sats.  That's why Eric wrote the article.
Thanks, missed that piece of evidence.

Offline DistantTemple

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Re: Starlink : Hardware Design / Manufacturing
« Reply #56 on: 09/07/2020 05:42 pm »
Will SX develop a new in-house routing layer? SRP, Starlink Routing Protocol? Existing networks do not have their nodes constantly moving, reshaping the routes via changing routers.
Also Since SX (we assume) plans to sell services to stock exchanges, international finance, the military, and "secret service", some way of hiding the routing from any kind of snooping....
I know too little about even TCP/IP to go on..... Just everyone else has to fit into the existing internet..... backbone, but SpaceX is effectively making a new network. At first it will rely heavily on the existing... but once the ISL are up, Many connections will be entirely within SL. And even those that only start or end within SL (subscribers/clients) may spend the majority of their journeys within SL, and only need (translation) to the local internet for the last few 10's of miles.
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Offline envy887

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Re: Starlink : Hardware Design / Manufacturing
« Reply #57 on: 09/07/2020 05:47 pm »
This guy is talking nonsense.

I am not familiar with Tim, but I can say that the transmission from the user terminal to the satellite goes normally on the one frequency, if you have a cross link, then you need to somehow divide the information streams one goes  to the ground gateway and the other to another satellite through the cross link , this can be done either by having  data processing on board or by having 2 separate frequences (2 signals)  at  at the user terminal, that is, you must have a terminal of a different design
 one for simple access to internet via gateway and second with two transmitters  and two receivers for  using cross link

According to the 2017 SpaceX filing, the user terminals receive on one frequency and transmit on another, at least for V band. Shouldn't they be able to do full duplex? Either with 2 antennas, or even using alternating elements in the phased array for Tx/Rx.

Also, why would you need different frequencies to use the ISLs? If the routing is done on the satellite, then the user terminal doesn't care about anything behind the router. It's just sending data to the sat, and getting data back.

If routing is done at the ground station, that is, the sats are just bent pipe(s), then there should only ever be one path from user terminal to ground station at a time. The user terminal shouldn't care how many ISL bounces there are before the single comes out the other end of the pipe at the ground station. It just sends data into the pipe, and data comes back out. Unless, (and this appears to be Tim's argument), the time-division duplexing gets messed up by the additional latency of the ISL hops. But that still shouldn't matter if they can either do full duplex, or reconfigure TDD timeslots on the fly.

In short: TDD over ISL should not be a problem that can only be surmounted by a new terminal and sat.

Offline russianhalo117

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Re: Starlink : Hardware Design / Manufacturing
« Reply #58 on: 09/07/2020 05:51 pm »
Will SX develop a new in-house routing layer? SRP, Starlink Routing Protocol? Existing networks do not have their nodes constantly moving, reshaping the routes via changing routers.
Also Since SX (we assume) plans to sell services to stock exchanges, international finance, the military, and "secret service", some way of hiding the routing from any kind of snooping....
I know too little about even TCP/IP to go on..... Just everyone else has to fit into the existing internet..... backbone, but SpaceX is effectively making a new network. At first it will rely heavily on the existing... but once the ISL are up, Many connections will be entirely within SL. And even those that only start or end within SL (subscribers/clients) may spend the majority of their journeys within SL, and only need (translation) to the local internet for the last few 10's of miles.
TCP is out dated and used by HTTP/1.1 and HTTP/2 (slated for depreciation). HTTP/3 uses QUIC (Quick UDP Internet Connections) and is the successor to TCP.
Source: https://quicwg.org/base-drafts/draft-ietf-quic-http.html

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Re: Starlink : Hardware Design / Manufacturing
« Reply #59 on: 09/07/2020 05:55 pm »
I've been wondering how the inter-satellite links would work.  With optical links, don't the send and receive elements both need to be actively pointed at each other?  If so then a satellite sending information can't randomly pick another satellite on some instantaneously calculated optimal path to send the data to, because that other satellite wouldn't know to receive the information.  Wouldn't the data need to go over predefined routes within the constellation?  With a large number of satellites there could be a large number of defined routes, but near the end points there may need to be some sub-optimal routing for a small number of hops.  For really high value routes (New York to London or various other combinations of commercial centers) they could define routes to always keep those as low latency as possible.
In my understanding I'm going to make use of a general comparison to geo survey mapping with modern automated instruments
To install permanent GPS receivers and other instruments in the Pacific Northwest's quadrangles they align mapping instruments laser beams based on a computer generated triangulation map so they get the best points for installation. These are used to study the clockwise rotation of the North American Plate below British Columbia occurring in the region that causes routine silent quakes that tensions the crusts lock zone further every 14 months.

In space this is easier as the spacecraft can have the inter satellite links permanently installed at the intended points around the spacecraft as the center of the spacecraft is the node of the surrounding right triangles. Each optical link would have say 7 DOF to adjust to real time conditions compared to the onboard map. The position info would be continuously updated aboard each sat. The alternative path is the follow on to eLISA which expands the number of sats beyond three sats any they use fixed mounting with micro steering of the optical lenses to get alignment. With radio waves you steer the Digital beams on the patch panel attennae. These are used to relay position and other data to each sat.
As far as routing on a disjointed wireless network with endpoints transitioning between infrastructure with significantly different routing. This has already been solved by the Cell Phone industry. The Starlink case is just a little more extreme but would use same methodologies. Think of Starlink as a very distributed 5G network. Which literally it is. Except it does not use the Cell frequencies.

To link up Laser comms initially and maintain the positional data of Starlink sat  neighbors in relationship to the sat's own position and orientation is maintained by uplinking this data from the ground. Once linked in then a simple optical tracking mechanism  is used to maintain pointing accuracy on the prefered object that is also pointing back at the sat with it's own Laser. The problem comes when one leg of the by directional Laser comm fails and there is no longer any incoming Laser to track to refine optical tracking. This would cause the Laser subsystem to forever be in acquisition mode until it is disabled entirely.

Added: Think of this case. You are streaming a show on your Cell Phone while sitting at home over your wireless network but then your power goes out. If you have that one little setting on your phone that says use Cell data to backup weak WiFi your show streaming may not even falter or go into buffering mode even though the routing is completely different across a completely different ISP. The highly dynamic rapid changing routing between endpoints has been solved and is in operation currently. Even between to wire endpoints the route is changing due to traffic congestion along the current route causing another route that has higher delay to be chosen but with fewer packet drops since that other route has less traffic congestion. This is happening seamlessly and without much visibility of it's occurrence to the users at the endpoints.
« Last Edit: 09/07/2020 06:14 pm by oldAtlas_Eguy »

Offline DaveH62

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Re: Starlink : Hardware Design / Manufacturing
« Reply #60 on: 09/07/2020 06:07 pm »
Great question about the routing. Will they create a new routing protocol. They will need unique routing protocols. I did a short search, but didn’t scour Reddit. I see early research and a pilot for IRIS from Cisco. Early versions don’t appear to be scalable to meet the Starlink architecture. This will be one of and potentially the largest commercial network in the world. Once the “starlink laser cloud” is running it would have a significant advantage for high frequency traders hedging between markets, and all cloud service providers. Bezos os in a losing position, but will probably spends 10’s of billions to try to be a close competitor to support AWS. SpaceX appears to have a 3 to 5+ year advantage on any competition. Figuring out the logic to make this work well will be up there with the pioneers of the internet.

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Re: Starlink : Hardware Design / Manufacturing
« Reply #61 on: 09/07/2020 06:20 pm »
Great question about the routing. Will they create a new routing protocol. They will need unique routing protocols. I did a short search, but didn’t scour Reddit. I see early research and a pilot for IRIS from Cisco. Early versions don’t appear to be scalable to meet the Starlink architecture. This will be one of and potentially the largest commercial network in the world. Once the “starlink laser cloud” is running it would have a significant advantage for high frequency traders hedging between markets, and all cloud service providers. Bezos os in a losing position, but will probably spends 10’s of billions to try to be a close competitor to support AWS. SpaceX appears to have a 3 to 5+ year advantage on any competition. Figuring out the logic to make this work well will be up there with the pioneers of the internet.
The software and protocols already exist. Starlink just is a more extreme case which may require some tweaking of existing algorithms for routing. But also may not. With Cell phone data usage being a large part of the internet traffic these days the routing algorithms have moved in the direction of Starlink's case and may already be able to handle very well any Starlink routing problem.

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Re: Starlink : Hardware Design / Manufacturing
« Reply #62 on: 09/07/2020 06:29 pm »
I'm guessing here...
Unperturbed orbits are very reliable, and every satellite could have the database for the current Starlink fleet, and a routine for keeping up to the microsecond positioning of all near neighbours. Reasonable pointing from that is just maths. Maybe there is a homing routine to center the beam once acquired.

Once calculations loosely say where to point, A simple 1 degree divergent laser can provide an initial locating beacon, then adaptive optics can lock onto it and negotiate a transfer to the link lasers for data transmission at high rates. Both ends would have to do this. The reason to use a separate beacon laser is it will need to be much much stronger because it's light is more spread out at the receiving end. Once the link is established, it can be turned off to save power.

The biggest issue for link stability will be the rapid motions of the other laser link telescopes slewing when changing from one satellite to another. Ion thrusters are so weak, tracking while firing will be easy. To an extent the reaction wheels used for stabilizing the satellite can be used to counter their motions, but it isn't perfect. It would need to be well coordinated.

For adaptive optics, look up "tilt mirror adaptive optics for telescopes".
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Re: Starlink : Hardware Design / Manufacturing
« Reply #63 on: 09/07/2020 06:58 pm »
Will SX develop a new in-house routing layer? SRP, Starlink Routing Protocol? Existing networks do not have their nodes constantly moving, reshaping the routes via changing routers.
Also Since SX (we assume) plans to sell services to stock exchanges, international finance, the military, and "secret service", some way of hiding the routing from any kind of snooping....
I know too little about even TCP/IP to go on..... Just everyone else has to fit into the existing internet..... backbone, but SpaceX is effectively making a new network. At first it will rely heavily on the existing... but once the ISL are up, Many connections will be entirely within SL. And even those that only start or end within SL (subscribers/clients) may spend the majority of their journeys within SL, and only need (translation) to the local internet for the last few 10's of miles.
TCP is out dated and used by HTTP/1.1 and HTTP/2 (slated for depreciation). HTTP/3 uses QUIC (Quick UDP Internet Connections) and is the successor to TCP.
Source: https://quicwg.org/base-drafts/draft-ietf-quic-http.html

TCP and QUIC are both Transport layer protocols, one layer above IP, which is the principal Network layer protocol of the TCP/IP stack. The Network layer sends packets around the network, routing them to their destinations. So IP is the layer that does routing.

TCP is a transport layer protocol, one level up. It adds error checking, retransmission, reordering of packets that arrive out of order, etc. IP makes its best effort and TCP adds reliability.

What Starlink needs first of all is a network protocol, at the level of IP, and the routing piece is likely to need to be smarter than IP's to handle Starlink routing peculiarities efficiently.

QUIC is an experimental transport layer protocol so far supported by the Chrome web browser, and experimentally in Edge, Firefox, and Safari--and not much else. TCP is used by almost the whole internet, not just web browsers. The TCP part of the TCP/IP stack isn't going away until just about every networking application on the internet is rewritten to use a different protocol. But networks can support multiple simultaneous Transport layer protocols over the Network layer. No doubt QUIC and TCP will both go over the Starlink network protocol, whatever it ends up being.


Offline russianhalo117

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Re: Starlink : Hardware Design / Manufacturing
« Reply #64 on: 09/07/2020 07:22 pm »
Will SX develop a new in-house routing layer? SRP, Starlink Routing Protocol? Existing networks do not have their nodes constantly moving, reshaping the routes via changing routers.
Also Since SX (we assume) plans to sell services to stock exchanges, international finance, the military, and "secret service", some way of hiding the routing from any kind of snooping....
I know too little about even TCP/IP to go on..... Just everyone else has to fit into the existing internet..... backbone, but SpaceX is effectively making a new network. At first it will rely heavily on the existing... but once the ISL are up, Many connections will be entirely within SL. And even those that only start or end within SL (subscribers/clients) may spend the majority of their journeys within SL, and only need (translation) to the local internet for the last few 10's of miles.
TCP is out dated and used by HTTP/1.1 and HTTP/2 (slated for depreciation). HTTP/3 uses QUIC (Quick UDP Internet Connections) and is the successor to TCP.
Source: https://quicwg.org/base-drafts/draft-ietf-quic-http.html

TCP and QUIC are both Transport layer protocols, one layer above IP, which is the principal Network layer protocol of the TCP/IP stack. The Network layer sends packets around the network, routing them to their destinations. So IP is the layer that does routing.

TCP is a transport layer protocol, one level up. It adds error checking, retransmission, reordering of packets that arrive out of order, etc. IP makes its best effort and TCP adds reliability.

What Starlink needs first of all is a network protocol, at the level of IP, and the routing piece is likely to need to be smarter than IP's to handle Starlink routing peculiarities efficiently.

QUIC is an experimental transport layer protocol so far supported by the Chrome web browser, and experimentally in Edge, Firefox, and Safari--and not much else. TCP is used by almost the whole internet, not just web browsers. The TCP part of the TCP/IP stack isn't going away until just about every networking application on the internet is rewritten to use a different protocol. But networks can support multiple simultaneous Transport layer protocols over the Network layer. No doubt QUIC and TCP will both go over the Starlink network protocol, whatever it ends up being.


Quick note that Google QUIC (gQUIC) is what you are referring to. I'm referring to the IETF QUIC draft standard which last I checked was in Internet Draft (I-D) per scheduled release for review issued this month. Next up is the release candidate stage after which it becomes an official Internet Standard upon approvals.

gQUIC and QUIC started as the same thing but IETF has deviated in certain aspects which gQUIC is working on implementing these changes to align with the final draft of the proposed standard.

Offline Tommyboy

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Re: Starlink : Hardware Design / Manufacturing
« Reply #65 on: 09/07/2020 08:30 pm »
Great question about the routing. Will they create a new routing protocol. They will need unique routing protocols. I did a short search, but didn’t scour Reddit. I see early research and a pilot for IRIS from Cisco. Early versions don’t appear to be scalable to meet the Starlink architecture. This will be one of and potentially the largest commercial network in the world. Once the “starlink laser cloud” is running it would have a significant advantage for high frequency traders hedging between markets, and all cloud service providers. Bezos os in a losing position, but will probably spends 10’s of billions to try to be a close competitor to support AWS. SpaceX appears to have a 3 to 5+ year advantage on any competition. Figuring out the logic to make this work well will be up there with the pioneers of the internet.
The software and protocols already exist. Starlink just is a more extreme case which may require some tweaking of existing algorithms for routing. But also may not. With Cell phone data usage being a large part of the internet traffic these days the routing algorithms have moved in the direction of Starlink's case and may already be able to handle very well any Starlink routing problem.
Routing is simple, nothing more than a lookup table. My home firewall (FortiGate 60F) is capable of routing 10Gb/s complete with full-BGP peering while using less than 30W. Yes, this requires custom silicon, but I have a sneaking suspicion that Starlink sats are already full with custom silicon. Only topology changes will require any form of CPU load, but my gut feeling tells me that 1 change per second should suffice for a 12k sat Starlink constellation, and that an 8-core ARM CPU (as the one in my FortiGate 60F) is more than capable of calculating that.

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Re: Starlink : Hardware Design / Manufacturing
« Reply #66 on: 09/07/2020 09:44 pm »
Mark Handley did a series of crosslink routing simulations a few years ago, prior to Starlink cutting crosslinks from the initial deployments. They should still be essentially valid and are interesting simulations. Each satellite would have several links which would be periodically updated as the planes move relative to each other. This would result in relatively static routing tables - yes they would be updated often, but very infrequently compared to packet count.

And as I recall (from reading threads here on NSF), Starlink originally was going to use custom silicon via Broadcom and then brought the design in house. Crosslinks were part of the original plan so this is not a case of trying to shoehorn crosslinks into an existing design, rather they have certainly been working on it all along in the background.




Offline TheEmbeddedGuy

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Re: Starlink : Hardware Design / Manufacturing
« Reply #67 on: 09/08/2020 12:15 am »
I've been wondering how the inter-satellite links would work.  With optical links, don't the send and receive elements both need to be actively pointed at each other?  If so then a satellite sending information can't randomly pick another satellite on some instantaneously calculated optimal path to send the data to, because that other satellite wouldn't know to receive the information.  Wouldn't the data need to go over predefined routes within the constellation?  With a large number of satellites there could be a large number of defined routes, but near the end points there may need to be some sub-optimal routing for a small number of hops.  For really high value routes (New York to London or various other combinations of commercial centers) they could define routes to always keep those as low latency as possible.
I always thought that configuring that mess would be way harder than building the hardware. Long term links with the two neighbors in your orbit and to others in the next plane over with the same altitude and inclination might be simple, but trying to figure routing and setting up links between sats in different altitudes and inclinations just hurts my brain.
Yeah, just when you figure it's gonna take you a long time just to design that, some youngster comes along and pulls an all-nighter and implements it.

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Re: Starlink : Hardware Design / Manufacturing
« Reply #68 on: 09/08/2020 12:52 am »
I've been wondering how the inter-satellite links would work.  With optical links, don't the send and receive elements both need to be actively pointed at each other?  If so then a satellite sending information can't randomly pick another satellite on some instantaneously calculated optimal path to send the data to, because that other satellite wouldn't know to receive the information.  Wouldn't the data need to go over predefined routes within the constellation?  With a large number of satellites there could be a large number of defined routes, but near the end points there may need to be some sub-optimal routing for a small number of hops.  For really high value routes (New York to London or various other combinations of commercial centers) they could define routes to always keep those as low latency as possible.

I was thinking control vs data... a radio link sends a "I want to connect" message, and the ACK means "ready to receive, my laser receiver is pointed your way, send it!!!"

(this is a different question than deciding which bird to talk to)
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Offline butters

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Re: Starlink : Hardware Design / Manufacturing
« Reply #69 on: 09/08/2020 12:58 am »
Each Starlink satellite incorporates 60-69 (exact count unclear) modern(ish) Intel compute cores on the same fault-tolerant computer boards used for Dragon and Falcon 9. To the extent that we are willing to ascribe any good faith to Tim Farrar's arguments, perhaps he's not taking into account the unprecedented processing power of these satellites to run software routing algorithms.

These aren't your father's rad-hardened satellite computers, and continuous iteration / continuous deployment of high-performance software systems is one of the things that every Elon Musk company does best. Starlink is almost certainly designed on the premise that they are going to be pushing frequent software updates to the satellites and the terminals to keep improving the network as the constellation is built out and the userbase grows. That's how Elon likes to engineer his products.

Offline Robotbeat

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Re: Starlink : Hardware Design / Manufacturing
« Reply #70 on: 09/08/2020 02:28 am »
These satellites have extremely high bandwidth connections to the ground. There's no reason the heavier duty routing calculations couldn't be run on the ground.
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Re: Starlink : Hardware Design / Manufacturing
« Reply #71 on: 09/08/2020 02:40 am »
Each Starlink satellite incorporates 60-69 (exact count unclear) modern(ish) Intel compute cores on the same fault-tolerant computer boards used for Dragon and Falcon 9. To the extent that we are willing to ascribe any good faith to Tim Farrar's arguments, perhaps he's not taking into account the unprecedented processing power of these satellites to run software routing algorithms.

These aren't your father's rad-hardened satellite computers, and continuous iteration / continuous deployment of high-performance software systems is one of the things that every Elon Musk company does best. Starlink is almost certainly designed on the premise that they are going to be pushing frequent software updates to the satellites and the terminals to keep improving the network as the constellation is built out and the userbase grows. That's how Elon likes to engineer his products.

I read a Starlink story, on Arstechnica I think, describing how the engineers were doing updates almost every day after the early deployments.

You are correct, Elon is relentless at iteration.  Get up, get going, learn and improve. 

By the time they get around to 2.0 it should be a very well run machine.
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Offline Eka

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Re: Starlink : Hardware Design / Manufacturing
« Reply #72 on: 09/08/2020 04:19 am »
These satellites have extremely high bandwidth connections to the ground. There's no reason the heavier duty routing calculations couldn't be run on the ground.
Routing isn't that hard even though the satellites move. Biggest issue is avoiding congestion, and that can be handled with a reroute calculation at the edge of the congestion. So, Starlink Terminal(SLT) has a packet with a destination IP address not in the routes tables. It asks the Starlink DNS system which ground downlink to send it to. The reply will have the GPS coordinate. It then calculates the best path. Next it sends the downlink info, path, and any queued packets with it to the first Starlink Satellite(SLS). It looks at the path and uses it if not congested. If congested the SLS calculates a new path to avoid the congestion, and sends it on with the new path info. Packets that come after just use the existing path. Every so often the originating terminal recalculates the path, and sends the next packet out with it, and the same use or recalculate process goes on. For moving downlinks like on aircraft or boats, recalculation can happen more often.
edit: d/the/
« Last Edit: 09/08/2020 04:23 am by Eka »
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Offline lonestriker

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Re: Starlink : Hardware Design / Manufacturing
« Reply #73 on: 09/08/2020 04:38 am »
Elon has hinted that they are indeed writing their own protocol:

https://twitter.com/elonmusk/status/967712110661615616

Quote
André Staltz
@andrestaltz
·
Feb 25, 2018
If SpaceX's Starlink will provide internet access, obviously it will also provide a single IPv6 network, and could be a great opportunity for NAT-less peer-to-peer connections within Starlink only.

I hope
@elonmusk
 chooses wisely.
Elon Musk
@elonmusk
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Feb 25, 2018
Will be simpler than IPv6 and have tiny packet overhead. Definitely peer-to-peer.

Offline Nomadd

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Re: Starlink : Hardware Design / Manufacturing
« Reply #74 on: 09/08/2020 05:12 am »
I've been wondering how the inter-satellite links would work.  With optical links, don't the send and receive elements both need to be actively pointed at each other?  If so then a satellite sending information can't randomly pick another satellite on some instantaneously calculated optimal path to send the data to, because that other satellite wouldn't know to receive the information.  Wouldn't the data need to go over predefined routes within the constellation?  With a large number of satellites there could be a large number of defined routes, but near the end points there may need to be some sub-optimal routing for a small number of hops.  For really high value routes (New York to London or various other combinations of commercial centers) they could define routes to always keep those as low latency as possible.

I was thinking control vs data... a radio link sends a "I want to connect" message, and the ACK means "ready to receive, my laser receiver is pointed your way, send it!!!"

(this is a different question than deciding which bird to talk to)
The best thing I can come up with is everybody monitoring a master control channel. Sort of like a trunking system times several thousand. The hardest part would coming up with cool names for the controllers. Several of them rotating duty and picking up if something goes wrong. Do an upgrade and it goes south, you just turn it off and the next one in line picks up using the previous version.
« Last Edit: 09/08/2020 05:17 am by Nomadd »
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Re: Starlink : Hardware Design / Manufacturing
« Reply #75 on: 09/08/2020 06:10 am »
I've been wondering how the inter-satellite links would work.  With optical links, don't the send and receive elements both need to be actively pointed at each other?  If so then a satellite sending information can't randomly pick another satellite on some instantaneously calculated optimal path to send the data to, because that other satellite wouldn't know to receive the information.  Wouldn't the data need to go over predefined routes within the constellation?  With a large number of satellites there could be a large number of defined routes, but near the end points there may need to be some sub-optimal routing for a small number of hops.  For really high value routes (New York to London or various other combinations of commercial centers) they could define routes to always keep those as low latency as possible.

I was thinking control vs data... a radio link sends a "I want to connect" message, and the ACK means "ready to receive, my laser receiver is pointed your way, send it!!!"

(this is a different question than deciding which bird to talk to)
The best thing I can come up with is everybody monitoring a master control channel. Sort of like a trunking system times several thousand. The hardest part would coming up with cool names for the controllers. Several of them rotating duty and picking up if something goes wrong. Do an upgrade and it goes south, you just turn it off and the next one in line picks up using the previous version.
If it only has a ground link, just use it to get the orbit info for the constellation. Have the ground station send the messages for linking up via ground paths to the network.

If it only has a neighboring satellite links up, use it to try to pass messages to the satellites it wants to hook up to via them. Also it can get the constellation data from the neighbor.

Once it has orbit information, it calculates where it thinks the neighbor will be, and tries to link up. If fails and is the leading satellite, then only during the first half of the scan period it scans for the other satellite. If still failed, it returns to pointing where it thinks the other should be, and the trailing satellite scans during the second half. Calculated link finding period is a short we both point at the other's calculated position for a few minutes at the beginning of the repeat period. If link fails, then scanning happens. First the leading satellite scans, then trailing satellite scans. Repeat period is say 15 minutes long tied to the quarter hour. As long as the satellite's clock is still running it the timing will be right. Any ground station or active terminal can relay the correct time.

Some sort of star tracker would help establish the orientation of the satellite so it can more easily find it's neighbors from calculations. Once one link to a neighbor is up, scanning for others will be faster. With two up, it becomes quick and links should come up on first try.
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Offline woods170

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Re: Starlink : Hardware Design / Manufacturing
« Reply #76 on: 09/08/2020 06:42 am »
First orbital test of optical com between Starlink sats.
https://www.teslarati.com/spacex-starlink-space-lasers-first-orbital-test/
This is significant.

Just need SpaceX direct confirmation.

Where do you think Teslarati got this information from?
It was mentioned by the SpaceX host during the Starlink v1.0 L11 launch of September3, 2020.

https://forum.nasaspaceflight.com/index.php?topic=51758.msg2128005#msg2128005

Offline Semmel

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Re: Starlink : Hardware Design / Manufacturing
« Reply #77 on: 09/08/2020 07:10 am »
I've been wondering how the inter-satellite links would work.  With optical links, don't the send and receive elements both need to be actively pointed at each other?  If so then a satellite sending information can't randomly pick another satellite on some instantaneously calculated optimal path to send the data to, because that other satellite wouldn't know to receive the information.  Wouldn't the data need to go over predefined routes within the constellation?  With a large number of satellites there could be a large number of defined routes, but near the end points there may need to be some sub-optimal routing for a small number of hops.  For really high value routes (New York to London or various other combinations of commercial centers) they could define routes to always keep those as low latency as possible.

My understanding/speculation:
Each sat has 4 laser connections, I assume 2 for the in-plane and 2 for out plane connections. These lasers can track satellites individually, within reason of the pointing of the host satellite.

Sats in the same orbital plane: Here the host sat could potentially switch to further away satellites by slightly pointing the laser to a different sat. But realistically, say each sat is connected at all times to its predecessor and successor in the orbital plane. All sats know where they are relative to each other by communicating with ground stations.

Sats out of plane: The laser trackers have to do a lot of work pointing to the correct sats. Sats that are on neighboring planes move relative to each other. Not sure how this works, but there is probably a fixed rule how the sats are connected and they hand off connections pretty fast.

Routing: I dont think the normal routing layer on earth applies to starlink. On the ground, we use IPs and IP tables to find the correct route from the source to the destination because our routing infrastructure is relatively static. This makes no sense in space. Rather, I guess the geo-location of the receiver would be encoded in the data package. The geo-location is known because the receiver has to be logged into the system to communicate. Each data package would encode the geo location of the destination. When a sat receives the data package, it sends it to the next free satellite in the direction of the receiver geo location. There must be a deterministic rule which satellite is responsible for transmitting the data to the ground at the destination to avoid random hand offs at the receiver between satellites.

In this scenario, load balancing is done with a greedy algorithm as well. Each satellite knows the free capacity of its neighbors. If the preferred receiver satellite is close to its capacity, the data package will get some random probability to be send to the second best satellite. If that sat is also at capacity, the data gets send back to the previous sat to find a different receiver. This might cause more congestion but is probably fine as long as the network doesnt approach its capacity limit over multiple connected satellites. The beauty of this is, it doesnt require expensive routing algorithms and it doesnt require baby sitting each connection. If the network is operating at close to 80/90 % capacity, it starts to break down due to hot spots.

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Re: Starlink : Hardware Design / Manufacturing
« Reply #78 on: 09/08/2020 07:34 am »
I've been wondering how the inter-satellite links would work.  With optical links, don't the send and receive elements both need to be actively pointed at each other?  If so then a satellite sending information can't randomly pick another satellite on some instantaneously calculated optimal path to send the data to, because that other satellite wouldn't know to receive the information.  Wouldn't the data need to go over predefined routes within the constellation?  With a large number of satellites there could be a large number of defined routes, but near the end points there may need to be some sub-optimal routing for a small number of hops.  For really high value routes (New York to London or various other combinations of commercial centers) they could define routes to always keep those as low latency as possible.

My understanding/speculation:
Each sat has 4 laser connections, I assume 2 for the in-plane and 2 for out plane connections. These lasers can track satellites individually, within reason of the pointing of the host satellite.

Sats in the same orbital plane: Here the host sat could potentially switch to further away satellites by slightly pointing the laser to a different sat. But realistically, say each sat is connected at all times to its predecessor and successor in the orbital plane. All sats know where they are relative to each other by communicating with ground stations.

Sats out of plane: The laser trackers have to do a lot of work pointing to the correct sats. Sats that are on neighboring planes move relative to each other. Not sure how this works, but there is probably a fixed rule how the sats are connected and they hand off connections pretty fast.
If you watch the video in @NaN's message #66 above, video pos 1m50s, you can see the links are rather stable satellite to satellite wise from one plane to the neighboring planes. The satellites all kinda move together. This means satellite to satellite links in the network are long lived. The only issue is the sides swap twice an orbit.
« Last Edit: 09/08/2020 07:44 am by Eka »
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Re: Starlink : Hardware Design / Manufacturing
« Reply #79 on: 09/08/2020 08:56 am »
I've been wondering how the inter-satellite links would work.  With optical links, don't the send and receive elements both need to be actively pointed at each other?  If so then a satellite sending information can't randomly pick another satellite on some instantaneously calculated optimal path to send the data to, because that other satellite wouldn't know to receive the information.  Wouldn't the data need to go over predefined routes within the constellation?  With a large number of satellites there could be a large number of defined routes, but near the end points there may need to be some sub-optimal routing for a small number of hops.  For really high value routes (New York to London or various other combinations of commercial centers) they could define routes to always keep those as low latency as possible.

My understanding/speculation:
Each sat has 4 laser connections, I assume 2 for the in-plane and 2 for out plane connections. These lasers can track satellites individually, within reason of the pointing of the host satellite.

Sats in the same orbital plane: Here the host sat could potentially switch to further away satellites by slightly pointing the laser to a different sat. But realistically, say each sat is connected at all times to its predecessor and successor in the orbital plane. All sats know where they are relative to each other by communicating with ground stations.

Sats out of plane: The laser trackers have to do a lot of work pointing to the correct sats. Sats that are on neighboring planes move relative to each other. Not sure how this works, but there is probably a fixed rule how the sats are connected and they hand off connections pretty fast.
If you watch the video in @NaN's message #66 above, video pos 1m50s, you can see the links are rather stable satellite to satellite wise from one plane to the neighboring planes. The satellites all kinda move together. This means satellite to satellite links in the network are long lived. The only issue is the sides swap twice an orbit.

I know, but do the tracking lasers have 360° field of view? Maybe, but probably difficult to pull off. So they have to hand off every 45 minutes or so. If they swap sides or target entirely new satellites is what I dont know.

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Re: Starlink : Hardware Design / Manufacturing
« Reply #80 on: 09/09/2020 02:43 pm »
I've been wondering how the inter-satellite links would work.  With optical links, don't the send and receive elements both need to be actively pointed at each other?  If so then a satellite sending information can't randomly pick another satellite on some instantaneously calculated optimal path to send the data to, because that other satellite wouldn't know to receive the information.  Wouldn't the data need to go over predefined routes within the constellation?  With a large number of satellites there could be a large number of defined routes, but near the end points there may need to be some sub-optimal routing for a small number of hops.  For really high value routes (New York to London or various other combinations of commercial centers) they could define routes to always keep those as low latency as possible.

My understanding/speculation:
Each sat has 4 laser connections, I assume 2 for the in-plane and 2 for out plane connections. These lasers can track satellites individually, within reason of the pointing of the host satellite.

Sats in the same orbital plane: Here the host sat could potentially switch to further away satellites by slightly pointing the laser to a different sat. But realistically, say each sat is connected at all times to its predecessor and successor in the orbital plane. All sats know where they are relative to each other by communicating with ground stations.

Sats out of plane: The laser trackers have to do a lot of work pointing to the correct sats. Sats that are on neighboring planes move relative to each other. Not sure how this works, but there is probably a fixed rule how the sats are connected and they hand off connections pretty fast.
If you watch the video in @NaN's message #66 above, video pos 1m50s, you can see the links are rather stable satellite to satellite wise from one plane to the neighboring planes. The satellites all kinda move together. This means satellite to satellite links in the network are long lived. The only issue is the sides swap twice an orbit.

I know, but do the tracking lasers have 360° field of view? Maybe, but probably difficult to pull off. So they have to hand off every 45 minutes or so. If they swap sides or target entirely new satellites is what I dont know.
They don't need to switch satellites, but would need to switch sides. If the com lasers for the side links were placed on a rotatable stalk, then they could retain communications. That stalk would have to be set off to the side so it doesn't interfere with the phased array antennas. Of course that adds complexity and the need for slip ring connections. Best avoided if possible. Otherwise I'm not seeing how unless more than 4 com lasers are present. The issue I see is that switch off interrupts routes, but they are being interrupted all the time. At the switch off time, those links are not needed other than for traffic volume. E/W traffic can go to the next satellite in the same orbital plane.

If 6 comm lasers were put on each satellite, then they could hand the side links off.

The big issues are how long are those links are down, is it really a problem, how much slewing both com lasers at the same time upsets the satellite, and wear and tear on the flex connectors.
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Offline Nomadd

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Re: Starlink : Hardware Design / Manufacturing
« Reply #81 on: 09/09/2020 04:04 pm »

If you watch the video in @NaN's message #66 above, video pos 1m50s, you can see the links are rather stable satellite to satellite wise from one plane to the neighboring planes. The satellites all kinda move together. This means satellite to satellite links in the network are long lived. The only issue is the sides swap twice an orbit.
By the time they start deploying lasers en masse, they won't be far from launching in other inclinations. Won't the other inclinations be at slightly different altitudes for traffic reasons? Or maybe slightly elliptical if they're the same period to avoid crossing paths? Or is the orbital simulator in my brain I got mostly from watching Duck Dodgers cartoons way off?
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Offline Eka

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Re: Starlink : Hardware Design / Manufacturing
« Reply #82 on: 09/09/2020 06:44 pm »

If you watch the video in @NaN's message #66 above, video pos 1m50s, you can see the links are rather stable satellite to satellite wise from one plane to the neighboring planes. The satellites all kinda move together. This means satellite to satellite links in the network are long lived. The only issue is the sides swap twice an orbit.
By the time they start deploying lasers en masse, they won't be far from launching in other inclinations. Won't the other inclinations be at slightly different altitudes for traffic reasons? Or maybe slightly elliptical if they're the same period to avoid crossing paths? Or is the orbital simulator in my brain I got mostly from watching Duck Dodgers cartoons way off?
Other orbital inclinations likely will have to be at other altitudes due to all the crossing of orbits. Talking between altitudes may require more lasers or they could have a satellite every few satellites link between orbit altitudes using their side comm lasers.
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Offline su27k

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Re: Starlink : Hardware Design / Manufacturing
« Reply #83 on: 09/12/2020 04:17 am »
New(?) SpaceX phased array antenna patent found by reddit: Uni-dimensional steering of phased array antennas

Quote
U.S. patent number 10,770,790 [Application Number 15/908,602] was granted by the patent office on 2020-09-08 for uni-dimensional steering of phased array antennas. This patent grant is currently assigned to Space Exploration Technologies Corp.. The grantee listed for this patent is Space Exploration Technologies Corp.. Invention is credited to Alireza Mahanfar.

Abstract
A phased array antenna system configured for communication with a satellite that emits or receives radio frequency (RF) signals and has a repeating ground track in a first direction, the antenna system includes a phased array antenna including a plurality of antenna elements distributed in a plurality of M columns oriented in the first direction and a plurality of N rows extending in a second direction normal to the first direction, and a plurality of fixed phase shifters aligned for phase offsets between antenna elements in the first direction and a gain-enhancement system configured for gain enhancement in the second direction of radio frequency signals received by and emitted from the phased array antenna.

Offline niwax

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Re: Starlink : Hardware Design / Manufacturing
« Reply #84 on: 09/12/2020 10:10 am »
New(?) SpaceX phased array antenna patent found by reddit: Uni-dimensional steering of phased array antennas

Quote
U.S. patent number 10,770,790 [Application Number 15/908,602] was granted by the patent office on 2020-09-08 for uni-dimensional steering of phased array antennas. This patent grant is currently assigned to Space Exploration Technologies Corp.. The grantee listed for this patent is Space Exploration Technologies Corp.. Invention is credited to Alireza Mahanfar.

Abstract
A phased array antenna system configured for communication with a satellite that emits or receives radio frequency (RF) signals and has a repeating ground track in a first direction, the antenna system includes a phased array antenna including a plurality of antenna elements distributed in a plurality of M columns oriented in the first direction and a plurality of N rows extending in a second direction normal to the first direction, and a plurality of fixed phase shifters aligned for phase offsets between antenna elements in the first direction and a gain-enhancement system configured for gain enhancement in the second direction of radio frequency signals received by and emitted from the phased array antenna.

Interesting. This idea seems so obvious after the fact. If you increase resolution along the orbital planes but not across them, you can resolve more satellites per plane while the separation between planes will always likely stay higher tat between satellites.
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Offline RedLineTrain

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Re: Starlink : Hardware Design / Manufacturing
« Reply #85 on: 09/12/2020 02:59 pm »
New(?) SpaceX phased array antenna patent found by reddit: Uni-dimensional steering of phased array antennas

It seems that two years ago, the patent author moved on to Amazon.

Offline su27k

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Re: Starlink : Hardware Design / Manufacturing
« Reply #86 on: 10/16/2020 02:04 am »
In MainEngineCutOff podcast episode T+171, Anthony mentioned he heard some crazy low cost for a standard Starlink satellite, in the price range of a car, not a Ferrari, but a Cybertruck.

He also mentioned there're rumors that SpaceX has bigger/heavier Starlink bus than the current one, which are used for the SDA missile warning satellite bid, and this fits the speculation that the 1 metric ton tracking satellite in the SDA bid is from SpaceX (see here for related discussion on NSF)
« Last Edit: 10/16/2020 02:05 am by su27k »

Offline su27k

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Offline su27k

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Re: Starlink : Hardware Design / Manufacturing
« Reply #88 on: 05/27/2021 04:04 am »
Some information about Starlink Gateway V3 was revealed in filings to Brazilian regulator Anatel:

Reddit thread 1: Starlink ground station antenna certified by Brazilian regulator, revealing some hardware information

Reddit thread 2: This is how Gateway V3 looks inside the dome

Quick Summary from first thread:

Quote from: RichardG867
https://tecnoblog.net/445448/anatel-libera-equipamentos-da-starlink-internet-via-satelite-de-elon-musk/

Brazil's telecom regulator Anatel has certified the Starlink Gateway V3 ground station antenna. The certification, requested by Starlink Brazil on behalf of SpaceX, covers two variants of the Gateway V3 which differ in operating frequencies. The certificate reveals that the Ku-band antenna has a bandwidth capacity of up to 4 Gbit/s, and features a built-in modem (whatever that would mean in this context).

An attached picture provides a glimpse into the antenna's underside, as well as the identification nameplate mounted there, which contains the following hardware information:

Weight: 1750 kg (3858 lbs)
Part number: 01425000-5
Year of manufacture
Serial number
IP rating: IP55
Power input: AC 200-240 V (50/60 Hz) @ 33 A
Short-circuit current rating: 10 kA
Made in USA by SpaceX

Attached zip file is filing downloaded from Anatel's website using the step by step instruction here

Attached images are from the 2nd thread, captured from the filing document.

Online gongora

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Re: Starlink : Hardware Design / Manufacturing
« Reply #89 on: 05/27/2021 04:43 am »
They're Ka-band antennas (although technically I guess they dip into the top 200MHz of the Ku-band).  According to the slide deck that listed weight includes the concrete base and post.

Offline AC in NC

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Re: Starlink : Hardware Design / Manufacturing
« Reply #90 on: 06/19/2021 06:12 am »
https://arstechnica.com/information-technology/2021/06/starlink-dish-overheats-in-arizona-sun-knocking-user-offline-for-7-hours/

Quote
Thermal shutdowns affect other users

Officially, SpaceX has said that "Dishy McFlatface" is certified to operate from 22° below zero up to 104° Fahrenheit. Temperatures reached about 120° yesterday in Martin's town of Topock, near Arizona's border with California, he said. Though Dishy doesn't go into thermal shutdown until it hits 122°, the dish can obviously get hotter than the air temperature.

"I'm thinking the radiating heat from the ground is effectively cooking the bottom of the dish, [while] the top of the dish is cooked by the sun," Martin told Ars.

Offline markbike528cbx

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Re: Starlink : Hardware Design / Manufacturing
« Reply #91 on: 10/18/2021 09:01 pm »
Being curious (nosey), I looked up the location of the local Starlink Gateway.
See attached FCC license.

When I went to that location I saw that the Starlink gateway antennas are mushroom (dome) shaped.   
I didn't get any ground level pics as there was a truck in the driveway and we were on a long car trip.

In the Google earth pic (from April 2021) the flat roofed white building has been there since 2003, so not a Starlink building.
The set of 9 domes are new and I assume to be Starlink antennas.   
I am sort of surprised that the antennas are dishes, not phased array (from upthread).

The area is pretty flat.  And no the lines on the grounds are not alien Nazca lines, it is dryland wheat farming. :-)
I'm surprised that the powerlines along the road to the north (top of pic) are left in place.
Nevermind, I got my old trig cards out and realized a 40ft pole 208 ft from the antenna is 10.8 degrees, which is lower than the 25 degree minimum for Starlink.
« Last Edit: 10/18/2021 09:09 pm by markbike528cbx »

Online gongora

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Re: Starlink : Hardware Design / Manufacturing
« Reply #92 on: 10/18/2021 09:26 pm »
Starlink is currently using phased array antennas for Ku-band (between satellite and end user), and parabolic dishes for Ka-band (between satellite and gateway), both on the satellites and on the ground.

Offline markbike528cbx

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Re: Starlink : Hardware Design / Manufacturing
« Reply #93 on: 10/18/2021 09:48 pm »
Starlink is currently using phased array antennas for Ku-band (between satellite and end user), and parabolic dishes for Ka-band (between satellite and gateway), both on the satellites and on the ground.
I don't recall seeing parabolic dishes on the Starlink satellites.

Online gongora

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Re: Starlink : Hardware Design / Manufacturing
« Reply #94 on: 10/18/2021 09:49 pm »
Starlink is currently using phased array antennas for Ku-band (between satellite and end user), and parabolic dishes for Ka-band (between satellite and gateway), both on the satellites and on the ground.
I don't recall seeing parabolic dishes on the Starlink satellites.

They're on the ends (the v0.9 test sats didn't have them, but you can see them on every launch since v1.0 started)
« Last Edit: 10/18/2021 09:49 pm by gongora »

Offline joek

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Re: Starlink : Hardware Design / Manufacturing
« Reply #95 on: 10/18/2021 11:03 pm »
...
In the Google earth pic (from April 2021) the flat roofed white building has been there since 2003, so not a Starlink building.
The set of 9 domes are new and I assume to be Starlink antennas.
...

Likely that building is backbone provider (Level3, CenturyLink, Verizon, ...). Not unusual to see those out in the boonies along major roads, as that is where power is available and fiber is laid. Many Starlink ground stations have been co-located with such. If you have the specific FCC filing or lat-long information, we could probably identify the provider and its interconnect(s)

Offline joek

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Re: Starlink : Hardware Design / Manufacturing
« Reply #96 on: 10/18/2021 11:09 pm »
Starlink is currently using phased array antennas for Ku-band (between satellite and end user), and parabolic dishes for Ka-band (between satellite and gateway), both on the satellites and on the ground.

May also be using a hybrid phased array? Been quite a bit of work on those for Ku-Ka over the past few years.

Online gongora

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Re: Starlink : Hardware Design / Manufacturing
« Reply #97 on: 10/18/2021 11:18 pm »
Starlink is currently using phased array antennas for Ku-band (between satellite and end user), and parabolic dishes for Ka-band (between satellite and gateway), both on the satellites and on the ground.

May also be using a hybrid phased array? Been quite a bit of work on those for Ku-Ka over the past few years.

At least for normal operations, they're currently using phased array for Ku-band and parabolic dishes for Ka-band.  I guess if someone like DoD wanted to use a Ka-band phased array for a gateway they probably could, but the v1.0 sats don't have phased arrays for Ka-band.

Offline Scintillant

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Re: Starlink : Hardware Design / Manufacturing
« Reply #98 on: 10/18/2021 11:52 pm »
...
In the Google earth pic (from April 2021) the flat roofed white building has been there since 2003, so not a Starlink building.
The set of 9 domes are new and I assume to be Starlink antennas.
...

Likely that building is backbone provider (Level3, CenturyLink, Verizon, ...). Not unusual to see those out in the boonies along major roads, as that is where power is available and fiber is laid. Many Starlink ground stations have been co-located with such. If you have the specific FCC filing or lat-long information, we could probably identify the provider and its interconnect(s)

Looks like it's at 46.1273134, -119.6840400. Prosser, WA.

Offline markbike528cbx

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Re: Starlink : Hardware Design / Manufacturing
« Reply #99 on: 10/19/2021 06:42 pm »
...
In the Google earth pic (from April 2021) the flat roofed white building has been there since 2003, so not a Starlink building.
The set of 9 domes are new and I assume to be Starlink antennas.
...

Likely that building is backbone provider (Level3, CenturyLink, Verizon, ...). Not unusual to see those out in the boonies along major roads, as that is where power is available and fiber is laid. Many Starlink ground stations have been co-located with such. If you have the specific FCC filing or lat-long information, we could probably identify the provider and its interconnect(s)

Looks like it's at 46.1273134, -119.6840400. Prosser, WA.
I linked a copy of the license in my first topic post. It is a PDF, so it didn't expand to visibility.  Can't repost it from my IPad 2 :-(

Offline vsatman

Re: Starlink : Hardware Design / Manufacturing
« Reply #100 on: 10/20/2021 09:01 pm »
I don't recall seeing parabolic dishes on the Starlink satellites.
see left  from red caps   


Offline su27k

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Re: Starlink : Hardware Design / Manufacturing
« Reply #101 on: 10/21/2021 11:26 am »
Modern Flat Panel Antenna Technology for Ku-/Ka-Band User Terminals in LEO Satellite Communications Systems

Quote from: Microwave Journal
In recent years, an increasing number of broadband satellite systems have been launched into low earth orbit (LEO), connecting people across the globe. Flat panel antennas are especially attractive for LEO satellites due to their tracking ability, low profile and easy installation. This article discusses three major antenna technologies: electronically scanned array (ESA), variable inclination continuous transverse stub (VICTS) and lens antenna. ESAs consist of arrays of individually controlled radiating antenna elements with different phase delays that coherently form and scan the antenna beam in the far field. Within the category of ESA antennas are analog, digital and hybrid antennas with passive or active radios. VICTS antennas consist of rotating disks that steer the beam and change polarization based on the relative position of the disks. Lens antennas consist of modular lens sets that steer the beam by individually controlling the source of energy relative to the focus of each lens. Each of these technologies has strengths and weaknesses that are compared in this article using the size, weight, power consumption and cost (SWaP-C) metric.

Author says SpaceX's system is ESA Active Hybrid, but didn't say how he got this information.

Offline markbike528cbx

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Re: Starlink : Hardware Design / Manufacturing
« Reply #102 on: 10/22/2021 08:43 am »
I don't recall seeing parabolic dishes on the Starlink satellites.
see left  from red caps   
Thanks  vasatman  ! 
Nice specific point-out for the pic.  Needed that.  So often the picture is posted and the poster says about a small feature "it is in the picture " with no text aid to find the small feature.

Offline su27k

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Re: Starlink : Hardware Design / Manufacturing
« Reply #103 on: 11/09/2021 03:47 am »
Starlink Deepens Cooperations With Taiwan on Solar Cells

Quote from: techtaiwan.com
Taiwan Solar Energy Corp. (TSEC), Taiwan’s largest manufacturer of photovoltaic (PV) systems, has become a supplier of Starlink. Founded in 2010, TSEC produces both multicrystalline and monocrystalline silicon solar cells and modules.

<snip>

Starlink satellites reportedly used silicon-based solar cells, traditionally used for terrestrial applications, instead of the III-V compound solar cells more commonly used by the space industry. While the solar cells based on compound semiconductors are more efficient and more resilient to harsh space environment, they are also prohibitively expensive. Driven by cost reduction as well as the shorter life expectancy of Starlink satellites, SpaceX opted for the silicon-based solar cells that are less durable in space environment.


Offline su27k

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Re: Starlink : Hardware Design / Manufacturing
« Reply #104 on: 01/29/2022 03:24 am »

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« Last Edit: 05/27/2022 07:52 pm by Teppich »

Offline Asteroza

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Re: Starlink : Hardware Design / Manufacturing
« Reply #106 on: 05/29/2022 10:59 pm »
Some interesting job postings

https://twitter.com/idontwa86202030/status/1530271541279219718?s=20&t=jj71QRoAK1BViRI45d5EUg

https://twitter.com/idontwa86202030/status/1530272631890518018?s=20&t=jj71QRoAK1BViRI45d5EUg

Looks like SpaceX is getting into packaging as well as ASIC design for Starlink

Silicon Development Engineer, Packaging Technology https://boards.greenhouse.io/spacex/jobs/6174603002?gh_jid=6174603002

Principal SOC Physical Design Engineer https://boards.greenhouse.io/spacex/jobs/6163663002?gh_jid=6163663002

You would think they would just dragoon SOC jockeys from Tesla instead...

Offline Tomness

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Re: Starlink : Hardware Design / Manufacturing
« Reply #107 on: 05/29/2022 11:36 pm »
Some interesting job postings

https://twitter.com/idontwa86202030/status/1530271541279219718?s=20&t=jj71QRoAK1BViRI45d5EUg

https://twitter.com/idontwa86202030/status/1530272631890518018?s=20&t=jj71QRoAK1BViRI45d5EUg

Looks like SpaceX is getting into packaging as well as ASIC design for Starlink

Silicon Development Engineer, Packaging Technology https://boards.greenhouse.io/spacex/jobs/6174603002?gh_jid=6174603002

Principal SOC Physical Design Engineer https://boards.greenhouse.io/spacex/jobs/6163663002?gh_jid=6163663002

You would think they would just dragoon SOC jockeys from Tesla instead...

They just might, I thought they we moving the terminal production to Austin near Tesla. Be a win-win. Its not the first time Tesla & SpaceX have marvel teamed up.

Online gongora

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Re: Starlink : Hardware Design / Manufacturing
« Reply #108 on: 05/30/2022 02:04 pm »
SpaceX has had internal chip designers for years now.

Online oldAtlas_Eguy

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Re: Starlink : Hardware Design / Manufacturing
« Reply #109 on: 05/30/2022 10:42 pm »
A custom Silicon chip design acheives multiple goals all of which SpaceX is very interested in.

Move more of the varied circuit board components onto a single chip which has these advantages:

- Higher overall reliability in harsh environments
- Lower power consumption
- Less mass
- Lower overall unit costs per circuit implementation produced

An example would be a complete implementation of an ISL onto a single chip. Each V1.5 has 5+ ISL's and a V2 will probably have 4 times that at 20. The ISL is a case where if anything fails the ISL is useless. So by integrating everything into a single chip that also achieves a better reliability even though it represents a single point of failure for a specific ISL unit. Achieves the four above items which over a production run for V2 over a period about 3 years could be chips numbering into 600,000. Highly successful chip design could e around for 10 years before a newer chip design with even better advantages is produced again in the .5 to 1 million units production run. If the ISL terminal designs becomes very popular then the production runs could number into the millions.

Another example is the terminal antenna circuits. These will run into the 10s of millions chip unit production runs. Lower number of components means lower cost and faster manufacture of the terminals.

So even with the added cost of doing their own chip design and a custom production run at a fab. SpaceX should still be able to achieve a lower total cost per unit for chip design.

Offline andrewi

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Re: Starlink : Hardware Design / Manufacturing
« Reply #110 on: 09/06/2022 03:13 pm »
Recommend good video on how Starlink works - esp Dishy ie how steered phase arrays work.  More detail than most would want but really only a primer so to speak.  Wasn't sure which to post in.

How does Starlink Satellite Internet Work?  by Branch Education


The video indicates Dishy switches satellites every 4 mins (based  100 degree field of view) but other posts and websites on the Starlink API indicate that dishy does this every 15 seconds which is also reflected in looking at tcp traffic flows  - saw a comment the this indicates that Starlink v1 UT (Round User Terminal) would remain compatible  with the larger V2 Starlink sats which would be deployed in denser shells so require ground UT to switch more often (ie can switch every 15 seconds not the often assumed 4 minutes requirement of current deployed shells)

eg su27k posted in Re: Starlink Internet Connection equipment - Home/Office user
« Reply #264 on: 07/06/2021 02:47 am »
Some friendly hacking of the protocol between app and Dishy:
SpaceX shutdown part of Dishys API because of me (and others)
Starlink Dishy: getting some deeper status
Biggest discovery is Dishy switches satellite every 15 seconds. They was able to get real time satellite and gateway id used by Dishy, but that API is locked down now.

Online DanClemmensen

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Re: Starlink : Hardware Design / Manufacturing
« Reply #111 on: 09/06/2022 03:50 pm »
The video indicates Dishy switches satellites every 4 mins (based  100 degree field of view) but other posts and websites on the Starlink API indicate that dishy does this every 15 seconds which is also reflected in looking at tcp traffic flows  - saw a comment the this indicates that Starlink v1 UT (Round User Terminal) would remain compatible  with the larger V2 Starlink sats which would be deployed in denser shells so require ground UT to switch more often (ie can switch every 15 seconds not the often assumed 4 minutes requirement of current deployed shells)

Dishy switches Satellites about once every 4 mins, but each satellite throws multiple beams (i.e. footprints) that move across the ground as the satellite moves. Your Dishy is switching from beam to beam about once every 15 seconds, on the same satellite. I'm not sure of the Starlink beam pattern, but the OneWeb satellites throw 16 long skinny beams whose long axis is roughly perpendicular to the direction of motion of the satellite, so each terminal ends up switching to each of the beams in turn as the pattern sweeps across the terminal. Starlink probably does something similar.

Online FutureSpaceTourist

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Re: Starlink : Hardware Design / Manufacturing
« Reply #112 on: 11/21/2022 05:42 am »
https://twitter.com/virtuallynathan/status/1594359493332455425

Quote
SpaceX is hiring engineers to work on v2.0 solar panel production using teamtechnik Stringer Systems -- the TT2100: https://www.teamtechnik.com/en/new-energy/stringer-systems/solar-stringer-tt2100-i8 A single system can build 72.5MW-peak per year.

Offline docmordrid

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Re: Starlink : Hardware Design / Manufacturing
« Reply #113 on: 11/21/2022 03:12 pm »
https://twitter.com/virtuallynathan/status/1594359493332455425

Quote
SpaceX is hiring engineers to work on v2.0 solar panel production using teamtechnik Stringer Systems -- the TT2100: https://www.teamtechnik.com/en/new-energy/stringer-systems/solar-stringer-tt2100-i8 A single system can build 72.5MW-peak per year.

DM

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Re: Starlink : Hardware Design / Manufacturing
« Reply #114 on: 01/15/2023 06:03 am »
twitter.com/virtuallynathan/status/1614486135211962369

Quote
SpaceX just got their own IDRA casting machine delivered last month to Houston... possibly destined for the new factory near Austin? Maybe in-house production of the Starlink metal stand and/or other metal parts...

https://twitter.com/virtuallynathan/status/1614487490169311232

Quote
In the past year, they've imported 455,971kg of metal stands

Offline RedLineTrain

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Re: Starlink : Hardware Design / Manufacturing
« Reply #115 on: 01/17/2023 04:16 pm »
twitter.com/virtuallynathan/status/1614486135211962369

Quote
SpaceX just got their own IDRA casting machine delivered last month to Houston... possibly destined for the new factory near Austin? Maybe in-house production of the Starlink metal stand and/or other metal parts...

https://twitter.com/virtuallynathan/status/1614487490169311232

Quote
In the past year, they've imported 455,971kg of metal stands

Aren't the dish back shells also metal?  Metal stands are a dime a dozen.

Offline Remes

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Re: Starlink : Hardware Design / Manufacturing
« Reply #116 on: 01/17/2023 08:47 pm »
Aren't the dish back shells also metal?  Metal stands are a dime a dozen.

The tear down videos on yt seem to show that it is plastic.

Also die casting sheet metal like structures is the worst thing. With the beginning of the injection process the molten material starts to cool down. As thinner, as faster the material solidifies. It would also be more economic to have smaller machines for smaller parts, and not making 100 dishes in one shot.

Thinking of a Tesla die casting part (thing between the rear tyres), I could imagine rather big (in the order of meters) parts. Parts which have to carry load, like a thrust structure. The thrust puck could be replaced for a SS. Lot of stamping, cutting, bending, fixturing, welding, ... Could be replaced by a couple of parts.

Things which carry too much load, like the engine swivel mounts, are maybe to hard to create with magnesia alloys (and typcially to small for such a big press).

Maybe with the bigger 2.0 Starlink satellites they want to replace some structures in the satellite? Replacing extremely work intensive carbon/honeycomb plates with heavier but way easier producible die cast structures?
« Last Edit: 01/17/2023 08:51 pm by Remes »

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Re: Starlink : Hardware Design / Manufacturing
« Reply #117 on: 01/21/2023 08:04 pm »
https://twitter.com/felixschlang/status/1616894544867479552

Quote
Here's @CosmicalChief's SpaceX Starlink v2 Satellite stack picture from Starbase, January 20th, with brightened Shadows for a clearer view of the stack!

I am counting 33 Starlink v2 Sats in this picture! Are any other estimates out there? ❤️🚀

Offline su27k

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Re: Starlink : Hardware Design / Manufacturing
« Reply #118 on: 01/28/2023 03:23 am »
https://twitter.com/olegkutkov/status/1619118201803251712

Quote
The new #Starlink UT is upcoming?
Board name: board_rev_rev4_proto1
The most exciting difference is 4 digital beamformer ICs instead of 16.  Huge production optimization.

It looks like the codename of the new DBF IC is "bamboo". It's still based on ST xp70 DSP.

Offline seb21051

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Re: Starlink : Hardware Design / Manufacturing
« Reply #119 on: 01/28/2023 06:39 pm »
"Thinking of a Tesla die casting part (thing between the rear tyres)"

Tesla has moved on a little from only having a casting between the rear wheels. They have one between the front wheels too now on the Model Y. These castings are partially responsible for the significant margins Tesla maintains. They are reported to replace around 170 discrete components, reduce the number of assembly robots required, and reduce the time it takes to assemble the vehicle.

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Re: Starlink : Hardware Design / Manufacturing
« Reply #120 on: 02/24/2023 12:25 pm »
https://twitter.com/cosmicalchief/status/1628916650492801029

Quote
Starlinks in the payload processing building are about to be loaded onto a cargo truck. The Starlink box moved out earlier and may have some loaded into it, but looks like most of these are about to go away for now.
#Starbase #Starship #SpaceX
📸 Me for WAI Media @FelixSchlang

Offline virtuallynathan

Re: Starlink : Hardware Design / Manufacturing
« Reply #121 on: 02/24/2023 12:48 pm »
https://twitter.com/cosmicalchief/status/1628916650492801029

Quote
Starlinks in the payload processing building are about to be loaded onto a cargo truck. The Starlink box moved out earlier and may have some loaded into it, but looks like most of these are about to go away for now.
#Starbase #Starship #SpaceX
📸 Me for WAI Media @FelixSchlang
As I replied to his tweet, you can see they loaded something on the truck, but it's not satellites, it appears to be some kind of metal jig/stand.

Offline RedLineTrain

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Re: Starlink : Hardware Design / Manufacturing
« Reply #122 on: 02/24/2023 02:07 pm »
Related to the terminals, STMicro of Switzerland just published its 2022 annual report.  For the first time, it stated that SpaceX is among its top 10 customers.  In 2022, it doubled capital expenditures (plant and equipment) in order to, in part, handle growth from SpaceX.

https://www.sec.gov/Archives/edgar/data/932787/000156459023002312/stm-20f_20221231.htm

Here's a bit of related STMicro marketing material at pages 17-24.

https://cmd.st.com/static-files/28f9ad09-da99-45ab-b8e5-f49e0a515df3

Offline geza

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Re: Starlink : Hardware Design / Manufacturing
« Reply #123 on: 11/13/2023 08:50 am »
Do we have any more detailed information about the laser inter-sattelite links? Like distance, mirror diameter, pointing accuracy, power, bandwith... If Elon expects the first Starship flight to Mars in 4 years, then improvement of laser communication is needed by quite a few order of magnitude in a few years. Is there any info about this?

Offline JayWee

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Re: Starlink : Hardware Design / Manufacturing
« Reply #124 on: 11/17/2023 04:48 pm »
New Dishy released:

https://www.starlink.com/specifications?spec=4


https://twitter.com/SawyerMerritt/status/1725569551490752556

Quote from: Sawyer Merit
BREAKING: SpaceX has introduced their next generation Starlink terminal.

• New design that's slimmer & more portable
• Starlink kit also includes Gen 3 router with improved range & speeds
• No motors. Simple kickstand
• 10% better field of view vs previous gen
• Higher IP67 waterproof rating
• Can operate in 60+mph wind speeds (vs 50+ before)
« Last Edit: 11/17/2023 04:49 pm by JayWee »

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Re: Starlink : Hardware Design / Manufacturing
« Reply #125 on: 12/06/2023 11:30 am »
https://twitter.com/starlinkinsider/status/1732264733548425665

Quote
Side-by-side comparison of the new Gen3 dish vs. the previous Gen2 Standard antenna

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