What is the current information on when we might see a version of the hardware with laser interlinks?
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?
Quote from: Roy_H on 01/26/2020 01:13 amI 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.
Quote from: Roy_H on 01/26/2020 01:13 amI 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.
Quote from: ulm_atms on 01/26/2020 01:31 amQuote from: Roy_H on 01/26/2020 01:13 amI 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.
Quote from: Eka on 01/26/2020 08:36 pmQuote from: ulm_atms on 01/26/2020 01:31 amQuote from: Roy_H on 01/26/2020 01:13 amI 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.
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....
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)
Quote from: dondar on 01/30/2020 01:05 pmbeside 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?
https://ieeexplore.ieee.org/document/5680175QuoteOptical 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)
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?)
🛰 albedo will drop significantly on almost every successive launch
When are you going to add laser links for comms? Is that even necessary for starting to offer service later this year?
Direct links aren’t needed to offer service. Starlink will initially bounce signals off ground/ocean relays to get from 🛰 to 🛰.
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.
https://twitter.com/chenry_sn/status/1237013319896240134QuoteJonathan 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.
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.
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.
twitter.com/thesheetztweetz/status/1240258825078353920QuoteSpaceX 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/1240259238141796358QuoteSpaceX 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."
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."
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."
I can’t remember seeing the tension rods on the Starlink stack in such detail before
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?
The crux of the argument seems to be the satellites cannot host enough compute to handle the routing themselves...
Quote from: exilon on 09/07/2020 05:59 amThe 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.
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/1301529567308337152It 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.
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.
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->terminalThe 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.
This guy is talking nonsense.
First orbital test of optical com between Starlink sats.https://www.teslarati.com/spacex-starlink-space-lasers-first-orbital-test/
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.
Quote from: geza on 09/07/2020 10:31 amFirst 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.
Quote from: JamesH65 on 09/07/2020 02:35 pmThis 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
Quote from: oldAtlas_Eguy on 09/07/2020 05:12 pmQuote from: geza on 09/07/2020 10:31 amFirst 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.
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.
Quote from: gongora on 09/07/2020 05:03 pmI'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 instrumentsTo 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.
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.
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.
Quote from: DistantTemple on 09/07/2020 05:42 pmWill 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
Quote from: russianhalo117 on 09/07/2020 05:51 pmQuote from: DistantTemple on 09/07/2020 05:42 pmWill 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.htmlTCP 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.
Quote from: DaveH62 on 09/07/2020 06:07 pmGreat 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.
Quote from: gongora on 09/07/2020 05:03 pmI'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.
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.
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.
André Staltz@andrestaltz·Feb 25, 2018If 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·Feb 25, 2018Will be simpler than IPv6 and have tiny packet overhead. Definitely peer-to-peer.
Quote from: gongora on 09/07/2020 05:03 pmI'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)
Quote from: Lar on 09/08/2020 12:52 amQuote from: gongora on 09/07/2020 05:03 pmI'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.
Quote from: gongora on 09/07/2020 05:03 pmI'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.
Quote from: Semmel on 09/08/2020 07:10 amQuote from: gongora on 09/07/2020 05:03 pmI'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.
Quote from: Eka on 09/08/2020 07:34 amQuote from: Semmel on 09/08/2020 07:10 amQuote from: gongora on 09/07/2020 05:03 pmI'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.
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.
Quote from: Eka on 09/08/2020 07:34 amIf 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?
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.AbstractA 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.
New(?) SpaceX phased array antenna patent found by reddit: Uni-dimensional steering of phased array antennasQuoteU.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.AbstractA 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.
New(?) SpaceX phased array antenna patent found by reddit: Uni-dimensional steering of phased array antennas
For now. Costs are decreasing rapidly.
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: 01425000-5Year of manufactureSerial numberIP rating: IP55Power input: AC 200-240 V (50/60 Hz) @ 33 AShort-circuit current rating: 10 kAMade in USA by SpaceX
Thermal shutdowns affect other usersOfficially, 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.
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.
Quote from: gongora on 10/18/2021 09:26 pmStarlink 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.
...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....
Quote from: gongora on 10/18/2021 09:26 pmStarlink 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.
Quote from: markbike528cbx on 10/18/2021 09:01 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)
Quote from: joek on 10/18/2021 11:03 pmQuote from: markbike528cbx on 10/18/2021 09:01 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 don't recall seeing parabolic dishes on the Starlink satellites.
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.
Quote from: markbike528cbx on 10/18/2021 09:48 pmI don't recall seeing parabolic dishes on the Starlink satellites. see left from red caps
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.
Starlink Dishy PCB artworks
Some interesting job postingshttps://twitter.com/idontwa86202030/status/1530271541279219718?s=20&t=jj71QRoAK1BViRI45d5EUghttps://twitter.com/idontwa86202030/status/1530272631890518018?s=20&t=jj71QRoAK1BViRI45d5EUgLooks like SpaceX is getting into packaging as well as ASIC design for StarlinkSilicon Development Engineer, Packaging Technology https://boards.greenhouse.io/spacex/jobs/6174603002?gh_jid=6174603002Principal SOC Physical Design Engineer https://boards.greenhouse.io/spacex/jobs/6163663002?gh_jid=6163663002
Quote from: Teppich on 05/27/2022 07:50 pmSome interesting job postingshttps://twitter.com/idontwa86202030/status/1530271541279219718?s=20&t=jj71QRoAK1BViRI45d5EUghttps://twitter.com/idontwa86202030/status/1530272631890518018?s=20&t=jj71QRoAK1BViRI45d5EUgLooks like SpaceX is getting into packaging as well as ASIC design for StarlinkSilicon Development Engineer, Packaging Technology https://boards.greenhouse.io/spacex/jobs/6174603002?gh_jid=6174603002Principal SOC Physical Design Engineer https://boards.greenhouse.io/spacex/jobs/6163663002?gh_jid=6163663002You would think they would just dragoon SOC jockeys from Tesla instead...
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)
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.
https://twitter.com/virtuallynathan/status/1594359493332455425QuoteSpaceX 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.
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...
In the past year, they've imported 455,971kg of metal stands
twitter.com/virtuallynathan/status/1614486135211962369QuoteSpaceX 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/1614487490169311232QuoteIn 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.
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? ❤️🚀
The new #Starlink UT is upcoming?Board name: board_rev_rev4_proto1The 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.
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
https://twitter.com/cosmicalchief/status/1628916650492801029QuoteStarlinks 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
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)
Side-by-side comparison of the new Gen3 dish vs. the previous Gen2 Standard antenna
I'm assuming this is legit as it came from the Starlink twitter account. That camera view is not what I was expecting a starlink sat to look like, the solar array looks very... sketchy. https://twitter.com/Starlink/status/1777441354588791206
I'm assuming this is legit as it came from the Starlink twitter account. That camera view is not what I was expecting a starlink sat to look like, the solar array looks very... sketchy.
Quote from: heerohawwah on 04/09/2024 08:03 pmI'm assuming this is legit as it came from the Starlink twitter account. That camera view is not what I was expecting a starlink sat to look like, the solar array looks very... sketchy. Is that one of the v2 minis? I imagine they had to try every trick in the book to get weight and size down, given the capability was originally supposed to be supported by Starship-sized payloads.
The latest @Starlink terminal (available in many markets, coming soon to others) is an excellent product - nice write-up by @PCMag . Good performance, sleek, highly manufacturable, and comes with our WiFi-6 router.
First Tests: How Fast Are Starlink's New Dish V4 and Router V3?
Starlink MINI (REV MINI1_PROD2) with built-in WiFi.28.9x24.8 cm (11.4″ x 9.8″)
What version of WiFi? No external antenna option?
802.11b/g/n/ax. Three built-in antennas. No external.
What seems like our first look at the upcoming @Starlink mini product. Eager to learn more - will be a day one order for me!
It’s awesome. Will have massive demand in lower income parts of the world.
Following up on the factory expansion, the other day, Joe Tegtmeyer did a drone flyover. It appears that the pier drilling that they are doing is supportive of a much larger addition than 150,000 square feet -- perhaps an addition of 500,000 square feet footprint (equal to the original facility) or larger.