15 ms·
Lasers enable satellite internet backbone, might remove need for deep-sea cables
- okasaki 3y agoNeat, but won't it be slower?
- CorrectHorseBat 3y agoIt should be faster, the speed of light in optical fiber is only 2/3 of that in vacuum (and air). I'm more concerned about clouds and storms.
- supriyo-biswas 3y agoDoes it bring any latency improvements for users?
- CAP_NET_ADMIN 3y ago> Although the laser system was not directly tested with an orbiting satellite, they accomplished high-data transmission over a free-space distance of 53km (33 miles). This is peanuts compared to under sea cables and issues you will find penetrating atmosphere and increasingly, space. We should keep under sea cables and work on additional connections to make our networks more resilient, both to natural phenomena, equipment failures and sabotage.
- pushfoo 3y ago> more resilient, both to natural phenomena, equipment failures and sabotage. I think you're understating the risks from geomagnetic storms. In comparison to satellites, fiber optic cables seem like they'd be relatively unaffected even if the equipment attached to them needs replacement.
- zamfi 3y agoPerhaps the ocean is protective to some degree, but beyond very short lengths undersea cables have powered repeaters that draw considerable current, and which would plausibly be destroyed if the base stations are too.
- adrian_b 3y agoI would not say "very short lengths", because undersea cables without powered repeaters (only with optical amplifiers) are possible until a few hundred kilometer. But you are right that transoceanic cables need powered repeaters.
- CAP_NET_ADMIN 3y agoCurrently, you can cut internet connections to most countries with a small deep water sub. China, for example, was busy building one that can be used at 10k+ depth and has arms.
- giobox 3y agoIts widely assumed China, Russia and the US have "kinetic kill" abilities on satellites in space too, its just capabilities are not as widely known. Projects Like the US/Boeing X-37 space drone etc, whose purposes still haven't really been revealed: > https://en.wikipedia.org/wiki/Boeing_X-37 https://en.wikipedia.org/wiki/Boeing_X-37 Russia has already demonstrated its satellite destroying tech: > https://www.cnbc.com/video/2021/11/16/russia-blows-up-satellite-in-asat-weapon-test-threatens-space-station-with-debris.html https://www.cnbc.com/video/2021/11/16/russia-blows-up-satell...
- CAP_NET_ADMIN 3y ago"Kinetic kill" is arguably easier to detect and harder to deny. I haven't said that we should only focus on sea cables, I said that we should do both so that the overall reliability and resiliency increases.
- kelnos 3y agoCan those be deployed "anonymously" though? Publicly destroying another nation's satellite would be an act of war. Quietly and secretly cutting an undersea cable, while being able to plausibly deflect blame, is a bit safer.
- wcoenen 3y agoAlso, India. List of anti-satellite tests: https://www.researchgate.net/publication/368223169/figure/tbl1/AS:11431281117593250@1675470275795/List-of-anti-satellite-tests-conducted-by-different-nations.png https://www.researchgate.net/publication/368223169/figure/tb...
- elzbardico 3y agoThe problem is that it is fairly difficult to do it cleanly without risking precipitating Kessler syndrome. https://en.wikipedia.org/wiki/Kessler_syndrome https://en.wikipedia.org/wiki/Kessler_syndrome It is basically automatic MAD (Mutually Assured Destruction) out there in space.
- piyh 3y agoAre solar storms an issue for LEO sats?
- Beached 3y agoyeah, but having both means if one is a victim, the other keeps chugging along. a bad anchor drag take out cables? or a sub cut the wire? lasers go pew pew. weather take out lasers? cables go zoom. and in normal operating conditions, both go and increase bandwidth and speed
- dermesser 3y agoIt's not peanuts at all, given that it's an entirely different technology. Free space optics will have different applications, of course, but those applications where fiber is currently not feasible stand to profit quite a bit from this.
- Beached 3y agoI can think of all of rural America underserved with fast internet, forced to share puny fiber runs to towers retransmitting over low speed radio. implementing the same infra, but using lasers as the backbone could speed up a large area of the country, make rolling out dense radio networks like 5g way faster and cheaper, etc.
- huijzer 3y agoEliminate deep sea cables? How are they going to send the lasers in a curve from one base station to the next? Starlink is already working on a backhaul from satellite to satellite. Interestingly, they claim that they can speed up data transfers by 50% over long distances. Musk said that in a Tweet which I cannot find now. I looked a bit into it and the reason seems to be that light trough a cable can only reach 70% of the speed of light while lasers through the vacuum of space can reach the speed of light.
- ceejayoz 3y ago> Eliminate deep sea cables? How are they going to send the lasers in a curve from one base station to the next? Multiple satellites. The ISS can see about a thousand miles in each direction to the horizon, so you'd only need to bounce across a couple to cross the Atlantic.
- toast0 3y agoSending lasers in a curve should be easy if you use circular polarization. /s You would send to a satellite in view; my orbital dynamics are poor, but I think with the LEO orbits, you may need to relay in space for a cross ocean link, as it seems unlikely one satelite would have a view of both sides. But Telstar 1 and 2 were used for cross-Atlantic microwave relay with a single satellite in view at a time. Future Telstars were geostationary, because satellite tracking was a lot of work (and with only two satellites, service was intermittent as they were only in view for a portion of their orbits). I imagine satellite tracking for lasers is going to be very difficult as well.
- SiempreViernes 3y agoGreat for countries that think they can control space, not so great for those without ASAT capabilities.
- deepspace 3y agoFTA: "However, scaling up is not something Leuthold and his team will be concerning themselves with". As an engineer, the words "devil" and "details" come to mind.
- NoMoreNicksLeft 3y agoWhy is scaling always necessary? Can't we just do this same thing, but more of and bigger? I mean, that makes it easy-peasy.
- oneplane 3y agoBecause 'more and bigger' can be summed up as 'scaling'...
- grimgoldgo 3y agoThey transmit in near infrared in an environment that is full of particles, wouldn't this cause light pollution in a spectrum many animals would be impacted by? Also, doesn't this have the issue that anything passing through the beam cuts off internet? A bird, a kite, a malicious actor, a dust storm?
- ted_dunning 3y agoThere won't be any significant light pollution since the beams are so narrow. The problem of interference from clouds and precipitation is real, but the problem of physical occlusion probably isn't because the satellites move pretty fast. That would make it hard to persistently block the beam unless you have something as big as a storm cloud.
- throwway120385 3y agoThis seems like a reasonable question, on its face. I have NIR illumination on my surveillance cameras and insects are VERY interested in it. Every night I get at least one bat hanging out by my camera. I'm fairly certain it's because the camera attracts insects.
- pests 3y agoLaser is for satellite to satellite communication so far. I don't know of any birds or bikes flying around up in space. :D
- Aeroi 3y agoHFT bros jizzing in their pants
- cvs268 3y agoWhat pants? :-D
- ortusdux 3y agoCurrent fiber optic cables transmit signals at 2/3rds the speed of light. Modeling has shown that starlink's laser backbone would allow it to beat deep-sea cables in some situations. This article estimates a NYSE -> FTSE reduction from 76ms to 43ms. I wouldn't be surprised to learn that there is a HFT bidding war going on. https://archmeregreenarch.org/1456/news/starlink-and-the-rise-of-a-new-space-internet/ https://archmeregreenarch.org/1456/news/starlink-and-the-ris... There is a newer version of fiber optic cable that uses a hollow core. Testing has shown it transmits signals at nearly the speed of light. It is very difficult to produce at scale and will require a generational shift to deploy. https://www.nature.com/articles/s41467-020-19910-7 https://www.nature.com/articles/s41467-020-19910-7
- HWR_14 3y agoWouldn't they have to relay between many satellites due to line of sight? And wouldn't that eat up any decrease in time of flight for the signal itself?
- nine_k 3y agoI suspect that retransmission with amplification only, without much processing, can be really fast. Modern electronics can routinely do sub-nanosecond latency.
- londons_explore 3y agoIndeed. If the system is designed with latency in mind, then the receive to send latency can be as low as a few feet of distance equivalent.
- posnet 3y agoThe question isn't whether satellite links can beat deep-sea cables, it's whether they can beat shortwave. https://sniperinmahwah.wordpress.com/2018/05/07/shortwave-trading-part-i-the-west-chicago-tower-mystery/ https://sniperinmahwah.wordpress.com/2018/05/07/shortwave-tr...
- NelsonMinar 3y agoThe key thing here is it allows for very high bandwidth to go almost anywhere on earth, not just spots where it's easy to land a cable. Starlink's already demonstrated how great that is for consumer bandwidth (50Mbps); a multi-gigabit link terminated at a satellite is fantastic. The part that impresses me most is they're talking about LEO satellites. Those move fast! Starlink does this with a very impressive phased array antenna design. Conceptually tracking a moving satellite with a laser is as easy as rotating a mirror, not sure how hard it is in practice.
- oceanplexian 3y agoIt also circumvents the biggest problem with fiber, politics. Starlink doesn’t need permission to run a backbone across (or rather over) a country. This will be revolutionary for people in Africa, South America, and huge swaths of Asia/Australia where a few telecom monopolies have artificially jacked the price of transit.
- falcolas 3y agoIIUC, it only circumvents politics due to existing treaties. Those old treaties are likely ripe for revision with the extensive commercialization and the increasing number of countries capable of launching payloads into space. https://en.wikipedia.org/wiki/Politics_of_outer_space https://en.wikipedia.org/wiki/Politics_of_outer_space
- thecosas 3y agoIt definitely helps mitigate the infrastructure buildout hurdles (which are not small), but they would still need to jump through any "I need to do business in this country" regulations, etc.
- asadotzler 3y agoOnly if they want to bring a signal down to the ground. Unlike fiber, LEO sats can send data across an entire continent of countries or states without getting permission from any of them. Wanna connect Toronto to Mexico City with fiber, gotta get the US and half a dozen states and dozens of counties all to give you easement. Not so with space lasers :-)
- looofooo 3y agohttps://en.m.wikipedia.org/wiki/Chappe_telegraph https://en.m.wikipedia.org/wiki/Chappe_telegraph Might be cheaper to build an Tower with PV and battery every 30km than running lines. Cell-Tower in remote Locations etc.
- nine_k 3y agoCongrats, you've reinvented microwave lines, widely deployed in exactly this manner.
- Tuna-Fish 3y agoThe big difference between open air laser and microwave links is that one of them doesn't require licensed spectrum. The costs of doing it will be much lower.
- nine_k 3y agoFair! And the existing MW re-translator towers can be upgraded / reused this way. Lasers have a downside though: optical and near IR light is much more readily absorbed by water vapor than microwaves. I wonder if a maser would be an acceptable solution, if cheaper versions of it existed.
- looofooo 3y ago1550nm water is super transparent.
- adrian_b 3y agoNot at all. While 1550 nm falls between two absorption maxima of water, so it is not the worst choice, the absorption in water is still more than one hundred times higher than at e.g. 905 nm. Because of this, 1550 nm is absorbed through fog or clouds at least 3 to 5 times more than shorter wavelengths like 905 nm. Even the latter is absorbed a lot by water, while being much more dangerous for eyes than 1550 nm. There is no near infrared wavelength where the water absorption is negligible. See the graphs at: https://en.wikipedia.org/wiki/Electromagnetic_absorption_by_water https://en.wikipedia.org/wiki/Electromagnetic_absorption_by_...
- hbogert 3y agoare they trying to the feed the flat earthers?
- JoshTko 3y agoWe should keep both, Solar flares, space junk, etc. can knock out satellites
- _R_ 3y agoHope to see it deployed in GEO, as this would significantly increase bandwidth and reduce costs in remote areas.
- agnosticmantis 3y agoAren’t lasers extremely susceptible to weather conditions? E.g. when it’s raining/snowing/cloudy, can the base station communicate with a satellite via laser?
- looofooo 3y agoNo, it is 1550nm Laser.
- adrian_b 3y agoThe lasers are used only between the Starlink satellites, not in the uplinks or downlinks. While this experiment has demonstrated that it is possible to compensate for the turbulence of the air, there is no solution for the attenuation caused by bad weather. It might be possible to use lasers between a base station and satellites only if the base station is located at high altitude in a dry place, like those typically chosen for astronomical observatories, so that the links will be blocked by bad weather only infrequently. So I do not believe that there is even a remote chance of replacing most undersea cables.
- samtho 3y agoThis tech is really cool, but as they mentioned, they have not tested this with a moving satellite. Because any antenna would need to be localized on a satellite for transmission, you’re going to be stuck with having to maintain (likely) expensive and precise motors who’s job it will be to run in perpetuity. However, I would be confident that stepper motors of this grade will come down in price or will become more available. My primary concern comes down to reliably. Your ground station must now accurately target moving satellites, negotiate handoffs, and reroute when necessary. Architecturally, you will need to develop the ground station with at least three transponders: an A link, B link, and a redundant Z link. The A and B take turns localizing to their satellite where one is only allowed to move positions if the other is currently active. The backup Z link is on standby in case of failure or maintenance. The three would likely rotate roles periodically to keep time on each of the motors more evenly distributed amongst them. This system must work in harmony with all the satellites in its network. The satellite system has its own maintenance burden too, including orbital decay requiring you to periodically adjust its position until it runs out of propellant, and send more up when it’s reached the end of its useful life. To me, this is a ton of moving parts. An undersea cable by contrast, will pretty much be maintenance free once laid only requiring infrequent repairs in the event of a wayward ship anchor. Yes, the data center components will need to upgraded periodically but you don’t need to replace the transmission mode. There are no moving parts, no need To track objects hundreds of miles away, just sending light down a tube. Is this tech cool? Absolutely. Will it replace undersea cables? Probably not soon, but I can see this as a great solution to link remote islands where it does not make strategic sense to run a cable, or where it is difficult or uneconomical to run a terrestrial connection.
- colinsane 3y ago> Because any antenna would need to be localized on a satellite for transmission, you’re going to be stuck with having to maintain (likely) expensive and precise motors who’s job it will be to run in perpetuity. However, I would be confident that stepper motors of this grade will come down in price or will become more available. the article says they direct the laser using a MEMS device. not dissimilar to the micromirror arrays used in DLPs for decades, i would assume. you’ve definitely got options that don’t require stepper motors or any macroscopic moving parts here.
- teeray 3y agoI genuinely hope one of these systems gets called “Tightbeam”
- eqvinox 3y agoThis sure sounds useful, but "might remove need for deep-sea cables" is quite silly. Anything they do to cram bandwidth into their laser link can reasonably also be applied to fiber optical cables. Except the fiber optical cables come in bundles of 12 to 144 with absolutely no separation issues. Replicating that over open space (air or vacuum), if reasonably possible at all, will chug significant amounts of power in signal processing at the receive end. There are major benefits to free-space optics - - quicker to build - lower latency - in some cases, large coverage But deep-sea cables compete on bandwidth, and that's not something free-space optics can beat them on. Why diminish this research achievement by conflating it with that? :(
- NohatCoder 3y agoOn top of this I really doubt the claim about working in bad weather. Some weather will work, sure, maybe at reduced speeds. But if there is a proper cloud in the way, the near-visible 1550 nm light will be scattered completely.
- Havoc 3y agoI could see both being in use, but replacement seems unlikely to me. If nothing else I could see governments insisting on both just for strategic reasons. Both techs are vulnerable to being fk'd with so doubling up makes sense
- 1970-01-01 3y agoLast I checked, there is a 1% chance of a Carrington Event within the next decade. Leaving cables behind and trusting new wireless links before we have a "full DR" situation would be stupid.
- aj7 3y agoI suspect the tracking and switching infrastructure, the sophistication of free space lasers with their adaptive optics, and the inclusion of satellite receiver-transmitters with their own adaptive optics will not be competitive with laying a passive undersea cable for at least a decade.
- cycomanic 3y agoI like the ETH result and it is an impressive feat (I know some people involved in that work). That said the article is a lot of rubbish. First there is the weird focus on lasers, all (relevant) Optical Communication uses lasers, including fibre comms. Then they make it sound like this is to replace fibre, again rubbish. The amount of data going through fibres is absolutely staggering, replacing this with intersatellite links is just not going to happen. First you still need fibre to connect your ground stations (and you need quite a bit of redundancy due to weather) and there are still a lot of unsolved problems (tracking and pointing for example). However there are many interesting applications of optical satellite links and quite a few players are investing in it, the big one is actually data connections for scientific space missions.
- eqvinox 3y ago(really off-topic) The Z on ETHZ is important, ETH on its own is just (loosely) "university", the Z makes it the Zürich one ;D. There is exactly one other: EPFL in Lausanne. (And you can technically call them EPFZ and ETHL if you really want to confuse people.) (EPF [École Polytechnique Fédérale] is just the French version of German ETH [Eidgenössische Technische Hochschule]. Funnily enough both have pretty good international reputations, but due to the primary regional language being different are rarely recognized to be the same type of Swiss education entity.)
- spicybright 3y agoHalf the reason I log onto HN is for the obscure random facts like these :) ty!
- dermesser 3y ago...yet, when saying "ETH" everyone knows what is being referred to. Except for crypto bros.
- looofooo 3y agoETH Lausanne or Zürich?
- ryanwaggoner 3y agoSure, because we only need the internet on sunny days.
- irq-1 3y agooff topic: NASA is working on lasers in space. > The Deep Space Optical Communications (DSOC) package aboard NASA’s Psyche mission utilizes photons -- the fundamental particle of visible light -- to transmit more data in a given amount of time. The DSOC goal is to increase spacecraft communications performance and efficiency by 10 to 100 times over conventional means, all without increasing the mission burden in mass, volume, power and/or spectrum. https://www.nasa.gov/directorates/spacetech/tdm/feature/Deep_Space_Communications https://www.nasa.gov/directorates/spacetech/tdm/feature/Deep...
- sleepybrett 3y agoUsed to work, in the early naughts, for a company that had a laser uplink in seattle from their office building to the westin. I sat in the office with the uplink for awhile, pointed out the window with a big gimble, you could watch it adjust for building sway. Uplink went to shit in heavy fog though...
- efitz 3y agoDid anyone else notice that they failed to mention clouds?
- mrinterweb 3y agoWhat about solar storms? I would expect the damage would be more catastrophic if a major solar wind storm took down a decent percentage of the the satellites than terrestrial fiber. A satellite network seems more vulnerable and harder to fix. I'm sure deep sea cables are no picnic to fix, and they are susceptible to sabotage too. https://www.space.com/solar-storms-destroy-satellites https://www.space.com/solar-storms-destroy-satellites
- killjoywashere 3y agoWhenever I hear of exotic comms stuff like this, I think about command and control use cases. Quantum computing is about security of the cryptographic security infrastructure (PKI, TLS, etc). New physical layers are all about diversification. It's less about disruption and more about security.
- WatchDog 3y agoInteresting, fibre optic cables can be tapped by an adversary, it's difficult to physically secure the entire length of the cable. Satellite radio communications can be monitored, as the signal is cast over a wide area. Satellite laser communications however, would be much more difficult to tap into.
- thadjones 3y agoLasercom has been demonstrated well on Earth but it still is a very nascent technology in the space domain. There are several challenges that lasercom faces. First, in order to enable global communication you need a constellation and good constellation management. This requires fewer spacecraft if you are in GEO, but GEO spacecraft tend to be larger and more expensive. Second, lasers draw a lot of power. Most is waste heat as far as the spacecraft is concerned, but this can become a problem if the duty cycle is high. High power means much larger arrays, and for a LEO constellation, serious eclipse challenges. Finally and most importantly, pointing is a challenge. Maintaining pointing control in space is hard, and lasers require much greater accuracy as compared to RF. With RF, the lobes are relatively large and allow some play when it comes to downlink to ground. Lasers are unforgiving. I’ve led several spacecraft missions with lasercom terminals, and every time it has made development markedly more challenging. I think it will be quite a while before it is mainstream, and certainly before it replaces fiber.
- asadotzler 3y agoISLs are active today, providing low-latency broadband to thousands, perhaps tens of thousands of Starlink's 1.7-ish million customers where there are no nearby ground stations. I'm not sure if that's "mainstream" but when major cruise lines and Alaskans are happy active customers, it feels like it's getting mainstream to me.
- happytiger 3y agoUntil we have a volcano or solar storm event. This is an evolutionary step for driving down the cost of high speed backbone capable links perhaps, but it’s not a fiber replacement by any means.
- dmbche 3y agoUnrelated - I'm reminded of the plans for beaming energy from orbital stations gathering sunlight, which instead uses microwaves. I wonder how much these beams interact with the atmosphere? I can imagine lasers interact little, but wouldn't microwaves heat up water vapor on it's way?
- tempestn 3y agoThe mirror array sounds like a micro version of what's used in large Earth-based telescopes for the same purpose. Their primary mirrors are made out of movable segments to cancel out atmospheric effects. They're just a bit bigger...
- throwaway_dhv7k 3y agoThe need to hide cables under water exists, among other things, because satellites will be the first thing that will fly down in the event of a global conflict. Of course, underwater cables also have their vulnerabilities, but at least the technology for repairing them and laying new ones is much simpler than satellites.
- ilyt 3y agoFollowup news: "Man with a drone caused intermitten internet outage lasting hours"
- qa_acc 3y agoIMHO this article is garbage because moving internet backbone in space isn't a sustainable choice in the short, medium and especially long period. Starlink knows that, they are operating in loss, burning money of investors, hoping that some kind of new sci-fi tech will change the game, but honestly that won't happen. Image if the current cellphone network was in space, every time the tech has a generational step forward you should burn all the satellites and re- launch a new constellation. Moreover, you need to reach consumers (the last mile ) on Earth and you can't do that with lasers. Customers will rely in radio communications, that in this case have low quality compared to other alternatives, when they are available. In fact the point of satellite Internet is to cover a niche market: you use that solution if there are no alternative and if you can afford the costs. So you can accept lower connection speed, variale QoS, etc , hoping in a better alternative in the future and, when that alternative arrive in form of a wired traditional connection, instantly the customers migrate there. So that market constantly decrease, not increase. If competitors realise that exist clusters of satellite customers in some rural zones and they are willing to pay more for Internet connection they will take over completely and , anyway, in times of remote working, someone should invest in providing fast internet in remote places that are characteristic of better quality of life for remote workers want a better life, instead of invest in satellite internet. Laser telecommunications are already a thing but in optic fibre and there in fact they have more sense than in a fragile and expansive satellite constellation.