[HN Gopher] World-first gigabit laser link between aircraft and ...
       ___________________________________________________________________
        
       World-first gigabit laser link between aircraft and geostationary
       satellite
        
       Author : giuliomagnifico
       Score  : 158 points
       Date   : 2026-03-01 16:49 UTC (4 days ago)
        
 (HTM) web link (www.esa.int)
 (TXT) w3m dump (www.esa.int)
        
       | xnx wrote:
       | Impressive! I believe round trip latency would be 0.5 seconds.
        
         | 1e1a wrote:
         | That's ~162.5 MB in transit at any time
        
           | zppln wrote:
           | Weird.
        
           | htgb wrote:
           | Shouldn't it be 1000/16 = 62.5? Impressive nonetheless, of
           | course!
        
             | 1e1a wrote:
             | The article says 2.6 gigabits/second which is 2,600,000,000
             | bits/second, 2,600,000,000b/s * 0.5s / 8 is 162,500,000
             | bytes, 162,500,000 / 1,000,000 is 162.5 megabytes
        
               | htgb wrote:
               | Right, thanks
        
           | kevincox wrote:
           | Excellent for pingfs (https://github.com/yarrick/pingfs)
        
           | arethuza wrote:
           | That could you used like RAM like the delay-line memory used
           | by early computers!
        
           | kipchak wrote:
           | There's a patent (2017/0280211 A1) for using this as a data
           | storage method, and there was a company called Lyteloop
           | trying to leverage the idea for data storage with estimations
           | for petabytes across constellation.
        
       | myrmidon wrote:
       | I'm really curious how the tracking works in such a system, and
       | how "bad" the beam spread is (my impression is that from the
       | diffraction limit alone the beam has to be spread over at least a
       | ~10m radius after travelling 36000km).
       | 
       | Some info on the laser itself would also be very interesting
       | (power? wavelength?).
       | 
       | Really cool project though!
        
         | amelius wrote:
         | > and how "bad" the beam spread is
         | 
         | The spread makes the tracking easier, I suppose.
        
           | TimorousBestie wrote:
           | Perhaps a little, however. Different paths through the
           | atmosphere will perturb the phase of the signal; depending on
           | conditions not all of that ~10m beam width is going to decode
           | with an acceptable bit error rate.
        
         | mytailorisrich wrote:
         | Tracking and actuation is nothing new or particularly
         | challenging, IMHO. It's the laser/optical part combined with
         | throughput at that distance that is the main area of R&D, I
         | think.
        
       | cm2187 wrote:
       | But that means you need to have a different laser pointed at
       | every single individual aircraft right? Doesn't really scale.
        
         | amelius wrote:
         | I suppose you can do time-sharing. And use mems-mirrors to
         | quickly move the beam between different targets.
        
           | esseph wrote:
           | Laser TDMA! :-)
           | 
           | https://en.wikipedia.org/wiki/Time-division_multiple_access
        
         | voidUpdate wrote:
         | If starlink satellites get laser downlink, it might work :P
        
           | cm2187 wrote:
           | laser downlink to one point, isn't it? Not to 300 moving
           | aircrafts at once.
        
         | eqvinox wrote:
         | You can probably do phased arrays. (It might already be a
         | phased array.)
        
           | mohaine wrote:
           | Pretty sure phased array LASERs are not yet a thing.
        
             | eqvinox wrote:
             | Yeah but this is research, if they're to come up somewhere,
             | where else would it be?
        
             | aidenn0 wrote:
             | Lasers are coherent emitters; you can definitely make
             | interference patterns with them, so I don't see why LASER
             | MIMO wouldn't be possible, in theory.
        
             | buildbot wrote:
             | I was not sure, but they are!
             | 
             | https://cga.anu.edu.au/research/activities/laser-beam-
             | steeri...
             | 
             | https://www.darpa.mil/research/programs/excalibur
             | 
             | I guess in some ways even the fancy multi diode fiber
             | lasers are phased arrays, just with the single goal of
             | higher output power.
        
               | axus wrote:
               | Looks like these are in early development and nowhere
               | near ready like this test was.
        
       | Meneth wrote:
       | "low-latency links", says the article. I wonder if they consider
       | 500 ms ping to be low, or if they want to replace Geostationary
       | with Low Earth Orbit.
        
         | fidotron wrote:
         | Getting it to work with one end stationary first sounds like a
         | reasonable development plan. LEO adds a lot of complexity, but
         | with huge benefits.
         | 
         | OTOH the number of engineers that focus on throughput over
         | latency is quite staggering.
        
           | IrishTechie wrote:
           | I guess if your goal is just to stream aircraft telemetry and
           | black box like recordings then latency may not be high on the
           | agenda.
        
             | SiempreViernes wrote:
             | I think it's the opposite? For small telemetry you want it
             | _now_ , but for the big data products there's no hope of
             | "now" and so you settle for _soon_.
        
             | connicpu wrote:
             | Black box data doesn't need that crazy throughput either
             | though. Traditional RF is much easier to get right, and
             | works even when the aircraft starts losing track of where
             | it is and stops being able to track the satellite with its
             | laser
        
           | amarant wrote:
           | Leo seems easier to me. Geostationary is really far away. Leo
           | is much, much closer. It's easier to hit a buck thats running
           | right past you than to hit a stationary target across the
           | Atlantic.
           | 
           | Especially if you yourself are on a moving platform
        
         | pottertheotter wrote:
         | I'll take 500ms ping for those speeds while temporarily on a
         | plane.
        
           | oofbey wrote:
           | No doubt! I've measured literal 5 minute ping times on
           | airplanes. 300,000ms. Where are the buffering the packets!?
        
             | raddan wrote:
             | My guess is that you're getting retransmissions because of
             | dropped frames, not because there's some huge buffer in the
             | sky.
        
               | reactordev wrote:
               | Indicated airspeed 280kts, ground speed 470kts, FL410,
               | the packets are trying to catch up...
        
               | JackFr wrote:
               | I like "huge buffer in the sky".
               | 
               | That's where I imagine all my deleted data goes.
        
               | 0_____0 wrote:
               | we're all just riding the ring buffer of samsara, maaan
        
               | BobbyTables2 wrote:
               | There's one huge buffer in the sky!
               | 
               | The huge buffers are at the two endpoints (:->
        
         | adev_ wrote:
         | > "low-latency links", says the article. I wonder if they
         | consider 500 ms ping to be low, or if they want to replace
         | Geostationary with Low Earth Orbit.
         | 
         | Directional laser beams are orders of magnitude to jam compared
         | to radio wave. That alone makes it of big interest for military
         | applications, even with 500 ms latency.
         | 
         | There is several known cases where jamming caused the loss of
         | costly military drones.
         | 
         | https://en.wikipedia.org/wiki/Iran%E2%80%93U.S._RQ-170_incid...
         | 
         | Laser comms could prevent that entirely.
        
           | shagie wrote:
           | > Directional laser beams are orders of magnitude to jam
           | compared to radio wave. That alone makes it of big interest
           | for military applications, even with 500 ms latency.
           | 
           | I am reminded of RFC 1217 - Memo from the Consortium for Slow
           | Commotion Research (CSCR) https://www.rfc-
           | editor.org/rfc/rfc1217                   2. Jam-Resistant
           | Land Mobile Communications                 This system uses a
           | highly redundant optical communication technique
           | to achieve ultra-low, ultra-robust transmission.  The basic
           | unit is            the M1A1 tank.  Each tank is labelled with
           | the number 0 or 1 painted            four feet high on the
           | tank turret in yellow, day-glo luminescent            paint.
           | Several detection methods are under consideration:
        
             | Spoom wrote:
             | I love that this was ostensibly written by Vint Cerf.
        
               | shagie wrote:
               | It's listed in his computer science bibliography
               | https://dblp.org/pid/c/VintonGCerf.html and
               | https://en.wikipedia.org/wiki/Vint_Cerf#Author
               | 
               | Though the edit for that authorship to the RFC came much
               | later. https://datatracker.ietf.org/doc/rfc1217/history/
        
           | SlightlyLeftPad wrote:
           | Could these not be jammed by blasting the same wavelength
           | laser at said geostationary satellite?
        
             | tiagod wrote:
             | Please correct me if I'm wrong, but I guess if you aim well
             | enough, there could be a very long, narrow, non-reflective
             | cylinder in front of the receiver that would block all
             | light that is not coming exactly from the direction of the
             | target satellite.
        
               | Onavo wrote:
               | You will probably need to increase the gain (better lens,
               | photomultipliers) on the receiver photodiode too.
        
               | scottLobster wrote:
               | "If you aim well enough" is doing a ton of work there.
               | Precise real-time optical tracking of a satellite from a
               | moving platform is an extremely difficult problem. Even
               | if the satellite itself is geostationary, it would also
               | have to rotate to keep the "cylinder" pointed in the
               | right direction to maintain signal.
               | 
               | I suppose you could make a "cylinder" or "cone" broad
               | enough that, if the threat was static, could blot-out
               | attempted jamming from only certain regions while staying
               | open facing toward friendly zones.
        
         | rtkwe wrote:
         | Geostationary is easier to hit than a LEO constellation like
         | Starlink. With an LEO target you need to switch at least every
         | 2-4 minutes, Starlink ground stations can switch multiple times
         | per minute but that's for obstacle avoidance in the air you'd
         | only have to switch when the current target moves out of LOS
         | entirely.
        
       | utopiah wrote:
       | Nice, if you want a bit more details on the TNO side
       | https://www.tno.nl/en/newsroom/2026/02/airbus-tno-demonstrat...
       | relying on
       | https://connectivity.esa.int/archives/projects/ultraair
        
       | db48x wrote:
       | Some miniaturization required.
        
       | tart-lemonade wrote:
       | > These developments entail a future where travellers could enjoy
       | reliable, high-speed internet while flying, and where people on
       | ships or in vehicles crossing remote regions can stay connected
       | without interruption.
       | 
       | How reliable/feasible would this be on the ground? From what I
       | understand, shining non-trivial lasers in the sky is a massive
       | liability because of the potential to interfere with aircraft. I
       | don't see anything about the wavelength used, but even if it's
       | outside the visible spectrum, it would still be subject to
       | interference from aircraft when used on the ground or at sea.
        
         | Jtsummers wrote:
         | Optical links are being developed for use from fixed ground
         | stations.
         | 
         | https://news.ycombinator.com/item?id=46709548 - Discussion from
         | a month ago with several links for a recent example.
        
         | joezydeco wrote:
         | It's being implemented. I thought I saw that Amazon Leo (nee
         | Kuiper) was going to lean on it pretty heavily.
         | 
         | https://www.techbriefs.com/component/content/article/47300-u...
        
           | mynameisvlad wrote:
           | That talks about inter-satellite links (which Starlink uses
           | already). Parent comment asked about ground <-> sat
        
       | philipwhiuk wrote:
       | > Because laser beams spread far less than radio waves, they
       | provide more secure links
       | 
       | Basing your security on laser diffusion seems sus.
        
         | Schlagbohrer wrote:
         | It's worth it as another layer of security. The beam width
         | being so narrow means even intercepting it becomes harder. This
         | is more relevant for down-to-earth links where the spot hitting
         | the earth is so narrow it could be confined withing a
         | geographically controlled area, rather than hitting an entire
         | continent like longer wavelengths do.
        
         | Tepix wrote:
         | These beams are much harder to detect and eavesdrop upon. You
         | increase the difficulty for a remote attacker. I wouldn't stop
         | encrypting the data, however: The Alphasat TDP-1 has a
         | telescope with an 135mm aperture. The beam diameter is likely
         | to be at least 700m wide according to the diffraction limit.
        
         | kube-system wrote:
         | All security is based on a combination of individually flimsy
         | ideas
        
       | nashashmi wrote:
       | How does Air force one accomplish their data connection?
        
         | icegreentea2 wrote:
         | Air Force One (and all of the other US flying command posts)
         | are basically giant collections of various antennas.
         | 
         | Here's an article from 2017 about (then) recent installation of
         | what were almost certainly satellite communication antenna.
         | 
         | https://www.twz.com/10470/air-force-one-jet-reemerges-with-u...
        
       | icegreentea2 wrote:
       | Here's a paper (from July 2025) on previous steps in this
       | program, getting up the initial testing in flight. Maximum uplink
       | laser power of 20W, though they got good performance all the way
       | down to 2W. The sat has a laser pointing down that was used to
       | help lock on, but it's not clear if it has any meaningful
       | downlink capability, all discussions are about uplink capability.
       | Lots a nerdy details here.
       | 
       | https://www.spiedigitallibrary.org/conference-proceedings-of...
       | 
       | In addition, here's a random paper on the testing performed on
       | the space borne laser terminals -
       | https://icsos2012.nict.go.jp/pdf/1569586689.pdf
       | 
       | This tells us that the laser terminals have a FOV of +/-2.5mrad
       | in acquisition mode (so before lock on), and +/-0.5mrad in
       | communication/tracking mode. This corresponds ~100km and ~20km
       | radius FOV from GEO to surface.
        
       | burnt-resistor wrote:
       | I marvel at the ability to track a target in _both directions_
       | ~40k+ km away _while moving quickly (kinematic)_ considering
       | atmospheric and relativistic effects.
        
       ___________________________________________________________________
       (page generated 2026-03-05 23:00 UTC)