[HN Gopher] Stargaze: SpaceX's Space Situational Awareness System
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Stargaze: SpaceX's Space Situational Awareness System
Author : hnburnsy
Score : 181 points
Date : 2026-01-30 03:11 UTC (19 hours ago)
(HTM) web link (starlink.com)
(TXT) w3m dump (starlink.com)
| drivingmenuts wrote:
| Who knew that Big Brother would name himself after a 1990s movie
| about a completely different premise?
| Hextinium wrote:
| Seems like a generally good idea, the satellites already need to
| use star trackers, they need an almanac of what should be there
| so deviations need to be tracked.
|
| I can entirely see the military perspective though, this is
| almost a direct challenge for any adversary that any maneuver you
| perform, we will know about it.
| reed1234 wrote:
| The Space Force already tracks satellites (and debris). I
| imagine this is more of an improvement for small debris such as
| bolts, etc.
| sfblah wrote:
| It's not.
| pjscott wrote:
| If you're familiar with the technical specs, I'd be
| interested in hearing what size of objects the star
| trackers can sense and at what range. In theory the fancier
| star trackers can see objects around 10 cm diameter
| hundreds of kilometers away, without needing to worry about
| a pesky atmosphere [1], but I don't know how sensitive the
| sensors on Starlink's current generation satellites are,
| and this web site isn't saying.
|
| They're mostly touting the improvement in latency over
| existing tracking, from delays measured in hours to ones
| measured in minutes. Which is very nice, of course, but the
| lack of other technical detail is mildly frustrating.
|
| [1]
| https://www.mit.edu/~hamsa/pubs/ShtofenmakherBalakrishnan-
| IA...
| mikkupikku wrote:
| NASA _tracks_ debris 10cm or larger. They also _detect
| and statistically estimate_ debris as small as 3mm in
| LEO.
|
| This is my source, from 2021 fwiw:
| https://oig.nasa.gov/office-of-inspector-general-
| oig/ig-21-0...
| pjscott wrote:
| So it looks to be just the latency improvement that's
| noteworthy, then. Thank you!
| sfblah wrote:
| Yes. Sorry for the brief answer. Too bad I got downvoted.
| There's no size improvement.
| egl2020 wrote:
| Maybe coverage, too?
| wolvoleo wrote:
| 10cm is huge, that could even be a functioning 1U
| cubesat.
| jcims wrote:
| Note from analysis in the paper: (CST = Commercial Star
| Tracker, for which they model several common ones flown
| on satellites)
|
| >From Fig. 1, it is clear that many typical CSTs can be
| used to detect debris with characteristic length less
| than 10 cm at distances as far as roughly 50 km. These
| same sensors have the potential to detect debris as small
| as 1 cm in diameter as far as 5 km away. Even space-
| limited CubeSats using nanosatellite-class CSTs can
| detect 10-cm-class debris at roughly 25 km away or 1-cm-
| class debris at a distance of 2.5 km. Higher-performing
| imagers like the MOST telescope can further characterize
| orbital debris of 10 cm diameter as far as 400 km away or
| be used to characterize orbital debris smaller than 1 cm
| at ranges not exceeding 40 km.
| pjscott wrote:
| Honestly, these two paragraphs are one of the most compelling
| things they could possibly say in a press release:
|
| > Stargaze already has a proven track record in its utility for
| space safety. In late 2025, a Starlink satellite encountered a
| conjunction with a third-party satellite that was performing
| maneuvers, but whose operator was not sharing ephemeris. Until
| five hours before the conjunction, the close approach was
| anticipated to be ~9,000 meters--considered a safe miss-distance
| with zero probability of collision. With just five hours to go,
| the third-party satellite performed a maneuver which changed its
| trajectory and collapsed the anticipated miss distance to just
| ~60 meters. Stargaze quickly detected this maneuver and published
| an updated trajectory to the screening platform, generating new
| CDMs which were immediately distributed to relevant satellites.
| Ultimately, the Starlink satellite was able to react within an
| hour of the maneuver being detected, planning an avoidance
| maneuver to reduce collision risk back down to zero.
|
| > With so little time to react, this would not have been possible
| by relying on legacy radar systems or high-latency conjunction
| screening processes. If observations of the third-party satellite
| were less frequent, conjunction screening took longer, or the
| reaction required human approval, such an event might not have
| been successfully mitigated.
|
| Looks like a non-trivial upgrade to previous systems, and they're
| making Stargaze's data available to other satellite operators
| free of charge. Nice!
| Coeur wrote:
| Now I would really love to know who the other operator was.
| jacquesm wrote:
| And what the goal of that maneuver was.
| ge96 wrote:
| Cause problems and deny it
| phkahler wrote:
| It seems like it deliberately came close to the Starlink
| sat, but the "why" is still a good question.
| bell-cot wrote:
| A test of SpaceX's awareness & response would be ample
| reason.
| notahacker wrote:
| If so, SpaceX's longer term response being "here's our
| SSA data for everyone and here's how we source it" is a
| good one for all parties involved (even more so for
| SpaceX and govt customers they share it with if they have
| other capabilities...)
| bell-cot wrote:
| Speculation:
|
| SpaceX has considerably better data than what they
| disclose, and offer free of charge.
|
| The USSF enjoys full access to that better data, for
| $[TOP_SECRET]/month.
| notahacker wrote:
| Well we already know Starshield (the military version)
| has specialist space domain awareness capabilities that
| aren't being shared, and it's entirely plausible that
| data from regular Starlink sensors/receivers (other than
| the disclosed star trackers) can be fused into something
| useful by SpaceX and/or the Space Force.
| rkagerer wrote:
| Weapons test springs to mind, or as a sibling comment
| suggested a test of Starlink response capabilities.
|
| How confident are we the intent was nefarious? Do you
| ever see accidental near-misses with this type of flight
| profile?
| butvacuum wrote:
| The system exists- ergo, people in the know are concerned
| about accidental collisions.
| NitpickLawyer wrote:
| > In a statement posted on social media late Dec. 12, Michael
| Nicolls, vice president of Starlink engineering at SpaceX,
| said a satellite launched on a Kinetica-1 rocket from China
| two days earlier passed within 200 meters of a Starlink
| satellite.
|
| > CAS Space, the Chinese company that operates the Kinetica-1
| rocket, said in a response that it was looking into the
| incident and that its missions "select their launch windows
| using the ground-based space awareness system to avoid
| collisions with known satellites/debris." The company later
| said the close approach occurred nearly 48 hours after
| payload separation, long after its responsibilities for the
| launch had ended.
|
| > The satellite from the Chinese launch has yet to be
| identified and is listed only as "Object J" with the NORAD
| identification number 67001 in the Space-Track database. The
| launch included six satellites for Chinese companies and
| organizations, as well as science and educational satellites
| from Egypt, Nepal and the United Arab Emirates.
| ge96 wrote:
| > 48 hours after payload separation, long after its
| responsibilities for the launch had ended
|
| This is funny, the way things are just discarded in space,
| not our problem anymore vs. deorbit
| NitpickLawyer wrote:
| I think they are saying "this is not on us, this is on
| the sat operator". Which may or may not be true, who
| knows.
| butvacuum wrote:
| unless the sat operator is sueing for a refund because
| they were put in the wrong orbit... its the sat operator.
| panzagl wrote:
| I think this is more that the offending satellite was at
| that point the responsibility of the satellite operator,
| not the launch operator.
| IncreasePosts wrote:
| If you get hit by a car 5 minutes after you get let off
| at a bus stop it isn't the bus drivers fault.
| thesmtsolver2 wrote:
| Nah, in this case the driver is the person who gets off
| and goes and bumps into another person.
| ge96 wrote:
| Yeah while I didn't directly mention it, I'm referring to
| stages being discarded in space by a specific party
| c22 wrote:
| It will be interesting when multiple parties are using these
| systems and still failing to communicate out of band. Like
| trying to pass someone in a hallway who keeps trying to make
| the same course correction as you until you both make eye
| contact and come to a real agreement.
| infinitewars wrote:
| When you're SpaceX and building this[1], others aren't going
| to try too hard to avoid your satellites..
|
| [1] https://wikipedia.org/wiki/Golden_Dome_(missile_defense_s
| yst...
| close04 wrote:
| > they're making Stargaze's data available to other satellite
| operators free of charge
|
| With so many Starlink satellites odds are that one false move
| on anyone's part ends up in an incident involving them. Sharing
| this data makes the field safer for everyone, and Starlink gets
| to steer clear of any bad news titles.
| jasonpeacock wrote:
| > react within an hour of the maneuver being detected
|
| I'm curious at what steps were involved took an hour. Running
| the calculations should be quick (computers are fast), as is
| transmitting commands.
|
| This sounds like there's human in the loop that had to make
| decisions.
| Polizeiposaune wrote:
| Orbital mechanics can be somewhat counterintuitive.
|
| If you want to change the altitude of your orbit at a certain
| place, the most efficient place for that is generally when
| you're on the other side of the planet from that place.
|
| In low earth orbit it takes about 90 minutes to go around the
| planet, so a small nudge 45 minutes before the potential
| intercept is going to be vastly more efficient than a big
| shove when the collision is 5 minutes away.
|
| Starlink uses high efficiency ion thrusters so it has to do
| small nudges anyway..
|
| So I would not be surprised if most of that hour is spent
| waiting for the right time to fire the thrusters.
| jasonpeacock wrote:
| Maybe I misinterpreted the statement - I thought it was
| talking about the time from detection to sending the
| command to the satellite, not the time until the satellite
| actually took action.
| globalnode wrote:
| all this tech is nice and dandy n' all but the guy in charge of
| it is so distasteful that id rather live in a cave with stone
| tools than rely on any of it.
| alphabetag675 wrote:
| I wonder what you have to say about our new generation
| fertilizers and vaccines.
| sidcool wrote:
| I was just having this discussion in the other thread where
| people were blatantly lying about Tesla because they hate Elon
| Musk. Hate him all you want, but his companies are truly
| successful.
| sfblah wrote:
| I was just thinking about that the other day while relaxing
| in my Hyperloop pod from Los Angeles to San Francisco. I was
| reminiscing about how I'd avoided all the traffic in LA by
| using the Boring Company's tunnels in my second-generation
| Tesla Roadster. I'd been in LA for a conference about the
| hugely successful Starship space launch system, which has
| revolutionized cost to orbit with fully reusable second
| stages. When I got to San Francisco, I hopped in a Tesla
| fully self-driving robotaxi, and when I got home, my Optimus
| robot served me tea after I instructed it to do so using my
| Neuralink probe. I then sent a video voicemail to my parents,
| who live in a city of 1 million people on Mars, which has
| recently been terraformed. I flipped on CNN and was gratified
| to see that, for the first time in 25 years, the US
| government was operating at a surplus, thanks to the $2T of
| annual savings delivered by DOGE.
| sidcool wrote:
| Starship is iterating fast and flying in another 5 weeks.
| Boring company is executing slowly but steadily, the Vegas
| tunnel is progressing. Unsupervised robotaxis has started
| in Austin. Optimus started a few years ago only, it is
| disingenuous to expect it to be available immediately.
| Neuralink has 18 patients now. Mars is happening, Elon
| never promised it will be possible this decade.
|
| Your comment makes it seem that Elon's companies have done
| nothing. I know you are being disingenuous, but I am trying
| my luck to respond.
| macintux wrote:
| > "Starship is going to Mars at the end of 2026."
|
| https://www.futura-sciences.com/en/elon-musk-promises-a-
| trip...
|
| > New video evidence shows that Tesla's supposedly
| "unsupervised" Robotaxis in Austin are being closely
| followed by black Tesla trailing cars with safety
| monitors inside. Tesla didn't remove the safety monitors
| - it just moved them to a different vehicle.
|
| https://electrek.co/2026/01/22/tesla-starts-robotaxi-
| rides-w...
| sidcool wrote:
| Lol. So a fully self driving car with a following car is
| not impressive? Elon over promised, no doubt. But don't
| tell me their tech is not amazing. Pure vision general
| purpose autonomy. It's going to be a game changer. It
| could be late but inevitable.
|
| Remember when it was supervised FSD? They have come a
| long way.
| sfblah wrote:
| We can both be correct. I'm not saying he's done nothing.
| I'm saying he lies, A LOT.
| inemesitaffia wrote:
| Microsoft Bob, Google Inbox and Plus
| comboy wrote:
| better stay out of biography books
| navigate8310 wrote:
| Would this sort of operational prowess be possible if it
| weren't for Musk? Will the future be kind and reflect back in
| the hindsight when Musk dies?
| globalnode wrote:
| > Will the future be kind and reflect back in the hindsight
| when Musk dies?
|
| id hazard a guess and say it will, people love to hero
| worship but he's his own biggest fan. nothing he built wasnt
| done before in some way. if im being generous id say hes a
| good integrator of tech, which in itself isnt such a bad
| thing, if thats all it was.
| genewitch wrote:
| Uh huh, i get 300mbit burst 200mbit sustained download and
| 20mbit sustained upload, midday, from a forest in the dead
| center of louisiana. oh and with a consistent 59ms ping to
| our DC on the east coast (not aws), 24/7, over millions of
| pings.
|
| can you tell me what other provider is doing that? for $120
| a month? Were you thinking of hughesnet? because that was
| ADSL speeds with 20 times the latency. seriously, upwards
| of 1000ms round trip time.
|
| yes, a century and a quarter ago there were electric cars.
| that went 15 units per hour for 20 minutes or whatever.
| Then Saturn EV-1 by GM was lease only, i wanted to own one
| and was unable to. what happened between the EV-1 and Tesla
| that made it to mass market? was there a fEV that i am not
| aware of that had sales numbers similar to Tesla's?
|
| is it about the flamethrower? those already existed. So did
| tunnels. I guess you got me.
|
| too bad all this is buried.
| moritonal wrote:
| I think it should. Hate it or not he has a proven ability to
| create environments where people thrive and want to work the
| hardest they ever have. Moreover, an ability to understand
| how much money is required to build something alongside the
| daring to actually try it. Again, I wish he never got into
| politics, but generally he knows how to build things people
| want, and uniquely wants to try.
| soiax wrote:
| There it is... the usual ELON MUSK BAD.
| Culonavirus wrote:
| I usually don't comment on politically charged topics (because
| I don't shit where I eat), but the amount of champagne
| socialists around here is borderline Reddit and its negatively
| influencing the discoverability of the news I'm coming here to
| see.
|
| Like... SpaceX is the world leader in rocket and satellite
| tech. This site is supposed to be about tech. Not to mention
| that the article itself is really interesting. Yet you come in
| here and dump your musky load like it's a public toilet. What
| the hell is wrong with you.
| genewitch wrote:
| virtue signalling. in-band and out-of-band.
| wtcactus wrote:
| "To maximize safety for all satellites in space, SpaceX will be
| making Stargaze conjunction data available to all operators, free
| of charge, via its space-traffic management platform."
|
| Many people don't still realize it, but the problem of low orbit
| debris is only getting worse. So, this is a really nice gesture.
| Thank you, Elon Musk.
| lionkor wrote:
| It sounds like a hook, like "don't like all the space debris?
| use our management platform" and then it'll suddenly start
| costing money
| bigfatkitten wrote:
| SpaceX has a very, very large financial interest in avoiding
| collisions. Providing this service helps ensure that.
| wtcactus wrote:
| Several governments have an even bigger interest in
| avoiding these collisions, so, these systems should have
| existed for decades now.
|
| But, you can always trust the government to spend 10x more
| to do 10x worst...
| mikkupikku wrote:
| > _so, these systems should have existed for decades
| now._
|
| Dubious. Perhaps if Congress could be persuaded to invest
| in tons of radio telescopes / radars, positioned all
| around the world, but good luck with that. The space-
| based approach used by SpaceX is something that presently
| only SpaceX is equipped to implement. Tracking star
| conjunctions only gives you high quality data on space
| debris / satellite maneuvers if you have a huge net of
| star trackers in orbit, and that's something which only
| SpaceX has been able to do.
| notahacker wrote:
| The US already provides publicly accessible conjunction
| avoidance data based on data points they have. They don't
| have the same number of satellites in the sky to make
| real time observations in as many different directions
| though.
| iNic wrote:
| The one advantage of monopolies is that they tend the commons.
| uyzstvqs wrote:
| You're free to start your own space exploration company.
| dmd wrote:
| Er, no, you're not. That's the big problem with monopolies
| that execute regulatory capture.
| atonse wrote:
| Sure you are. SpaceX did exactly this and went against
| the well-connected monopoly at the time (ULA, a
| consortium of defense contractors) and beat it.
|
| Nobody said it would be easy though.
| toomuchtodo wrote:
| You too can start your own space exploration company if
| you are lucky enough to somehow obtain capital and your
| luck compounds sufficiently from that capital.
|
| That luck is out of grasp of the vast majority of the
| population. It isn't a matter of effort, but mostly luck.
| Playing the lottery is not a realistic strategy to put
| forth from a monopoly competition perspective. 90% of
| startups fail, for example. They worked hard, but were
| unlucky.
| 01HNNWZ0MV43FF wrote:
| Damn it. I wanted to use that name
| w10-1 wrote:
| This seems necessary and desirable, but pretty much a government
| function. I can't see how simple good-faith cooperation prevents
| abuse.
|
| Possible abuses:
|
| (1) Use the information to actually interfere or collide with
| satellites
|
| (2) Use the information to track secret satellites by excluding
| traces from non-secret ones
|
| (3) Free riders gaining secondary access without providing data
|
| (4) Use access to this when traffic is more contended to enforce
| hegemony
|
| (5) Anti-competitive coordination under the rubric of cooperation
|
| And while the system might be helpful under ordinary peacetime
| conditions, will it make a war more or less destructive?
|
| It's silly that NASA is planning for Mars and the moon but hasn't
| already solved this coordination problem on a world scale.
| nlitened wrote:
| As far as I understand, bad faith actors already have wide
| possibilities for disruption and abuse. This system allows for
| better good-faith coordination for mutual benefit.
| notahacker wrote:
| NASA already provides publicly accessible tracking data. They
| don't have 30,000 star trackers in orbit though, whereas the
| world's largest satellite constellation does and therefore has
| a lot more data points.
| thatjoeoverthr wrote:
| Kessler problems require Kessler solutions
| user3939382 wrote:
| DARPA from long back had a project for tracking space debris
| related to this. I have an impossibility proof and some other
| math after many years of thinking about this problem which proves
| that what they really need (and have explicitly asked for) is
| impossible but also how theoretically close to it we could get.
| Hoping to publish soon but working on other things.
| neom wrote:
| I was kinda hoping the collision risk stuff might be what stops
| the sky quickly getting totally polluted. This is cool but... I
| presume just enables more and more and more density.
| lazyfanatic42 wrote:
| At some point in the future, will there be wars fought in LEO?
| Seems like a cold war already.
| atonse wrote:
| I believe the US and China (and Russia according to the
| Wendover video [1]) already have anti-satellite weapons to be
| used in a conflict, but they aren't like "blow this up" because
| of space debris. I'm not exactly sure how they work, but they
| aren't what we expect with terrestrial weapons.
|
| 1: https://www.youtube.com/watch?v=V0DmliiUFHk
| mgoetzke wrote:
| Didnt russia cause a lot of debris due to one of their tests
| and endanger the ISS crew ?
| atonse wrote:
| Yeah I just watched my own video and was surprised to see
| exactly that. Because I remember reading somewhere else
| years ago that an ideal anti-satellite weapon would either
| de-orbit a satellite (like bumping it off orbit so it burns
| up) or use some kind of net/capture to push it off orbit,
| rather than blow it up.
|
| Now this is going to have to be a rabbit hole for me (and
| some AI) this weekend.
| Rebelgecko wrote:
| Their test was in a low-ish orbit so most of the debris is
| gone now.
|
| I haven't looked at stats lately but I'd guess the #1
| source of debris in space right now is still the Chinese
| ASAT test which threw a bunch of crap into Medium Earth
| Orbit. Before that, the main source of debris was leaking
| coolant from some nuclear reactors the Soviet sent up
| krisbolton wrote:
| This article is a short history of anti-satellite weapons,
| discussing who has demonstrated their capability:
| https://www.raf.mod.uk/what-we-do/centre-for-air-and-
| space-p...
|
| I'm sure I read a more recent account of a satellite moving
| another satellite around in order to degrade its orbit, but I
| can only find this 2022 instance:
| https://www.twz.com/44054/a-chinese-satellite-just-
| grappled-...
| rkagerer wrote:
| Didn't the Pentagon give SpaceX a bunch of money a while back?
| Any chance this was developed alongside, or as a component of,
| military applications?
|
| Getting 30,000 new eyes in the sky actively monitoring objects in
| orbit seems pretty appealing if that's your theater...
|
| How does this compare in scope and quality to traditional
| tracking networks (ground or space based)?
| aero-glide2 wrote:
| Nah sounds like regular starlink they have 10,000 of them
| Rebelgecko wrote:
| The Pentagon has been giving SpaceX a bunch of money for over a
| decade
| 6d6b73 wrote:
| Spacex creating solutions to the problems they caused.. great
| mrcwinn wrote:
| That seems... responsible? Maybe you meant "great" literally.
| In that case, I agree. Good job SpaceX.
| krisbolton wrote:
| There's an interesting podcast covering space situational
| awareness from RUSI (Royal United Services Institute, UK). Link:
| https://podcasts.apple.com/gb/podcast/eyes-in-orbit-space-si...
| fnord77 wrote:
| Isn't this just a twist on celestial navigation?
| GMoromisato wrote:
| Casey Handmer was speculating that they could use these Starlink
| images to detect Near-Earth Asteroids using star occultations:
|
| https://x.com/CJHandmer/status/2017124903057838374
|
| You basically have thousands of cameras taking constant images of
| the sky. If you could upgrade the cameras, you could deploy a
| continuous all-sky astronomical survey as a by-product.
| toomuchtodo wrote:
| Rough estimate on the cost delta for the camera upgrades?
| GMoromisato wrote:
| No idea--but he thinks the asteroid detection could be done
| even without an upgrade, assuming current cameras can see
| down to magnitude 7 (which is not that faint--human eye
| should be able to see down to 7 or 8 in space).
| egl2020 wrote:
| Does anyone know what the "30,000 star trackers" are? There are
| about that many satellites in orbit, so does this mean almost
| everyone is contributing data?
| voxic11 wrote:
| I think it just means each starlink satellite has multiple star
| trackers. Probably pointed in different directions so that if
| one is blinded by the sun the others can still see the stars.
| aero-glide2 wrote:
| Quite common for a sat to have 3 star trackers so it is
| possible just starlinks
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