Comment by pjscott

Comment by pjscott 2 days ago

26 replies

View on Hacker News

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!

close04 2 days ago

> 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.

Reply View 0 replies
c22 2 days ago

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.

Reply View 2 replies
  • imglorp 2 days ago

    > still failing to communicate out of band.

    I don't understand countries or operators that do this.

    There's no secrets about hardware position and orbit. Even amateur astronomers can track spacecraft.

    There's no benefit to trashing orbit from failure to coordinate and cooperate. Any collision in LEO will deny it to everyone for several years.

    So who is being insular and why is it to their advantage?

    Reply View 0 replies
Coeur 2 days ago

Now I would really love to know who the other operator was.

Reply View 18 replies
  • NitpickLawyer 2 days ago

    > 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.

    Reply View 7 replies
    • ge96 2 days ago

      > 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

      Reply View 6 replies
      • panzagl 2 days ago

        I think this is more that the offending satellite was at that point the responsibility of the satellite operator, not the launch operator.

        Reply View 0 replies
      • NitpickLawyer 2 days ago

        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.

        Reply View 1 reply
        • butvacuum 2 days ago

          unless the sat operator is sueing for a refund because they were put in the wrong orbit... its the sat operator.

          Reply View 0 replies
      • IncreasePosts 2 days ago

        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.

        Reply View 2 replies
  • jacquesm 2 days ago

    And what the goal of that maneuver was.

    Reply View 9 replies
    • phkahler 2 days ago

      It seems like it deliberately came close to the Starlink sat, but the "why" is still a good question.

      Reply View 7 replies
      • rkagerer 2 days ago

        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?

        Reply View 2 replies
      • bell-cot 2 days ago

        A test of SpaceX's awareness & response would be ample reason.

        Reply View 3 replies
    • ge96 2 days ago

      Cause problems and deny it

      Reply View 0 replies
jasonpeacock 2 days ago

> 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.

Reply View 2 replies
  • Polizeiposaune 2 days ago

    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.

    Reply View 1 reply
    • jasonpeacock 2 days ago

      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.

      Reply View 0 replies