Starlink satellites being lowered from 550 km to 480 km(twitter.com)
48 pointsby wmf7 hours ago8 comments
  • TOMDM3 hours ago
    Is this potentially a response to Russia's posturing around anti satellite weapons?

    https://www.pbs.org/newshour/world/intelligence-agencies-sus...

  • Havoc4 hours ago
    That would surely also mean their expected lifespan is shorter too? Faster decay doesn’t just affect dead satellites

    Idk seems like a strange move and the stated reason seems flimsy

    • JumpCrisscross3 hours ago
      > would surely also mean their expected lifespan is shorter too?

      Are Starlinks being deörbited due to propellant exhaustion?

      In many respects, Starlink satellites are small servers. They’re probably profitable to replace quicker than decay would force them to be.

  • jagaerglad6 hours ago
    So instead of having to launch new satellites to replace the deorbited ones ever couple of years, do they have to send new ones every couple of months? Or can the functioning ones maintain their orbits somehow and this is only for the malfunctioning ones?
    • jws6 hours ago
      It sounds like this corresponds to an atmospheric contraction. They are lowering to avoid extending the lifetime of possible debris, but that also probably means the regular lifetime is not shortened. They are just staying in the designed density to match their designed service lives. The field of view of the satellites will be reduced, but presumably they have enough units up there to maintain full coverage.

      This is distinct from the FCC application they have made for another Starlink shell in VLEO (~330km) for another 15000 satellites to better serve cellular phones.

      • verzali6 hours ago
        At 480km there will be increased drag, even as we get closer to the solar minimum. The trade-off may be between using propellant for collision avoidance vs using it to counter altitude loss and for station keeping.

        Maybe it is also linked to the falling altitude of the ISS? 480km is about the upper bound of its altitude but they seem unlikely to actually raise it that high before it is deorbited.

        • DoctorOetkeran hour ago
          is it conceivable that collision avoidance maneuvers become cheaper in fuel consumption by using the slightly less thin atmosphere to steer a satellite (only use propellant for attitude control, less direct linear acceleration?

          i.e. if the propellant consumption for collision avoidant steering at 550 km in practice turns out to be higher than the consumption to negate the drag incurred for using atmosphere for steering, it could be a logical choice.

    • 6 hours ago
      undefined
    • manmal6 hours ago
      They have ion thrusters that prevent them from losing altitude as long as they are operational.
      • JumpCrisscross3 hours ago
        > ion thrusters that prevent them from losing altitude as long as they are operational

        Unintentional tautology. A satellite is by definition operational as long as it can station keep.

        That said, yes, they should be able to station keep with ions alone. But also, ion propulsion still requires propellant. Until we figure out orbital magnetic suspension, it’s all reaction engines.

    • lefra6 hours ago
      They have an ion thruster to compensate for atmospheric drag.
      • m4rtink5 hours ago
        There has been some research (IIRC by ESA) for using the upper atmosphere to feed a ion engine. That way you should be able to put satellites even lower as long as they have enough power from solar panels and are functional.
  • vipa1234 hours ago
    How much Delta-V would that take, and how much would they typically have onboard at the start of their life?
    • wmf4 hours ago
      Drag is constantly pulling them down so maybe they won't have to use any propellant.
  • GeertB4 hours ago
    I wonder if this will improve latency and signal strength
    • rented_mule2 hours ago
      It seems plausible that it would help with latency, but not by a game changing amount. This is 70/550 or 13% closer. Not all of the latency is caused by distance to the the satellites (e.g., terrestrial latency is not 0), so my guess would be that the latency experienced by users would improve by less than 13%.
  • NedF5 hours ago
    [dead]
  • thot_experiment3 hours ago
    great move, we're continually about 2 days away from kessler if we lost maneuvering control on a constellation like starlink (ofc that's vanishingly unlikely, but it's important to understand that continual maneuvering is what keeps space accessible to humanity)

    anything we can do to lower that risk is a good move, and dropping 70km of elevation for the largest satellite constellation is definitely going to make a dent in the risk profile

    https://arxiv.org/pdf/2512.09643

    i hope to see progress with air breathing ion engine satellites in the coming years to further lower the minimum altitudes that these constellations can operate at

    • Veedrac2 hours ago
      The paper says we are 2.8 days away from a collision. It doesn't say we're '2 days away from kessler'. In fact, the paper explicitly warns against your interpretation.

      > We emphasize that the CRASH Clock does not measure the onset of KCPS, nor should it be interpreted as indicating a runaway condition.

    • JumpCrisscross3 hours ago
      > we're continually about 2 days away from kessler if we lost maneuvering control on a constellation like starlink

      To be clear, we’d be at risk of losing those specific orbits for a few years. Nothing would block all orbits much less access to space. And nothing above those orbits would be any more statistically likely to suffer an impact afterwards.

  • wmf6 hours ago
    Usually orbits are reserved years in advance. AFAIK this kind of move is unprecedented (although everything about Starlink is unprecedented since it's the first megaconstellation).

    Two weeks ago, a Starlink satellite exploded. SpaceX believes it wasn't caused by a collision which means the explosion was probably caused by a malfunction in the satellite itself. Now 4,400 Starlink satellites are moving to a lower orbit for "safety". Is this an emergency change to account for a design flaw that they just discovered?

    • JumpCrisscross3 hours ago
      > Usually orbits are reserved years in advance

      Because planning missions took years to plan. Holidaygoers book hotels months and sometimes a year or more in advance. Business travelers don’t. That doesn’t make the latter unusual, just a different use case.

      > Is this an emergency change to account for a design flaw that they just discovered?

      Zero evidence or precedent for this.

      • wmfan hour ago
        If the existing orbit is safe enough, why bother "increasing space safety"? The cost of this reconfiguration must be quite large. And why have no public comment period?