ceejayoz a day ago

They may have lost the second stage, though.

  • echoangle a day ago

    Yes, very much looks like it.

    I wonder how much of the second stage flight is autonomous and if they need to continually need to give it a go to continue, or if it aborts automatically after some time of lost telemetry. But maybe it already exploded anyways.

    • philipwhiuk 17 hours ago

      The automated FTS is triggered if it leaves a pre-defined corridor (which is wider than the flight plan - substantially so in some places).

      The AFTS has independent, hardened, validated inertial measurement systems.

    • moeadham a day ago

      Probably self destructs if anything goes wrong

      • echoangle a day ago

        If it has control issues or similar absolutely, but does losing comms count as going wrong for the FTS? If the flight itself is on track?

        • elteto a day ago

          Absolutely. All those contingencies are planned out and coded down in software.

    • timewizard a day ago

      The flight control loops are strongly latched. They are constantly checking the state of discretes, control surfaces, and intended guidance. If any critical parameter gets out of range for a period of time or if any group of standard parameters gets out of range the vehicle will simply cease powered flight.

      In the Space Shuttle, given that it was human rated, the "Range Safety" system was completely manual. It was controlled by a pair of individuals and they manually made the call to send the ARM/FIRE sequence to the range safety detonators.

  • lysace a day ago

    "we currently don't have comms on the ship"

    edit: the spacex stream just confirmed the loss.

    • ceejayoz a day ago

      Telemetry showed them lose engines one at a time, which isn’t a great sign.

      • echoangle a day ago

        I think that’s the normal shutdown order to reduce shock, the timing was exactly the expected second stage shutoff time if I understood it correctly.