a screenshot from starship ift3 with visible reentry plasma on the ship

  • Anony Moose
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    68 months ago

    ELI5 what entry plasma is, and why it’s a big deal? Please, and thanks!

    • @sleep_deprived
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      8 months ago

      As spacecraft reenter the atmosphere from orbital speeds, they’re going so fast that the atmosphere is compressed enough (and so gets hot enough) to free the electrons from the atoms in the air. This forms plasma. The special thing here is that we got live video during this portion of reentry; the free electrons in plasma heavily interfere with radio communications, so in previous missions there has been a full communications blackout at that time. Starship did not experience that blackout, which is unique. I’m not qualified to say exactly why, but the team was stressing that Starship is big enough that it “punches a hole through the atmosphere”. Another factor could be the 4(?) starlink terminals on the leeward side providing redundant communications signals.

      • threelonmusketeersM
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        8 months ago

        I’m not qualified to say exactly why, but the team was stressing that Starship is big enough that it “punches a hole through the atmosphere”

        I think Starship is just wider than most spacecraft which have reentered so far, and so the plasma doesn’t completely surround the vehicle. I think the Space Shuttle also had a small hole in the plasma near the tail, through which communications could be sent. Smaller gumdrop-shaped capsules (like Dragon and Soyuz) are completely enveloped in plasma, and thus experience blackout periods.

        • @[email protected]OP
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          8 months ago

          pretty sure it’s because starship can communicate with starlink satellites up in orbit, unlike others that have to communicate with ground stations

      • @[email protected]
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        8 months ago

        Starship has 2 starlink dishes that unlike every others system today communicate back up to orbit to the satellite and then streams the data back down to earth. As long as one dish is pointed towards space (and therefore would have less plasma) communication will still work.

        If you’re mind is blown is really should be. Everything about starship seemed near impossible only 5 years ago. No one else in the world is even close.

      • @[email protected]
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        17 months ago

        How does the size and design of SpaceX’s Starship spacecraft contribute to its ability to maintain communication during reentry , despite the formation of plasma battleship game and the resulting interference with radio communications?