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The structural problems for space vessels vs submersibles I might believe to be quite different. In space the main issue is containing internal pressure - so t

The structural problems for space vessels vs submersibles I might believe to be quite different. In space the main issue is containing internal pressure - so the skin is all in tension. While a submersible the pressure is from without - so the skin is all in compression.

the__alchemist 3y ago
Also of note, the pressure differences are much higher in submersibles.
- vrosas 3y ago
  Professor: Good Lord! That's over 150 atmospheres of pressure! Fry: How many atmospheres can the ship withstand? Professor: Well, it’s a spaceship, so I’d say anywhere between zero and one…
  - ajessup 3y ago
    I love this line - one of my favorites of the show. Thanks for sharing.
    - jonathankoren 3y ago
      And then JJ Abrams put Enterprise underwater, ostensibly to hide it from a stone age civilization. Such a hack. Ruined both of the biggest and beloved scifi franchisee. smh
      - wombatpm 3y ago
        I still have problems with Voyager and Enterprise landing at all. Besides the maxim that everything is airdroppable at least once.
        fnord77 3y ago
        I had problems with their hulls absorbing 75 megaton equivalent torpedoes and only having a minor breech
        jonathankoren 3y ago
        Voyager I’ll allow since it’s small and pointy, and came with landing gears. The Enterprise is too big. You only get to “hot drop” that saucer section once. (Galaxy class only. Any other saucer sep is apocryphal.) I hate that Rogue One had Star Destroyers hovering in atmosphere. That’s just dumb, and destroyed the lore about Victory versus Imperial class Star Destroyers.
        hef19898 3y ago
        I loved Rogue One for all the EU hardware they used. And the new TIEs they introduced were cool, too, the TIE Striker is the new canon version of the Scimitar in my head. If they had parked a VSD over the city so, that would have been the crown!
      - stickfigure 3y ago
        A series with teleporters, time travel, warp drive, artificial gravity, deflector shields, all manner of ESP-type woo... and submerging a spacecraft is what ruins it for you?
        jonathankoren 3y ago
        Yes. It breaks the established rules of the world. I also have problems with the Enterprise being built in a canyon in… checks notes Iowa?!? Also, I hate the transgalactic teleporter JJ has Kahn use to to escape, and pretty much the entire plot of JJ’s Star Trek 2. I already saw that movie, done better. It was called Star Trek II.
      - voxadam 3y ago
        At risk of defending JJ Abrams, hadn't Leonard Nimoy already submerged the Enterprise (NCC-1701-A) back in 1986 when he directed Star Trek IV? That said, I've long agreed with others here who take issue with the idea of landing star ships that are supposedly so large and structurally precarious they more or less must be built in space. On reentry the dynamic stresses on the hulls of those ships would be insane to the point of absurdity.
        midoridensha 3y ago
        >At risk of defending JJ Abrams, hadn't Leonard Nimoy already submerged the Enterprise (NCC-1701-A) back in 1986 when he directed Star Trek IV? Huh? No, where did you get that crazy idea? There was no Enterprise in the movie, because it was destroyed in the previous movie. The crew used a Klingon bird of prey to go back in time, and they didn't go underwater, they built a tank inside the ship and beamed some whales (and water) into it. >On reentry the dynamic stresses on the hulls of those ships would be insane to the point of absurdity. And how does that compare to the stresses on ships that can (in most sci-fi) accelerate to a significant fraction of lightspeed very quickly, or perform extreme maneuvers during space battles? Even in Star Trek, they recognized that inertia and structural forces would be a big problem with the plot, so they "invented" the "inertial dampers" and the "SIF": structural integrity field, which somehow manages to make the ship strong enough to handle crazy forces well beyond the strengths of the materials it's made from.
        voxadam 3y ago
        It would seem that I'm in desperate need of a rewatch of the Star Trek movies, it has been more than a few years, my father would be ashamed.
    - spoonfeeder006 3y ago
      What show was that?
      - matthewfcarlson 3y ago
        Futurama
- jaclaz 3y ago
  Yes, but not only, there is number of pressurizing/de-pressurizing cycles to be taken into account (that lead to fatigue), this is more known for hulls of (pressurized) planes. They esperience at least two full cycles per flight, a submarine has as well at least two of them, but with much larger pressure values, for each immersion. Some reference: https://navalpost.com/how-deep-can-a-submarine-dive/ https://navalpost.com/how-deep-can-a-submarine-dive/ AFAICT, steel is still preferred to titanium because (besides the costs) this latter tends to become (after a certain number of cycles) more brittle than the particular kind of steel used in submarines.

the__alchemist 3y ago

Also of note, the pressure differences are much higher in submersibles.

vrosas 3y ago
Professor: Good Lord! That's over 150 atmospheres of pressure! Fry: How many atmospheres can the ship withstand? Professor: Well, it’s a spaceship, so I’d say anywhere between zero and one…
- ajessup 3y ago
  I love this line - one of my favorites of the show. Thanks for sharing.
  - jonathankoren 3y ago
    And then JJ Abrams put Enterprise underwater, ostensibly to hide it from a stone age civilization. Such a hack. Ruined both of the biggest and beloved scifi franchisee. smh
    - wombatpm 3y ago
      I still have problems with Voyager and Enterprise landing at all. Besides the maxim that everything is airdroppable at least once.
      - fnord77 3y ago
        I had problems with their hulls absorbing 75 megaton equivalent torpedoes and only having a minor breech
      - jonathankoren 3y ago
        Voyager I’ll allow since it’s small and pointy, and came with landing gears. The Enterprise is too big. You only get to “hot drop” that saucer section once. (Galaxy class only. Any other saucer sep is apocryphal.) I hate that Rogue One had Star Destroyers hovering in atmosphere. That’s just dumb, and destroyed the lore about Victory versus Imperial class Star Destroyers.
        hef19898 3y ago
        I loved Rogue One for all the EU hardware they used. And the new TIEs they introduced were cool, too, the TIE Striker is the new canon version of the Scimitar in my head. If they had parked a VSD over the city so, that would have been the crown!
    - stickfigure 3y ago
      A series with teleporters, time travel, warp drive, artificial gravity, deflector shields, all manner of ESP-type woo... and submerging a spacecraft is what ruins it for you?
      - jonathankoren 3y ago
        Yes. It breaks the established rules of the world. I also have problems with the Enterprise being built in a canyon in… checks notes Iowa?!? Also, I hate the transgalactic teleporter JJ has Kahn use to to escape, and pretty much the entire plot of JJ’s Star Trek 2. I already saw that movie, done better. It was called Star Trek II.
    - voxadam 3y ago
      At risk of defending JJ Abrams, hadn't Leonard Nimoy already submerged the Enterprise (NCC-1701-A) back in 1986 when he directed Star Trek IV? That said, I've long agreed with others here who take issue with the idea of landing star ships that are supposedly so large and structurally precarious they more or less must be built in space. On reentry the dynamic stresses on the hulls of those ships would be insane to the point of absurdity.
      - midoridensha 3y ago
        >At risk of defending JJ Abrams, hadn't Leonard Nimoy already submerged the Enterprise (NCC-1701-A) back in 1986 when he directed Star Trek IV? Huh? No, where did you get that crazy idea? There was no Enterprise in the movie, because it was destroyed in the previous movie. The crew used a Klingon bird of prey to go back in time, and they didn't go underwater, they built a tank inside the ship and beamed some whales (and water) into it. >On reentry the dynamic stresses on the hulls of those ships would be insane to the point of absurdity. And how does that compare to the stresses on ships that can (in most sci-fi) accelerate to a significant fraction of lightspeed very quickly, or perform extreme maneuvers during space battles? Even in Star Trek, they recognized that inertia and structural forces would be a big problem with the plot, so they "invented" the "inertial dampers" and the "SIF": structural integrity field, which somehow manages to make the ship strong enough to handle crazy forces well beyond the strengths of the materials it's made from.
        voxadam 3y ago
        It would seem that I'm in desperate need of a rewatch of the Star Trek movies, it has been more than a few years, my father would be ashamed.
  - spoonfeeder006 3y ago
    What show was that?
    - matthewfcarlson 3y ago
      Futurama
jaclaz 3y ago
Yes, but not only, there is number of pressurizing/de-pressurizing cycles to be taken into account (that lead to fatigue), this is more known for hulls of (pressurized) planes. They esperience at least two full cycles per flight, a submarine has as well at least two of them, but with much larger pressure values, for each immersion. Some reference: https://navalpost.com/how-deep-can-a-submarine-dive/ https://navalpost.com/how-deep-can-a-submarine-dive/ AFAICT, steel is still preferred to titanium because (besides the costs) this latter tends to become (after a certain number of cycles) more brittle than the particular kind of steel used in submarines.