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SpaceX likes to simplify and not to complexify things. And they demonstrated they can do landing accurately. Moreover I think Elon discusses the mechazilla arm

by jve 2y ago

SpaceX likes to simplify and not to complexify things. And they demonstrated they can do landing accurately. Moreover I think Elon discusses the mechazilla arms in one of Tim Dodd interviews. They dont want longer arms, ratger shoeter. Think about physics involved for longer arms and how much more stress you will putt on the connection points.

Jugurtha 2y ago
>SpaceX likes to simplify and not to complexify things. And they demonstrated they can do landing accurately. Yes. Something falling into a web of cables. I'd say it may be simpler than optimally controlling that last SnakeX maneuver to be hugged by a short-armed T-Rex. >Think about physics involved for longer arms and how much more stress you will putt on the connection points. That's why I wasn't talking about arms, but cables, as explained by most of the reply.
- jve 2y ago
  Good luck not ruining rocket with that cable web. Now you got other problems to target into some cell. Moreover cables could be lingering depending on thrust. Or maybe thrust will just cut em easily.
  - Jugurtha 2y ago
    >Good luck not ruining rocket with that cable web. What do you mean? >Now you got other problems to target into some cell. Moreover cables could be lingering depending on thrust. Or maybe thrust will just cut em easily. It's an iris diaphragm that's open but cinches on the booster.
- Faaak 2y ago
  Did you think about how you support the cables ? Surely they must be tensionned or else they will hang. How do you tension them ? Of course you know that the more the cable is tensionned, the more force you need. So you need a big-ass structure to hold all of these cables. They must be able to circulate around the perimeter, while being in tension, while not collapsing the structure that holds them, etc.. I'm sure you think it's easy, but I'm sure some people thought a bit more
  - Jugurtha 2y ago
    >Did you think about how you support the cables ? Surely they must be tensionned or else they will hang. How do you tension them ? Mechanical advantage. The booster weighs 250 tons. A 40' shipping container has a max payload of about 30 tons. There are cranes that can lift 250 tons, and it won't be one, but many. Have you seen gantry cranes? >So you need a big-ass structure to hold all of these cables. Similar to the big-ass structure holding the 250 ton booster with the T-Rex arms? >They must be able to circulate around the perimeter, while being in tension, while not collapsing the structure that holds them, etc.. Not circulate, but translate. The cinching in is a result of them translating. Again, see cranes and gantry cranes. Or, just see the actual chopsticks: circulating, not collapsing the structure that holds them, while being in tension, holding the booster at the free end. Are you seeing the shear and moment diagram of that cantilever beam with point load? (I know, it's an extension of a supported beam, but still cantilever). >I'm sure you think it's easy I'm not sure I think it's easy, I can't see how you're more sure than I about my own thoughts. >but I'm sure some people thought a bit more You are people, too. Nothing prevents you from thinking as well, if for nothing than to have a civil conversation on a forum. Now, that's all fun. Imagine they keep it the way it is, but they duplicate the setting to make a circle, so the booster lands in the middle of many chopsticks... What do you think about that?
    - jve 2y ago
      > so the booster lands in the middle of many chopsticks... And how exactly this requires less precision? I see multiple issues: - No way to escape/last second abort away from tower once you dipped into that net. - The booster arms must be longer/heavier, the tower support structure need to support more weight. - Cables have a lot less thermal mass than the tower/arms - if the torch coming out of raptor engines will touch the cable, it may either cut or soften the cables and they will behave in a different way. I mean we could have had this discussion previously but now they demonstrated on the first try that they can catch the booster... why bother?
      - Jugurtha 2y ago
        >I mean we could have had this discussion previously but now they demonstrated on the first try that they can catch the booster... why bother? Because these things must work every time, not just the first time. Because why not talk about it, it's an interesting topic and musing about it is amusing. Because it's not a bother. I'm surprised one needs a reason, but here are three already.

by jve 2y ago

Jugurtha 2y ago

>SpaceX likes to simplify and not to complexify things. And they demonstrated they can do landing accurately. Yes. Something falling into a web of cables. I'd say it may be simpler than optimally controlling that last SnakeX maneuver to be hugged by a short-armed T-Rex. >Think about physics involved for longer arms and how much more stress you will putt on the connection points. That's why I wasn't talking about arms, but cables, as explained by most of the reply.

jve 2y ago
Good luck not ruining rocket with that cable web. Now you got other problems to target into some cell. Moreover cables could be lingering depending on thrust. Or maybe thrust will just cut em easily.
- Jugurtha 2y ago
  >Good luck not ruining rocket with that cable web. What do you mean? >Now you got other problems to target into some cell. Moreover cables could be lingering depending on thrust. Or maybe thrust will just cut em easily. It's an iris diaphragm that's open but cinches on the booster.
Faaak 2y ago
Did you think about how you support the cables ? Surely they must be tensionned or else they will hang. How do you tension them ? Of course you know that the more the cable is tensionned, the more force you need. So you need a big-ass structure to hold all of these cables. They must be able to circulate around the perimeter, while being in tension, while not collapsing the structure that holds them, etc.. I'm sure you think it's easy, but I'm sure some people thought a bit more
- Jugurtha 2y ago
  >Did you think about how you support the cables ? Surely they must be tensionned or else they will hang. How do you tension them ? Mechanical advantage. The booster weighs 250 tons. A 40' shipping container has a max payload of about 30 tons. There are cranes that can lift 250 tons, and it won't be one, but many. Have you seen gantry cranes? >So you need a big-ass structure to hold all of these cables. Similar to the big-ass structure holding the 250 ton booster with the T-Rex arms? >They must be able to circulate around the perimeter, while being in tension, while not collapsing the structure that holds them, etc.. Not circulate, but translate. The cinching in is a result of them translating. Again, see cranes and gantry cranes. Or, just see the actual chopsticks: circulating, not collapsing the structure that holds them, while being in tension, holding the booster at the free end. Are you seeing the shear and moment diagram of that cantilever beam with point load? (I know, it's an extension of a supported beam, but still cantilever). >I'm sure you think it's easy I'm not sure I think it's easy, I can't see how you're more sure than I about my own thoughts. >but I'm sure some people thought a bit more You are people, too. Nothing prevents you from thinking as well, if for nothing than to have a civil conversation on a forum. Now, that's all fun. Imagine they keep it the way it is, but they duplicate the setting to make a circle, so the booster lands in the middle of many chopsticks... What do you think about that?
  - jve 2y ago
    > so the booster lands in the middle of many chopsticks... And how exactly this requires less precision? I see multiple issues: - No way to escape/last second abort away from tower once you dipped into that net. - The booster arms must be longer/heavier, the tower support structure need to support more weight. - Cables have a lot less thermal mass than the tower/arms - if the torch coming out of raptor engines will touch the cable, it may either cut or soften the cables and they will behave in a different way. I mean we could have had this discussion previously but now they demonstrated on the first try that they can catch the booster... why bother?
    - Jugurtha 2y ago
      >I mean we could have had this discussion previously but now they demonstrated on the first try that they can catch the booster... why bother? Because these things must work every time, not just the first time. Because why not talk about it, it's an interesting topic and musing about it is amusing. Because it's not a bother. I'm surprised one needs a reason, but here are three already.