4 ms·

SpaceX actually showed a mock-up of what point-to-point travel might look like in one of their videos.

Robotbeat 8y ago
Here: https://www.youtube.com/watch?v=zqE-ultsWt0 https://www.youtube.com/watch?v=zqE-ultsWt0
politician 8y ago
The vomit-comet ICBM video? I'm a big fan of SpaceX, but I think they'll get to Mars before governments on Earth allow that concept to happen. Your passengers do multiple g's to altitude, then go weightless, then go back to taking g-forces on descent. That's the vomit part. Not a great customer experience. Meanwhile, the Starship looks like an ICBM to every early warning radar on the planet. It's only during reentry that it stops looking like an ICBM, but most missile defense strategies call for intervention in the boost phase. Let's suppose that they address those false positive detection issues. If you're a military planner, though, you're probably asking yourself how many MIRV warheads could fit inside a militarized Starship retrofitted for a preemptive strike?
- politician 8y ago
  Ok, I did some rough math. The W88 has a diameter of 55cm, a length of 175cm, and a blast yield of 475 kilotons. The unpressurized cargo hold of the Starship per Wikipedia is 88m^3, and the diameter of the vehicle is 9m. Let's assume that the unpressurized cargo hold is a cylinder 9m in diameter with a length of 9m. It looks like a hold of that size could fit 15 units per 200cm length, or 60 units, with space for structural rails and deployment gear. For comparison, that's 7.5x the capacity of the Trident II SLBM which was designed to accommodate 8 W88s. In terms of potential, one W88 detonated in an airburst would produce a fireball over 1.56 sq km, an air blast to 5psi overpressure over 91.9 sq km, and 3rd degree burns over 233 sq km. The scale of the human tragedy involved in a first-strike deployment of 60 of these things is too gruesome to write down here, but you can play with it on NukeMap [1] if you're so inclined. Suffice it to say that no sane government on the planet will want Starship to land anywhere nearby unless we're living in a global utopia where this sort of thing is unthinkable. [1] https://nuclearsecrecy.com/nukemap/ https://nuclearsecrecy.com/nukemap/
  - wbl 8y ago
    Or they have ability to strike back no matter what.
    - politician 8y ago
      Maybe, but if governments of the world decide to treat every Starship launch as a potential ICBM, wouldn't it be cheaper and easier to just deny landing rights entirely? A sky full of friendly traffic makes the hostile traffic more difficult to spot, after all.
  - JulianMorrison 8y ago
    Isn't the same math applicable to a jumbo jet? Or a container ship?
    - politician 8y ago
      Certainly, but neither a jumbo jet nor a container ship has a 30 minute delivery time, and presumably that many warheads has a significant radiation signature.
- rb666 8y ago
  Let's also not forget about the climate impact of turning rockets into business class travel. It's pretty ridiculous. If we want any change and chance for this planet we should squash initiatives like this in the butt.
  - adrianN 8y ago
    Fuel them with Hydrogen/Oxygen produced from electrolysis with solar power.
    - avmich 8y ago
      Or with methane synthesized from CO2 taken from air. You're going to always have CO2 in air, plants need that, so a healthy loop of using it as an energy storage may eventually make sense, today's climate crisis notwithstanding.

Here: https://www.youtube.com/watch?v=zqE-ultsWt0 https://www.youtube.com/watch?v=zqE-ultsWt0

The vomit-comet ICBM video? I'm a big fan of SpaceX, but I think they'll get to Mars before governments on Earth allow that concept to happen. Your passengers do multiple g's to altitude, then go weightless, then go back to taking g-forces on descent. That's the vomit part. Not a great customer experience. Meanwhile, the Starship looks like an ICBM to every early warning radar on the planet. It's only during reentry that it stops looking like an ICBM, but most missile defense strategies call for intervention in the boost phase. Let's suppose that they address those false positive detection issues. If you're a military planner, though, you're probably asking yourself how many MIRV warheads could fit inside a militarized Starship retrofitted for a preemptive strike?

politician 8y ago
Ok, I did some rough math. The W88 has a diameter of 55cm, a length of 175cm, and a blast yield of 475 kilotons. The unpressurized cargo hold of the Starship per Wikipedia is 88m^3, and the diameter of the vehicle is 9m. Let's assume that the unpressurized cargo hold is a cylinder 9m in diameter with a length of 9m. It looks like a hold of that size could fit 15 units per 200cm length, or 60 units, with space for structural rails and deployment gear. For comparison, that's 7.5x the capacity of the Trident II SLBM which was designed to accommodate 8 W88s. In terms of potential, one W88 detonated in an airburst would produce a fireball over 1.56 sq km, an air blast to 5psi overpressure over 91.9 sq km, and 3rd degree burns over 233 sq km. The scale of the human tragedy involved in a first-strike deployment of 60 of these things is too gruesome to write down here, but you can play with it on NukeMap [1] if you're so inclined. Suffice it to say that no sane government on the planet will want Starship to land anywhere nearby unless we're living in a global utopia where this sort of thing is unthinkable. [1] https://nuclearsecrecy.com/nukemap/ https://nuclearsecrecy.com/nukemap/
- wbl 8y ago
  Or they have ability to strike back no matter what.
  - politician 8y ago
    Maybe, but if governments of the world decide to treat every Starship launch as a potential ICBM, wouldn't it be cheaper and easier to just deny landing rights entirely? A sky full of friendly traffic makes the hostile traffic more difficult to spot, after all.
- JulianMorrison 8y ago
  Isn't the same math applicable to a jumbo jet? Or a container ship?
  - politician 8y ago
    Certainly, but neither a jumbo jet nor a container ship has a 30 minute delivery time, and presumably that many warheads has a significant radiation signature.
rb666 8y ago
Let's also not forget about the climate impact of turning rockets into business class travel. It's pretty ridiculous. If we want any change and chance for this planet we should squash initiatives like this in the butt.
- adrianN 8y ago
  Fuel them with Hydrogen/Oxygen produced from electrolysis with solar power.
  - avmich 8y ago
    Or with methane synthesized from CO2 taken from air. You're going to always have CO2 in air, plants need that, so a healthy loop of using it as an energy storage may eventually make sense, today's climate crisis notwithstanding.