4 ms·

I think you underestimate the sheer mass of water.

• jp555 9y ago
  Well, if you've got people on board, you're going to need lots of water anyway. I guess it depends on the cost of lifting mass out of Earth's gravity well compared to the cost of making a highly reliable plasma shield.
  • dTal 9y ago
    It's not just the lifting out of Earth's gravity; mass is a liability in all forms of space travel. For any sort of momentum transfer drive (i.e. all of them, barring a scifi breakthrough like reactionless or warp), adding mass will eat into your delta-vee.
    • jp555 9y ago
      That's a good point, but system complexity and failure risk is also a liability that needs to be considered. A few meters of ice around your ship will be pretty much 100% reliable and require zero power, but for the considerable extra fuel required to achieve your required delta-vee. An ice-hull will also stop micrometeorites which I'd imagine a plasma shield would not be able to deflect. Space is hard!