Spaceships: How to take off?

[Anthony]

Originally Posted by Ulzgoroth

I call your attention to the comparison I was making: is that more of a challenge than accomplishing the same thing off a solid surface that doesn't have a blast pit built in? I'd think that whatever amount of standoff your landing gear provides will be more satisfactory over a liquid surface than over a solid one.

You aren't going to use 'landing gear' to take off from water, you're going to use something like a raft with enough flotation to hold up your ship. Which is unlikely to survive takeoff. On land, you instead use a tower with enough strength to hold up your ship. This might survive takeoff, steel beams are a bit more durable than flotation structures, but it probably won't survive large numbers of takeoffs. Using your landing gear in either situation means that the landing gear takes the damage that would otherwise be taken by the ground structure, and thus likely isn't available to actually land with.

[Ulzgoroth]

Originally Posted by Anthony

You aren't going to use 'landing gear' to take off from water, you're going to use something like a raft with enough flotation to hold up your ship. Which is unlikely to survive takeoff. On land, you instead use a tower with enough strength to hold up your ship. This might survive takeoff, steel beams are a bit more durable than flotation structures, but it probably won't survive large numbers of takeoffs. Using your landing gear in either situation means that the landing gear takes the damage that would otherwise be taken by the ground structure, and thus likely isn't available to actually land with.

So you're making criticisms based on an obviously radically different presumed strategy that you didn't bother to bring up?

If someone wants a spaceship with serious ISP and also planetary takeoff capability, I'm generally going to assume that they're expecting it to be able to land and take off again without requiring the assistance of major industrial facilities.

[Anthony]

Originally Posted by Ulzgoroth

So you're making criticisms based on an obviously radically different presumed strategy that you didn't bother to bring up?

If someone wants a spaceship with serious ISP and also planetary takeoff capability, I'm generally going to assume that they're expecting it to be able to land and take off again without requiring the assistance of major industrial facilities.

Well, then they should proceed directly to superscience drives.