[Spaceships] Orion space drive: launch from underwater?

[Fred Brackin]

Originally Posted by Agemegos

G'day!

Does anyone know whether an external pulsed nuclear spaceship could be launched from underwater? My guess would be that the force from the first pulse below and the inertia of the water above would crush any possible craft.

What if a subaquatic civilisation floated their spacecraft to the surface and then lit off a nuke underneath. If the ship were big enough and the nuke small enough, could this put them into the air intact? If they are using non-fission-initiated advanced fusion, how bad is the radioactive contamination?

As most Orion proposals start with "assume a viable pusher plate" it is very difficult to make assumptions about what the acceptable level of stress would be.

Spaceships assumes a 2G Orion drive but as this would be the average accel over a period of time, peak accel would be far higher. An Orion spaceship would have to be _very_ rugged in any event. Spaceships requires a dDR 50 (DR500) rear hull.

Still, there's no reason not to float to the surface.

If your propellant bombs are pure fusion with no fissiles or fissionables the only source of contaminants will be neutron activated elements in the water or pieces of your pusher plate ablating away.

Hydrogen and oxygen do not become radioactive when hit be neutrons but I can't tell you about sodium or chlorine. Gawd only knows what your pusher plate is made of or how much of it you lose with each explosion.