ELI5: why don't they use "tiny nukes", basically engineer a small (less than 10cm/1in) nuclear bombs that explode in a chamber at the back of the space ship?
- massive mess if it goes wrong in any way
- putting nukes in space is banned by treaty and would be an ugly precedent
-Japan has committed to not making nukes and has for obvious historical reasons a difficult relationship with the topic.
(If Japan wanted to become a nuclear power, they relatively easily could for a country that doesn't have any, but that would be a major thing and not a side thing of some science project)
Isn't 155mm 15cm? Close enough I would say if it was an actual fission explosion.
As for safety, nukes in space are safe and you can launch them using conventional propulsion and use nukes only in space and also launch from point nemo or cook islands so you are at least 3000mi away from large populations.
I get these challenges are real but if the advantage over ion propulsion is great then it sounds like they are worth overcoming.
Lessening an absolutist stance on this in favor of a more nuanced regulatory policy that requires more in depth checking seems to me like something we'll regret later when we find the agency is toothless, either because it always was in regards to this or because it was slowly defanged without people noticing.
If something goes wrong during the launch and the rocket explodes, isn't that basically exploding a dirty bomb in the upper atmosphere? Is 3000 miles really enough of a buffer zone?
Since that paragraph is talking about detonation over a populated area, 3k miles away even in the atmosphere I would think wouldn't cause much of an actual harm.
But a solution might be to enrich the radioactive material in a space station in orbit.
Now I don't know how feasible is making a nuke as small as you suggest.
> Project Daedalus later proposed fusion explosives (deuterium or tritium pellets) detonated by electron beam inertial confinement. This is the same principle behind inertial confinement fusion. Theoretically, it could be scaled down to far smaller explosions, and require small shock absorbers.
That's an interesting tidbit about the size. Also reminds me of the Deadalus spaceship from the stargate universe.
But it sounds like politics is the only limit here, surely they can ammend the treaty to allow space-travel work under IAEA supervision.
As for what might be feasible within the laws of physics, rather than current engineering, I'm not sure there's a clear answer. Increasing the density of the fissile matter reduces its critical mass, which is why they implode the core with conventional explosives in most designs. There are other ways of compressing matter to very high densities. For example, subjecting it to hot enough plasma, like in a magnetic confinement fusion reactor, might work. But stuff like that is science fiction and will be for a long time.