[0] https://www.nasa.gov/mission_pages/station/expeditions/exped...
They are entirely constrained by thrust versus mass, so the designers make the structure as light/thin as possible while still being able to handle the acceleration forces when fuelled and pressurised.
If the weight of the rocket itself is too high it will not be able to lift any payload. If it is too light it falls apart in flight (or in one spectacular case, crumples in on itself when pressurisation fails).
https://en.m.wikipedia.org/wiki/1980_Damascus_Titan_missile_...
Also with nuclear weapons, as much engineering has gone into safety as into weapon design itself. It's astronomically improbable for a modern nuclear weapon to detonate prior to arming even if the explosive lens is set off.
The reentry vehicle is designed to come down at circa mach 14 so a little bit of heat and jostling isn't going to bother it.
Cool video about some of the engineering involved: https://www.youtube.com/watch?v=97t7Xj_iBv0
Not blowing up when you don't push the button doesn't have a name.
When they actually dropped a pair by accident from a B-52, both got very far into their ignition sequence before something failed. Questions were Asked, after. So it is probably better now. Here. Russia? Israel? India? No telling.
We have come a long, long way since then in nuclear safety both in weapons and reactors.
Does it include Rick Perry? You are aware that the supposed secret "nuke launch code" was seventeen zeroes?
By the time you've punched in the code, whether it's an OTP or seventeen zeroes, you've already committed a missile to a target and you're already 100% going to go through with the launch because two missile combat crew members turned their keys.
Russia doesn't even bother with these kinds of codes. Their second strike capability is fully autonomous and will launch even if all of c&c infra is destroyed.
This also has absolutely nothing to do with the mechanical intrinsic safety of the actual nuclear weapon during a fire or the RV that carries it. Which is the original topic at hand. The code is just an extra step to arm the weapon. The physical safeties are there to 99.999% guarantee that the weapon will not detonate unless armed. Even if you try really really hard to detonate it.
More thinking has gone into each tiny element of this process including the kind of paint used on bombs, than you have given to the topic as a whole.
Not far enough, though.
Poor bastard.