Apologies if this is off topic … but I thought the technical side of this belonged in this thread.
My simpleton understanding was that fission provided energy/power. That being the case, what is the propulsion on these, that can move, manuver and keep it up in the air for so long?
We could tell you but you may end up falling from a balcony later…
There is some speculation but Wikipedia has some details:
It uses a conventional rocket booster to get it up in the air and then may use Ramjet technology to fly (exhausting radioactivity as it does so).
The fact that it can fly for a long time is actually not really a benefit as it’s not too fast and the longer it is in the air, the easier it would be to track, and ultimately destroy.
@tom1234: You (plural) and me included 
i did look at wikipedia before posting. Ramjet is definitely an option at higher altitudes. Something else is needed to get it there.
In summary, i guess fission is used for energy, while something else is used for propulsion.
A small rocket booster gets it off the ground.
It apparently flies only 100m or so above the ground so the rocket doesn’t need to be big nor powerful.
Nuclear energy is only the heat source. Anyway, something with a mass has to exit the rocket in one direction, so the rocket goes in the opposite direction. It can fly for longer that other rockets but not indefinitely.
Anyway, the current war has shown that the limit is not technological but being able to build the artillery shells, bombs, keep airplanes operational, etc. Very boring manufacturing and logistics capabilities, not sexy rocket nuclear engines.
The Americans and I suppose also the soviets built and tested nuclear propulsion in jets in the 50ties.
It was a terribly bad, bad idea.
It is a bad idea. Rockets could experience rapid unscheduled disassembly dropping radionuclides over large areas before reaching enemy territory.
This is not commercial aviation with very high reliability. Weapons fail a lot.
There’s plenty of experience on what can happen if the rocket fails:
well, this is meant as a weapon - selfish and one time use for death and destruction. Not as a reusable human service tool like vehicle, planes, etc.
Keep it up in the air - MAD (mutually Assured Destruction) mentality.
If it starts acting up, drop it on the intended target or close enough?
Russia is always rattling the nuclear saber, at any given opportunity …
Although - we tend to “lose” nukes or accidentally drop them or otherwise have an accident on a regular basis…
so adding a few more won’t be anything new 
Funny story - I used to work in Newbury, without knowing in the slightest about the accident there… background radiation is regularly checked (allegedly) and no statistical difference if found there to the rest of the UK…
Ironically, my cellar in Switzerland has substantially higher radiation levels (I bought a geiger counter after a while) - this is attributed to Swizerland’s very high radon levels… despite having a radon pit… At some point, I might fit active ventilation, gotta keep the wine from glowing 
Putting nuclear materials in weapons turn them into dirty bombs. When they explode they will spread radioactive stuff over a large area.
We are able to learn from past mistakes, allegedly. That list is about what to avoid, not for inspiration or to make it normal
What make and model did you get?
I have always wanted a Geiger Counter.
https://aliexpress.com/item/1005003721636457.html
Interestingly, it came with the manual and everything else in Russian… I guess they have a bigger Russian speaking market than Switzerdeutch…?
History never repeats itself. Man always does… (I believe Voltaire). If we learn from our mistakes, then that’s something I haven’t seen. Across generations, we repeat the same mistakes time after time.
If you are a pessimist then the future is about damage limitation. If you are an optimist then maybe human society does evolve for the better in the long run.
In either case you have to deal with the shit that happens.
Ah but this is where I reckon you are wrong. To a true pessimist, the future doesn’t matter - we will all be dust in the wind soon enough.
Human existence is merely a blink of an eye, the bat of a butterfly’s wing or a grain of sand in a desert…
And on that cheerful note, goodnigth
Succesful hit by an airdefense missile would spread radio active material around the place
Russians don’t care about such stuff.
Project Pluto was a United States government program to develop nuclear-powered ramjet engines for use in cruise missiles.
They left a radioactive trail, the nuclear reactors were highly radioactive so had to be handled remotely with care