> you can't keep a liquid-fuelled rocket permanently fueled so the Minuteman was developed as a solid rocket fuel booster.

You absolutely can! The Soviet doctrine was to use storable liquid propellants in their ICBMs - typically unsymmetrical dimethylhydrazine (UDMH) as the fuel and nitrogen tetroxide as the oxidiser. I don’t know if they need the fuel/oxidiser replaced periodically but that combination is storable for over a decade.

The US went with solid rockets as they are more reliable - no turbines or valves etc - at the expense of performance, but the US perfected making large solid rockets before the USSR. The USSR however perfected oxidiser-rich staged combustion which extracted a lot more performance.

Storable liquid propellants are still used on satellites and deep space missions that need to perform large course corrections during their missions.

> Since the alert window is under 10 minutes, you can't keep a liquid-fuelled rocket permanently fueled so the Minuteman was developed as a solid rocket fuel booster.

Huh? The Titan II was developed to do precisely that and worked that way for decades, they were liquid-fuelled and kept fuelled in their silos.

Liquid propellants are generally less stable than solid fuel. I had read in multiple places (from reputable sources) that you generally couldn’t keep liquid missiles permanently fueled like that. The propellants are extremely corrosive and dangerous.

But you are right that the Titan II is liquid fueled and was kept permanently fueled in the silo. I’m not entirely sure how to resolve those two facts. The Wikipedia page about the Titan II does mention multiple accidents and fatalities related to propellant leaks, so I’m guessing that they were just more risky to operate?

There was an incident where a technician dropped a large socket down a silo that impacted the side of a Titan missile and set off a chain of events that ended in an explosion that nearly detonated a nuclear bomb on US soil.

The Damascus Incident[0]. There's a book called Command and Control: Nuclear Weapons, the Damascus Accident, and the Illusion of Safety by Eric Schlosser that details the incident, and a PBS based on the book about it.

[0] https://en.wikipedia.org/wiki/1980_Damascus_Titan_missile_ex...

I was hoping this book would be a recommended. It really, really focused, reinforced is really not the right word to use here, my views on nuclear weapons.

This should be required reading.

The main problem with traditional liquid fuelled rockets is keeping the propellant cold. It’s not feasible to keep a rocket with liquid oxygen fuelled for long periods. The Titan missiles use hypergolic fuel which is more storable, but also extremely toxic and volatile. More than 50 people have been killed in accidents involving this rocket.

It helps if you think of liquid-fueled rockets relying on cryogenics as something entirely different than those using hypergolics. Cryogenics can't sit there for a long time but hypergolics can.

Forgive me if you meant all of your comment historically.

> Most of our rockets use liquid propellants.

Which ones? As far as I know the US only has solid fuel nuclear armed missiles. The Minuteman and the Trident.

> others on mobile launchers, shorter range missiles deployed in Europe (eg MRBMs in Turkey),

The US only has aircraft dropped bombs in Europe. The US retired their nuclear capable rockets and cruise missiles under the INF treaty in 1988. They retired their nuclear artillery etc at the end of the Cold War.

The (liquid fuelled) Jupiter missiles were removed from Turkey in 1962 after the Cuban missile crisis, in exchange for the USSR removing their nukes from Cuba, though there are still US nukes in Turkey.

> Also, a lot of these weapons will be thernonuclear

All of them are.