China Ballistic Missiles and Nuclear Arms Thread

[OppositeDay]

With the reusable CZ-9 concept, I think the national space team is moving toward reusable liquid-fuel rockets. I can see a future where a fleet of reusable liquid fuel rockets is used in combination with solid fuel rockets for Chinese space launches.

Suppose a solid fuel ICBM has a 10 years operational lifespan, a fleet of 500 ICBMs will retire 50 rocket engines plus fuel each year. China does around 50 launches each year now. But the number will increase with the incoming national satellite Internet constellation. Depending on maintenance costs and interests rate, it could be surprisingly affordable.

 

[Kalec]

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整弹跌落安全性试验“重剑”突击队

Latest news from CASC solid rocket test center. It could be a drop test of either "a new missile" or "a new warhead", hard to confirm given the ambiguity of original language and lack of picture.

我所承担的最大规模的跌落试验任务，也是国内首次战略装备整弹跌落安全性考核

The largest (?) drop test mission the center ever took, also the first drop safety test of the "entire" strategic weapon in China. Honestly I dunno what it exactly is, either a warhead or missile, also ambiguous on what "entire" means. Does it mean the previous drop tests excluded some parts of the bomb or is it the first drop test of a strategic missile with warheads?

型号意义重大、外型尺寸巨大、产品质量巨大、试验周期短、试验工艺复杂

The drop test was carried out by a 50 ton gantry crane, which means that it can't be DF-41 or heavier ICBM with fuels in. But it could also be a drop test of first stage motor or safety review on one of old DF-31s.

The only thing 100% sure about: this is the first of a kind drop test on a strategic weapon in its entirety.

Highly likely to be related to silo construction. Since China never deploy silo-based solid-fueled ICBM before, so never have a drop test on it. DF-5 didn't need such test because it would explode when it dropped on the ground and everyone knew it. DF-31 and DF-41 will be in the tunnel in a first strike scenario and protected by launch tube.

Not likely to be a drop test of nuclear warhead, mainly based on that it is a test conducted by CASC and in Inner Mongolia. If it was a nuclear warhead drop test, it would be in Lop nor by CAEP.

 

[Strangelove]

Nothing new...just a pretty graphic from GT, like those from children's books.

 

[clockwork]

I think at least 12 DF-5Cs silos rn since every old liquid ICBM brigade operates "multiples of 6" silos.

Someone suggests 30 newly built, even up to 60, for DF-5Cs.

Do they have any actual reason to think this or just pulling random numbers out? The 18 figure I gave was of actual new construction spotted on satellite (well DF-5s, but I assume all new ones are C's). Would like to see any sources you have on this (incl in Chinese).

I doubt it'd be close to 60, because that's another obscene number of warheads given how many MIRVs these carry.

 

[Kalec]

Do they have any actual reason to think this or just pulling random numbers out? The 18 figure I gave was of actual new construction spotted on satellite (well DF-5s, but I assume all new ones are C's). Would like to see any sources you have on this (incl in Chinese).

I doubt it'd be close to 60, because that's another obscene number of warheads given how many MIRVs these carry.

Tbh, I dunno, but some random dudes on

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claimed that at least 30 new DF-5C is being built, quoting some evidences taken on the ground but not able to publish due to security reason. Personally I hope it is fake because DF-5C is not worth another expansion for economical reason. DF-5C should have a similar throw weight compared with heavy solid ICBM, but require far more personnel to operate.

Also I don't really think there are 18 DF-5C spotted on satellite. I think the most correct figure is 8, which Ben has everyone of them with satellite photos.

 

[FairAndUnbiased]

Yes but N2O4/UDMH is corrosive and toxic, meaning it will erode the valve throughout years and makes it unsafe to launch. U.S. didn't rely on liquid ICBM as much as Soviet did during cold war, and Soviet use membrane-valves to ensure missile safety on ICBMs, SLBMs such as SS-23 and SS-18/SS-30 series where US only deploy them in fixed silos.

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As of China, I think it also applies on safety concerns. Yes, you can fuel the tank during a crisis and launch within minutes but it is extremely expensive to refuel-empty-refuel over and over again. That's probably why each PLARF brigade only operates 6 silos.

Also these DF-5 silos need to distance themselves from each other, make it more expensive to operate. as communication line cost is one of the major costs in building silos clusters.

Neither UDMH not N2O4 are generally corrosive to stainless.

N2O4 is a non ionizing oxidizer which further passivates the stainless steel surface by very slowly removing exposed Fe and further enriching the surface with Cr over the course of months at the scale of angstroms (0.1 nm).

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However, attack is extremely limited in both oxidizers. It is finished after 550 days (and probably in less than 55 days) in dinitrogen tetroxide and corresponds to the oxidation of a 30- to 40-A layer of alloy. In dinitrogen tetroxide plus 3% nitric oxide only a fifth of the corrosion takes place, and then within a period of less than 50 days.

Anhydrous UMDH used in aerospace application is a reducing agent that is simply toxic to humans and animals but otherwise compatible with stainless steel.

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UDMH and the majority of its transformation products are not corrosive substances for steel structures, but their dilute aqueous solutions cause increased corrosion of aluminum and its alloys

They might erode the valve seal but typically those are fluoropolymer (FFKM in most heavily oxidizing applications), rest stainless steel. In addition, the valve seals can simply not be wetted during storage, with engine startup provided by a pressure feeder gas tank before the turbopump can get started (see Titan 2 design).

Also note the fact that hypergolics are used on decade long deep space missions where refueling is clearly impossible and storage must be stable for years.

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Main propulsion was provided by the 645 N, 317 sec. Isp bipropellant (hydrazine and nitrogen tetroxide) large velocity assist (LVA) thruster. The model used was the LEROS 1b, developed and manufactured at AMPAC‐ISP's Westcott works, in the United Kingdom. The spacecraft was designed to carry 607.8 kilograms (1,340 lb) of propellant and helium pressurizer for the LVA.

 

[Kalec]

Neither UDMH not N2O4 are generally corrosive to stainless.

N2O4 is a non ionizing oxidizer which further passivates the stainless steel surface by very slowly removing exposed Fe and further enriching the surface with Cr over the course of months at the scale of angstroms (0.1 nm).

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Anhydrous UMDH used in aerospace application is a reducing agent that is simply toxic to humans and animals but otherwise compatible with stainless steel.

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They might erode the valve seal but typically those are fluoropolymer (FFKM in most heavily oxidizing applications), rest stainless steel. In addition, the valve seals can simply not be wetted during storage, with engine startup provided by a pressure feeder gas tank before the turbopump can get started (see Titan 2 design).

Also note the fact that hypergolics are used on decade long deep space missions where refueling is clearly impossible and storage must be stable for years.

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Interesting food for thought. Because the whole idea of membrane seems like a Soviet innovation, and PRC was hugely influenced by Soviet back in 60s and probably adopted similar strategy to keep valve dry. Since nuclear war is less imminent while China actually deployed DF-5A in silos, China didn't fuel the tank anor install warheads on the rocket for a very long period of time.

Here is more background from Soviet/Russia

https://twitter.com/i/web/status/1443140591576043520

Also

https://twitter.com/i/web/status/1443127609181749257

I doubt it is a threshold for China to pre-fuel DF-5 before launch. China has such technology back in 70s when developing DF-14/DF-22 mobile liquid fueled IRBM (both cancelled due to safety and economy concerns) and even North Korea has achieved it since 2019.

One of the reasons could be China never take liquid ICBM seriously enough. Only 18 of them deployed, minor change in decades, no significant progress on rocket itself since 1980. Also it is why I have strong suspicion on "30 x DF-5C"

 

[escobar]

Interesting food for thought. Because the whole idea of membrane seems like a Soviet innovation, and PRC was hugely influenced by Soviet back in 60s and probably adopted similar strategy to keep valve dry. Since nuclear war is less imminent while China actually deployed DF-5A in silos, China didn't fuel the tank anor install warheads on the rocket for a very long period of time.

Here is more background from Soviet/Russia

https://twitter.com/i/web/status/1443140591576043520

Also

https://twitter.com/i/web/status/1443127609181749257

I doubt it is a threshold for China to pre-fuel DF-5 before launch. China has such technology back in 70s when developing DF-14/DF-22 mobile liquid fueled IRBM (both cancelled due to safety and economy concerns) and even North Korea has achieved it since 2019.

One of the reasons could be China never take liquid ICBM seriously enough. Only 18 of them deployed, minor change in decades, no significant progress on rocket itself since 1980. Also it is why I have strong suspicion on "30 x DF-5C"

Then Why they are building new silos for DF-5C when they have 300 silos for heavy solid ICBM

 

[FairAndUnbiased]

Then Why they are building new silos for DF-5C when they have 300 silos for heavy solid ICBM

having a few liquid silos is good for certain missions requiring ultra heavy lift capability.

 

[Kalec]

Then Why they are building new silos for DF-5C when they have 300 silos for heavy solid ICBM

To address Russia's threat, the new silo is too close to Russian border, make it vulnerable for a Russian first strike.

The new DF-5C will be similar to Sarmat in term of throw weight when target is Russia or India.