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Why China Needs More Nukes
China is adding more intercontinental nuclear missiles (ICBM) to the meager 200+ nuclear weapons it currently deploys:
China has begun construction of what independent experts say are more than 100 new silos for intercontinental ballistic missiles in a desert near the northwestern city of Yumen, a building spree that could signal a major expansion of Beijing’s nuclear capabilities.
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The acquisition of more than 100 new missile silos, if completed, would represent a historic shift for China, a country that is believed to possess a relatively modest stockpile of 250 to 350 nuclear weapons. The actual number of new missiles intended for those silos is unknown but could be much smaller. China has deployed decoy silos in the past.
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The minimum distance between the silos in the picture is about two 2 miles.
In the 1970s the U.S. developed an idea called the ICBM shell game and made a helpful video to explain that concept. To protect missiles from a decapitating first strike a lot of the silos would be kept empty and a few missiles would be shuffled between them. To attack that new 119 holes missile field in China the U.S. would have to fire at least 119 nuclear war heads at them to be sure that no missile is left to fire back at it. If China would add some missile defense to the field the U.S. would have to fire about three times as many war heads to be sure that every silo gets destroyed. All this for probably just a handful of weapons. That number game adds up to soon become very expensive.
[Jeffrey Lewis, an expert on China’s nuclear arsenal and part of a team that analyzed the suspicious sites,] said the silos are probably intended for a Chinese ICBM known as the DF-41, which can carry multiple warheads and reach targets as far away as 9,300 miles, potentially putting the U.S. mainland within its reach. Major excavation work on the sites began early this year, although preparations were probably underway for months, Lewis said.
The editors of the Chinese Global Times take issue with the Lewis' statement on the DF-41 and show that they do not know the technical side of the strategic nuclear weapon field. It's editor in chief Hu Xijin writes:
It's unknown if the construction sites mentioned by the Washington Post are really silos for intercontinental ballistic missiles. But I must say that Lewis is an amateur. In reality, DF-41 is solid-fueled road-mobile intercontinental ballistic missile and one of its biggest advantages is its mobility and vitality. There is no point to put it inside a silo. Lewis may not understand the basic features of DF-41 before shooting off his mouth at the media.
That is so wrong that it hurts.
For one Dr. Jeffrey Lewis is THE Arms Control Wonk and director of the East Asia Nonproliferation Program at the Center for Nonproliferation Studies, part of the Middlebury Institute of International Studies. He has likely forgotten more about missiles than Hu Xijin will ever know.
The difference between solid fueled and liquid fueled missiles is the reaction time. The U.S. has some 450 silo based ICBMs. Those missiles were named 'Minuteman' because they are solid fueled and can therefore be fired at a minutes notice. Liquid fueled missiles take time to prepare as the fuel is filled up only shortly before a launch. They are quite dangerous for their crews as the liquid fuels tend to be quite corrosive and explosive. That does not matter much for space operations but is very inconvenient for any military application.
A second strike force must be ready to launch the moment an incoming hostile first strike is detected. There might otherwise be no one left to launch it.
Lewis sees sound reasons for China to expand its arsenal:
“We believe China is expanding its nuclear forces in part to maintain a deterrent that can survive a U.S. first strike in sufficient numbers to defeat U.S. missile defenses.”
A Global Times editorial agrees with that reasoning:
The US wants China to stick to the line based around minimal deterrence. It's true that China has said it keeps its nuclear capabilities at the minimum level required for national security. But the minimum level would change as China's security situation changes. China has been defined as the top strategic competitor by the US and the US military pressure on China has continued to increase. Therefore, China must quicken the increase of its nuclear deterrence to curb the US strategic impulse. We must build credible nuclear second-strike capability, which needs to be guaranteed by enough nuclear warheads.
It then adds a remark that points to potential real life scenario:
China's security situation is changing rapidly. The US has the strategic ambition to subdue China. Once a military confrontation between China and the US over the Taiwan question breaks out, if China has enough nuclear capacity to deter the US, that will serve as the foundation of China's national will. We are facing different environments and risks from the past. The calculation methods for the minimum level must also be different. Regardless of what the US says, China must be sober and firm about what it should do.
If the U.S. sends ships to prevent China from reintegrating Taiwan it might try to stop China from attacking them by threatening a nuclear attack. If China has a credible second strike capability that U.S. threat would be empty. No U.S. president will risk New York over Taipei City.
The construction of the new missile silo field was launched only at the beginning of this year and has been continued at a fast pace. China seems to feel that there is no time to lose before the U.S. takes the next steps to push for Taiwan's independence. That would immediately become a military problem. The new missile field may help to alter U.S. plans.
Liquid-propellant missiles can be stored, ready-to-fire for years, even decades.
There is zero truth in this misconception that is repeated endlessly [and annoyingly] in the know-nothing US media [and among so-called ‘experts.’].
One of the latest Russian submarine-launched ballistic missiles, which entered service in 2014, the Layner, is liquid-propellant. It is the latest version of the long-running R29 family, which has been the backbone of the Russian sub-launched leg of its triad.
Needless to say, submarine-launched ICBMs [SLBMs] need to be ready to launch at the push of a button, and must sit stored for many years.
Even long-range air defense missiles, like the Russian S200 use liquid-fuel engines. These too need to go at the press of a button, and sit stored for literally decades.
This is an astonishing case of how badly educated the US public is—and the absolutely ridiculous level of science discourse among so-called ‘experts.’
These liquid-propellant engines are much more capable than solid-fuel rockets, with a much higher specific impulse, which is the cardinal performance measure of any rocket engine.
A solid rocket is nothing more than a big firecracker with a hole in the bottom. Once lit, it cannot be throttled or even shut down. Its casing needs to be very heavy, which greatly reduces the payload fraction [the percentage of the overall rocket mass that is actual payload like the warhead or spacecraft]. Combined with the poor specific impulse, solid rockets need to be much heavier than liquid rockets.
But they do have the advantage of being more volumetrically compact, due to their high density. This is an advantage in some applications, less so in others.
The key to the long storage in the liquid-fuel engines is the propellants, which are known as hypergolic, since they ignite upon contact with one another [the fuel and the oxidyzer].
They are also called storable propellants, and ‘room temperature propellants,’ because they are in liquid form at room temp, unlike cryogenic propellants like liquid oxygen and hydrogen, which obviously cannot be stored.
Liquid oxygen [LOX] was the oxidyzer of the early ICBMs, which needs to be at very low temperatures, obviously. That is why the early ICBMs needed to be fueled before launch. Of course manned rockets also use LOX, typically with kerosene, but also liquid hydrogen, which too is cryogenic [in fact just 10 degrees or so above absolute zero].
The drawback with hypergolic storable propellants is their extreme toxicity, which means working with them requires elaborate safety procedures. But once they are fueled in the rocket, they are just as storable as solid rockets.
That S200 missile, for instance, was, until just a couple of years ago the FASTEST Russian air defense missile, and also the longest-ranged, with a flight range in excess of 300 km. It also has the advantage that it can be throttled, from a speed of about 700 m/s to more than three times that speed!
It has been very difficult to match that S200 performance with the new S400 solid rockets, which need to be much heavier [although more compact in size]. These of course cannot be throttled, which is another disadvantage.
But they go with solid now [since S300], for the reason that these are road-mobile system carried on an all terrain truck chassis [unlike the fixed installation S200]. Any road mishap could damage a propellant tank and you will have a huge toxic nightmare. If both tanks get ruptured, you will have a huge explosion, because the fuel and oxidyzer ignite on contact [hypergolic].
The same is true for Russia’s road-mobile ICBMs, the Topol and its later derivatives. These are also solid-fuel rockets [same for the Chinese]. On a sub this isn’t an issue, since the Russian subs have their missile tubes outside the inner pressure hull. This two-hull design is a staple of Russian design and is why their boats can operate at much greater depths [typically double that of a US nuclear boat].
All the weapons are kept outside this inner hull, which is designed to take all the water pressure, while the outside hull can be light, since it is filled with water anyway and is therefore of equal pressure and sees no pressure differential.
The reason the US has been encouraging this liquid fuel myth is because the US is not good at building liquid rocket engines.
They are literally decades behind and never really mastered the finer points. The Shuttle used two massive solid boosters to provide 85 percent of the launch thrust.[With that humongous liquid hydrogen tank feeding the three liquid H2-LOX Shuttle engines that only provided 15 percent, since hydrogen has such low density].
One of these solid boosters exploded of course on Challenger. They would have been better off using the Rocketdyne F1 engine from the Saturn V rocket of the Apollo program.
But this engine too was troubled and was not nearly the legend that it is made out to be. Saturn V only made a grand total of 13 launches [compared to 1900 for the various Soyuz family, plus hundreds more for other Russian engines, including nearly 100 powering US rockets in the last number of years].
Ideally, they should have refined the F1 engine [I don’t want to get into the technical points now] and used that as the boosters for Shuttle. Solid rockets for manned flight is considered completely unacceptable by the Russians. The Buran Shuttle had boosters using the huge RD171 liquid engine.
As for Geoffrey Lewis, he has no formal training in any hard science related to the subject he writes about. His education is in political ‘science,’ not any kind of engineering, physics or even mathematics.
He really doesn’t have any technical knowledge at all, and relies simply on what he is told by so-called ‘experts’ [who may or may not know what they are talking about either].
Mr Hu is right in his characterization, lol! Lewis has no clue about crucially important technical matters, like the one I just discussed, and this is readily apparent to people who actually do know the science at a professional level!
There is no point reading anything he writes because it cannot be taken seriously.
PS: The newest Russian super-missile, the Sarmat super-heavy, is a liquid-propellant rocket. It would be impractical to try to make a solid rocket of this throw-weight, flight range and performance. The propellants are Dinitrogen Tetroxide [N2O4] and UDMH [Unsymmetrical dimethylhydrazine]. These are used in all the other storable liquid rockets also.
Posted by: Gordog | Jul 3 2021 2:03 utc | 53
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