Jeffrey LewisDF-21 Delta aka CSS-5 Mod 4

I am fascinated by China’s development of conventionally-armed ballistic missiles, particularly the development of a conventionally-armed DF-21 variant, the DF-21C (pictured above, it seems).

I recently read an article in Defense News by Wendell Minnick on conventionally-armed DF-21s and the threat to US carriers.

It’s a good article. One observation, though — the author and experts describe the conventionally-armed anti-ship ballistic missile (ASBM) as the DF-21 C or Charlie. The conventionally-armed DF-21 is the DF-21C. But I believe that the ASBM variant has a different number — the DF-21 D or Delta.

A brief history of the DF-21: China developed the solid-fuel, medium-range DF-21 through the 1980s, with deployment starting in the early 1990s. Deployments did not begin in earnest, however, until the late 1990s. The Chinese refer to having two variants of the missile — the DF-21 and the DF-21A, which correspond to the IC designation CSS-5 Mod 1 and Mod 2, respectively. (See the recent DOD/DOE white paper, for example.)

As early as 2005, descriptions of the long-awaited conventional DF-21 were described as the DF-21C — which would presumably correspond to a CSS-5 Mod 3. That seems to be the mystery missile carried by various pictures of China’s shiny new TEL. (Above is the most widely published of those images.) has a nice gallery of DF-21C images. I offer them with the disclaimer that I haven’t convinced Calluzzo to model them yet. So, I merely observe that other people think these are 21Cs and that seems like a reasonable working hypothesis to me.

That brings us to the ASBM. An anti-ship ballistic missile is a special kind of conventionally-armed ballistic missile. Chinese Military Power describes the new ASBM as a “based on a variant” of the DF-21. The “variant” is presumably the DF-21C/CSS-5 Mod 3. That would make the ASBM version the Delta and the Mod 4.

I am pretty sure that I am right about this. But your comments, dear readers, are welcome.


  1. Geoff Forden (History)

    Fascinating picture! This is the first time I have seen a canister of a TEL with what appears to be fold down scaffolding for pre-launch prep when the canister is in the raised position. Do you agree that is what those bulges are? If so, they appear to me to be at approximately the right size for a person to access a guidance system, if that is placed just below the warhead area; a natural place for it. You do not need to access the guidance system like that for loading the launch position into the missile. That is usually done on the ground with a theodolite setup that is pretty standard. However, it is just conceivable that if the position of the target is loaded at the last minute, or other information about the target such as ship profile etc., then you might need access to the guidance system. This would have important implications for understanding the state of China’s guidance technology as well as important tactical implications for how long it would take them to program and launch a conventionally armed DF-21 against a mobile—ether land- or sea-based—target.

  2. Haninah (History)

    A question from the non-experts… would you care to offer any insight on what the externally visible differences would be between a nuclear-armed version, a conventionally-armed version and a conventionally-armed anti-shipping version? Clearly there would be differences in the warhead and the guidance system, but what are the external cues you pick up on in a picture like this one? (I guess Geoff’s comment gives one suggestion…)

  3. Yossi

    There was a budgeting fight in Israel on precision SS missiles vs. aircraft. The Air Force won. The interesting point is an argument aired that missiles do the same job, much quicker, with similar accuracy and less than one third of the cost. If true, conventionally armed missiles are very important to arsenal diversification.

  4. kerbihan

    Following Geoff’s post, a sincere question – that I’m sure other readers have on their minds: how realistic is it for China to credibly threaten such moving targets as US ships with ballistic missiles? Despite Chinese advances in guidance technology, isn’t that a bridge too far? Would not a swarm of cruise missiles be a much more credible threat?

  5. Captain Ned (History)

    Am I just stupid or does the idea of taking out a carrier with a conventional-warhead MRBM just not work. Unless the warhead bus has some serious maneuvering capability (and/or has a nuke inside on the sly), the flight time alone will give the carrier more than enough time to get out of conventional-warhead blast damage range.

  6. kme

    If access to the guidance electronics in the vertical position is routinely needed, wouldn’t you just run some copper wiring down to an access port somewhere near the base?

  7. Allen Thomson

    The Soviet attempt to create an anti-ship ballistic missile, the SS-NX-13, used both a terminal homing device of some sort and a nuke. See

    Remember that the Chinese would also have to have some sort of real-time, long range ocean surveillance capability to provide initial targeting data. That could be patrol aircraft, ships or submarines, ELINT, OTH radar, satellites, etc.

  8. Geoff Forden (History)

    As Capt. Ned points out, a carrier can maneuver quite a lot during the flight time, most of which would be after the US DSP satellites have detected its launch. I estimate that a carrier could move anywhere up to 4 km from where China thought it might be when it launched. So attacks against ships at sea by ballistic missiles will require terminal guidance. But that doesn’t mean that China wouldn’t need to access the guidance before launch. For instance, and this is just an illustration, perhaps China needs to add liquid nitrogen to cool down any infrared sensor onboard.

    However, since this picture was declared to be only a conventionally armed DF-21 and not an anti-ship DF-21 (which Jeffrey thinks would have a different mod anyways), I actually think that the reason is not to do something to any terminal guidance but rather to start up a fully gimbaled—as opposed to a strap-down—guidance system. I can imagine reasons for doing something manually with such a system once it was in a vertical position. Not everything can be done from the ground by electronics!

  9. Smith (History)

    Pardon my ignorance, but I’m with Captain Ned: a conventionally-armed ballistic missile seems like an inefficient method of destroying things on the high seas.

    Has guidance technology come this far? Are there any examples or reference material about other systems that can grant the accuracy necessary?

    Then again, perhaps it doesn’t need to – I suppose a flight of multiple missiles could get the job done.

  10. John F. Opie (History)

    Hi –

    Interesting. Of course, it also makes the US Naval interest in ABM technology for Aegis-class ships that more understandable. If the -2 missile sets can deal with this, then China loses.

    Of course, the nightmare scenario would continue to be the firing of, say, several hundred of these at a naval task force. Given even a modicum of terminal guidance targeting, you’re gonna get hits, and with an interesting mixture of EMP, FAE, armour-piercing submunitions (think MRBM-Shotgun, release at 1000 ft above sea level for maximum coverage) and HE with terminal guidance, and that’s quite a threat.

    Of course, it is also a one-use option. You can’t reuse them, and you may actually need to fire 100-150 to ensure that a carrier is actually sunk with any degree of assurance.

    In the meantime, you could have several hundred cruise missile from the US fleet in flight to the launch areas from the fleet. While the aircraft of the fleet may be otherwise distracted, the SSNs wouldn’t be. They carry enough Tomahawks to ruin anyone’s day, and given the relatively small number of launchers and real-time intelligence, could be way up close and pop their Tomahawks off with a 10-minute flight time to cover the launch areas with submunitions: these launch vehicles are thin-skinned.

    Of course, this is all just speculation… 🙂

    Still, a disturbing development.

  11. 3.1415 (History)

    There is a close-up image of the DF21 missile at

    The article, which was published on the quasi-official, a newspaper affiliated with People’s Daily, refers to an article on Defense News about the US cancellation of DDG-1000 due to the new deployment of the DF21D.

  12. Rip (History)

    Sidebar: Who be Calluzzo? Are you talking drawing models or analytical models?

  13. Jeffrey Lewis (History)

    Hey … I hear there are pictures of the ASAT booster online.

    Anybody seen those?

  14. peter (History)

    I’m no expert, but it seems like an anti-ship ballistic missile would make sense only against ships in a port or harbor, where topography constrains movement…

  15. 3.1415 (History)

    Chinese internet sources said that the missile may have an EMP warhead. The actual kill may be effected by the sunburn or other things. EMP would also give China the option of not sinking the carrier, just letting it floating on sea peacefully, if it chooses to cease fire.

  16. Andy (History)

    The flight profiles of these conventionally armed ballistic misiles are identical to those of nuclear-armed missiles and therefore look the same to NORAD/NCA, right? In this scenario, are we going to wait for a carrier group to be converted to plasma before we respond, or is there a possibility that we would launch our nukes as soon as the missiles go into terminal guidance?

  17. 3.1415 (History)


    I found a Chinese eqivalent of you on the Internet, only more technical. Here are his two blog articles on the development of DF-21D:

    and a fairly technical thought experiment on the use of these missiles

    I have no idea how good his technical stuff is, but a lot of his basic information was from published and unclassified Chinese technical journals. Unfortunately, as your colleague in UCS pointed out, there is a great paucity of missile experts who are fluent in Chinese in this country. United States can get a very good picture of China’s military capabilities by analyzing the open technical journals published in China.

  18. nuc free korea (History)

    One point I didn’t see mentioned in all of these comments was the fact that a conventionally armed long-range (maybe even ICBM) missile has grave strategic consequences in terms of transparency and the risk of miscalculation by major powers. The U.S. has hesitated to do the same thing (despite the U.S. infatuation with precision missiles) just for this reason. If China has gone this route, Russia won’t be far behind (or the U.S.). Therefore, when a missile is in the air no one will be able to trust that it’s not a nuke and will react accordingly.

  19. dylan (History)

    Although sinodefence is an excellent source for those who can’t be bothered searching the Chinese internet or can’t read Chinese, it is perhaps important to point out that the image Jeffrey linked to is clearly photoshopped. Take a close look at the ground in front of the rear TEL.
    As to why the PRC might do this – first point is to stop thinking like Americans and think outside the box. Sure for a country with the capabilities of the US developing ballistic missile ASMs makes little sense, but the PRC has a very different mindset and geopolitical situation.
    The real question is when/if the capability will be demonstrated against an at sea target. Until then it is (mostly) theoretical.
    As to tageting, it is no secret that the PRC is expending significant resources developing an air/space/subsurface and electromagnetic recce system over the Western Pacific.

  20. user_hostile (History)

    EMP is a weapon used to damage electrical or electronic gear. Given the fact that an aircraft carrier is a giant Faraday cage on top of a conductive surface (the ocean), and hardened against EMP (along with aircraft) from nuclear weapons, I don’t see the efficacy of using this type of weapon. If anyone knows otherwise, please correct me.

  21. Jeffrey Lewis (History)

    That’s a good point — I mentioned that I used the pictured because “is the most widely published of those images” but I should have also added that many people think it is photoshopped.

    Thanks for adding that.

  22. Geoff Forden (History)

    dylan is right about the photoshopping! Those guys standing next to the rear TEL have had their feet erased. And, perhaps more importantly, it appears that there is a network of ground cables that have been erased. Why would they do that? It does sort of throw all the other features of the picture into question.
    In fact, the more I stare at the picture, the less the “scaffolding” seems like scaffolding and more like just boxes. Too bad!

  23. santiago

    Anybody with knowledge care to comment on the advantages / disadvantages of submunitions vs. large HE warheads? I’m assuming that the goal is a mission kill or a major disruption in flight operations.

  24. mike

    my understanding is that there would be very little time for any warhead guidance on re-entry making it near impossible to retarget against a moving carrier battle group.

    Whats the CEP on these against a fixed target?

  25. B. Walthrop

    It could be the angle, but the two missiles appear to have different nose fairings.

  26. Austin Long (History)

    There are three key elements to making the anti-ship ballistic missile feasible, all of which have been noted so I just want to amplify. First, ocean surveillance. Without this, forget it. China appears to be moving towards Over the Horizon skywave and/or groundwave radar for this purpose (see Mark Stokes SSI piece from a few years ago). Second, a maneuvering warhead. This is eminently feasible for an MRBM- we did it 25 years ago with Pershing II. Finally, a terminal seeker. Also plausible- could be active radar, optical, or IR. Chinese interest in IR terminal guidance is long-standing and progressing- the paper “Man-made target detection for imaging infrared terminal guidance missile considering turbulence degraded Wave-fronts features” was presented by three researchers from Beijing University in 2005. And if I recall my trajectories correctly there is not a huge reentry issue with MRBMs in terms of terminal guidance (but maybe Geoff F. or some other real scientist will correct me). The interaction of all three elements is also critical. Slow processing of OTHR means greater target location error; a highly maneuverable warhead buys more “footprint” for the terminal seeker, etc. Basically this seems feasible against even a fast-moving carrier but at the same time it is not the slam-dunk system many China threat inflators would have you believe it is. The OTHR for example will be a big juicy fixed target…

  27. Lao Tao Ren (History)

    I am not too sure if your readers realize how fast and how much Chinese policy makers are souring on ties with the US.

    The issues in business are now bleeding over to other policy areas.


    Conservative Voices Urge Pull-back from Western Financial Markets
    byCSC staff

    The investments made by Chinese institutions in western financial firms are not smelling rose-like. They mostly seem to have been the victims of bad timing, bad advice, or just plain bad luck. And while most of the problems still amount to book losses and may yet yield value, they add up to a considerable number of billions of dollars, and this has strengthened the voices of conservatism in Beijing who urge a retreat behind the old walls. In this climate, whether China will allow itself to join in the international effort to unclog the credit markets remains problematic.

    PingAn’s investment in Fortis, a European insurer-banker, may have suffered a loss of over $3 billion, or 93% of its original investment, within a year. China Investment Corporation’s (CIC) investment in Reserve Primary Fund, of $5.4 billion, is frozen, though it may be recouped, but that is the best it can expect. Its investment in Blackstone has also seen a 75% book loss. Chinese state-owned banks such as Bank of China and China Construction Bank still have around a hundred billion dollars invested in the US credit default swap market.

    Scholars in Beijing have suggested publicly that the government ought to be cautious in investment. The China Securities Regulatory Commission requires listed companies to be careful in investing in overseas futures products, and never be speculative.

    Chinese insurance companies, such as PingAn, under the pressure of huge book losses in their overseas investments, are putting more emphasis on domestic and traditional insurance business to relieve performance pressure.

    China Life Insurance Company (China Life), with smaller losses, is moving out into rural markets. China Life president Yang Chao says the company has decided to promote its business in rural areas and develop insurance among migrant workers, pension and medical insurance for farmers, and insurance for farmers who have lost land. China Life’s market share in China’s rural area has reached 54%.

    China Life has launched its rural insurance business in nine provinces, and is expected to make good progress this year.

    The China Insurance Regulatory Commission recently required insurance companies to find a balance between the insurance business and investing, and banned them from using investment gains to offset insurance losses. Supervisors’ are concerned that some domestic property insurance companies may be covering losses with investment returns.

    Dispute is still raging in Beijing over whether China should acquire equity in US financial institutions and other companies. Li Rongrong, director of State-owned Assets Supervision and Administration Commission of the State Council, has publicly encouraged Chinese state-owned enterprises to seize the opportunity and accelerate overseas M&A. Li believes M&A is an effective method for a company’s development.

    Ha Jiming, chief economist of the China International Capital Corporation, said in a report that China should buy more heavily into US national debt, and should do it before other countries do. In the process of the cooperation, China can reach favorable agreements with the US, including allowing US companies to sell high-tech products to China. But other scholars suggest China should be more cautious before the real situation of the overseas market reveals itself.

  28. 3.1415 (History)

    Austin’s post is very informational and corroborates the Chinese blogger on It seems that DF-21D might be a Chinese version of Pershing II, with synthetic aperture radar guidance as the Chinese blogger speculated. When the Chinese government decides to leak the image, the only logical interpretation is that the missile works and has been deployed. Unless, of course, one is inclined to believe that China is acting like Iran, which just learned to use Photoshop. If the situation warrants, China may decide to show more. But let’s hope that it becomes increasingly unnecessary as Taiwan feels more gravity on mainland China’s orbit. American arms sales to Taiwan will increasingly jeopardize the US national interests by antagonize the goodwill of Chinese people. The fundamental interests of the United States will not be significantly affected by a unification of Taiwan with the mainland, peaceful or otherwise. As long as United States stays in Japan, America is safe – from a future revenge by the Japanese for Hiroshima and Nagasaki. China fully respects that need of the Americans and does not want a nuclear-armed Japan either. But again, China does not have any major blood debt to anyone in the world and has much less worries about other people’s Paper Tigers.