DF-31, DF-31A

The newest generation of Chinese strategic missile, including the Dong Feng-31, narrowed the gap between current Chinese, US and Russian ballistic missile designs. This system, once thought to be designated the CSS-9 but now designated the CSS-10, is a solid-fueled, three-stage mobile missile with a range of 8000 km carrying a 700 kg, one-megaton warhead. The DF-31 limited-range ICBM will give China a major strike capability that will be difficult to counterattack at any stage of its operation, from pre-flight mobile operations through terminal flight phases. As with the JL-1/DF-21 combination, the DF-31 and JL-2 are land-based and sea-based variants of the same missile.

DOD's 2013 report stated "The Second Artillery continues to modernize its nuclear forces by enhancing its silo-based intercontinental ballistic missiles (ICBMs) and adding more survivable mobile delivery systems. In recent years, the road-mobile, solid-propellant CSS-10 Mod 1 and CSS-10 Mod 2 (DF-31 and DF-31A) intercontinental-range ballistic missiles have entered service. The CSS-10 Mod 2, with a range in excess of 11,200 km, can reach most locations within the continental United States."

China’s DF-31A is believed to be a land mobile MIRV variant of the single warhead solid propellant DF-31, land mobile LRICBM replacing the old liquid fueled CSS-3, CSS-3A / DF-4, 4A LRICBM. Many more of the DF-31 types (eight are indicated) are being displayed in parade this 2009, 60th anniversary parade verses the three seen in 2008.

The cancelled DF-25 conventionally armed IRBM was to have been based on the first two stages of the DF-31, and the DF-41 long-range ICBM will use these two stages with a large-diameter third stage. Development of these missiles was accelerated following the successful test of their common 2m-diameter solid rocket motor in late 1983. The missile is apparently comparable in size and performance to the American TRIDENT C-4 long-range multiple-warhead three-stage solid fuel missile missile that is launched from submerged submarines.

The DF-31 is believed to incorporate design aspects similar to those of current generation Russian missiles. These could include upgraded mobility for the transporter-erector launcher [TEL], advanced materials for the booster and payload, use of penetration aids such as decoys or chaff, and an improved solid propellant.

The DF-31 is being jointly developed by China Aerospace Corporation, the research institute of the 2d Artillery Corps, and other scientific research organizations. In March 1991 the CMC assigned the task of developing and testing the DF-31 to the Second Artillery Corps, since the new missile was expected to have a limited operational capability as soon as its design was finalized.

The DF-31 development program is highly ambitious, and has presented Beijing with substantial challenges. China has experienced difficulties in casting the large solid fuel motors for the DF-31, and ensuring an adequate seal between the fuel and the booster casing. The DF-31 is in the late stage of development following various delays, and is expected to be deployed about the turn of the century, based on the recent completion of silo construction at the Wuzhai Missile and Space Test Center.

The details of the testing history of the DF-31 remain obscure. While the open source literature contains a number of references to tests associated with the DF-31 program, as of 1998 the National Air Intelligence Center characterized the DF-31 as "not yet tested." Given the evident challenges associated with the DF-31 program, and the variety of operational missiles that are expected to derive from this development effort, it is plausible that there have been a number of flight tests of components associated with the DF-31 prior to an all-up full range test of the complete DF-31 missile.

1. It is reported that the new missile was test-fired for the first time on 29 April 1992. Because of quality problems in its components, the missile exploded after launch.
2. The second launch also failed due to similar problems.
3. Beginning in June 1995 four other missiles were test-fired successfully.
4. A test on 10 November 1995 possibly included endoatmospheric reentry decoys.
5. A test on 10 January 1996 possibly included endoatmospheric reentry decoys.
6. The fourth successful flight test of the DF-31 was conducted on December 28, 1996 from the Shanxi base in central China.
7. The missile was observed on a launch pad at Wuzhai in mid-October 1997, and a flight test was conducted soon thereafter.
8. In October 1997 the DF-31 also underwent tests simulating launch from nuclear-missile-submarine tubes.
9. An "ejection" (soft launch) test was conducted in December 1998.
10. On 02 August 1999 China successfully tested a DF-31 launched from the PLA Second Artillery base in Wuzhai Prefecture (Shanxi Province), with impact point somewhere in Lop Nor (Xinjiang Province). Chinese preparations for this DF-31 test began during the second half of 1998. The US deployed the tracking ship USS Observation Island to the Western Pacific to monitor the launch, but the PRC missile was not fired seaward.
11. China conducted two flight tests of the DF-31 in 2000, both of which were successful.
12. A test flight on 04 November 2000 was conducted during the first visit to China by US Chairman of the Joint Chiefs of Staff Gen. Henry H. Shelton.
13. In May 2001 it was reported that China was preparing a flight test of the DF-31, with test preparations at the Wuzhai Space and Missile Center in central China having been detected by US intelligence. Some [not particularly credible] reports claim that a newly-formed electronic warfare unit test-fired DF-31 with inputs from "military reconnaissance satellites that cruise above the Taiwan Strait" as part of the "Modern 1" exercise conducted on 28 June 2001.
14. A flight test in January 2002 failed.

The 50th Anniversary National Day parade on 01 October 1999, the largest in the past half a century, featured advanced weapons and equipment involving 11,000 soldiers in 17 ground phalanxes and 25 vehicles formations, and ten echelons consisting of 132 warplanes. The DF-31 was included in the parade, though it was in a large cannister that completely enclosed the missile.

As of 1996 it was expected that the DF-31 would enter full service by 1998. By 1999 it appeared that operational deployment of the DF-31 was expected as early as 2002 or 2003. Development of the DF-31 is progressing, by 2000 deployment was expected before mid-decade.

In September 2001, Bill Gertz reported "China will soon deploy its first road-mobile intercontinental ballistic missiles" citing "the Chinese military's formation of the first missile units equipped with Dong Feng-31 missiles in July."

The International Institute of Strategic Studies' Military Balance published in October 2004, reported that China had deployed eight DF-31 ICBMs. Although this is not the first report that the DF-31 (CSS-9) had been operationally deployed, this was the first time that a number of missiles had been specified. Given the wild inaccuracies of other IISS estimates of Chinese missilel deployments, this claim must be viewed cautiously.

In the 2004 edition of the US Department of Defense "Annual Report on the Military Power of the People/'s Republic of China" the deployment dates for two new Chinese ballistic missiles (DF-31 and JL-2) had slipped from "mid-to-late-decade" [reported in the 2003 edition] to "by the end of the decade". The US Department of Defense and CIA estimates have not reported that the DF-31 had been deployed as of early 2005. Other apparently reliable news reports indicated that as of mid-2005 operational deployment of the DF-31 had yet to be confirmed.

Once DF-31 deployment began, China was expected to decommission its CSS-3 ICBMs. China will then be on its way to a ballistic missile force based around road-mobile systems which will greatly improve Chinese nuclear ballistic missile survivability and will complicate the task of defeating the Chinese threat.

With an estimated range of only 8,000 km (4,300 nm), the DF-31 can only reach targets along the entire West Coast of the United States and in several northern Rocky Mountain states. Chinese incentives for deploying a missile with such limited capabilities are not self evident.

As of mid-2002 China had around 20 DF-5 ICBMs capable of targeting the United States. The total number of ICBMs capable of targeting the United States was anticipated to increase to around 25 by 2005 and may reach 60 by 2010.

The DF-41, a 3-stage 12,000 km-range missile similar to the American Minuteman and the Russian Topol SS-25, will apparently be developed using the first two stages of the DF-31 along with a much larger third stage. The larger third stage and longer range of the DF-41 is made possible by the fact that, unlike the DF-31, the size of the DF-41 is not constrained by the requirement that it be fitted into a submarine launch tube. The cancelled 1,700km-range DF-25 ground mobile missile was developed using the first two stages of the DF-31.

China has a "Dongfeng-31" missile transport vehicle used for rail motor transport. The vehicle was exposed in 2006, but this transport vehicle does not have the ability to launch Dongfeng 31 ballistic missiles.

Improved mobility is needed for the DF-31 TEL. Currently this TEL is probably restricted to improved surfaces. Improved chassis features will in turn improve off-road capabilities, increasing the number of potential deployment locations. Such improvements will increase system survivability by making the missile more difficult to locate. US intelligence has photographed a Belarussian six-axle mobile missile TEL [transporter-erector launcher] at the DF-31 production facility in Nanyuan, near Beijing.

The Belarussian MAZ launcher is the chassis used for former Soviet SS-20 intermediate-range ballistic missiles. The mobility of the MAZ vehicle is significantly better than that of heavy Chinese vehicles. It is unlikely the Chinese will simply convert the Belarussian launcher to a DF-31 launcher, but rather they would probably will adopt some of its features, including all-wheel independent suspension, higher ground clearance, driver-controlled central tire-inflation systems, and large tires. The Chinese will probably reverse-engineer the MAZ vehicle to better understand its superior characteristics, which can then be incorporated into the existing DF-31 TEL [transporter-erector launcher] design to enhance its mobility and performance. A Chinese scale model of the DF-31 TEL at a scale of 1:30 had an overall length of 55 centimeters, which implies a full scale length of 16.5 meters, or 53.5 feet.

DF-31A

In August 2001 it was reported that China was developing a longer range version of its DF-31, designated the DF-31A. The DF-31A will reportedly be able to cover targets throughout the continental US from mainland China. In January 2014, PLA Daily posted 17 photos of a live drill of the DF-31A on its website, the first public glimpse of the advanced weapon.

A Chinese scale model of the DF-31A TEL at 1:64 had an overall length of 26 centimeters, which implies a full scale length of 16.6 meters, or 54 feet.

DF-31B

The Free Beacon disclosed in September 2014 that China is building new missile labeled the DF-31B that was expected to be MIRVed. The Washington Free Beacon reported on 2 October 2014 that a DF-31B was tested on 25 September 2014 but provided no other details. The Second Artillery continued to modernize its nuclear delivery forces by both enhancing its silo-based ICBMs and adding more survivable mobile systems like the CSS-10 family of road-mobile, solid-propellant missiles. The CSS-10 MOD 2 has a range in excess of 11,200 kilometers, which will allow it to reach most targets in the continental United States.

In testimony given before the US House of Representatives' Armed Services Committee on 26 February 2015, Admiral Cecil D. Haney said China is "enhancing existing silo-based ICBMs, conducting flight tests of a new mobile missile and developing a follow-on mobile system capable of carrying multiple warheads".

Macau-based military expert Antony Wong Dong told the South China Morning Post in October 2014 that it was hard to tell the difference between the DF-31A and DF-31B, but the upgraded version might have better performance. "The DF-31A was designed to carry three warheads. I think the new DF-31B is possibly a multi-warhead version with higher accuracy," Wong said.

DF-31AG

On 19 February 2015 Chinese military web pages showed a new 16-wheel off-road-capable TEL with a four-door cab similar to previous ICBM TELs produced by the Tai'an Company. Mounted on the new launcher shown in the photo could be a new variant of the DF-31, the DF-31B. Partial views of the same TEL appeared on Chinese web pages in mid-2013. Tai'an has produced tractor-trailer truck-based TELs for the 8,000 km-range DF-31 and 11,200 km-range DF-31A ICBM and a larger 16 wheel off-road TEL for the 12,000 km-range DF-41.

The latest TEL differs from that of the DF-31 in that cab rests entirely before the missile tube, whereas the DF-41 missile tube straddles the top of the TEL cab. The missile's TEL features an extra pair of elevators near the aft of the missile unlike the TELs of the DF-31 or DF-31A, suggesting a heavier missile second and third stage than earlier variants. Whereas the DF-31 and DF-31A have a single pair of aft-mounted mechanisms for elevating the missile to launch position, the newer TEL appears to feature elevating mechanisms both fore and aft the missile tube. This could indicate that the DF-31B has heavier second and third stages.

What sets the new TEL vehicle apart from its predecessors is its apparent all-terrain characteristic. According to Richard Fisher, a Senior Fellow at the International Assessment and Strategy Center, the Chinese military at present stores its missiles in bases hidden underground. The weapons, loaded onto their TELs, must then be driven along paved roads to suitable launching sites.

The DF-31AG, an enhanced version of the DF-31A intercontinental ballistic missile, is a new type of solid-fuel, road-mobile missile that can be launched from an eight-axle vehicle that also transports the missiles, according to an article published on 03 August 2017 by an online outlet run by PLA Daily, the military's flagship newspaper. Compared with its predecessors, the DF-31 and DF-31A, the new missile features better mobility and survivability, the article said, without giving further details. Before the arrival of the DF-31AG, the DF-31A was the PLA's newest intercontinental ballistic missile known to the public.

The DF-31AG was first viewed by the public at a field parade on 30 July 2017 at the PLA's Zhurihe Training Base in the Inner Mongolia autonomous region. The parade was held to mark the 90th anniversary of the founding of the PLA. The PLA used the occasion to display many new weapons, such as the J-20 stealth fighter jet and HQ-22 air defense missile.

The military said the new ballistic missile and the older DF-31A, which also appeared in the parade, represent China's status as a world power and the country's defense prowess. It called them "trump cards" in strategic deterrence. Previous DF-31AG displays were models while this display was said to be of the actual working missile and launcher. The PLA announced that only fighting units and their equipment would be on display at the parade.

Footage of the DF-31AG in the parade showed it is carried by an integrated missile vehicle known as a transporter-erector-launcher, and the bottom of the launch tube has been equipped with a buffer device. By comparison, the DF-31A is still mounted on an older, two-part vehicle and has no buffer attached to its launch tube.

The upgrades indicate that the DF-31AG is capable of making off-road launch in most kinds of terrain, with a very short preparation time, said Yang Chengjun, a military observer close to China's missile programs. Du Wenlong, a senior researcher at the PLA Academy of Military Science, said that judging by the DF-31AG's extrinsic features and earlier information about it, the new model is likely to have a longer range, stronger penetration capability and larger destructive capacity than the DF-31A. "It is possible that the missile has a global coverage and is able to deliver multiple maneuverable re-entry vehicles," he said. "Its service will extensively strengthen the Rocket Force's strategic strike capability."

According to Western weapons analysts, research and development for the DF-31, the first in the series, began in the mid-1980s. In August 1999, the first launch of the missile was conducted, and two months later, it was displayed to the public at the National Day parade.

The PLA Rocket Force now operated at least three types of intercontinental ballistic missiles for its nuclear deterrence system — the DF-31A, DF-31AG and DF-5B. The DF-5B, which made its debut at a parade in September 2015, is a liquid-propelled model capable of carrying multiple nuclear warheads, according to information from the Chinese military.

A model displayed by China Aerospace Science and Technology Corporation (CASC) was seen next to a DF-31A model and an approximate estimate could be made about the size of the DF-31AG. The DF-31AG model was placed on a special wooden platform raising the height of the model, thus projecting it to be having a longer tube than the DF-31A. But the side view of the model’s aft portion makes it amply clear that DF-31AG is likely to be of the same length as that of DF-31A, if not shorter. The length of the DF-31A tube measured on Google Earth is 15.8 m. Considering that the DF-31AG’s TEL is the length of tube plus the cabin, the total length should work out to be not more than 18 m.

A field parade on 30 July 2017 at the PLA's Zhurihe Training Base in the Inner Mongolia autonomous region was held to mark the 90th anniversary of the founding of the PLA. The PLA used the occasion to display many new weapons, such as the J-20 stealth fighter jet and HQ-22 air defense missile. In addition to the DF-31AG, another ground-to-ground missile that emerged for the first time was the DF-16G medium-range ballistic missile. Compared with the DF-16, the upgraded variant has higher accuracy and an improved maneuverable terminal stage that can better infiltrate missile defense systems.

Specifications
Contractor	Academy of Rocket Motors Technology - ARMT
Operator	Second Artillery Corps
Basing	Tai-Hang Wuzhai
Configuration	Three Stage
Length [meters]	10+
Diameter [meters]	2.0
Mass [kilograms]	20,000+
Propellant	Solid
Guidance	Inertial
First Flight	29 April 1992
IOC	2000
Deployment	Mobile
Range (km)	3,000 - 8,000
Re-entry Vehicle Mass (kg)	700 kg
Warhead Yield	1 @ 0.35 - 1.0 MT or 3 @ 50-100 KT
CEP (meters)	300-500 ??
Launch Preparation Time	10-15 minutes