Chinese experimental hypersonic glide vehicle
The DF-ZF[1] is a Chinese hypersonic glide vehicle (HGV), previously denoted by the Pentagon as WU-14 and currently officially operational on October 1, 2019, in the 70th anniversary of the People's Republic of China.[2][3][4] The DF-ZF is designed to be mounted on a DF-17, a medium range ballistic missile specifically designed to carry the DF-ZFs.[5][6][7]
Testing
The DF-ZF, designated by the U.S. as the WU-14, is a hypersonic missile delivery vehicle that has been flight-tested by China seven times, on 9 January, 7 August and 2 December 2014; 7 June and 27 November 2015;[1] in April 2016[8] and twice in November 2017. The system is operational as of 2019.[9]
The Chinese Defense Ministry confirmed its January 2014 test and said the test was "scientific" in nature, although it was widely viewed as part of a broader Chinese military build-up.[10] All seven tests China performed so far were concluded successfully according to U.S. officials cited in The Washington Free Beacon.[11][12] All the test launches were performed at the Taiyuan Satellite Launch Center in Shanxi Province, the main long-range missile testing center for the People's Liberation Army.[1][8]
Capabilities and design
The DF-ZF is thought to reach speeds between Mach 5 (3,836 mph (6,173 km/h; 1,715 m/s)) and Mach 10 (7,680 mph (12,360 km/h; 3,430 m/s)).[8] The glider could be used for nuclear weapons delivery but could also be used to perform precision-strike conventional missions (for example, next-generation anti-ship ballistic missiles), which could penetrate "the layered air defenses of a U.S. carrier strike group."[1][8]
Hypersonic glide vehicles are less susceptible to anti-ballistic missile countermeasures than conventional reentry vehicles (RVs).[8] Conventional RVs descend through the atmosphere on a predictable ballistic trajectory. In contrast, a hypersonic glide vehicle such as the DF-ZF can pull-up after reentering the atmosphere and approach its target in a relatively flat glide, lessening the time it can be detected, fired at, or reengaged if an initial attack fails. Gliding makes it more maneuverable and extends its range.[13] Although gliding creates more drag, it flies further than it would on a higher trajectory through space, and is too low to be intercepted by exo-atmospheric kill vehicles. The tradeoff is that warheads have less speed and altitude as they near the target, making them vulnerable to lower-tier interceptors,[14] such as the Mach 17 Russian 53T6, ABM-3 Gazelle. Other potential counter-hypersonic interception measures may involve laser or railgun technologies,[15] but such technologies are not currently available.[16][17][18]
A vehicle like the DF-ZF could be fitted to various Chinese ballistic missiles, such as the DF-21 medium-range missile (extending range from 2,000 to 3,000 km (1,200 to 1,900 mi)), and the DF-31 intercontinental ballistic missiles (extending range from 8,000 to 12,000 km (5,000 to 7,500 mi)).[19] Analysts suspect that the DF-ZF will first be used in shorter-range roles as an anti-ship missile and for other tactical purposes to address the problem of hitting a moving target with a ballistic missile. Long-term goals may include deterrence of U.S. missile capabilities with the prospect of strategic bombardment against the United States, or other countries.
Since conventional interceptor missiles have difficulty against maneuvering targets traveling faster than Mach 5 (the DF-ZF reenters the atmosphere at Mach 10), a problem exacerbated by decreased detection times, the United States may place more importance on developing directed-energy weapons as a countermeasure.[13] However, after decades of research and development, directed-energy weapons are still very much at the experimental stage and it remains to be seen if or when they will be deployed as practical, high-performance military weapons.[16][17][18]
Complaints have been raised by one researcher over lack of access to high-performance computing power, required for development of the HGV. While China has a number of high performance supercomputers, access to them was not provided for the DF-ZF development project.[20]
Despite the difficulties that HGVs pose for mid-course SAM interception by systems like SM-3 and GBI, HGVs have yet to overcome substantial obstacles in order to achieve the same success in the terminal phase. For one thing, HGVs can only maneuver drastically in the mid-course phase of their flight path due to extreme pressures during their terminal phase.[21] Additionally, contemporary SAM systems like THAAD, PATRIOT and SM-6 are mostly optimized for terminal phase interception, with the exception of SM-3 and GBI.[22][23] Furthermore, when HGVs re-enter the atmosphere at hypersonic velocities a plasma sheet will develop which disrupts their communications and sensors.[24] There are two solutions to this. Firstly, HGVs can slow down to supersonic speeds, but this wouldn't make their terminal phase interception any harder than the missiles that current SAMs are designed to intercept.[25] Secondly, HGVs can maintain hypersonic speeds and rely on inertial navigation systems, though this would mean that HGVs can't target maneuvering targets like expensive aircraft carriers, yet these are the exact targets that are valuable enough for HGVs with costs in the tens of millions each, to be worth targeting.[26] These factors have likely contributed to DF-ZF currently being used for a land-attack role only, although an anti-ship variant is in development.[27]
