Dong Feng-21(DF-21) ASBM The Missile’s Mission
There is little doubt that a variant of the Dong Feng 21 (DF-21) missile is the candidate for the ASBM. Moreover, much of the work to adapt the DF-21 for such a mission appears to have been developed in the late 1990s, such as an ablative shield against aerodynamic heating during reentry, vibration resistance, and optimization of the payload. There is also discussion of adding a third stage to the missile, not only to increase its range but to provide extra maneuverability in midcourse fl ight (discussed below). The third stage appears to be in development, although several documents suggest that the missile and its maneuvering capabilities remain in the early research and experimental stages.
Chinese sources go into detail about various methods of maneuvering during a ballistic missile’s midcourse phase. Maneuvering increases the missile’s terminal target-seeking coverage so as to hit a moving target at sea. However, the impact of U.S. missile defenses primarily the sea-based Aegis system equipped with SM-3, Terminal High-Altitude Area Defense (THAAD), and the Kinetic Energy Interceptor on the missile’s survivability is also discussed. A number of measures are suggested to defeat them.
Altering the missile’s fl ight path by employing a wavelike trajectory rather than a traditional parabolic fl ight path is one method. In this scenario, the additional third stage of the DF-21 missile, with its hybrid liquid-solid fuel booster, is ignited several times to effect several wave patterns in the missile’s midcourse fl ight. Other methods include weaving, spiraling, spinning, and gliding—all of which would alter the traditional parabolic fl ight path of the ballistic missile and boost the missile’s penetration capabilities against American missile defenses, which depend heavily on prediction of a missile’s fl ight trajectory.
Controlled maneuvering in space should not be a “bottleneck technology,” according to one source, since China has already demonstrated real progress in “orbital maneuvering and docking” under the Shenzhou program. However, other publications suggest that research and experiments involving wave and gliding trajectories began only in 2003, de novo, and there is no evidence that China has made breakthroughs in this area. Moreover, the academic treatments of these exo-atmospheric maneuvers appear to be largely theoretical in nature. For instance, they do not systematically address the problem of how to “maintain guidance [for the target] during the whole trajectory,” which other articles insist is a technical challenge China must overcome.