Would a wall of supersonic metal be able to protect a nuclear missile silo from destruction? In the late Cold War, Soviet designers attempted to provide the answer in the form of a system as bold as it was mysterious: the Mozyr active protection complex, which would shield fixed intercontinental ballistic missile (ICBM) sites from incoming warheads by shooting them out of the sky with thick clouds of tungsten and steel.
Designed in the late 1970s under the immediate direction of Defense Minister Dmitry Ustinov, Mozyr nominally Project 171 was the charge of Kolomna’s KB Mashinostroyeniya. The project attracted over 250 enterprises from 22 ministries, a measure of its strategic significance. The idea strayed from conventional anti-ballistic missile (ABM) interceptors and instead took a page from armor protection systems such as the “Arena” complex: observe a threatening approach, determine its trajectory, and launch a salvo of kinetic missiles to obliterate it before impact.
The Mozyr launcher was a gigantic, multi-barreled setup accounts vary between 80 and “several hundred” barrels each charging a propellant charge and a hardened alloy penetrator. When a target was detected, the fire-control system calculated the projectile cloud’s needed density and direction. A maximum of 40,000 elements, moving at 1.8 kilometers per second, could be ejected in one volley to create what the designers referred to as an “iron cloud” at altitudes of up to six kilometers. The closing velocity toward a reentry vehicle was nearly six kilometers per second, which guaranteed devastating kinetic impact.
Tracking and detection were based on the 5N65 “Flat Twin” phased-array radar, as part of the larger 5K17 tracking system. Phased array technology made it possible to steer the beam quickly without the use of moving parts, allowing near-instantaneous updates of high-speed targets. This was essential for attacking ICBM warheads during their terminal phase, when air drag and predictable flight paths provided an extremely narrow window for attack. Radar performance matched contemporary homeland defense ideas, where multiple sensor layers enhance discrimination between genuine warheads and decoys.
Testing at the distant Kura range in Kamchatka during 1985-1988 consisted of a mock silo flanked by the Mozyr prototype. Non-nuclear SS-18 Mod 4 ICBMs, occasionally with multiple reentry vehicles, were fired from Baikonur or Plesetsk. There is one description of a nighttime test: Suddenly, a new star flashed brightly it quickly increased in diameter and exploded like fireworks a fireball the size of the moon emerged the target had been hit. Accounts indicate intercept success rates of nearly 90 percent, with scholarly evaluations concluding that their destruction in descent was “highly likely to prevent the initiation of a nuclear detonation.”
From a technical viewpoint, the challenge for Mozyr was computation speed. While ballistic targets were computationally tracked and engaged with high probability, aerodynamic threats like cruise missiles or maneuvering reentry vehicles required much more processing capability. Contemporary systems take advantage of digital fire-control designs that can solve intercept against hypersonic glide vehicles, a threat category which electronics of the Cold War era were not capable of handling. Current advocates of missile defense suggest incorporating such point-defense ideas into multilayered homeland designs, in which kinetic kill vehicles are a complement to long-range interceptors.
Mozyr’s cancellation in 1991 was a victim of Soviet collapse, not failure of technology. Some histories claim that work was suspended to prevent triggering U.S. withdrawal from the 1972 ABM Treaty a treaty which, as subsequent analysis reveals, limited deployment of systems that could defend ICBM fields. The United States investigated an analogous concept, “Swarmjet,” for its MX missile silos, employing thousands of unguided rockets, but it did not get beyond design studies.
The relevance of the system has reappeared with the advent of contemporary threats. Independently targetable reentry vehicles (MIRVs), penetration aids, and maneuvering hypersonic warheads make any silo defense problematic. Improvements in guidance technology and remote sensing have opened silo coordinates to the enemy, whereas counterforce striking capacity has undermined the survivability previously taken for granted in hardened silos. Against such threats, a high-density, kinetic, rapid-response shield could be employed as a last resort defense concentrating the “threat cloud” before it arrives at the silo.
Mozyr is a still-uncommon example of an operationally evaluated, point-defense anti-ICBM. Its pairing of phased-array radar, automatic fire control, and massed kinetic interceptors was a harbinger of technologies currently debated in next-generation missile defense communities. For military technologists and historians of the Cold War alike, it is a monument to the period’s readiness to engineer solutions to problems existent that were seemingly impossible.
