The A-135[5] (NATO: ABM-4 Gorgon) is a Russian anti-ballistic missile system deployed around Moscow to intercept incoming warheads targeting the city or its surrounding areas.

[6][7] A memo from the archives of Vitalii Kataev, written around 1985, had envisaged that the system "will be completed in 1987 to provide protection from a strike of 1–2 modern and prospective ICBMs and up to 35 Pershing 2-type intermediate-range missiles".

[11][12] Tests were undertaken at the prototype Don-2NP in Sary Shagan in 2007 to upgrade its software.

[12][13] Russian early-warning radar network consists of:[14] There are at least 68 active launchers of short-range 53T6 endoatmospheric interceptor nuclear armed missiles, 12 or 16 missiles each, deployed at five launch sites.

[4] The successor system, dubbed 'Samolet-M' (and more recently A-235) will employ a new, conventional, variant of the 53T6 missile to be deployed in the former 51T6 silos.